Education and career
Baccarelli graduated cum laude with his Doctor of Medicine from the University of Perugia,Italy in 1995,obtained his Master of Science in Epidemiology from the University of Turin,Italy,and his Ph.D. in Occupational Health and Industrial Hygiene from the Universita' degli Studi di Milano,Italy,in 2003. [3]
He completed his residency in endocrinology at the University of Milan and his postdoctoral fellowship at the National Cancer Institute’s Division of Cancer Epidemiology and Genetics (2000-2004). [4]
Baccarelli has served as the Dean of the Faculty at the Harvard T.H. Chan School of Public Health since January 2024. He previously taught at the Harvard Chan School as the Mark and Catherine Winkler Associate Professor of Environmental Epigenetics from 2010 to 2016. [5]
He also served as Professor and Chair of the Department of Environmental Health Sciences at the Columbia University Mailman School of Public Health from 2016 to 2023. [6] [7] While at Columbia,he led the NIEHS Center for Environmental Health and Justice in Northern Manhattan,which brought together scientists,advocates,community organizations and the public to understand health concerns caused by environmental exposures and to address inequities. [8]
Baccarelli's research has pioneered the field of public health epigenetics,which explores how environmental factors can modify gene expression without changing the DNA sequence. [9] His studies have demonstrated that air pollution can alter the epigenome,leading to changes in gene regulation that may contribute to the development of diseases such as cardiovascular disorders and neurodegenerative conditions. [10] [11]
Baccarelli conducted research showing that short-term exposure to air pollution,including levels considered "acceptable," can impair cognitive ability in the elderly. [12] [13] [14] Baccarelli also found that the use of nonsteroidal anti-inflammatory drugs such as aspirin partially protected against the negative cognitive effects of pollution. [15] He also conducted research showing that ambient air pollution is associated with an increased risk of osteoporosis and bone fractures in older individuals. [16] [17]
In biology, epigenetics is the study of heritable traits, or a stable change of cell function, that happen without changes to the DNA sequence. The Greek prefix epi- in epigenetics implies features that are "on top of" or "in addition to" the traditional genetic mechanism of inheritance. Epigenetics usually involves a change that is not erased by cell division, and affects the regulation of gene expression. Such effects on cellular and physiological phenotypic traits may result from environmental factors, or be part of normal development. They can lead to cancer.
5-Methylcytosine is a methylated form of the DNA base cytosine (C) that regulates gene transcription and takes several other biological roles. When cytosine is methylated, the DNA maintains the same sequence, but the expression of methylated genes can be altered. 5-Methylcytosine is incorporated in the nucleoside 5-methylcytidine.
Environmental health is the branch of public health concerned with all aspects of the natural and built environment affecting human health. In order to effectively control factors that may affect health, the requirements that must be met in order to create a healthy environment must be determined. The major sub-disciplines of environmental health are environmental science, toxicology, environmental epidemiology, and environmental and occupational medicine.
A neoplasm is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists in growing abnormally, even if the original trigger is removed. This abnormal growth usually forms a mass, which may be called a tumour or tumor.
Malignant transformation is the process by which cells acquire the properties of cancer. This may occur as a primary process in normal tissue, or secondarily as malignant degeneration of a previously existing benign tumor.
Transgenerational epigenetic inheritance is the transmission of epigenetic markers and modifications from one generation to multiple subsequent generations without altering the primary structure of DNA. Thus, the regulation of genes via epigenetic mechanisms can be heritable; the amount of transcripts and proteins produced can be altered by inherited epigenetic changes. In order for epigenetic marks to be heritable, however, they must occur in the gametes in animals, but since plants lack a definitive germline and can propagate, epigenetic marks in any tissue can be heritable.
Cancer epigenetics is the study of epigenetic modifications to the DNA of cancer cells that do not involve a change in the nucleotide sequence, but instead involve a change in the way the genetic code is expressed. Epigenetic mechanisms are necessary to maintain normal sequences of tissue specific gene expression and are crucial for normal development. They may be just as important, if not even more important, than genetic mutations in a cell's transformation to cancer. The disturbance of epigenetic processes in cancers, can lead to a loss of expression of genes that occurs about 10 times more frequently by transcription silencing than by mutations. As Vogelstein et al. points out, in a colorectal cancer there are usually about 3 to 6 driver mutations and 33 to 66 hitchhiker or passenger mutations. However, in colon tumors compared to adjacent normal-appearing colonic mucosa, there are about 600 to 800 heavily methylated CpG islands in the promoters of genes in the tumors while these CpG islands are not methylated in the adjacent mucosa. Manipulation of epigenetic alterations holds great promise for cancer prevention, detection, and therapy. In different types of cancer, a variety of epigenetic mechanisms can be perturbed, such as the silencing of tumor suppressor genes and activation of oncogenes by altered CpG island methylation patterns, histone modifications, and dysregulation of DNA binding proteins. There are several medications which have epigenetic impact, that are now used in a number of these diseases.
Behavioral epigenetics is the field of study examining the role of epigenetics in shaping animal and human behavior. It seeks to explain how nurture shapes nature, where nature refers to biological heredity and nurture refers to virtually everything that occurs during the life-span. Behavioral epigenetics attempts to provide a framework for understanding how the expression of genes is influenced by experiences and the environment to produce individual differences in behaviour, cognition, personality, and mental health.
An epigenetic clock is a biochemical test that can be used to measure age. The test is based on DNA methylation levels, measuring the accumulation of methyl groups to one's DNA molecules.
Epigenetic therapy refers to the use of drugs or other interventions to modify gene expression patterns, potentially treating diseases by targeting epigenetic mechanisms such as DNA methylation and histone modifications.
Kari C. Nadeau is the Chair of the Department of Environmental Health at Harvard School of Public Health and John Rock Professor of Climate and Population Studies. She is adjunct professor at Stanford University in the Department of Pediatrics and the co-chair of the Medical Societies Consortium for Climate Change and Health. She practices Allergy, Asthma, Immunology in children and adults. She has published over 400+ papers, many in the field of climate change and health. Her team focuses on quantifying health outcomes of solutions as they pertain climate change mitigation and adaptation at the local, regional, country, and global levels. Dr. Nadeau, with a team of individuals and patients and families, has been able to help major progress and impact in the clinical fields of immunology, infection, asthma, and allergy. Dr. Nadeau is a member of the National Academy of Medicine and the U.S. EPA Children’s Health Protection Committee.
An epigenome-wide association study (EWAS) is an examination of a genome-wide set of quantifiable epigenetic marks, such as DNA methylation, in different individuals to derive associations between epigenetic variation and a particular identifiable phenotype/trait. When patterns change such as DNA methylation at specific loci, discriminating the phenotypically affected cases from control individuals, this is considered an indication that epigenetic perturbation has taken place that is associated, causally or consequentially, with the phenotype.
Steve Horvath is a German–American aging researcher, geneticist, and biostatistician. He is a professor at the University of California, Los Angeles known for developing the Horvath aging clock, which is a highly accurate molecular biomarker of aging, and for developing weighted correlation network analysis. His work on the genomic biomarkers of aging, the aging process, and many age related diseases/conditions has earned him several research awards. Horvath is a principal investigator at the anti-aging startup Altos Labs and co-founder of nonprofit Clock Foundation.
Gene-environment interplay describes how genes and environments work together to produce a phenotype, or observable trait. Many human traits are influenced by gene-environment interplay. It is a key component in understanding how genes and the environment come together to impact human development. Examples of gene-environment interplay include gene-environment interaction and gene-environment correlation. Another type of gene-environment interplay is epigenetics, which is the study of how environmental factors can affect gene expression without altering DNA sequences.
Frederica Perera is an American environmental health scientist and the founder of the Columbia Center for Children's Environmental Health at the Columbia University Mailman School of Public Health. Her research career has focused on identifying and preventing harm to children from prenatal and early childhood exposure to environmental chemicals and pollutants. She is internationally recognized for pioneering the field of molecular epidemiology, incorporating molecular techniques into epidemiological studies to measure biologic doses, preclinical responses and susceptibility to toxic exposure.
Stephanie J. London is an American epidemiologist and physician-scientist specializing in environmental health, respiratory diseases, and genetic susceptibility. She is the deputy chief of the epidemiology branch at the National Institute of Environmental Health Sciences.
Francine Laden is an American epidemiologist who is Professor of Environmental Epidemiology at the Harvard T.H. Chan School of Public Health. Her research has investigated the environmental epidemiology of chronic disease. She serves as co-director of the Harvard University and Boston University center for research on environmental and social stressors in housing across the life course. Laden has also served on the United States Environmental Protection Agency advisory board.
Nutritional epigenetics is a science that studies the effects of nutrition on gene expression and chromatin accessibility. It is a subcategory of nutritional genomics that focuses on the effects of bioactive food components on epigenetic events.
In Environmental epigenetics, Exposure to certain materials or chemicals can cause an epigenetic reaction. The epigenetic causing substances cause issues like altered DNA methylation, CpG islands, chromatin, along with other transcription factors. Environmental epigenetics aims to relate such environmental triggers or substances to phenotypic variation. Numerrous studies have demonstrated how exposure to environmental pollutants, such as heavy metals, pesticides, and air pollutants, can induce epigenetic changes in various organisms. For example, research has shown that exposure to pollutants like biphenol A (BPA) and polycyclic acromatic hydrocarbons (PAHs) can lead to DNA methylation changes and histone modifications in plants, animals, and humans.
Epiphenotyping involves studying the relationship between DNA methylation patterns and phenotypic traits in individuals and populations to be able to predict a phenotype from a DNA methylation profile. In the following sections, the background of epiphenotyping, an overview of a general methodology, its applications, advantages, and limitations are covered.
