About Us

Professor of Pediatrics (Gastroenterology)/Cellular and Molecular Physiology, Yale School of Medicine is the Principal Investigator of the Ameen Laboratory

Nadia received her medical training from the University of the West Indies, Mona, Jamaica. Following completion of training, she completed a residency in pediatrics at the Children’s Hospital Wisconsin, Milwaukee, WI and served as Chief Resident before enrolling in a post-doctoral training fellowship program in Gastroenterology/Hepatology at Yale School of Medicine. Dr. Ameen also trained in immunocytochemistry in the laboratory of Fred Gorelick at Yale School of Medicine and trained in cryo-immunoelectron microscopy at the University of Utrecht, Netherlands, Cell Biology Department, under the leadership of Professor Peter Peters and Hans Hueze, where she began her research studies on CFTR trafficking in the intestine.

She was the first to demonstrate the physiologic importance of regulated traffic of the Cystic Fibrosis Transmembrane Conductance Regulator CFTR chloride channel from subapical endosomes into the brush border membrane as a major mechanism of intestinal fluid secretion that underlies secretory diarrhea.

Her NIH supported research over 20 years has focused on regulation of ion transporters by endocytic and endocytic traffic into and out of the brush border membrane and the implications of defects in the apical trafficking pathway for intestinal diseases. In that regard, she and her long-standing collaborator, Dr. Pedro Salas (University of Miami School of Medicine) were the first to identify an apical trafficking defect in Microvillus Inclusion Disease (MVID), a rare but deadly congenital diarrheal disease that affects newborns of Navajo Indians and leads to severe diarrhea.

She continues to investigate MVID pathogenesis and diarrhea, using state of the art tools including intestinal cell models of MVID that were developed in her laboratory, human organoids, that led to identification of targets for therapeutic intervention to ameliorate MVID diarrhea. She collaborates with investigators in academia at Yale and other medical schools, industry partners including Ironwood Inc. and Takeda to investigate the pathogenesis and treatment of intestinal diseases.

She has served on NIH, and SBIR/STTR NIDDK review panels, is on the editorial board of journals and a reviewer for many scientific journals. She serves on the admission committee and member of the MD/PhD Committee at Yale School of Medicine.

Associate Research Scientist

Md Kaimul Ahsan received his PhD degree (2001-2005) from the Department of Biological Responses, Institute for Virus, Kyoto University, Kyoto, Japan. He continued his postdoctoral training (2006-2008) for two years in translation research in the Department of Experimental Therapeutics, Translational Research Center, Kyoto University Hospital, Kyoto, Japan. He moved to the United States in 2008 and joined the Department of Surgery, Cardiovascular Research Center, University of Connecticut Heath Center.

From 2010-2013, he worked as a postdoctoral associate in the laboratory of Dr. Wajahat Mehal, Department of Internal Medicine, Section of Digestive Diseases, Yale University.

In July 2013, he joined Dr. Ameen's laboratory, Department of Pediatrics, Section of Digestive Diseases. Since joining the Ameen lab, he has been conducting studies to (1) elucidate the mechanism of action of the FDA approved drug Linaclotide (Linzess), a GCC receptor agonist in clinical use for treatment of chronic constipation and IBS-C. Studies utilize cultured intestinal cells and rodent models to examine Linaclotide induced trafficking pathways of the CFTR chloride channel into the intestinal brush border in collaboration with Ironwood Inc., (2) Role of the exocyst component Sec8 on cAMP mediated trafficking and apical exocytosis of CFTR, and (3) Physiological role of Myo1a and Myo6 in CFTR trafficking in to the intestinal brush border using Myo1 or Myo1-Myo6 double deficient mice in collaboration with Dr. Mark Mooseker, Yale University (4) development of human intestinal organoid and mouse models for studies of the genetic disease responsible for severe diarrhea in newborns called Microvillus Inclusion Disease (MVID).

Leandra K. Figueroa-Hall received her Master of Science degree (2008-2011) in Biomedical Research from the Department of Medical Technology at the University of Maryland, School of Medicine, where her project involved delineating the molecular mechanisms of LPS-induced TLR4 signaling between wild-type and its known single nucleotide polymorphisms, D299G and T399I, in peripheral immune cells. Thereafter, Leandra received her PhD (2011-2017) in Biomedical Sciences with a concentration in Neuroinflammation from the Department of Pharmacology & Physiology at Oklahoma State University-Center for Health Sciences.

Here, Leandra’s dissertation project focused on characterizing LPS-induced TLR4 signaling in a microglial cell line, CHME-5 and determining the effects of opioid agonists, fentanyl and morphine, on this inflammatory signaling.

Leandra joined Dr. Ameen’s laboratory in the Department of Pediatrics at Yale University to begin her postdoctoral training in August 2017, where she will focus investigations of the role of Myo5B in Microvillus Inclusion Disease. She will employ human stem cells, CRISPR- Cas 9 approaches and 2) human intestinal organoids in her studies. Employing this molecular approach will identify Myo5B’s mechanism of action in human intestinal epithelial cells/organoids to more closely reflect human disease pathogenesis and enable testing of potential therapies for MVID diarrhea developed in the Ameen laboratory.