October 9, 2009

Aliquots — highlights from VUMC laboratories

Clues to chronic pancreatitis

Autoimmune pancreatitis (AIP), a form of chronic inflammation of the pancreas, is difficult to distinguish from pancreatic cancer. What causes AIP is unclear. Neil Bhowmick, Ph.D., Chad Boomershine, M.D., Ph.D., and colleagues found that mice lacking a receptor fo r transforming growth factor beta (TGFß) in stromal cells died by 6 weeks of age with pancreatitis similar to human AIP.

In the September issue of Gut, the researchers report that mice lacking the TGFß type II receptor (Tgfbr2) in immune cells known as dendritic cells spontaneously develop AIP, displaying inflammatory infiltration in the pancreas and pancreatic autoantibody production. Transfer of dendritic cells from these mice into healthy 2-week-old mice led to the development of AIP by 6 weeks of age. Dendritic cell transfer into adult mice did not cause disease. The findings suggest that disrupted TGFß signaling can lead to loss of immune tolerance toward the pancreas during a critical period of tissue remodeling and can contribute to the development of AIP.

Melissa Marino


Claustrum comes out of hiding

The claustrum – a structure in the mammalian brain whose name means “hidden place” – has an odd shape and is surrounded by cells of different brain areas, which has made it difficult to define its borders, connections and function.

Brian Mathur, Ph.D., and Ariel Deutch, Ph.D., used “imaging mass spectrometry,” a proteomic method developed by Richard Caprioli, Ph.D., to probe for proteins in the rat claustrum. In the October issue of Cerebral Cortex, they report that the protein Gng2 is selectively expressed in the claustrum and that brain regions previously believed to be part of the

The findings resolve a long-standing controversy concerning the definition of the claustrum and open the door for making molecular lesions to study this brain region’s potential roles in attention and cognition.

Leigh MacMillan


Drug helps patients stand

Patients with postural tachycardia syndrome (POTS) experience symptoms such as lightheadedness, chest discomfort and blurred vision when they stand upright. The syndrome causes a poor quality of life and significant functional disability, but effective therapies are scarce.

The rapid heart rate (tachycardia) on standing suggests that drugs called beta-blockers, which lower heart rate, might be good treatments, but reports on the effectiveness of such drugs are conflicting. Satish R. Raj, M.D., M.S.C.I., and colleagues compared the beta-blocker propranolol to

They report in the Sept. 1 issue of Circulation that a low dose of oral propranolol was highly effective in decreasing the tachycardia and improving symptoms in patients with POTS. They also compared low and high doses of propranolol and found that a higher dose did not further improve symptoms. The findings match the clinical experience of the investigators and suggest that low-dose propranolol may be an effective treatment for POTS.

Leigh MacMillan


Stem cell source for heart lining

The lining of the heart, or endocardium, is one of the earliest cardiac tissues to form during embryonic development. However little is known about the origin of these cells.

Scott Baldwin, M.D., and colleagues generated transgenic mice with a marker that identifies endocardial cells as they first appear in the developing mouse heart. In the Sept. 1 issue of Developmental Biology, they report that endocardial cells are distinct from cells lining blood vessels outside the heart and that they appear to come from the same

Since the endocardium gives rise to the heart valves, the findings may offer insight into how congenital valve defects arise. And the ability to grow endocardial cells in the lab may provide a new source of cells that can serve as the building block for tissue engineered heart valves.

Carole Bartoo


We welcome suggestions for research to highlight in Aliquots. The items should be primary research articles (no reviews, editorials or commentaries) published within the last two months in a peer-reviewed journal. Please send the article citation (PDF if available) and any other feedback about the column to: aliquots@vanderbilt.edu.

Past Aliquots

June 22, 2012
June 8, 2012
May 11, 2012
April 27, 2012
April 13, 2012
March 30, 2012
March 16, 2012