Driving Along the Zinc Road

Abstract

After having written hundreds of research articles, reviews, and book chapters, I find it awkward to pen an autobiography. I still do use a pen. As stated by others in the nutrition field who have written of their own experiences in a perspective article for the Annual Review of Nutrition, my course through this field of science has been serendipitous. My interest in nutrition developed during my experiences with horses and then Angus cattle and entry into an animal science degree program. As the age of molecular biology was unfolding, I pursued a PhD in nutritional biochemistry with Hamilton Eaton at the University of Connecticut followed by postdoctoral work with Hector DeLuca at the University of Wisconsin, working on vitamins A and D, respectively. At Rutgers University, one of the two institutions where I have served on the faculty, I started my research program on trace elements with a focus on cadmium toxicity but soon thereafter began my research on zinc metabolism and function. I moved to the University of Florida in 1982 for an endowed position and have been a Florida Gator ever since. At the University of Florida, research expanded to include identification of zinc-responsive genes and physiological outcomes of zinc transport influencing health and disease, particularly as related to inflammation. I had the opportunity to contribute national science policy as president of both the Federation of American Societies for Experimental Biology and the American Society for Nutrition. As the time of this writing, I maintain an active laboratory.

Introduction

While serving as Editor of the Annual Review of Nutrition, I read many perspective articles and was amazed at the diverse career paths that successful contributors to the nutrition field have experienced. Hence it is humbling to have been asked to write my own perspective piece. My serendipitous path has been influenced by many individuals and events but was not a defined course by any stretch.

Early Years

My ancestral background is all European but from vastly different regions. I am essentially an American mutt, as is common to the United States. My maternal grandparents were Alsatian. When Alsace was German, my maternal great-grandfather, while on an art scholarship in London, was notified by the Kaiser that his services were required for the military. That order sent him to America for studies at Cooper Union in New York City in the late 1880s. He became a recognized sculptor, with examples at St. John the Divine in New York City and the Vanderbilt Mansion in Newport, Rhode Island. He settled in Fort Lee, New Jersey. In her youth, my grandmother would swim from Fort Lee to New York City near where the George Washington Bridge now spans the Hudson River. By contrast, my maternal grandfather's family, who considered themselves as French, but were also from Alsace, settled in America in Woodhaven, New York. This community was an enclave of French immigrants because work was available there for a French company. My grandmother loved technological advances, home movies in the 1920s, TV before 1950, etc. I believe I inherited that interest. My grandfather, with the typical sixth-grade education of the time, worked for the same family-owned company for about 50 years, retired as an executive, and was also a Long Island housing developer.

My dad's ancestry was English and Scots-Irish (pre-Revolution) on one side and German on the other. His family migrated to America and settled in western Pennsylvania. My paternal grandfather (Robert Cousins) interviewed for a job with the Pennsylvania Railroad (PRR). He was not hired because he was only 14 years old. At another PRR office, he applied as 16-year-old John Cousins and was hired. In the mid-1920s, the PRR acquired the Long Island Railroad in New York. He was asked to move to Long Island for an executive position, which he did. He too had only the traditional pre–high school education. He started chewing tobacco upon joining the PRR and did so until he died at age 99.

My parents met as a result of the PRR corporate move, probably an early example of what the United States would experience in the 1930s and beyond. I was born in 1941 and was an only child due to maternal medical issues. My dad volunteered and served with the US Marines, participating in the horrible battles of Okinawa and Guam in the later years of World War II. Veterans were required to be returned to their positions in corporations after the war. My dad returned to ESSO (ExxonMobil today), an oil company. Because his prewar position on Long Island was filled, he was placed in upstate New York (Kingston) in a sales position. This move was terrific for me as it transported me from suburban Long Island into the Catskill Mountains on the shores of the Hudson River. Schooling there was at public schools but was not a priority for me. College prep studies were just okay. In today's learning environment, I would have been classified as dyslexic and justifiably so. The New York State high school curriculum included, even for college prep students, shop courses in auto mechanics, electrical wiring, and other practical things. Those I enjoyed. Having indulgent parents, I participated in activities of the area, which had a heritage of equestrian activities. The interest in horses evolved into very memorable family experiences, with horse shows and like-minded friends. Some of the horse-related events were risky enough that had they gone wrong, they would have prevented me from living long enough to develop a career in the nutrition field or to have the opportunity to write this memoir. Nevertheless, these experiences gave me a perspective on animal biology that differs from that of most biological scientists. 

Undergraduate Years

After considering a prep school for me to finish high school, my parents acquiesced to my objections and allowed me to graduate from Kingston High School, a regional school with more than 2,000 students. Many East Coast colleges were on my application list. Of the few I visited, the University of Vermont (UVM) seemed to be a good fit. A friend from high school attended there and really liked it, as I did, so UVM became my choice. UVM, founded in 1791, is a small classic New England university; at the time I was there, its undergraduate enrollment was less than 5,000 students. UVM is in many ways the prototype of the land grant institution; Justin Morrill, author of the Land Grant College Act (Morrill Act) of 1862, represented Vermont in the US House of Representatives. The university is situated at the top of a hill in Burlington and overlooks Lake Champlain. This location accentuates the extremely cold winters. My college preselection visit was in the spring or summer, so reality set in when the snow began to fall as I started my freshman year. UVM is now recognized as one of the “public ivy universities.” Being an out-of-state student with modest family resources, I doubt if I could afford to go there today. I chose a zoology/chemistry major/minor, which was very competitive. I did not like the zoology courses, but chemistry was another matter. Consequently, I did the best in those classes. At that time, biochemistry was taught in the Agricultural Biochemistry Department. In my junior year, I took a course in introductory biochemistry. I really loved that course and regretted that I did not major in agricultural biochemistry. A laboratory course in biochemical methods furthered my interest in laboratory work. Unfortunately, at that time, in the early 1960s, undergraduate research experiences were not in vogue.

At the time I attended, UVM could provide on-campus housing for only one year. This limitation stimulated the Greek system greatly, as all fraternities and sororities had houses. I chose Sigma Alpha Epsilon (SAE) because I had friends there. Life in the Vermont Beta house of SAE was not exactly as depicted in the film National Lampoon's Animal House, but there were many similarities. This was at the dawn of rock and roll and the “Twist.” That phenomenon changed dating to more music-related activities. For parties, groups like ours would book musicians who knew the new music. Chubby Checker and others influenced this age group greatly. It was a refreshing time for a kid that had learned traditional dance, with orchestras such as Lester Lanin's. For some reason, I was elected to serve as fraternity president, The Eminent Archon. The job was primarily to help keep order in a house of more than 30 men where there was no resident adult. My fond memories of those in fraternities have been seriously tarnished with recent reports of racial and other hateful acts perpetrated by fraternity members. I encourage students to find groups with good societal values to foster the bonding instincts and maturation opportunities that all students need. Upon graduation from UVM, I became the first college graduate in my family.

Graduate School

My dad was to be retired by ESSO at their compulsory age of 55. His counter was to purchase their local fuel oil and LPS propane gas business and go out on his own. He eventually sold that and purchased a farm on the western shore of the Hudson River as a side venture. We purchased a few Angus cattle with the idea of a secondary business in cattle production. In an effort to explore that venture, knowing nothing about animal science except what I had learned from dealing with horses, I applied to the University of Connecticut (UConn) for an MS in Animal Sciences. The most attractive aspects of UConn were the tuition at $75 per semester and that the campus in Storrs was 88 miles from my home. UConn had an excellent beef cattle operation so it was a good fit; I started my MS degree studies in fall 1963. UConn was in a beautiful setting, classic New England with stone walls separating fields on farms and heavily wooded winding roads. Tragedy struck in November 1963, when President Kennedy was assassinated. I had just driven home from UConn for the weekend, in time to watch those memorable moments unfold.

Courses in feeds and feeding and graduate-level animal nutrition were part of my graduate course curriculum at UConn. I liked them, particularly the quantitative aspects of animal ration formulation. I was asked to do some lipid analyses in Robert Jensen's lab to gain some lab experience. Graduate biochemistry was a two-semester sequence. I liked this course immensely, and it helped set my career path. A member of my MS graduate committee was Hamilton Eaton, Professor of Animal Nutrition. He was funded by the National Institutes of Health (NIH) and offered me a graduate assistantship position in his lab to work toward a PhD. I accepted his offer and started doctoral studies in fall 1965. Many graduate students at this time faced uncertainty. The Cuban Missile Crisis of 1962 had passed, but the Vietnam War had started. There was a military draft, which placed all male students in limbo. My number in the draft was over 235. I do not remember the exact number because we all burned our draft cards at age 35 when we were no longer eligible to serve. That number made it unlikely that I would be called to service in that terrible and unnecessary conflict.

The didactic component of my doctoral program was rigorous, with graduate courses in enzymology, animal pathology, statistics, advanced chemistry, and the nascent area of molecular biology and gene regulation. At the time, I was a graduate assistant and the duties included half days on Saturdays and occasional weekend duties to provide diet supplements for experimental animals. The Eaton lab was a “work hard, play hard” lab. Some of the “play hard” events were legendary on the UConn campus of the 1950–1970 period. Many after-seminar events could extend late into the night. Ham Eaton respected me for enjoying these quasi-scholarly events. Such raucous activities would not be possible in today's environment. My graduate program was greatly aided by Joseph Rousseau. He was a chemist but received his PhD with Eaton after working as his assistant for years. He was extremely knowledgeable and had outstanding skills at the bench. He was like a personal tutor for me, which was a rare opportunity.

Professor Eaton had received wide acclaim for his exquisite design of experiments and use of statistics in the area of vitamin A requirements in dairy cattle. His work focused on the finding that vitamin A deficiency in the bovine led to elevated cerebral spinal fluid (CSF) pressure. As the earliest detectable change in vitamin A deficiency, Eaton used it to establish the vitamin A requirement in cattle. The animal model used in these experiments was the calf. These were obtained soon after birth at the State of Connecticut Prison Farms. These calves were very uniform and provided an excellent model. Previous doctoral students established that the increased CSF pressure was caused by decreased CSF reabsorption. K.C. Hayes, a veterinarian and a fellow graduate student, measured the dura mater and found that the tissue lining the cranial cavity was thicker in the vitamin A–deficient calf. My dissertation topic was to propose and study a potential mechanism. I hypothesized that overgrowth of the dura mater physically limited CSF reabsorption via the arachnoid villi, which are localized in the dorsal region of the dura. My assumption proved to be correct. There was an overproduction of specific glycoproteins from this collagen-rich tissue, and there was also an overgrowth of bone in the cranial area (8).

I was strongly influenced by my coursework in molecular biology at UConn. That interest led me to also examine ribonucleic acid (RNA) production in the dura mater of the vitamin A deficient calves and contrast those to changes in the RNA content seen in the liver. Colorimetric assays were all that was available in the late 1960s to study RNA metabolism in a large animal. There was a tissue-specific increase in RNA of the dura of the hypovitaminatic calves. I had read a paper by Professor Robert Olson, then at the University of Pittsburgh, on the novel idea that fat-soluble vitamins functioned through deoxyribonucleic acid (DNA)-dependent RNA replication (29). His model was based on the gene induction and repression concept proposed by François Jacob and Jacques Monod, who went on to win the 1965 Nobel Prize in Physiology or Medicine. My data on the increase in RNA in the vitamin A–deficient calves fit in with the Olson hypothesis. To my knowledge, the question about the relationship between CSF pressure and vitamin A has never been fully investigated. In humans, excess vitamin A and/or retinoic acid increases CSF pressure and may relate to idiopathic intracranial hypertension.

A life-changing event occurred in the fall of 1965. I was taking a course in animal pathology along with Richard Carrano, a fellow graduate student in the pharmacology doctoral program. We became close friends and did considerable partying. On November 9, 1965, just after 5 pm the lights dimmed and then went out in the northeastern United States and parts of Canada. The power grid experienced a massive failure that lasted overnight. The UConn campus was blacked out and in panic but in party mode. I met the UConn president that evening, Homer Babbage. He brought in power generators and portable lights to keep things quiet. That evening Rich Carrano met Elizabeth (Beth) Anne Ward at a party. He suggested we would like one another. A blind date was arranged, and Beth and I dated until she graduated in June 1967. We were married in January 1969, in Stamford, Connecticut.

A number of memorable, and yet unpleasant, historical events occurred during my doctoral program. One evening while working in the lab with Joe Rousseau, we heard that Martin Luther King Jr. had been assassinated in Memphis. Two months later, in June 1968, the morning I started the written part of my qualifying exam, we heard the news that Senator Robert F. Kennedy had been assassinated in Los Angeles. During this period, I was thinking about the future and felt that a postdoc was essential. I was influenced by the emerging area of molecular biology and realized that I needed more experience at the molecular level and with other techniques, particularly with radioisotopes. I contacted three outstanding potential postdoctoral mentors, George Wolf at the Massachusetts Institute of Technology (MIT), Robert Olson at St. Louis University, and Hector DeLuca at the University of Wisconsin. All had outstanding labs. All three offered me positions, due to a large degree to the reputation of the Eaton lab at UConn. I chose the DeLuca lab because of its approach to nutrition-related biochemistry, the scope of its projects at the time, and the history of the Wisconsin Biochemistry Department (40).

Postdoctoral Training 

The postdocs at Wisconsin and MIT were contingent on receipt of an NIH postdoctoral fellowship [individual National Research Service Award (NRSA)]. I was concerned about this, but Hector said he would not let me starve. He didn't, but things were tight. I did splurge and bought a color TV on credit. That was a luxury at the time, but having bought something on credit was helpful later. My early days in the lab were very troubling because my mother died of cancer a month after I started in Madison in September 1968. Fortunately, I received the NIH fellowship in the spring of 1969.

Just before I arrived in the lab, the DeLuca team had identified 25-OH vitamin D3 as the active metabolite of vitamin D3. After completing a few small projects, I was given the opportunity to study the metabolism of 3H–25-OH vitamin D3 in rats. We initially focused on the intestine where vitamin D3, through the experiments of Robert Wasserman at Cornell, was believed to induce a calcium-binding protein (calbindin). This protein provided a target to aim for in the vitamin D research at Wisconsin. A few chromatography experiments made it clear that 3H–25-OH D3 was rapidly metabolized to a more polar metabolite that could be found in the nucleus (7). The search for another metabolite, which I called the tissue active form, was under way rapidly thereafter. Graduate student Michael Holick and I took two approaches: isolating the metabolite from large numbers of chicken intestines and injecting 3H–vitamin D3 to chicks to monitor the isolation. This latter approach by Holick proved successful. That project was under way at the time I left the lab to start a position at Rutgers University. They graciously included me on the initial report on the identification of 1,25-(OH)2D3 (20).

The Biochemistry Department at Wisconsin had a collection of faculty who, at the time, were interested in nutrition-related research. William Hoekstra, an expert on zinc metabolism, was particularly helpful in my career mentoring. Upon reflection, I gained from Hector DeLuca an understanding of how an extensive knowledge of the literature allows a lab leader to place new and novel data into a mechanistic perspective. In addition, the use of a wide variety of approaches to focus on one central theme (vitamin D) was another valuable lesson I learned from DeLuca that I used later in my own research.

After two years at Wisconsin, about the average time for a postdoc at that time, Beth and I decided in the fall of 1970 for me to accept a position as Assistant Professor in the Animal Sciences Department at Rutgers University (the State University of New Jersey). It was close to family that we missed and was on the east coast, where we wanted to live at the time. The economy was in a recession in 1970 and job opportunities were scarce, so joining the faculty of a major institution is a decision I never regretted.

Rutgers University

I reported to the Animal Sciences departmental office just after New Year's Day in 1971. My lab was joint with other faculty in the animal science division of the department. The building had been built in the 1920s and looked it. I had reservations about the position at Rutgers because of the lack of good facilities. During my interview in fall 1970, Hans Fisher and Paul Griminger of the Department of Nutrition assured me that I would be included in the nutrition program within a few years. I took a gamble. The Rutgers College of Agriculture added “and Environmental Science” to the name around 1965 to signal an expansion in mission. Coincidentally, I had seen an article in a Sunday New York Times that described a human bone disease in Japan that was likely related to cadmium accumulation in the kidney. The kidney had just been shown to be the site of the 1-hydroxylase step for 25-OH vitamin D3 activation. On the basis of that idea, I developed a project that focused on cadmium and calcium metabolism because it fit into the environmental theme of the College.

Because I was in an animal sciences department and had access to pigs, my first studies on cadmium metabolism were in that species (6). Those studies allowed the development of cadmium assays by atomic absorption and the accumulation of preliminary data to apply for the NIH funding. Professor of Physiology Paul Sturkie counseled me to take my time with the grant application, which was excellent advice. Also helpful was that Ham Eaton had given me a copy of a recently funded NIH application. The preliminary work included liquid chromatography of kidney cytosol and demonstrated that cadmium from the diet was bound to metallothionein (MT), a low-molecular-weight metal-binding protein. MT levels were found to be proportional to the dietary cadmium level. My NIH application focused on MT synthesis and calcium metabolism in rats. In April 1972, I received my first R01 grant from the NIH (ES00777), which allowed me to purchase a new liquid scintillation counter (a major research tool at the time).

As frequently occurs with new faculty, I attracted a number of talented graduate students: Jeanne Freeland (Graves), Katherine Squibb, Mark Richards, Stuart Feldman, and Philip Washko. Working on the hypothesis that cadmium regulated MT synthesis de novo, we were greatly aided by using actinomycin D to block mRNA transcription of the Mt gene. Because zinc is also a Group IIB element on the periodic table, we initiated concurrent studies with zinc. We were excited about these data because the idea that a trace element could induce the expression of a gene, Mt in this case, was very novel (30, 36, 37). An investigator in the United Kingdom was studying the same system but incorrectly administered actinomycin D after the metal, which precluded the action of the drug on prior transcriptional events.

I developed a technique to study the synthesis of metal-binding proteins using liquid scintillation counting (LSC). Gamma rays emitted by radioisotopes such as 65Zn, 109Cd, and 203Hg produce Auger electrons that produce photons in liquid scintillation cocktails. When appropriately paired with 3H-, 14C-, or 35S-labeled amino acids, the bound metal and labeled proteins can be measured by dual-label LSC (10). Another advance we were very proud of was the use of the vascularly perfused rat intestine to study zinc absorption. An undergraduate honors student worked out the surgery required. Kenneth T. Smith, another doctoral student, used the technique to study zinc absorption using both 65Zn and Zn as measured by atomic absorption (35, 34). The latter is an assay method I have used for 45 years.

These were great times working in the lab with students, where techniques could be worked out as there was time to do so. The pace of research was such that meaningful projects with undergraduates could be undertaken. The research on MT was extended to metal-dependent degradation of the protein (14). Work on the mechanism of MT synthesis was greatly aided when it became possible to translate mRNA in vitro (27, 33). These studies led to an R01 grant from the National Institute of Diabetes and Digestive and Kidney Diseases. Attracted by the evolving use of rat liver primary cultures, I had another undergraduate honors student bound for medical school determine the surgery necessary for the organ perfusion that was required to liberate the cells. The arrival of Mark Failla, my first postdoctoral associate, allowed us to study the hormonal regulation of zinc and cadmium metabolism under in vitro conditions (13). Charlie McCormick and Ken Etzel joined as postdoctoral associates and worked on induction of MTmRNA as modulated by the dietary zinc level (27) and endotoxin/hormonal control of zinc metabolism (12), respectively. Research on the influence of endotoxin on zinc and copper metabolism led to a fourth R01 grant, which was from the National Institute of Dental Research.

After I had been at Rutgers for about 10 years, I became interested in moving from New Jersey. I never felt at home in New Brunswick because it was not a defined entity and was not a university-oriented town. Rutgers had and still does have a strong faculty union, which had advantages but, at the time, also provided little opportunity for merit increases for the salaries of younger faculty. Fortunately, with Hans Fisher's support, I was promoted to Full Professor in six years and Professor II (Distinguished Professor) two years later. A six-month sabbatical leave in 1980 gave me time to really think about alternatives. Those opportunities would come in 1981 with offers from Virginia Polytechnic Institute and State University (Virginia Tech) to chair their Biochemistry and Nutrition Department and from the University of Florida for a newly established endowed chair in nutrition.

Move to the Sunshine State and the University of Florida

The chair of the University of Florida's (UF) Food Science and Human Nutrition Department, James Kirk, called me in May 1981 to ask if I would apply for an endowed chair that was newly established. The state had established an Eminent Scholar Chair program, where a $600,000 donation was matched with $400,000 in state funds to create principal for an endowment. This chair, the Boston Family Professor of Nutrition, was the second such endowment at UF. James Dinning, who at the time was editor of the Journal of Nutrition (9), chaired the search committee. The committee had a campus-wide membership. The UF President Robert Marston, who was the director of the NIH prior to coming to UF, also provided input because this position was a UF Presidential appointment. Dinning and Marston were both class acts.

The lab moved to Florida in May 1982. Beth and our children followed at the end of the school year in June. I was able to bring about $100,000 in lab equipment purchased with NIH grant funds. Moving an active productive lab is difficult. Established procedures needed to be modified to work in the new setting, etc. With time and with the help of Mavis Swerdel, a great technical assistant who moved with us from Rutgers, we were back in operation and focused on the hormonal and cytokine regulation of zinc metabolism. Of note was a kinetic model done by Michael Dunn on zinc redistribution during stress induced by cAMP (cyclic adenosine monophosphate) (11). During this period, sequence-specific polynucleotides could be synthesized and used as probes to study gene regulation. Linda Steel and James Hoadley established the parameters of zinc absorption in rats and found that the animals' dietary zinc intake could program the intestine to control the extent of absorption (19, 38).

In the early 1990s, we developed an ELISA (enzyme-linked immunosorbent assay) for human MT, carried out by Arthur Grider in collaboration with faculty colleague Lynn Bailey, to study the influence of zinc intake on MT as a zinc biomarker (16). This research extended into quantitative polymerase chain reactions, microarray profiling, and proteomic signatures of zinc restriction and repletion. Vicki Sullivan, Jay Cao, Tolunay Beker Aydemir, and Moon-Suhn Ryu were the major contributors to this work with human zinc restriction and supplementation (1, 5, 32, 31, 39). This research has unfortunately not been extensively evaluated in clinical or field conditions. Understandably, doing so would require a paradigm shift in nutrition research in the field.

In the early 1990s, we also initiated differential gene expression studies with the hypothesis that a zinc-specific transcript would relate to function or transport. Numerous candidates were identified. Neil Shay, Jennifer Bernadette Moore, and Ray Blanchard conducted these studies. Jim Hempe, Cathy Levenson, Pearl Fernandes, Barbara Davis, and Christina Khoo worked on our project to define the function of cysteine-rich intestinal protein (15, 18, 21, 22). In the late 1990s, the lab transitioned to zinc transporter research, first with rats and then with mice. Robert McMahon, Steve Davis, Juan Liuzzi, Tolunay Beker Aydemir, Luang Guo, and Louis Lichten were heavily involved in these projects (1–4, 17, 23–25, 28, 41, 42). Overall, our zinc transporter research identified tissue specificity and multiple physiologic stimuli as regulators of zinc transport. Upon using transporter gene knockouts, it is becoming clear that zinc has many silent influences on carbohydrate and lipid metabolism as a signaling molecule with important phenotypic outcomes that influence health. This research continues as this perspective article is being written, hopefully with many exciting discoveries yet to come.

In the mid-1980s, an opportunity to participate in a competition for a nutrition center arose. The Pew National Nutrition Program was established under the leadership of Malden Nesheim at Cornell University. The competition started a campus-wide effort, and, thanks to UF President Marshall Criser, a Center for Nutritional Sciences was established. UF was selected as one of the five Pew Centers.

This award did numerous things. It made the agricultural units collaborate with the medical units. It also enhanced the visibility of nutritional sciences at UF. In the 30 years since the award, the Center-sponsored seminar program has yielded hundreds of presentations. Today, indirect cost (IDC) funds continue to support the seminar program and provide funds for graduate students to travel to meetings. It represents an enlightened use of IDC for programmatic goals.

It is appropriate here for me to comment on life in a nutrition department versus a combined food science and nutrition department, as I have experienced both. In my opinion, the disciplines should not be combined because the cultures are different. Combined departments can certainly share some benefits, but these units are difficult to manage. Faculty and students of such units realize that two departments exist within the combined department. In retrospect, I had reservations about joining a combined food science and nutrition department in 1981. I have the same reservations 35 years later.

Political Biology 

Around the mid-1980s, Richard Allison, the executive officer of the American Institute of Nutrition (AIN, now American Society for Nutrition), asked if I was interested in a governance role in the society. Soon I was elected to the AIN council, a role I enjoyed. Later I served on the Federation of American Societies for Experimental Biology (FASEB) Board of Directors, occupying one of the two AIN slots on the Board. After a FASEB retreat where AIN was represented by Sam Foman, governance was charged to have the FASEB president elected by the Board rather than rotating through the constituent societies. In 1991, the FASEB Board elected me as the first elected FASEB president.

Shortly thereafter, there were challenges. The NIH Office of Scientific Integrity staff was flexing its muscle, with some nasty face-to-face confrontations occurring between the Office of Scientific Integrity and FASEB. The second challenge was to keep the biochemists [the American Society for Biochemistry and Molecular Biology (ASBMB)] in the FASEB fold. Doing so was also a nasty process, but thanks to ASBMB representatives on the Board they stayed with FASEB. Years later, I let my ASBMB membership expire and joined the American Physiological Society, which I found more welcoming. Michael Jackson, the executive officer of FASEB, was very helpful to me and the Federation during the trying times of revising FASEB's relationship with the member societies. An interesting aspect of my term as FASEB president was to interact with Bernadine Healy. She was the NIH director appointed by the G.H.W. Bush administration. She liked nutrition and created a bionutrition initiative. We had a good rapport, and had she stayed on as the director, it may have helped the nutrition field at the NIH.

After my year as president, I remained active in FASEB affairs related to biomedical and life sciences research funding recommendations, i.e., the FASEB Consensus Conferences on Research Funding. At my insistence, these documents came to be developed by policy professionals at FASEB rather than by society members brought in to Bethesda and asked to work in late-night drafting sessions. I also had a hand in forcefully precluding some lobbyists from influencing special recommendations. One consensus conference I chaired was on indirect costs. At that time, indirect costs were growing faster than direct costs for research projects. Of contemporary interest is a quote from the FASEB Consensus Conference document for the 1996 fiscal year. The rationale for the NIH funding recommendation was: “[T]his increase will allow NIH to fund a larger percentage of the meritorious proposals that it receives, which for new, unsolicited research grants has fallen to an all-time low of 15%.” Does that statement sound familiar? Over the years, these consensus conferences have become the gold standard for funding recommendations.

Following the FASEB experience, many asked why I did not seek a university administrative position. The major reasons are that I did not wish to subject my family to an itinerant lifestyle, which is usually necessary for administrative advancement, and I also did not want to give up the excitement and creative outlet derived from running a research lab. In addition, I enjoyed life at home, the Florida weather, my numerous hobbies, my British sports cars, and spending evenings by the pool.

I was also privileged to serve on the Institute of Medicine's Food and Nutrition Board (FNB) for two terms (1997–2002). This was a very special time for the FNB because it was during the period when the Dietary Reference Intakes for micronutrients were being formulated. That process was of special interest to me. 

 American Society for Nutrition Affairs

I was involved with a reorganization of the Journal of Nutrition with Willard Visek as editor-in-chief. Willard asked Alfred Merrill Jr. of Emory and me to be editors. His concept was a good one for a journal: share the burden. I was able to bring Florida colleagues Lynn Bailey, Jesse Gregory, and Rachel Sherman in as associate editors. Within a year (1991) four additional editors were added. The next year the editors became associate editors and Willard was editor and no longer editor-in-chief. None of us cared because Willard was such a great guy. The workloads increased, but the quality of the papers also improved substantially.

In 1996, I had the privilege of being elected president of the AIN, which had just been renamed American Society for Nutritional Sciences. This was at a time of a strained relationship with the American Society for Clinical Nutrition (ASCN). The ASCN leadership saw their society as coequal to AIN. Unfortunately, it was AIN that was a constituent society of the incorporated organizational structure of FASEB. In less than 10 years, the memberships of both combined with the international nutrition society were merged to form the American Society for Nutrition (ASN). The ASN has been generous in recognizing my research with both the Mead Johnson Award for Research (1979) and the Osbourne and Mendel Award for Outstanding Basic Research (1989).

Millennial Highlights 

The turn of the century was a great period in my life, but it also presented challenges. In April 2000, just after I turned 59, I was elected to the National Academy of Sciences (NAS). It was a humbling experience considering all the wonderful scientists in the United States. The following year Vernon and Janice Young joined Beth and me for a memorable evening at the NAS Presidents Dinner.

Another humbling honor was receiving the Bristol-Myers Squibb Award for Distinguished Achievement in Biomedical (Nutrition) Research in 2003. That year, one of the last years that the award was given, the presentation ceremony was held in New York City at the Hall of Ocean Life of the American Museum of Natural History. My family was able to attend, making it a spectacular and memorable event. Also very gratifying was to receive the United States Department of Agriculture (USDA) Secretary's Honor Award (2000), the American College of Nutrition Research Award (2003), and the Danone Mentorship Award for 2010, presented at the Experimental Biology 2011 meeting. At that meeting, I was honored by the USDA with the opportunity to present the W.O. Atwater Lecture.

An activity I came to enjoy greatly was my service to this journal, the Annual Review of Nutrition. I served as an Editorial Committee member with Editors Bob Olson and Don McCormick, as Associate Editor, and then two terms as Editor (2005–2015). My terms were helped along with the skillful assistance of Production Editor Lisa Dean. This experience provided the opportunity to review the field from a distance with the goal of highlighting work that is cutting edge and of interest to both researchers and those who teach in the nutritional sciences.

Perspectives 

As one can tell from reading this perspective, I lament the days when a student and mentor could work out a research technique and then answer the question of interest. We are now in the age of collaboration among investigators on research projects. The complexity of the technologies needed makes this understandable. I am concerned that papers appear with 20+ authors from multiple institutions to drive impact factors; this seems like piecework science. The increasing rate of paper retractions may be related to this mega-author phenomenon.

It should be no surprise that I am also concerned about research funding for individual investigators. Although the NIH budget doubled, the same situation, discussed above, involving funding of individual investigation is occurring today. Many new initiatives now compete with investigator-initiated proposals. I am also concerned about the sustainability of major salary support being charged to research grants. That includes sustainability of the principal investigator's career on soft money as well as the limit it places on the funds available for research. In a career of 45 years as a faculty member in a College of Agriculture and Life Science, I have never received salary support from a research grant, which has allowed the extramural funding to support my graduate students, the postdoctoral trainees, and my research program.

The future of nutrition research is bright. Journals that characteristically have published only reductionist research now include papers where animals and humans are being fed diets with modifications to alter nutritionally relevant pathways to produce changes that influence health. This broadening of nutrition-related research beyond the traditional nutrition community is a very healthy sign that addresses the relevance of the field. 

Epilogue

All the professional activities I have described were made possible by my wife, Beth, and our three children, Sarah, Jonathan, and Allison, who have been very understanding and supportive. I also receive support and enjoyment from being with grandsons Dylan and Samuel.

I have spent my entire career, starting as a college freshman, at land grant institutions and associated with Colleges of Agricultural and Life Science. It has been a true privilege as a faculty member at two land grant institutions to have the freedom to pursue basic biological research but always with the goal of potential application of that knowledge.

At the current time I am still running an active research lab with postdocs and doctoral students with whom I interact daily. The NIH has been generous with continuous funding since 1972. The ability to use knockout mouse models for discovery provides a daily stimulus to the lab. The opportunity to alter a phenotype and then examine the influence of nutritional intervention is a powerful research tool. It is wonderful to be in a research area that is flexible enough where one can propose a hypothesis or experiment on Monday and by Friday have the answer. I regret that space does not permit me to list all the undergraduates, graduate students, and postdocs who have been in the lab over the years or to list the fine positions they have held. I hope that the bibliography captures most of those names.

Literature Cited

1. Aydemir TB, Blanchard RK, Cousins RJ. 2006. Zinc supplementation of young men alters metallo-thionein, zinc transporter, and cytokine gene expression in leukocyte populations. PNAS 103:1699–704

2. Aydemir TB, Chang SM, Guthrie GJ, Maki AB, Ryu MS, et al. 2012. Zinc transporter ZIP14 functions in hepatic zinc, iron and glucose homeostasis during the innate immune response (endotoxemia). PLOS ONE 7(10):e48679

3. Aydemir TB, Liuzzi JP, McClellan S, Cousins RJ. 2009. Zinc transporter ZIP8 (SLC39A8) and zinc influence IFN-γ expression in activated human T cells. J. Leukoc. Biol. 86:337–48

4. Aydemir TB, Sitren HS, Cousins RJ. 2012. The zinc transporter Zip14 influences c-Met phosphorylation and hepatocyte proliferation during liver regeneration in mice. Gastroenterology 142:1536–46

5. Cao J, Cousins RJ. 2000. Metallothionein mRNA in monocytes and peripheral blood mononuclear cells and in cells from dried blood spots increases after zinc supplementation of men. J. Nutr. 130:2180–87

6. Cousins RJ, Barber AK, Trout JR. 1973. Cadmium toxicity in growing swine. J. Nutr. 103:964–72

7. Cousins RJ, DeLuca HF, Suda T, Chen T, Tanaka Y. 1970. Metabolism and subcellular location of 25-hydroxycholecalciferol in intestinal mucosa. Biochemistry 9:1453–59

8. Cousins RJ, Eaton HD, Rousseau JE Jr, Hall RC Jr. 1969. Biochemical constituents of the dura mater in vitamin A deficiency. J. Nutr. 97:409–18

9. Cousins RJ, Olson JA. 1996. James Smith Dinning, 1922–1991. J. Nutr. 126:2461–65 This article is not from the author's lab.

10. Cousins RJ, Wynveen RA, Squibb KS, Richards MP. 1975. Double label counting of metal nuclides with 3H or 14C by liquid scintillation counting. Anal. Biochem. 65:412–17

11. Dunn MA, Cousins RJ. 1989. Kinetics of zinc metabolism in the rat: effect of dibutyryl cAMP. Am. J. Physiol. 256:E420–30

12. Etzel KR, Swerdel MR, Swerdel JN, Cousins RJ. 1982. Endotoxin-induced changes in copper and zinc metabolism in Syrian hamster. J. Nutr. 112:2363–73

13. Failla ML, Cousins RJ. 1978. Zinc accumulation and metabolism in primary cultures of rat liver cells: regulation by glucocorticoids. Biochem. Biophys. Acta 543:293–304

14. Feldman SL, Failla ML, Cousins RJ. 1978. Degradation of rat liver metallothioneins in vitro. Biochem. Biophys. Acta 544:638–46

15. Fernandes PR, Samuelson DA, Clark WR, Cousins RJ. 1997. Immunohistochemical localization of cysteine-rich intestinal protein in rat small intestine. Am. J. Physiol. 272:G751–59

16. Grider A, Bailey LB, Cousins RJ. 1990. Erythrocyte metallothionein as an index of zinc status in humans. PNAS 87:1259–62

17. Guthrie GJ, Aydemir TB, Troche C, Martin AB, Chang SM, Cousins RJ. 2014. Influence of ZIP14 (slc39A14) on intestinal zinc processing and barrier function. Am. J. Physiol. Gastrointest. Liver Physiol. 308:G171–78

18. Hempe JM, Cousins RJ. 1991. Cysteine-rich intestinal protein binds zinc during transmucosal zinc transport. PNAS 88:9671–74

19. Hoadley JE, Leinart AS, Cousins RJ. 1987. Kinetic analysis of zinc uptake and serosal transfer by vascularly perfused rat intestine. Am. J. Physiol. 252:G825–31

20. Holick MF, Schnoes HK, DeLuca HF, Suda T, Cousins RJ. 1971. Isolation and identification of 1,25-dihydroxycholecalciferol. A metabolite of vitamin D active in intestine. Biochemistry 10:2799–804

21. Khoo C, Blanchard RK, Sullivan VK, Cousins RJ. 1997. Human cysteine-rich intestinal protein: cDNA cloning and expression of recombinant protein and identification in human peripheral blood mononuclear cells. Protein Expr. Purif. 9:379–87

22. Levenson CW, Shay NF, Lee-Ambrose LM, Cousins RJ. 1993. Regulation of cysteine-rich intestinal protein by dexamethasone in the neonatal rat. PNAS 90:712–15

23. Lichten LA, Liuzzi JP, Cousins RJ. 2009. Interleukin-1 contributes via nitric oxide to the up-regulation and functional activity of the zinc transporter Zip14 (Slc39A14) in murine hepatocytes. Am. J. Physiol. Gastrointest. Liver Physiol. 296:G860–67

24. Lichten LA, Ryu MS, Guo L, Embury J, Cousins RJ. 2011. MTF-1-mediated repression of the zinc transporter Zip10 is alleviated by zinc restriction. PLOS ONE 6:e21526

25. Liuzzi JP, Bobo JA, Lichten LA, Samuelson DA, Cousins RJ. 2004. Responsive transporter genes within the murine intestinal-pancreatic axis form a basis of zinc homeostasis. PNAS 101:14355–60

26. Liuzzi JP, Lichten LA, Rivera S, Blanchard RK, Aydemir TB, et al. 2005. Interleukin-6 regulates the zinc transporter Zip14 in liver and contributes to the hypozincemia of the acute-phase response. PNAS 102:6843–48

27. McCormick CC, Menard MP, Cousins RJ. 1981. Induction of hepatic metallothionein by feeding zinc to rats of depleted zinc status. Am. J. Physiol. 240:E414–21

28. McMahon RJ, Cousins RJ. 1998. Regulation of the zinc transporter ZnT-1 by dietary zinc. PNAS 95:4841–46

29. Olson RE. 1965. The regulatory function of the fat-soluble vitamins. Can. J. Biochem. 43:1565–73 This article is not from the author's lab.

30. Richards MP, Cousins RJ. 1975. Mammalian zinc homeostasis: requirement for RNA and metallothionein synthesis. Biochem. Biophys. Res. Comm. 64:1215–23

31. Ryu MS, Guthrie GJ, Maki AB, Aydemir TB, Cousins RJ. 2012. Proteomic analysis shows the upregulation of erythrocyte dematin in zinc-restricted human subjects. Am. J. Clin. Nutr. 95:1096–102

32. Ryu MS, Langkamp-Henken B, Chang SM, Shankar MN, Cousins RJ. 2011. Genomic analysis, cytokine expression, and microRNA profiling reveal biomarkers of human dietary zinc depletion and homeostasis. PNAS 108:20970–75

33. Shapiro SG, Squibb KS, Markowitz LA, Cousins RJ. 1978. Cell-free synthesis of metallothionein directed by rat liver polyadenylated messenger ribonucleic acid. Biochem. J. 175:833–40

34. Smith KT, Cousins RJ, Silbon BL, Failla ML. 1978. Zinc absorption and metabolism by isolated, vascularly perfused rat intestine. J. Nutr. 108:1849–57

35. Smith KT, Failla ML, Cousins RJ. 1979. Identification of albumin as the plasma carrier for zinc absorption by perfused rat intestine. Biochem. J. 184:627–33

36. Squibb KS, Cousins RJ. 1974. Control of cadmium binding protein synthesis in rat liver. Environ. Physiol. Biochem. 4:24–30

37. Squibb KS, Cousins RJ, Feldman SL. 1977. Control of zinc-thionein synthesis in rat liver. Biochem. J. 164:223–28

38. Steel L, Cousins RJ. 1985. Kinetics of zinc absorption by luminally and vascularly perfused rat intestine. Am. J. Physiol. 248:G46–53

39. Sullivan VK, Burnett FR, Cousins RJ. 1998. Metallothionein expression is increased in monocytes and erythrocytes of young men during zinc supplementation. J. Nutr. 128:707–13

40. Suttie JW. 2011. Nutritional scientist or biochemist? Annu. Rev. Nutr. 31:1–14 This article is not from the author's lab.

41. Troche C, Aydemir TB, Cousins RJ. 2016. Zinc transporter Slc39a14 regulates inflammatory signaling associated with hypertrophic adiposity. Am. J. Physiol. Endocrinol. Metab. 310:E258–68

42. Wessels I, Cousins RJ. 2015. Zinc dyshomeostasis during polymicrobial sepsis in mice involves zinc transporter Zip14 and can be overcome by zinc supplementation. Am. J. Physiol. Gastrointest. Liver Physiol. 309:G768–78

Related References

Blalock TL, Dunn MA, Cousins RJ. 1988. Metallothionein gene expression in rats: tissue-specific regulation by dietary copper and zinc. J. Nutr. 118:222–28

Blanchard RK, Cousins RJ. 1996. Differential display of intestinal mRNAs regulated by dietary zinc. PNAS 93:6863–68

Blanchard RK, Cousins RJ. 1997. Upregulation of rat intestinal uroguanylin mRNA by dietary zinc restriction. Am. J. Physiol. 272:G972–78

Blanchard RK, Moore JB, Green CL, Cousins RJ. 2001. Modulation of intestinal gene expression by dietary zinc status: effectiveness of cDNA arrays for expression profiling of a single nutrient deficiency. PNAS 98:13507–13

Cousins RJ. 1985. Absorption, transport and hepatic metabolism of copper and zinc: special reference to metallothionein and ceruloplasmin. Physiol. Rev. 65:238–309

Cousins RJ, Blanchard RK, Popp MP, Liu L, Cao J, et al. 2003. A global view of the selectivity of zinc deprivation and excess on genes expressed in human THP 1 mononuclear cells. PNAS 100:6952–57

Cousins RJ, Lee-Ambrose LM. 1992. Nuclear zinc uptake and interactions and metallothionein gene expression are influenced by dietary zinc in rats. J. Nutr. 122:56–64

Cousins RJ, Leinart AS. 1988. Tissue-specific regulation of zinc metabolism and metallothionein genes by interleukin 1. FASEB J. 2:2884–90

Cowen LA, Bell DE, Hoadley JE, Cousins RJ. 1986. Influence of dietary zinc deficiency and parenteral zinc on rat liver fructose 1,6-biphosphatase activity. Biochem. Biophys. Res. Comm. 134:944–50

Davis BA, Blanchard RK, Lanningham-Foster L, Cousins RJ. 1998. Structural characterization of the rat cysteine rich intestinal protein gene and overexpression of this LIM-only protein in transgenic mice. DNA Cell Biol. 17:1057–64

DiSilvestro RA, Cousins RJ. 1984. Mediation of endotoxin-induced changes in zinc metabolism in rats. Am. J. Physiol. 247:E436–41

Etzel KR, Cousins RJ. 1983. Hyperglycemic action of zinc in rats. J. Nutr. 113:1657–63

Richards MP, Cousins RJ. 1977. Isolation of an intestinal metallothionein induced by parenteral zinc. Biochem. Biophys. Res. Comm. 75:286–94

Etzel KR, Shapiro SG, Cousins RJ. 1979. Regulation of liver metallothionein and plasma zinc by the glucocorticoid dexamethasone. Biochem. Biophys. Res. Comm. 89:1120–26

Gordon DT, Leinart AS, Cousins RJ. 1987. Portal copper transport in rats by albumin. Am. J. Physiol. 252:E327–33

Huber KL, Cousins RJ. 1988. Maternal zinc deprivation and interleukin-1 influence metallo-thionein gene expression and zinc metabolism of rats. J. Nutr. 118:1570–76

Liuzzi JP, Blanchard RK, Cousins RJ. 2001. Differential regulation of zinc transporter 1, 2, and 4 mRNA expression by dietary zinc in rats. J. Nutr. 131:46–52

Menard MP, Cousins RJ. 1983. Zinc transport by brush border membrane vesicles from rat intestine. J. Nutr. 113:1434–42

Quinones SR, Cousins RJ. 1984. Augmentation of dexamethasone induction of rat liver metallothionein by zinc. Biochem. J. 219:959–63

Moore JB, Blanchard RK, Cousins RJ. 2003. Dietary zinc modulates gene expression in murine thymus: results from a comprehensive differential display screening. PNAS 100:3883–88

Ryu MS, Lichten LA, Liuzzi JP, Cousins RJ. 2008. Zinc transporters ZnT1 (Slc30a1), Zip8 (Slc39a8), and Zip10 (Slc39a10) in mouse red blood cells are differentially regulated during erythroid development and by dietary zinc deficiency. J. Nutr. 138: 2076–83

Schroeder JJ, Cousins RJ. 1991. Maintenance of zinc-dependent hepatic functions in rat hepatocytes cultured in medium without added zinc. J. Nutr. 121:844–53

Shay NF, Cousins RJ. 1993. Cloning of rat intestinal mRNAs affected by zinc deficiency. J. Nutr. 123:35–41

Washko PW, Cousins RJ. 1977. Role of dietary calcium and calcium binding protein in cadmium toxicity in rats. J. Nutr. 107:920–28

Weiner AL, Cousins RJ. 1980. Copper accumulation and metabolism in primary monolayer cultures of rat liver parenchymal cells. Biochim. Biophys. Acta 629:113–25

Yuzbasiyan-Gurkan V, Grider A, Nostrant T, Cousins RJ, Brewer GJ. 1992. Treatment of Wilson's disease with zinc: X. Intestinal metallothionein induction. J. Lab. Clin. Med. 120:380–86

Other Cited Publications

Cousins, R.J. and J.A. Olson (1996) James Smith Dinning, 1922-1991.  J. Nutr. 126:2461-2465.

Olson, R.E. (1965). The Regulatory function of the fat-soluble vitamins. Can. J. Biochem., 43:1565.

J.W. Suttie (2011). Nutritional scientist or biochemist? Annu. Rev. Nutr. 21(31):1-14.    

Key Words

University of Connecticut; University of Wisconsin, Rutgers University, University of Florida, Cadmium, Zinc, Gene Regulation, Metabolism, Nutrition, Biochemistry.