In zebrafish (Danio rerio), the ammonia-transporting Rhesus glycoprotein Rhcgb is implicated in mechanisms of ammonia excretion and Na+ uptake. In particular, Rhcgb is thought to play an important role in maintaining ammonia excretion in response to alkaline conditions and high external ammonia (HEA) exposure, in addition to facilitating Na+ uptake via a functional metabolon with the Na+/H+-exchanger Nhe3b, specifically under low Na+ conditions. In the present study, we hypothesized that CRISPR/Cas9 knockout of rhcgb would reduce ammonia excretion and Na+ uptake capacity, particularly under the conditions listed above that have elicited increases in Rhcgb-mediated ammonia excretion and/or Na+ uptake. Contrary to this hypothesis, however, larval and juvenile rhcgb knockout (KO) mutants showed no reductions in ammonia excretion or Na+ uptake under any of the conditions tested in our study. In fact, under control conditions, rhcgb KO mutants generally displayed an increase in ammonia excretion, potentially due to increased transcript abundance of another rh gene, rhbg. Under alkaline conditions, rhcgb KO mutants were also able to maintain ammonia excretion, similar to wild-type fish, and stimulation of ammonia excretion after HEA exposure also was not affected by rhcgb KO. https://www.selleckchem.com/products/pifithrin-alpha.html Surprisingly, ammonia excretion and Na+ uptake were unaffected by rhcgb or nhe3b KO in juvenile zebrafish acclimated to normal (800 μmol/L) or low (10 μmol/L) Na+ conditions. These results demonstrate that Rhcgb is expendable for ammonia excretion and Na+ uptake in zebrafish, highlighting the plasticity and flexibility of these physiological systems in this species.Mitochondria-associated membranes (MAM), physical platforms that enable communication between mitochondria and the endoplasmic reticulum (ER), are enriched with many proteins and enzymes involved in several crucial cellular processes, such as calcium (Ca2+) homeostasis, lipid synthesis and trafficking, autophagy and reactive oxygen species (ROS) production. Accumulating studies indicate that tumor suppressors and oncogenes are present at these intimate contacts between mitochondria and the ER, where they influence Ca2+ flux between mitochondria and the ER or affect lipid homeostasis at MAM, consequently impacting cell metabolism and cell fate. Understanding these fundamental roles of mitochondria-ER contact sites as important domains for tumor suppressors and oncogenes can support the search for new and more precise anticancer therapies. In the present review, we summarize the current understanding of basic MAM biology, composition and function and discuss the possible role of MAM-resident oncogenes and tumor suppressors.Glucolipotoxicity following nutrient overload causes cardiomyocyte injury by inhibiting TFEB and suppressing lysosomal function. We ascertained whether in addition to the amount, the type of fatty acids (FAs) and duration of FA exposure regulate TFEB action and dictate cardiomyocyte viability. Saturated FA, palmitate, but not polyunsaturated FAs decreased TFEB content in a concentration- and time-dependent manner in cardiomyocytes. Hearts from high-fat high-sucrose diet-fed mice exhibited a temporal decline in nuclear TFEB content with marked elevation of diacylglycerol and triacylglycerol, suggesting that lipid deposition and TFEB loss are concomitant molecular events. Next, we examined the identity of signaling and metabolic pathways engaged by the loss of TFEB action in the cardiomyocyte. Transcriptome analysis in murine cardiomyocytes with targeted deletion of myocyte TFEB (TFEB-/-) revealed enrichment of differentially expressed genes (DEG) representing pathways of nutrient metabolism, DNA damage and repair, cell death and cardiac function. Strikingly, genes involved in macroautophagy, mitophagy and lysosome function constituted a small portion of DEGs in TFEB-/- cardiomyocytes. In myoblasts and/or myocytes, nutrient overload-induced lipid droplet accumulation and caspase-3 activation were exacerbated by silencing TFEB or attenuated by overexpressing constitutively active TFEB. The effect of TFEB overexpression were persistent in the presence of Atg7 loss-of-function, signifying that the effect of TFEB in the myocyte is independent of changes in the macroautophagy pathway. In the cardiomyocyte, the non-canonical effect of TFEB to reprogram energy metabolism is more evident than the canonical action of TFEB on lysosomal autophagy. Loss of TFEB function perturbs metabolic pathways in the cardiomyocyte and renders the heart prematurely susceptible to nutrient overload-induced injury.Objectives The main objective of the study was to assess the meningeal penetration of cefazolin and cloxacillin in patients treated for methicillin-susceptible staphylococcal meningitis. Methods We retrospectively identified patients treated for Staphylococcus meningitis with measurements of cefazolin or cloxacillin concentrations in cerebrospinal fluid (CSF) using a liquid-chromatography coupled with mass-spectrometry validated assay at the Nantes University Hospital between January 2009 and October 2019. Staphylococcus meningitis was defined by a compatible clinical presentation and a microbiological confirmation (positive CSF culture or positive specific polymerase chain reaction). Medical charts were retrospectively reviewed to collect microbiological, clinical data and to assess therapeutic success. Results Among the 17 included patients, 8 (47%) were treated with cefazolin and 9 (53%) with cloxacillin. Median daily dosages of cefazolin and cloxacillin were 8 (range 6-12) and 12 (range 10-13) grams respectively. Cefazolin and cloxacillin were mainly administered via continuous infusion. Eleven patients (65%) were males, median (IQR) age was 54 years (50;70), 14 (82%) had post-operative meningitis and 3 (18%) hematogenous meningitis. Median (IQR) antibiotic CSF concentrations were 2.8 (2.1;5.2) and 0.66 (0.5;0.9) mg/L for cefazolin and cloxacillin groups respectively. Cloxacillin was discontinued in 2 patients for therapeutic failure. Conclusions Patients with staphylococcal meningitis treated with high-dose continuous intravenous infusion of cefazolin achieved therapeutic concentrations in CSF. Cefazolin appears to be a therapeutic candidate which should be properly evaluated in this indication.