Biology subjects

Gusarova, G. A.

Publications and source records attributed to Gusarova, G. A..

2 recordsLinked to original sources

bioRxiv2021

Actin fence therapy with exogenous V12Rac1 protects against Acute Lung Injury

High mortality in Acute Lung Injury (ALI) results from sustained proinflammatory signaling by alveolar receptors, such as TNF receptor type 1 (TNFR1). Factors that determine the sustained signaling are not known. Unexpectedly, optical imaging of live alveoli revealed a major TNF-induced surge of alveolar TNFR1 due to a Ca2+-dependent mechanism that decreased the cortical actin fence. Mouse mortality due to inhaled LPS was associated with cofilin activation, actin loss and the TNFR1 surge. The constitutively active form of the GTPase, Rac1 (V12Rac1), given intranasally as a non-covalent construct with a cell-permeable peptide, enhanced alveolar F-actin and blocked the TNFR1 surge. V12Rac1 also protected against ALI-induced mortality resulting from intranasal (i.n.) instillation of LPS, or of Pseudomonas aeruginosa. We propose a new therapeutic paradigm in which actin enhancement by exogenous Rac1 strengthens the alveolar actin fence, protecting against proinflammatory receptor hyperexpression, hence blocking ALI.

physiology↗

bioRxiv2021

The Mitochondrial Calcium Uniporter of Pulmonary Type 2 Cells Determines Severity of ARDS

Acute lung immunity to inhaled pathogens elicits defensive pneumonitis that may convert to the Acute Respiratory Distress Syndrome (ARDS), causing high mortality. Mechanisms underlying the conversion are not understood, but are of intense interest because of the ARDS-induced mortality in the ongoing Covid-19 pandemic. Here, by optical imaging of live lungs we show that key to the lethality is the functional status of mitochondrial Ca2+ buffering across the mitochondrial Ca2+ uniporter (MCU) in the lungs alveolar type 2 cells (AT2), which protect alveolar stability. In mice subjected to ARDS by airway exposure to lipopolysaccharide (LPS), or to Pseudomonas aeruginosa, there was marked loss of MCU expression in AT2. The ability of mice to survive ARDS depended on the extent to which the MCU expression recovered, indicating that the viability of Ca2+ buffering by AT2 mitochondria critically determines ARDS severity. Mitochondrial transfer to enhance AT2 MCU expression might protect against ARDS.

physiology↗