Acute metabolic changes in plasma membrane (PM) lipids, such as those mediating signalling reactions, are rapidly compensated by homeostatic responses whose molecular basis is poorly understood. Here we show that the extended synaptotagmins (E-Syts), endoplasmic reticulum (ER) proteins that function as PtdIns(4,5)P2- and Ca(2+)-regulated tethers to the PM, participate in these responses. E-Syts transfer glycerolipids between bilayers in vitro, and this transfer requires Ca(2+) and their lipid-harbouring SMP domain. Genome-edited cells lacking E-Syts do not exhibit abnormalities in the major glycerolipids at rest, but exhibit enhanced and sustained accumulation of PM diacylglycerol following PtdIns(4,5)P2 hydrolysis by PLC activation, which can be rescued by expression of E-Syt1, but not by mutant E-Syt1 lacking the SMP domain. The formation of E-Syt-dependent ER-PM tethers in response to stimuli that cleave PtdIns(4,5)P2 and elevate Ca(2+) may help reverse accumulation of diacylglycerol in the PM by transferring it to the ER for metabolic recycling.
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http://dx.doi.org/10.1038/ncb3339 | DOI Listing |
Chin J Integr Med
January 2025
Department of Ultrasound in Medicine, the Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, 310009, China.
Objective: To evaluate the therapeutic effects of Kuanxiong Aerosol (KXA) on ischemic stroke with reperfusion and elucidate the underlying pharmacological mechanisms.
Methods: In vivo pharmacological effects on ischemic stroke with reperfusion was evaluated using the transient middle cerebral artery occlusion (t-MCAO) mice model. To evaluate short-term outcome, 30 mice were randomly divided into vehicle group (n=15) and KXA group (n=15).
Cancer Chemother Pharmacol
January 2025
Institute of Medicine, Chung-Shan Medical University, Taichung, 40201, Taiwan.
Objective: Based on our previous research, which demonstrated that elevated plasma endoglin (ENG) levels in lung cancer patients were associated with a better prognosis, increased sensitivity to pemetrexed, and enhanced tumor suppression, this study aims to validate these findings at the cellular level. The focus is on membrane and extracellular ENG and their influence on drug response and tumor cell behavior in non-small cell lung cancer (NSCLC) cells.
Methods: The correlation between ENG expression and pemetrexed-induced cytotoxicity in eight human non-squamous subtype NSCLC cell lines was analyzed.
ACS Appl Bio Mater
January 2025
School of Chemistry, Pharmacy and Food Biosciences, University of Reading, Whiteknights, Reading RG6 6AD, U.K.
A series of tripodal (three-arm) lysine-based peptides were designed and synthesized and their self-assembly properties in aqueous solution and antimicrobial activity were investigated. We compare the behaviors of homochiral tripodal peptides (KKY)K and a homologue containing the bulky aromatic fluorenylmethoxycarbonyl (Fmoc) group Fmoc-(KKY)K, and heterochiral analogues containing k (d-Lys), (kkY)K and Fmoc-(kkY)K. The molecular conformation and self-assembly in aqueous solutions were probed using various spectroscopic techniques, along with small-angle X-ray scattering (SAXS) and cryogenic-transmission electron microscopy (cryo-TEM).
View Article and Find Full Text PDFInvest Ophthalmol Vis Sci
January 2025
Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China.
Purpose: Dry eye disease (DED) is a common ocular surface inflammatory disease with a complex pathogenesis. Herein, the role and effect of gasdermin E (GSDME) in DED pathogenesis were explored.
Methods: In vitro, flow cytometry, Cell Counting Kit-8 (CCK-8) and lactate dehydrogenase (LDH) release assays were used to determine the effects of hyperosmotic stress on pyroptosis, apoptosis, and cell viability in human corneal epithelial cells (HCECs).
Invest Ophthalmol Vis Sci
January 2025
Department of Physics, Boise State University, Boise, Idaho, United States.
Purpose: To elucidate the mechanical properties of the bovine lens cortical membrane (CM), the nuclear membrane (NM) containing cholesterol bilayer domains (CBDs), and whole bovine lenses.
Methods: The total lipids (lipids plus cholesterol) from the cortex and nucleus of a single bovine lens were isolated using the monophasic methanol extraction method. Supported CMs and NMs were prepared from total lipids extracted from the cortex and nucleus, respectively, using a rapid solvent exchange method and probe-tip sonication, followed by the fusion of unilamellar vesicles on a flat, freshly cleaved mica surface.
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