Navigation Links
Single cell studies identify coactivator role in fat cell maturation

HOUSTON - (Jan. 10, 2011) All fat cells are not the same a fact that has implications in the understanding and treatment of type 2 diabetes and obesity, said researchers from Baylor College of Medicine ( in a report that appears in the current issue of the Journal of Cell Biology (

The amount of fat in each cell and the central transcription factor, PPAR gamma (peroxisome proliferator activated receptor gamma), can vary widely, but the fat cells (adipocytes) can maintain stable levels of master switches known as steroid receptor coactivators (SRC)-2 and -3, said Dr. Sean M. Hartig, a postdoctoral fellow, and Dr. Michael Mancini (, an associate professor of molecular and cellular biology at BCM and the director of the Integrated Microscopy Core at BCM ( Hartig is first author and Mancini senior author of the report.

"The difference was the SRCs," said Hartig. "They control the transcriptional switch for PPAR gamma to maximize fat accumulation."

PPAR gamma is known to regulate the production of adipocytes or fat cells. It regulates transcription making an RNA copy of DNA, which is the first step in gene expression.

"Our research shows that there isn't always a linear connection between this transcriptional regulator PPAR gamma and the lipid in a cell," said Mancini. "It's dogma that one equals the other, but as you dive into the population of cells using high throughput microscopy and with custom-built software 'pipelines,' you find lots of exceptions. Then Sean (Hartig) connected it to the coregulators."

New drug-screening technology that automates both microscopy and image analysis allows experts like Mancini and Hartig to collect pictures and quantify thousands of cells in a short period of time. In this case, it allowed them to analyze the composition of different populations of human fat cells.

"Sean measured the amount of lipid in every cell," said Mancini. "This new technology uses fluorescent dyes and antibodies and enabled him to quantify both the amount of fat in each cell, but also how much of the transcriptional regulator PPAR gamma was expressed."

"There was a continuum," said Hartig. "There were cells that did not have any PPAR gamma but still had somehow become adipocytes. There were cells that had increased levels of PPAR gamma but had never developed the characteristics of adipocytes."

The finding supports the theory that these cells represent a continuum of factors with modulated levels of PPAR gamma and lipids. "PPAR-equals-fat simply didn't hold up to this level of scrutiny," Mancini said.

Mancini pointed to a population of cells with high lipid levels and low levels of PPAR gamma. There were cells with the opposite situation.

Hartig said reduced levels of SRC-2 and 3 resulted in more cells with low levels of lipid and increased PPAR gamma.

This is important because some drugs used to treat type 2 diabetes increase the activity of PPAR gamma. These include the thiazolidines such as Actos and Avandia, which increase the levels of genes associated with sensitivity to insulin. However, because PPAR gamma stimulates fat cell production, these drugs can also lead to increased abdominal fat and, more recently, cardiovascular complications.

"If you could find a way to increase the proportion of cells that have PPAR gamma but don't accumulate lipids, you might have a positive outcome. That would probably require a drug with a different structure," said Mancini.

The automated microscopy makes it possible to monitor the effects of drugs on different populations of a large number of cells, said Mancini.

"Had we not been able to analyze the cell-to-cell differences, we would not necessarily have understood how this favorable switch controlling PPAR gamma transcriptional activity might manifest itself. Identification of compounds that target the SRC and PPAR gamma interface might be alternatives to current therapeutic strategies for type 2 diabetes," said Hartig.


Contact: Dipali Pathak
Baylor College of Medicine

Related biology news :

1. Iowa State, Ames Lab researcher develops new way to study single biological molecules
2. Single parenthood doesnt pay off for plants
3. Study shows a single shot of morphine has long lasting effects on testosterone levels
4. NIH renews Nanomedicine Center focused on treating single-gene disorders for $16.1 million
5. JFK single-gunman theory shot down by science
6. U-M researchers receive largest single collection of psoriasis DNA samples
7. Scared snails opt for single parenthood rather than wait for a mate
8. Single cell injections
9. Math model of colon inflammation singles out dangerous immune cells
10. Biosensors reveal how single bacterium gets the message to split into a swimming and a stay-put cell
11. Single-molecule manipulation for the masses
Post Your Comments:
(Date:4/5/2017)... -- KEY FINDINGS The global market for ... of 25.76% during the forecast period of 2017-2025. The ... the growth of the stem cell market. ... INSIGHTS The global stem cell market is segmented on ... stem cell market of the product is segmented into ...
(Date:3/30/2017)... The research team of The Hong Kong Polytechnic University (PolyU) ... ground breaking 3D fingerprint minutiae recovery and matching technology, pushing contactless ... use in identification, crime investigation, immigration control, security of access and ... ... A research team led by Dr Ajay Kumar ...
(Date:3/27/2017)... ROCKVILLE CENTRE, N.Y. , March 27, 2017 ... by Healthcare Information and Management Systems Society (HIMSS) ... Analytics Outpatient EMR Adoption Model sm . In ... top 12% of U.S. hospitals using an electronic ... recognized CHS for its high level of EMR ...
Breaking Biology News(10 mins):
(Date:10/10/2017)... , ... October 10, 2017 , ... Dr. Bob Harman, ... his local San Diego Rotary Club. The event entitled “Stem Cells ... and had 300+ attendees. Dr. Harman, DVM, MPVM was joined by two human ...
(Date:10/10/2017)... 10, 2017 SomaGenics announced the receipt of ... develop RealSeq®-SC (Single Cell), expected to be the first ... (including microRNAs) from single cells using NGS methods. The ... to accelerate development of approaches to analyze the heterogeneity ... "New techniques for measuring levels of mRNAs in individual ...
(Date:10/10/2017)... PITTSBURGH, PA (PRWEB) , ... October 10, 2017 ... ... this year’s recipients of 13 prestigious awards honoring scientists who ... be presented in a scheduled symposium during Pittcon 2018, the world’s leading conference ...
(Date:10/9/2017)... ... , ... The award-winning American Farmer television series will feature 3 Bar Biologics ... at 8:30aET on RFD-TV. , With global population estimates nearing ten billion people ... to feed a growing nation. At the same time, many of our valuable resources ...
Breaking Biology Technology: