Mount Sinai Scientists Discover the Cellular Functions of a Family of Proteins Integral to Inflammatory Diseases
In a scientific breakthrough, Mount Sinai researchers have revealed the biological mechanisms by which a family of proteins known as histone deacetylases (HDACs) activate immune system cells linked to inflammatory bowel disease (IBD) and other inflammatory diseases.
This discovery, reported in Proceedings of the National Academy of Sciences (PNAS), could potentially lead to the development of selective HDAC inhibitors designed to treat types of IBD such as ulcerative colitis and Crohn’s disease.
“Our understanding of the specific function of class II HDACs in different cell types has been limited, impeding development of therapies targeting this promising drug target family,” says senior author Ming-Ming Zhou, PhD, Dr. Harold and Golden Lamport Professor in Physiology and Biophysics and Chair of the Department of Pharmacological Sciences at the Icahn School of Medicine at Mount Sinai. “Through our proof-of-concept study, we’re unraveling the mechanisms of class II HDACs, providing essential knowledge to explore their therapeutic potential for safer and more effective disease treatments.”
The Mount Sinai team focused specifically on class IIa HDACs, which exhibit more tissue-specific functions than class I HDACs, which act more broadly. Among the 18 histone deacetylases discovered to date in mammals, HDAC4 and HDAC7—both class IIa HDACs—stand out for their roles in regulating the development and differentiation of Th17 cells. These cells are known for producing interleukin-17 (IL-17), a highly inflammatory cytokine associated with a spectrum of disorders, including IBD, multiple sclerosis, and rheumatoid arthritis. Given the strong correlation between excessive Th17 cell activity and human disease, scientists have focused on pharmacological or genetic interventions targeting HDAC4/7 to mitigate Th17 cell-mediated inflammation.
In their groundbreaking study, the Mount Sinai researchers delineated a previously unrecognized mechanism by which HDAC4 and HDAC7 operate independently yet cooperatively to govern Th17 cell differentiation and transcription. Transcription is the initial step of gene expression involving copying of the DNA sequence to generate RNA molecules; it is crucial for most biological processes.
“The role of class IIa HDACs in Th17 cells and inflammatory disease has been largely unexplored until now,” notes lead author Ka Lung Cheung, PhD, Assistant Professor of Pharmacological Sciences at Icahn Mount Sinai. “Mechanistically, we’ve discovered that class IIa HDACs orchestrate both gene transcriptional activation and repression to steer the process of Th17 cell differentiation. This significant revelation deepens our comprehension of the previously ambiguous role of class IIa HDACs in biology and human disease.”
As a critical aspect of their investigation, the research team found that a potent class IIa HDAC inhibitor, TMP269, influenced the differentiation of Th17 cells in a mouse model of ulcerative colitis. This pivotal discovery underscores the potential of pharmacological inhibition of class IIa HDACs as a promising therapeutic approach for addressing Th17-related inflammatory and autoimmune diseases, the study reported.
Expanding on this foundation of knowledge, researchers in the Zhou Lab and the Cheung Lab at Mount Sinai plan to concentrate on refining class IIa HDAC inhibitors with better efficacies for treating various types of Th17-mediated diseases.
“While our study primarily examined inflammatory bowel disease, specifically colitis,” says Dr. Zhou, “we believe our findings pave the way for extensive research into advanced therapies targeting severe inflammation in various other pathologies within the human body.”
About the Icahn School of Medicine at Mount Sinai
The Icahn School of Medicine at Mount Sinai is internationally renowned for its outstanding research, educational, and clinical care programs. It is the sole academic partner for the eight- member hospitals* of the Mount Sinai Health System, one of the largest academic health systems in the United States, providing care to a large and diverse patient population.
Ranked 13th nationwide in National Institutes of Health (NIH) funding and among the 99th percentile in research dollars per investigator according to the Association of American Medical Colleges, Icahn Mount Sinai has a talented, productive, and successful faculty. More than 3,000 full-time scientists, educators, and clinicians work within and across 44 academic departments and 36 multidisciplinary institutes, a structure that facilitates tremendous collaboration and synergy. Our emphasis on translational research and therapeutics is evident in such diverse areas as genomics/big data, virology, neuroscience, cardiology, geriatrics, as well as gastrointestinal and liver diseases.
Icahn Mount Sinai offers highly competitive MD, PhD, and Master’s degree programs, with current enrollment of approximately 1,300 students. It has the largest graduate medical education program in the country, with more than 2,000 clinical residents and fellows training throughout the Health System. In addition, more than 550 postdoctoral research fellows are in training within the Health System.
A culture of innovation and discovery permeates every Icahn Mount Sinai program. Mount Sinai’s technology transfer office, one of the largest in the country, partners with faculty and trainees to pursue optimal commercialization of intellectual property to ensure that Mount Sinai discoveries and innovations translate into healthcare products and services that benefit the public.
Icahn Mount Sinai’s commitment to breakthrough science and clinical care is enhanced by academic affiliations that supplement and complement the School’s programs.
Through the Mount Sinai Innovation Partners (MSIP), the Health System facilitates the real-world application and commercialization of medical breakthroughs made at Mount Sinai. Additionally, MSIP develops research partnerships with industry leaders such as Merck & Co., AstraZeneca, Novo Nordisk, and others.
The Icahn School of Medicine at Mount Sinai is located in New York City on the border between the Upper East Side and East Harlem, and classroom teaching takes place on a campus facing Central Park. Icahn Mount Sinai’s location offers many opportunities to interact with and care for diverse communities. Learning extends well beyond the borders of our physical campus, to the eight hospitals of the Mount Sinai Health System, our academic affiliates, and globally.
About the Mount Sinai Health System
Mount Sinai Health System is one of the nation’s leading integrated academic health systems and one of the largest in the New York metropolitan area. Its comprehensive system includes seven hospitals, more than 400 outpatient practices, over 600 research and clinical laboratories, the Icahn School of Medicine at Mount Sinai, the Graduate School of Biomedical Sciences, and the Mount Sinai Phillips School of Nursing. Together, the Health System comprises approximately 48,000 employees, more than 9,000 physicians, and 8,600 nurses.
As a leading learning health system, Mount Sinai combines clinical expertise with scientific discovery to improve patient care while training the next generation of health care and biomedical leaders. The Health System provides care across every stage of life, from prenatal care through geriatrics, while advancing personalized medicine through artificial intelligence, data science, and biomedical research.
Mount Sinai is consistently recognized among the nation’s leading academic health systems for patient care, research, and education. The Mount Sinai Hospital is ranked No. 1 in New York by Newsweek and No. 5 on the magazine’s World’s Best Hospitals list. The Icahn School of Medicine at Mount Sinai ranks No. 11 among U.S. medical schools and No. 1 among freestanding medical schools for National Institutes of Health funding, reflecting the strength of its scientific enterprise and leadership in biomedical research.