Descoberta da calvície: microRNA estimula o crescimento do cabelo em folículos envelhecidos

Por Northwestern University, 8 de junho de 2023

Os cientistas da Northwestern Medicine descobriram que a rigidez das células-tronco dos folículos capilares envelhecidos dificulta o crescimento do cabelo. Eles descobriram que amaciar essas células usando um pequeno RNA, miR-205, estimula o crescimento do cabelo em camundongos. Experimentos futuros testarão se o miR-205 aplicado topicamente pode promover o crescimento capilar potencialmente em humanos.

O amaciamento das células-tronco do folículo piloso rígido com um microRNA regenera o cabelo.

Assim como as articulações das pessoas podem ficar rígidas à medida que envelhecem e dificultar a movimentação, as células-tronco do folículo piloso também ficam rígidas, dificultando o crescimento do cabelo, relata um novo estudo da Northwestern Medicine.

Mas se as células-tronco do folículo piloso forem amolecidas, é mais provável que elas produzam cabelo, descobriram os cientistas.

Northwestern scientists discovered how to soften up those stem cells to enable them to grow hair again. In a study in mice published recently in the journal PNAS, the investigators report that they can soften the stem cells by boosting the production of a tiny RNARibonucleic acid (RNA) is a polymeric molecule similar to DNA that is essential in various biological roles in coding, decoding, regulation and expression of genes. Both are nucleic acids, but unlike DNA, RNA is single-stranded. An RNA strand has a backbone made of alternating sugar (ribose) and phosphate groups. Attached to each sugar is one of four bases—adenine (A), uracil (U), cytosine (C), or guanine (G). Different types of RNA exist in the cell: messenger RNA (mRNA), ribosomal RNA (rRNA), and transfer RNA (tRNA)." data-gt-translate-attributes="[{"attribute":"data-cmtooltip", "format":"html"}]"> RNA, miR-205, que relaxa a dureza das células. Quando os cientistas manipularam geneticamente as células-tronco para produzir mais miR-205, isso promoveu o crescimento do cabelo em camundongos jovens e velhos.

"They started to grow hair in 10 days," said corresponding author Rui Yi, the Paul E. Steiner Research Professor of Pathology and professor of dermatology at Northwestern UniversityEstablished in 1851, Northwestern University (NU) is a private research university based in Evanston, Illinois, United States. Northwestern is known for its McCormick School of Engineering and Applied Science, Kellogg School of Management, Feinberg School of Medicine, Pritzker School of Law, Bienen School of Music, and Medill School of Journalism. " data-gt-translate-attributes="[{"attribute":"data-cmtooltip", "format":"html"}]"> Faculdade de Medicina Feinberg da Universidade Northwestern. "Não são novas células-tronco sendo geradas. Estamos estimulando as células-tronco existentes a fazer crescer cabelo. Muitas vezes ainda temos células-tronco, mas elas podem não ser capazes de gerar o cabelo.

"Nosso estudo demonstra a possibilidade de estimular o crescimento do cabelo regulando a mecânica celular. Devido ao potencial de fornecer microRNA por nanopartículas diretamente na pele, a seguir testaremos se o miR-205 administrado topicamente pode estimular o crescimento do cabelo primeiro em camundongos. Se for bem-sucedido, vamos projetar experimentos para testar se este microRNA pode potencialmente promover o crescimento do cabelo em humanos."

This study was conducted in genetically engineered mouse models. The scientists used advanced microscopy tools, including atomic force microscopy, to measure the stiffness and two-photonA photon is a particle of light. It is the basic unit of light and other electromagnetic radiation, and is responsible for the electromagnetic force, one of the four fundamental forces of nature. Photons have no mass, but they do have energy and momentum. They travel at the speed of light in a vacuum, and can have different wavelengths, which correspond to different colors of light. Photons can also have different energies, which correspond to different frequencies of light." data-gt-translate-attributes="[{"attribute":"data-cmtooltip", "format":"html"}]"photon microscopy to monitor cell behaviors in live animals./p>

This study was funded by the National Institute of Arthritis and Musculoskeletal and Skin Diseases grants AR066703, AR071435, AR043380, AR041836, and P30AR075049 of the National Institutes of HealthThe National Institutes of Health (NIH) is the primary agency of the United States government responsible for biomedical and public health research. Founded in 1887, it is a part of the U.S. Department of Health and Human Services. The NIH conducts its own scientific research through its Intramural Research Program (IRP) and provides major biomedical research funding to non-NIH research facilities through its Extramural Research Program. With 27 different institutes and centers under its umbrella, the NIH covers a broad spectrum of health-related research, including specific diseases, population health, clinical research, and fundamental biological processes. Its mission is to seek fundamental knowledge about the nature and behavior of living systems and the application of that knowledge to enhance health, lengthen life, and reduce illness and disability." data-gt-translate-attributes="[{"attribute":"data-cmtooltip", "format":"html"}]"National Institutes of Health./p>