Mitochondrial injury and endoplasmic reticulum (ER) stress are considered to be the key mechanisms of renal ischemia-reperfusion (I/R) injury. Mitochondria are membrane-bound organelles that form close physical contact with a specific domain of the ER, known as mitochondrial-associated membranes. The close physical contact between them is mainly restrained by ER-mitochondria tethering complexes, which can play an important role in mitochondrial damage, ER stress, lipid homeostasis, and cell death. Several ER-mitochondria tethering complex components are involved in the process of renal I/R injury. A better understanding of the physical and functional interaction between ER and mitochondria is helpful to further clarify the mechanism of renal I/R injury and provide potential therapeutic targets. In this review, we aim to describe the structure of the tethering complex and elucidate its pivotal role in renal I/R injury by summarizing its role in many important mechanisms, such as mitophagy, mitochondrial fission, mitochondrial fusion, apoptosis and necrosis, ER stress, mitochondrial substance transport, and lipid metabolism.
Endoplasmic Reticulum/metabolism* ; Endoplasmic Reticulum Stress ; Humans ; Mitochondria ; Mitochondrial Membranes/metabolism* ; Mitophagy ; Reperfusion Injury/metabolism*

Endoplasmic reticulum (ER) is an important organelle where folding and post-translational modification of secretory and transmembrane proteins take place. During virus infection, cellular or viral unfolded and misfolded proteins accumulate in the ER in an event called ER stress. To maintain the equilibrium homeostasis of the ER, signal-transduction pathways, known as unfolded protein response (UPR), are activated. The viruses in turn manipulate UPR to maintain an environment favorable for virus survival and replication. Herpesviruses are enveloped DNA viruses that produce over 70 viral proteins. Modification and maturation of large quantities of viral glycosylated envelope proteins during virus replication may induce ER stress, while ER stress play both positive and negative roles in virus infection. Here we summarize the research progress of crosstalk between herpesvirus infection and the virus-induced ER stress.
Endoplasmic Reticulum/metabolism* ; Endoplasmic Reticulum Stress ; Herpesviridae ; Signal Transduction ; Unfolded Protein Response

OBJECTIVE: To investigate effects of antioxidant stress protein heme oxygenase-1 (HO-1) on lipopolysaccharide (LPS)-induced endoplasmic reticulum stress (ERS) of rat hepatocytes. METHODS: The BRL cells (rat hepatocyte cell line) were cultured. The hepatocytes were treated with LPS, LPS+HO-1 siRNA, HO-1 siRNA and PBS solution, respectively. The cell viability was measured by trypan blue exclusion test. The apoptosis cells were detected by the fluorescent dye Hoechst 33258. Expressions of GRP78, CHOP, caspase-12 and HO-1 were detected by Western blotting. RESULTS: LPS caused an increase of HO-1 protein expression of rat hepatocytes in a dose-dependent and time-dependent manner, a up-regulation of GRP78, CHOP and caspase-12, a decrease in cell viability, and an increase in apoptosis rate of hepatocytes. Pretreatment of HO-1 siRNA inhibited the up-regulation of LPS-induced HO-1, however, aggravated ERS and cellular injury. CONCLUSION HO-1 inhibites ERS-mediated cellular injury of rat hepatocytes induced by LPS.
Animals ; Apoptosis/physiology* ; Endoplasmic Reticulum/metabolism* ; Endoplasmic Reticulum Stress/physiology* ; Heme Oxygenase-1/pharmacology* ; Hepatocytes/metabolism* ; Lipopolysaccharides/pharmacology* ; Rats

Nogo-B receptor (NgBR) is a specific receptor of Nogo-B, a member of reticulon 4 protein family. It is widely expressed in many tissues and mainly located in cell membrane and endoplasmic reticulum. Previous studies have revealed that NgBR is involved in a variety of physiological and pathophysiological processes, such as dolichol synthesis, lipid metabolism, cholesterol trafficking, insulin resistance, vascular remodeling and angiogenesis, tumorigenesis and nervous system diseases. Further studies on the molecular characteristics and biological function of NgBR might be of great significance to understand its role in diverse diseases and provide possible clinical strategies for the treatment of diseases.
Carrier Proteins/metabolism* ; Endoplasmic Reticulum/metabolism* ; Lipid Metabolism ; Nogo Proteins/metabolism* ; Receptors, Cell Surface/metabolism*

Cytosol ; metabolism ; DNA-(Apurinic or Apyrimidinic Site) Lyase ; metabolism ; Endoplasmic Reticulum ; metabolism ; Humans ; Receptors, sigma ; metabolism

Endoplasmic Reticulum ; genetics ; metabolism ; Plasmodium berghei ; genetics ; metabolism ; Plasmodium falciparum ; genetics ; metabolism ; Protozoan Proteins ; genetics ; metabolism

Lipids droplets are organelles that store neutral lipids and are closely related to lipid accumulation. Long chain acyl-coenzyme A synthetase 3 (ACSL3) is a lipid droplet-associated protein mainly distributed in the cell membrane, endoplasmic reticulum, and intracellular lipid droplets, and its distribution depends on cell type and fatty acid supply. ACSL3 is a key regulator of fatty acid metabolism that is closely related to intracellular lipid accumulation, and plays an important role in various pathophysiological processes such as lipid droplet synthesis and lipid metabolism, cellular inflammation, and ferroptosis. This paper mainly reviews the role of ACSL3 in lipid synthesis, ferroptosis, and inflammatory response, with focus on the mechanism of its role in lipid accumulation in atherosclerosis, and provides new ideas for exploring potential therapeutic targets in atherosclerotic diseases.
Humans ; Atherosclerosis ; Coenzyme A Ligases/metabolism* ; Endoplasmic Reticulum/metabolism* ; Fatty Acids/metabolism* ; Lipid Metabolism

Animals ; Endoplasmic Reticulum ; metabolism ; Fatty Liver ; metabolism ; pathology ; Humans ; Mitochondria ; metabolism ; Non-alcoholic Fatty Liver Disease

OBJECTIVES: To explore the role of high mobility group B1 （HMGB1） protein in the post-traumatic endoplasmic reticulum stress （ERS） in rat lung tissues. METHODS: The rat model of acute lung injury was established by crushing the hind limbs of rats with standard weight. The first experiment was to divide rats into postural control group and crush groups （6 h, 18 h and 30 h after crushing）. The second experiment was to divide rats into postural control group, 18 h crush group, HMGB1 inhibitor sodium butyrate （SB） group and 18 h crush+SB group. The protein expression changes of HMGB1 and ERS- related proteins （GRP78, caspase-12, CHOP and IRE1α） in rat lung tissues were detected with Western blotting. Meanwhile, the pathological changes of rat lungs were observed by HE stain. RESULTS: Compared with the postural control group, the expression levels of ERS-related proteins （GRP78, caspase-12, CHOP and IRE1α） and HMGB1 protein in rat lung tissues by crushing the hind limbs of rats were obviously increased. The protein levels reduced at 30 h after crushing but were still higher than those of postural control group and obvious pathological changes of acute lung injury were observed simultaneously in rats. Compared with the 18 h crush group, the expression levels of the ERS-related proteins and HMGB1 protein in rat lung tissues were attenuated in 18 h crush+SB group, and the pathological changes of rat lung injury began to alleviate. CONCLUSIONS HMGB1-ERS pathway activated by traumatic stress can lead to acute lung injury in rats.
Animals ; Apoptosis ; Endoplasmic Reticulum Chaperone BiP ; Endoplasmic Reticulum Stress ; Endoribonucleases ; HMGB1 Protein/metabolism* ; Heat-Shock Proteins ; Lung/metabolism* ; Protein Serine-Threonine Kinases ; Rats ; Rats, Sprague-Dawley

OBJECTIVE: To explore the role of heat shock protein 90α (HSP90α) and endoplasmic reticulum (ER) stress pathway in allergic airway inflammation induced by house dust mite (HDM) in bronchial epithelial cells. METHODS: A HDM- induced asthmatic cell model was established in human bronchial epithelial (HBE) cells by exposure to a concentration gradient (200, 400 and 800 U/mL) of HDM for 24 h. To test the effect of siHSP90α and HSP90 inhibitor 17-AAG on HDM-induced asthmatic inflammation, HBE cells were transfected with siHSP90α (50 nmol, 12 h) or pretreated with 17-AAG (900 nmol, 6 h) prior to HDM exposure (800 U/mL) for 24 h, and the changes in the expression of HSP90α and ER stress markers were assessed. We also tested the effect of nasal drip of 17-AAG, HDM, or their combination on airway inflammation and ER stress in C57BL/6 mice. RESULTS: In HBE cells, HDM exposure significantly up-regulated the expression of HSP90α protein (P=0.011) and ER stress markers XBP-1 (P=0.044), ATF-6α (P=0.030) and GRP-78 (P=0.027). Knocking down HSP90α and treatment with 17-AAG both significantly inhibited HDM-induced upregulation of XBP-1 (P=0.008). In C57BL/6 mice, treatment with 17-AAG obviously improved HDM-induced airway inflammation and significantly reduced the number of inflammatory cells in the airway (P=0.014) and lowered the levels of IL-4 (P=0.030) and IL-5 (P=0.035) in alveolar lavage fluid. Immunohistochemical staining showed that the expressions of XBP-1 and GRP-78 in airway epithelial cells decreased significantly after the treatment of 17-AAG. CONCLUSIONS HSP90α promotes HDM-induced airway allergic inflammation possibly by upregulating ER stress pathway in bronchial epithelial cells.
Animals ; Asthma/metabolism* ; Endoplasmic Reticulum Stress ; Epithelial Cells ; Inflammation/metabolism* ; Mice ; Mice, Inbred C57BL ; Pyroglyphidae