Newly identified gut cells nurture lymph capillaries

August 14, 2020

You have just enjoyed a delicious summer BBQ. After approximately eight hours, food molecules reach your small intestine, where specialized lymph capillaries, called lacteals, absorb fat nutrients. Lacteals are different from other lymphatics, as they continue to regenerate during adulthood, with a slow, but steady pace. Their unique renewal capacity is still poorly understood.

A team of scientists led by KOH Gou Young at the Center for Vascular Research, within the Institute for Basic Science (IBS, South Korea) have identified new subsets of gut connective cells, which are crucial for lymphatic growth. Their new findings have been reported in the journal Nature Communications.

The walls of the small intestine are covered with fingerlike projections, called villi. Lining these villi, heterogeneous populations of epithelial, immune, vascular, connective and even neural cells co-exist and help the digestive process. Lacteals and blood capillaries run inside the villi and take in different food molecules. The gut environment needs to cope with water secretion and reabsorption (osmotic stress), as well as the repetitive muscular activity that moves food through the intestine. How all these complex mechanisms are harmonized is still a mystery.

The research team was able to place a new piece towards completing this mysterious puzzle. The researchers found that the regulatory proteins YAP/TAZ in villi's connective cells, the intestinal stromal cells, play a role in the growth of nearby lacteals. In mice with an abnormal hyperactivation of YAP/TAZ, the team observed atypical sprouting of lacteals and impaired dietary fat uptake.

"The lacteals in these mice looked like tridents, which is very intriguing, since we did not manipulate the lacteals themselves, but the surrounding cells," says HONG Seon Pyo, first co-author of this study.

The researchers took a step further and discovered that intestinal stromal cells belong to several subtypes, with distinct gene expression and localizations within the villi. Among these subsets, three newly identified populations secrete VEGF-C - an essential molecule for lymphatic growth - upon YAP/TAZ activation. YANG Myung Jin, first co-author of this study, explains, "We were very surprised to see such heterogeneity in a cell population that was considered homogeneous."

Lastly, researchers showed that mechanical force and osmotic stress regulate YAP/TAZ activity in stromal cells. In summary, mechanical stimulation activates YAP/TAZ in the intestinal stromal cells, which in turn release VEGF-C and can account for lacteal growth. CHO Hyunsoo, first co-author of this study notes, "This result implies a crucial link between the physiology of intestinal environment and biological interactions between cell types."

"We are interested in investigating how each newly identified cell type works in healthy and diseased conditions," adds Koh.
-end-


Institute for Basic Science

Related Small Intestine Articles from Brightsurf:

Coronavirus SARS-CoV-2 infects cells of the intestine
Researchers from the Hubrecht Institute in Utrecht, Erasmus MC University Medical Center Rotterdam, and Maastricht University have found that the coronavirus SARS-CoV-2, which causes COVID-19, can infect the cells of the intestine and multiply there.

The best things come in small packages
A low-cost miniaturized carbon dioxide monitoring instrument has been developed.

Dana-Farber scientists solve long-debated puzzle of how the intestine heals itself
Scientists find that normal intestinal cells 'de-differentiate' en masse into stem cells that generate the cells needed for a healthy intestinal lining.

Intestine-chip populated with organoids demonstrates superior function vs. organoids alone
Emulate, Inc. published a study in the peer-reviewed journal eLife demonstrating superior human-relevant intestine function of the Duodenum Intestine-Chip populated with organoids, compared to organoids alone.

New findings on satiety signaling from intestine
A previously unknown mechanism that suppresses satiety signals from the small intestine is the main finding of a new study.

How small is a small-world network?
This is the subject of a study published on 14 November in Nature Physics Communications by Gorka Zamora-López, a researcher at the Center for Brain and Cognition (CBC), and Romain Brasselet, a researcher at the International School for Advanced Studies (SISSA) in Trieste (Italy).

Multifunctional small brains
Researchers from the Netherlands Institute for Neuroscience in Amsterdam, discovered that not only the cerebral cortex is responsible for higher perceptual abilities but that the cerebellum also plays a role.

A remote control for everything small
Special light beams can be used to manipulate molecules or small biological particles.

We know we're full because a stretched intestine tells us so
We commonly think a full stomach is what tells us to stop eating, but it may be that a stretched intestine plays an even bigger role in making us feel sated, according to new laboratory research led by UC San Francisco neuroscientist Zachary Knight, Ph.D.

Adult fly intestine could help understand intestinal regeneration
Intestinal epithelial cells (IECs) are exposed to diverse types of environmental stresses such as bacteria and toxins, but the mechanisms by which epithelial cells sense stress are not well understood.

Read More: Small Intestine News and Small Intestine Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.