A cytoskeletal anchor connects ischemic mitochondrial fission to myocardial senescence
The interplay between the actin cytoskeleton and mitochondria has been implicated in cell and tissue homeostasis and physiological function. In this issue of Science Signaling, Nishimura et al. demonstrate that inhibiting the interaction of filamin A, an actin cytoskeleton regulator, with Drp1, a modulator of mitochondrial dynamics, attenuates mitochondrial hyperfission and cardiomyocyte senescence after myocardial infarction. (Source: Signal Transduction Knowledge Environment)
Source: Signal Transduction Knowledge Environment - November 13, 2018 Category: Science Authors: Boyer, M. J., Eguchi, S. Tags: STKE Focus Source Type: news
Hypoxia-induced interaction of filamin with Drp1 causes mitochondrial hyperfission-associated myocardial senescence
Defective mitochondrial dynamics through aberrant interactions between mitochondria and actin cytoskeleton is increasingly recognized as a key determinant of cardiac fragility after myocardial infarction (MI). Dynamin-related protein 1 (Drp1), a mitochondrial fission–accelerating factor, is activated locally at the fission site through interactions with actin. Here, we report that the actin-binding protein filamin A acted as a guanine nucleotide exchange factor for Drp1 and mediated mitochondrial fission–associated myocardial senescence in mice after MI. In peri-infarct regions characterized by mitochondrial hy...
Source: Signal Transduction Knowledge Environment - November 13, 2018 Category: Science Authors: Nishimura, A., Shimauchi, T., Tanaka, T., Shimoda, K., Toyama, T., Kitajima, N., Ishikawa, T., Shindo, N., Numaga-Tomita, T., Yasuda, S., Sato, Y., Kuwahara, K., Kumagai, Y., Akaike, T., Ide, T., Ojida, A., Mori, Y., Nishida, M. Tags: STKE Research Articles Source Type: news
How mitochondria deploy a powerful punch against life-threatening bacteria
(Michigan Medicine - University of Michigan) Researchers discover that mitochondria play an important role in supporting the immune system's response against MRSA infection. (Source: EurekAlert! - Medicine and Health)
Source: EurekAlert! - Medicine and Health - November 12, 2018 Category: International Medicine & Public Health Source Type: news
Big change from small player -- Mitochondria alter body metabolism and gene expression
(University of Alabama at Birmingham) Mitochondria have their own DNA, but the 13 genes in human mitochondria -- along with DNA sequences for tRNAs, rRNAs and some small peptides -- are massively overshadowed by the 20,000 genes in the human nucleus. Nevertheless, these diminutive mitochondria may have a strong influence on cellular metabolism and susceptibility to metabolic diseases like heart failure or obesity, according to preliminary research by Scott Ballinger, Ph.D., professor of pathology at the University of Alabama at Birmingham. (Source: EurekAlert! - Medicine and Health)
Source: EurekAlert! - Medicine and Health - November 9, 2018 Category: International Medicine & Public Health Source Type: news
Medical News Today: Melanoma: More evidence that antioxidants speed up tumor spread
New research reveals that antioxidants that bind to mitochondria — the main source of free radicals — either have no effect or cause tumors to grow faster. (Source: Health News from Medical News Today)
Source: Health News from Medical News Today - November 5, 2018 Category: Consumer Health News Tags: Melanoma / Skin Cancer Source Type: news
RNA-protein network may explain why melanoma grows more
(Tokyo University of Agriculture and Technology) A collaboration led by scientists from KU Leuven, Belgium, with Tokyo University of Agriculture and Technology (TUAT), Japan, revealed a new way to fight melanoma. They realize that a melanoma-specific long non-coding RNA, named SAMMSON, interacts with the protein CARF, to properly coordinate protein synthesis in both the cytosol and mitochondria of melanoma cells. This mechanism ensures the maintenance of proteostasis during cell growth, thus avoiding the induction of cell death. (Source: EurekAlert! - Cancer)
Source: EurekAlert! - Cancer - October 29, 2018 Category: Cancer & Oncology Source Type: news
Evolutionary shift toward protein-based architecture in trypanosomal mitochondrial ribosomes
Ribosomal RNA (rRNA) plays key functional and architectural roles in ribosomes. Using electron microscopy, we determined the atomic structure of a highly divergent ribosome found in mitochondria of Trypanosoma brucei, a unicellular parasite that causes sleeping sickness in humans. The trypanosomal mitoribosome features the smallest rRNAs and contains more proteins than all known ribosomes. The structure shows how the proteins have taken over the role of architectural scaffold from the rRNA: They form an autonomous outer shell that surrounds the entire particle and stabilizes and positions the functionally important regions...
Source: ScienceNOW - October 25, 2018 Category: Science Authors: Ramrath, D. J. F., Niemann, M., Leibundgut, M., Bieri, P., Prange, C., Horn, E. K., Leitner, A., Boehringer, D., Schneider, A., Ban, N. Tags: Biochemistry, Molecular Biology, Online Only r-articles Source Type: news
ER-mitochondria cross-talk is regulated by the Ca2+ sensor NCS1 and is impaired in Wolfram syndrome
Communication between the endoplasmic reticulum (ER) and mitochondria plays a pivotal role in Ca2+ signaling, energy metabolism, and cell survival. Dysfunction in this cross-talk leads to metabolic and neurodegenerative diseases. Wolfram syndrome is a fatal neurodegenerative disease caused by mutations in the ER-resident protein WFS1. Here, we showed that WFS1 formed a complex with neuronal calcium sensor 1 (NCS1) and inositol 1,4,5-trisphosphate receptor (IP3R) to promote Ca2+ transfer between the ER and mitochondria. In addition, we found that NCS1 abundance was reduced in WFS1-null patient fibroblasts, which showed redu...
Source: Signal Transduction Knowledge Environment - October 23, 2018 Category: Science Authors: Angebault, C., Fauconnier, J., Patergnani, S., Rieusset, J., Danese, A., Affortit, C. A., Jagodzinska, J., Megy, C., Quiles, M., Cazevieille, C., Korchagina, J., Bonnet-Wersinger, D., Milea, D., Hamel, C., Pinton, P., Thiry, M., Lacampagne, A., Delprat, B Tags: STKE Research Articles Source Type: news
Advanced sequencing technology provides new insights into human mitochondrial diseases
(University of Helsinki) Researchers have for the first time been able to investigate the abundance and methyl modifications of all mitochondrial tRNAs in patients suffering from one of the most common inherited mitochondrial tRNA mutations. The analysis pipeline revealed quantitative changes that had dramatic effects on protein synthesis within mitochondria. (Source: EurekAlert! - Biology)
Source: EurekAlert! - Biology - October 18, 2018 Category: Biology Source Type: news
A 150-year-old drug might improve radiation therapy for cancer
(Ohio State University Wexner Medical Center) A drug first identified 150 years ago and used as a smooth-muscle relaxant might make tumors more sensitive to radiation therapy. Researchers found that the drug papaverine inhibits the respiration of mitochondria, the oxygen-consuming and energy-making components of cells, and sensitizes model tumors to radiation. They found that the drug does not affect the radiation sensitivity of well-oxygenated normal tissues. (Source: EurekAlert! - Medicine and Health)
Source: EurekAlert! - Medicine and Health - October 17, 2018 Category: International Medicine & Public Health Source Type: news
How a common drug causes liver failure
(American Society for Biochemistry and Molecular Biology) A study of liver cells exposed to the common painkiller acetaminophen found a novel mechanism for the drug's toxicity at high doses. Researchers say a protein modification called glutathionylation, kicked off by acetaminophen treatment, impairs liver cell mitochondria. (Source: EurekAlert! - Medicine and Health)
Source: EurekAlert! - Medicine and Health - October 11, 2018 Category: International Medicine & Public Health Source Type: news
Chemotherapy may lead to mitochondrial dysfunction in skeletal muscle
(American Physiological Society) Chemotherapy drugs to treat breast cancer may promote muscle mitochondrial dysfunction, according to new research. Dysfunctional mitochondria, the energy centers of the cells, may contribute to fatigue and weakness that some people with breast cancer experience through the course of disease treatment. The study is published ahead of print in the American Journal of Physiology--Cell Physiology. (Source: EurekAlert! - Cancer)
Source: EurekAlert! - Cancer - October 4, 2018 Category: Cancer & Oncology Source Type: news
The LKB1-AMPK-{alpha}1 signaling pathway triggers hypoxic pulmonary vasoconstriction downstream of mitochondria
Hypoxic pulmonary vasoconstriction (HPV), which aids ventilation-perfusion matching in the lungs, is triggered by mechanisms intrinsic to pulmonary arterial smooth muscles. The unique sensitivity of these muscles to hypoxia is conferred by mitochondrial cytochrome c oxidase subunit 4 isoform 2, the inhibition of which has been proposed to trigger HPV through increased generation of mitochondrial reactive oxygen species. Contrary to this model, we have shown that the LKB1–AMPK-α1 signaling pathway is critical to HPV. Spectral Doppler ultrasound revealed that deletion of the AMPK-α1 catalytic subunit blocke...
Source: Signal Transduction Knowledge Environment - October 2, 2018 Category: Science Authors: Moral-Sanz, J., Lewis, S. A., MacMillan, S., Ross, F. A., Thomson, A., Viollet, B., Foretz, M., Moran, C., Hardie, D. G., Evans, A. M. Tags: STKE Research Articles Source Type: news
Mitochondrial diseases could be treated with gene therapy
Researchers have developed a genome editing tool for the potential treatment of mitochondrial diseases. The study applied an experimental gene therapy treatment in mice and successfully targeted and eliminated the damaged DNA in mitochondria. (Source: Medical Research Council General News)
Source: Medical Research Council General News - September 25, 2018 Category: Research Source Type: news
Is AI the Key to Diving Deeper into Images and Pathology?
In a tale of two studies, it appears artificial intelligence is helping researchers analyze cells in ways that weren't possible before.
In one study, published this week in Nature Methods, scientists at the Allen Institute in Seattle, WA used machine learning to train computers to see parts of the cell that the human eye cannot easily distinguish. Using 3D images of fluorescently labeled cells, the team taught computers to find structures inside living cells without fluorescent labels, using only black and white images generated by an inexpensive technique known as brightfield microscopy.
Fluorescence microscop...
Source: MDDI - September 19, 2018 Category: Medical Devices Authors: Amanda Pedersen Tags: Imaging Source Type: news
