Autophagy (here refers to macroautophagy) is a catabolic pathway by which large protein aggregates and damaged organelles are first sequestered into a double-membraned structure called autophago-some and then delivered to lysosome for destruction. Recently, tremen-dous progress has been made to elucidate the molecular mechanism and functions of this essential cellular metabolic process. In addition to being either a rubbish clearing system or a cellular surviving program in response to different stresses, autophagy plays important roles in a large number of pathophysiological conditions, such as cancer, diabetes, and especially neurodegenerative disorders. Here we review recent progress in the role of autophagy in neurological diseases and discuss how dysregulation of autophagy initiation, autophagosome formation, maturation, and/or au-tophagosome-lysosomal fusion step contributes to the pathogenesis of these disorders in the nervous system.
Mitochondria serve as an energy plant and participate in a variety of signaling pathways to regulate cellular metabolism, survival and immunity. Mitochondrial dysfunction, in particular in cardiomyocytes, is associated with the development and progression of cardiovascular disease, resulting in heart failure, cardiomyopathy, and cardiac ischemia/reperfusion injury. Therefore, mitochondrial quality control processes, including post-translational modifications of mitochondrial proteins, mitochondrial dynamics, mitophagy, and formation of mitochondrial-driven vesicles, play a critical role in maintenance of mitochondrial and even cellular homeostasis in physiological or pathological conditions. Accumulating evidence suggests that mitochondrial quality control in cardiomyocytes is able to improve cardiac function, rescue dying cardiomyocytes, and prevent the deterioration of cardiovascular disease upon external environmental stress. In this review, we discuss recent progress in understanding mitochondrial quality control in cardiomyocytes. We also evaluate potential targets to prevent or treat cardiovascular diseases, and highlight future research directions which will help uncover additional mechanisms underlying mitochondrial homeostasis in cardiomyocytes.
Membrane contact sites (MCSs) are defined as regions where two organelles are closely apposed, and most MCSs associated with each other via protein-protein or protein-lipid interactions. A number of key molecular machinery systems participate in mediating substance exchange and signal transduction, both of which are essential processes in terms of cellular physiology and pathophysiology. The endoplasmic reticulum (ER) is the largest reticulum network within the cell and has extensive communication with other cellular organelles, including the plasma membrane (PM), mitochondria, Golgi, endosomes and lipid droplets (LDs). The contacts and reactions between them are largely mediated by various protein tethers and lipids. Ions, lipids and even proteins can be transported between the ER and neighboring organelles or recruited to the contact site to exert their functions. This review focuses on the key molecules involved in the formation of different contact sites as well as their biological functions.
Background Exposure to stress plays a detrimental role in the pathogenesis of hypertension via nonin ammatory pathways. Microglial neuroin ammation in the rostral ventrolateral medulla (RVLM) exacerbates stress-induced hypertension (SIH) by increasing sympathetic hyperactivity. Mitochondria of microglia are the regulators of innate immune response. Sigma-1R (σ-1R) localizes to the mitochondriaassociated membranes (MAMs) and regulates endoplasmic reticulum (ER) and mitochondria communication, in part through its chaperone activity. The present study aims to investigate the protective role of σ-1R on microglial-mediated neuroin ammation.Methods Stress-induced hypertension (SIH) was induced in rats using electric foot shocks and intermittent noise. Arterial blood pressure (ABP), heart rate (HR), and renal sympathetic nerve activity (RSNA) were measured to evaluate the sympathetic nervous system (SNS) activities. SKF10047 (100µM), an agonist of σ-1R, was administrated to rats, then σ-1R localization and MAMs alterations were detected by immuno-electron microscopy. Mitochondrial calcium homeostasis was examined in primary microglia and/or BV-2 cells. The effect of SKF10047 treatment on the mitochondrial respiratory function of cultured microglia was measured using a Seahorse Extracellular Flux Analyzer. Confocal microscopic images were performed to indicate mitochondrial dynamics.Results Stress reduced σ-1R in the MAMs localization, leading to decreased ER-mitochondria contact and IP3R-GRP75-VDAC calcium transport complexes expression in the RVLM of rats. SKF10047 promotes the length and coverage of MAMs in the prorenin treated microglia. Prorenin treatment increases mitoROS levels, and inhibits Ca 2+ signaling between the two organelles, therefore negatively affects ATP production in BV2 cells, and these effects are reversed by SKF10047 treatment. We nd that mitochondrial hyperfusion and M1 polarization in prorenin-treated microglia. SKF10047 suppresses microglial M1 phenotype and RVLM neuroin ammation, subsequently ameliorates sympathetic hyperactivity in stress-induced hypertensive rats. Conclusion Sigma-1 receptor activation suppresses microglia M1 polarization and neuroin ammation via regulating endoplasmic reticulum-mitochondria contact and mitochondrial functions in stress-induced hypertension rats.
Rationale:Ectopic pancreas, which is a kind of rare congenital disease, forms during embryonic development. It can occur throughout the whole gastrointestinal tract, but has a low tendency to develop in the wall of the small intestine. It is easy for patients with ectopic pancreases to be misdiagnosed because the symptoms are untypical and can vary.Patient concerns:In the present study, we reported two rare cases of ectopic pancreatic tissue in the wall of the small intestine, which presented with obvious abdominal pain and distention.Diagnosis:The laboratory tests and computed tomography (CT) scans didn’t reveal any evidence of ectopic pancreas.Interventions:The two patients received small intestine masses resection and intestinal anastomosis.Outcomes:During surgery, an intestinal mass with a diameter of 4.0 cm was found in the first patient. An intestinal mass with a diameter of 0.8 cm, jejunum perforation, and diffuse peritonitis were found in the second patient. Histological analyses of the dissected intestinal masses confirmed them as ectopic pancreatic tissue. Interestingly, for the second patient, the intestinal perforation and diffuse peritonitis were not induced by the ectopic pancreas, but by a jujube pit that was found in the perforated site of the intestine.Lessons:Our study demonstrated that an ectopic pancreas should be considered in cases of untypical abdominal symptoms with intestinal masses.
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