#mtor

Too Small Intestines

The rarity of some genetic disorders can make them difficult to study in patients. An animal model that replicates some of the disease mechanisms can help researchers, and a new study has developed the first zebrafish model for Feingold syndrome type 1, which causes incomplete development of the gastrointestinal tract among other symptoms. The condition is caused by mutations in the gene Mycn (stained green, active throughout the intestines of healthy fish, pictured). The mutant fish developed short intestines with reduced folding, and the deletion of Mycn impacted other genes as well, including those in a central regulator of protein synthesis, the mTOR signalling pathway. Supplementation with leucine, a building block that activates the mTOR pathway, helped restart protein synthesis and led to a partial recovery of intestine size. If the mechanisms translate to human biology, this simple supplement could bring relief to patients with Feingold syndrome type 1.

Written by Anthony Lewis

< >Image from work by Yun-Fei Li, Tao Cheng and colleagues

Zhejiang University School of Medicine, Hangzhou, China

Image originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)

Published in PLOS Biology, November 2022

mTOR, fat mass and longevity

A phosphorylation switch alters lipid uptake and lifespan in mice

by Nature

Insider Interference

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Elephantiasis, or lymphatic filariasis, is a disfiguring and painful disease affecting millions throughout the tropics and sub-tropics. It is caused by a parasitic worm transmitted through insect bites, and improved treatment and prevention is much needed. The parasite establishes a chronic infection by manipulating the immune system. Researchers examined how, during an early stage of the life cycle, the parasite infiltrates cells with extracellular vesicles – small packages of dangerous chemicals. They found that these vesicles (green) are absent from the surface of immune cells (red, left), but were absorbed fully inside (middle), with some even appearing in the cell control centre, the nucleus (blue, right). Once inside, they interfere with essential molecular pathways, hampering the immune cells’ attempts to ward off the infection like an undercover spy scheming behind enemy lines. Preventing this infiltration could empower the body’s defences, and provide new strategies to prevent and manage the disease.

Written by Anthony Lewis

Image adapted from work by Alessandra Ricciardi and colleagues

Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD, USA

Image originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)

Published in PLOS Neglected Tropical Diseases, January 2021

لطالما راود حلم إبطاء الشيخوخة البشرية خيال العلماء لقرون، واليوم يقترب العلم خطوة جديدة نحو تحقيق هذا الحلم. والمفاجأة أن المرشح لذلك هو عقار رافامايسين، الذي استُخدم في الأصل لتثبيط جهاز المناعة ومنع رفض الأعضاء المزروعة. لكن أبحاثًا حديثة كشفت أن رافامايسين قد يقوم بمهمة أعمق بكثير: حماية الحمض النووي ذاته. من زراعة الأعضاء إلى إبطاء الشيخوخة تم تطوير رافامايسين أولاً لمنع رفض الأعضاء لدى مرضى…