Autophagy and ER stress in LPS/GalN-induced acute liver injury

Autophagy attenuates placental apoptosis, oxidative stress and fetal growth restriction in pregnant ewes

Bisphenol A (BPA)-induced oxidative stress (OS) and its potentially associated autophagy and apoptosis have not been studied previously in pregnant ewes. Accordingly, this study investigated the underlying mechanisms of BPA-induced autophagy and apoptosis in the placenta and primary trophoblasts of pregnant ewes exposed to BPA both in vivo and in vitro. In vivo experiment, pregnant Hu ewes (n = 8) were exposed to 5 mg/kg/d of BPA compared to control ewes (n = 8) receiving only corn oil from day 40 through day 110 of gestation. Exposure to BPA during gestation resulted in placental insufficiency, fetal growth restriction (FGR), autophagy, endoplasmic reticulum stress (ERS), mitochondrial dysfunction, OS, and apoptosis in type A placentomes. Regarding in vitro model, primary ovine trophoblasts were exposed to BPA, BPA plus chloroquine (CQ; an autophagy inhibitor) or BPA plus rapamycin (RAP; an autophagy activator) for 12 h. Data illustrated that exposure to BPA enhanced autophagy (ULK1, Beclin-1, LC3, Parkin, and PINK1), ERS (GRP78, CHOP10, ATF4, and ATF6) and apoptosis (Caspase 3, Bcl-2, Bax, P53) but decreased the antioxidant (CAT, Nrf2, HO-1, and NQO1)-related mRNA and protein expressions as well as impaired the mitochondrial function. Moreover, treatment with CQ exacerbated the BPA-mediated OS, mitochondrial dysfunction, apoptosis, and ERS. On the contrary, RAP treatment counteracted the BPA-induced trophoblast dysfunctions mentioned above. Overall, the findings illustrated that BPA exposure could contribute to autophagy in the ovine placenta and trophoblasts and that autophagy, in turn, could alleviate BPA-induced apoptosis, mitochondrial dysfunction, ERS, and OS. These results offer new mechanistic insights into the role of autophagy in mitigating BPA-induced placental dysfunctions and FGR.

Caffeine alleviates acute liver injury by inducing the expression of NEDD4L and deceasing GRP78 level via ubiquitination

BACKGROUND

Acute liver injury is liver cell injury that occurs rapidly in a short period of time. Caffeine has been shown to maintain hepatoprotective effect with an unclear mechanism. Endoplasmic reticulum stress (ERS) has significant effects in acute liver injury. Induction of GRP78 is a hallmark of ERS. Whether or not caffeine's function is related to GRP78 remains to be explored.

METHODS

Acute liver injury model was established by LPS-treated L02 cells and in vivo administration of LPS/D-Gal in mice. Caffeine was pre-treated in L02 cells or mice. Gene levels was determined by real-time PCR and western blot. Cell viability was tested by CCK-8 assay and cell apoptosis was tested by flow cytometry. The interaction of GRP78 and NEDD4L was determined by Pull-down and co-immunoprecipitation (Co-IP) assay. The ubiquitination by NEDD4L on GRP78 was validated by in vitro ubiquitination assay.

RESULTS

Caffeine protected liver cells against acute injury induced cell apoptosis and ERS both in vitro and in vivo. Suppression of GRP78 could block the LPS-induced cell apoptosis and ERS. NEDD4L was found to interact with GRP78 and ubiquitinate its lysine of 324 site directly. Caffeine treatment induced the expression of NEDD4L, resulting in the ubiquitination and inhibition of GRP78.

CONCLUSION

Caffeine mitigated the acute liver injury by stimulating NEDD4L expression, which inhibited GRP78 expression via ubiquitination at its K324 site. Low dose of caffeine could be a promising therapeutic treatment for acute liver injury.

Cold exposure-induced endoplasmic reticulum stress regulates autophagy through the SIRT2/FoxO1 signaling pathway

Cold is a factor affecting health in humans and animals. The liver, a major metabolic center, is highly susceptible to ambient air temperature. Recent studies have shown that endoplasmic reticulum (ER) stress is associated with the liver, and regulates the occurrence and development of liver injury and autophagy. However, the mechanism underlying the relationship between cold exposure and ER stress in the liver is not well understood. In this study, we investigated the effect of ER stress on liver autophagy and its mechanism under cold exposure. AML12 cells were treated with Tg to construct an ER stress model, and the level of autophagy increased. To further explore the mechanism through which ER stress regulates autophagy, we knocked down SIRT2 with shRNA in Tg-treated AML12 cells. Knockdown of SIRT2 significantly increased ER stress and autophagy, increased FoxO1 acetylation, and promoted its entry into the nucleus. To further verify the results of in vitro experiments, we exposed mice to 4°C for 3 h per day for 3 weeks to exacerbate the burden on the liver after cold exposure. Cold exposure damaged the structure and function of the liver and promoted the inflammatory response. It also activated ER stress and promoted autophagy. In addition, cold exposure inhibited the expression of SIRT2, promoted FoxO1 acetylation, and enhanced the interaction with autophagy. Our findings indicated that cold exposure induces liver damage, ER stress, and autophagy through the SIRT2/FoxO1 pathway. These findings suggest that SIRT2 may be a potential target for regulating health under cold exposure.

Thymol Alleviates LPS-Induced Liver Inflammation and Apoptosis by Inhibiting NLRP3 Inflammasome Activation and the AMPK-mTOR-Autophagy Pathway

Thymol is a natural antibacterial agent found in the essential oil extracted from thyme, which has been proven to be beneficial in food and medicine. Meanwhile, the NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome and autophagy have been reported to play key roles in the progression of liver injury. However, the effects of thymol on the NLRP3 inflammasome and autophagy in protecting the liver remain unclear. The present study used a mouse model with liver injury induced by lipopolysaccharides (LPS) to investigate the regulatory mechanisms of thymol. We found that thymol alleviated LPS-induced liver structural damage, as judged by reduced inflammatory cell infiltration and improved structure. In addition, elevated levels of the liver damage indicators (alanine transaminase (ALT), aspartate transaminase (AST), and total bilirubin (TBIL)) dropped after thymol administration. The mRNA and protein expression of inflammatory cytokines (tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-22), apoptosis-related genes (caspase3 and caspase9), and the activity of apoptosis-related genes (caspase3 and caspase9) were increased in LPS-treated livers, whereas the changes were alleviated after thymol administration. Thymol inhibited LPS-induced increment in lactate dehydrogenase (LDH) activity in primary hepatocytes of the mouse. In addition, thymol protected mice from liver injury by inhibiting NLRP3 inflammasome activation induced by LPS. Mechanistically, the present study indicates that thymol has liver protective activity resulting from the modulation of the AMP-activated protein kinase—mammalian target of rapamycin (AMPK–mTOR) to regulate the autophagy pathway, hence curbing inflammation.

STIM1–Orai1 Interaction Exacerbates LPS-Induced Inflammation and Endoplasmic Reticulum Stress in Bovine Hepatocytes through Store-Operated Calcium Entry

(1) Background: The basic mechanism of store-operated Ca²⁺ entry (SOCE) in bovine hepatocytes (BHEC) is related to the activation of STIM1 and Orai1. The effect of STIM1- and Orai1-dependent calcium ion signaling on the NF-κB signaling pathway is unclear. (2) Methods: In this study, the expression of STIM1 and Orai1 in BHEC was regulated. RT-qPCR, Western blotting, and an immunofluorescence antibody (IFA) assay were performed to elucidate the effect of inflammation and endoplasmic reticulum stress (ERS) in BHEC. (3) Results: First of all, in this study, RT-PCR and Western blotting were used to detect the levels of IκB, NF-κB, and inflammatory factors (IL-6, IL-8, and TNF-α) and the expression of genes and proteins related to ERS (PERK, IRE1, ATF6, GRP78, and CHOP), which reached peak levels simultaneously when BHEC were treated with 16 μg/mL LPS for 1 h. For STIM1, we overexpressed STIM1 in BHEC by using plasmid transfection technology. The results showed that after overexpression of STIM1, the gene and protein expression of STIM1 levels were significantly upregulated, and the expression of Orai1 on the cell membrane was also upregulated, which directly activated the SOCE channel and induced inflammation and ERS in BHEC. The overexpression group was then treated with LPS, and it was found that the overexpression of STIM1 could enhance LPS-induced BHEC inflammation and ERS in BHEC. For Orai1, BHEC were pretreated with 8 μg/mL of the specific inhibitor BTP2 for 6 h. It was found that BTP2 could inhibit the expression of mRNA in Orai1, significantly reduce the gene expression of STIM1, inhibit the activation of the NF-κB signaling pathway, and alleviate inflammation and ERS in BHEC under LPS stimulation. (4) Conclusions: In conclusion, STIM1/Orai1 can intervene and exacerbate LPS-induced inflammation and ERS in bovine hepatocytes through SOCE.

Milk Fat Globule Membrane Alleviates Short Bowel Syndrome-Associated Liver Injury in Rats Through Inhibiting Autophagy and NLRP3 Inflammasome Activation

Background

The milk fat globule membrane (MFGM), a tri-layer membrane structure surrounding the milk fat globule, has been shown to have immune-modulating properties. This study aimed to investigate the effects of MFGM supplementation in a rat model of short bowel syndrome (SBS) associated liver disease and its possible mechanisms.

Materials and Methods

Twenty one male Sprague-Dawley rats were randomly divided into three groups: Sham, SBS (underwent massive small bowel resection), and SBS+MFGM (SBS rats supplemented with 1.5 g/kg/d MFGM). Liver pathology, myeloperoxidase (MPO) staining, serum levels of aspartate aminotransferase (AST)/alanine aminotransferase (ALT), endotoxin concentration, protein expression of autophagy and nucleotide binding oligomerization domain, leucine-rich repeat and pyrin domain-containing protein 3 (NLRP3) pathway in the liver tissue were measured.

Results

Both SBS and SBS + MFGM groups had higher serum levels of ALT and liver endotoxin levels than the Sham group (P < 0.05), with no difference detected between each other. Compared with the SBS group, the SBS+MFGM group showed lower liver pathology scores of steatosis and inflammation, less MPO positive cells and reduced expressions of NLRP3, apoptosis-associated speck-like protein containing a CARD (ASC), Caspase-1, interleukin (IL)-1β(P < 0.05) in the liver. Additionally, the expression of Beclin-1 and microtubule-associated protein1 light chain 3(LC3) B, the fluorescence intensity of NLRP3 and LC3B in the SBS + MFGM group were lower than the SBS group (P < 0.05). The LC3B expression was positively correlated with the NLRP3 level.

Conclusion

Enteral supplementation of MFGM help to alleviate liver injury in SBS rats, which might be related to inhibition of aberrant activation of autophagy and NLRP3 inflammasome pathways.

Maternal organic selenium supplementation alleviates LPS induced inflammation, autophagy and ER stress in the thymus and spleen of offspring piglets by improving the expression of selenoproteins

The thymus and spleen are the main reservoir for T lymphocytes, which can regulate the innate immune response and provide protection against pathogens and tissue damage. Oxidative stress, excessive inflammation, abnormal autophagy and endoplasmic reticulum (ER) stress can all lead to dysfunction of the thymus and spleen. This study was conducted to investigate the effect of maternal 2-hydroxy-4-methylselenobutanoic acid (HMSeBA, an organic Se source) supplementation during pregnancy on the selenoprotein expression, inflammation, ER stress and autophagy of their young offspring's thymus and spleen. Thirty sows were randomly assigned to receive one of the following two diets during gestation: control diet (control, basal diet, n = 15) or HMSeBA supplemented diet (HMSeBA, basal diet +0.3 mg Se kg^-1 as HMSeBA, n = 15). Tissues of thymus and spleen were collected from the offspring at birth and weaning after the lipopolysaccharide challenge. Results showed that maternal HMSeBA supplementation significantly up-regulated the gene expression of selenoproteins in the thymus and spleen of newborn piglets compared with the basal diet (p < 0.05), as well as the protein abundance of GPX1 and GPX4 (p < 0.05). In addition, maternal HMSeBA supplementation effectively decreased the expression of inflammation and autophagy related proteins in the thymus and spleen of newborn piglets as compared with the control group (p < 0.05). In weaning piglets, maternal HMSeBA significantly increased the antioxidative capacity of thymus and spleen (p < 0.05), and reversed LPS induced MDA content as compared with the control group (p < 0.05). Furthermore, maternal HMSeBA supplementation during gestation reversed the activation of the MAPK/NF-κB pathway, ER stress and autophagy induced by the LPS challenge in the thymus and spleen of weaning piglets (p < 0.05). In conclusion, maternal HMSeBA supplementation during gestation could decrease the level of inflammation, autophagy and ER stress in the thymus and spleen of young offspring by improving the antioxidative capacity and selenoprotein expression in these tissues. Therefore, maternal HMSeBA supplementation during gestation might be beneficial for the immune function of their offspring by alleviating inflammation, autophagy and ER stress levels in the thymus and spleen. This study showed more evidence for the function of Se on mater-offspring integrated nutrition.

ARRB1 suppresses the activation of hepatic macrophages via modulating endoplasmic reticulum stress in lipopolysaccharide-induced acute liver injury

Acute liver injury (ALI) caused by multiple inflammatory responses is a monocyte-/macrophage-mediated liver injury that is associated with high morbidity and mortality. Liver macrophage activation is a vital event that triggers ALI. However, the mechanism of liver macrophage activation has not been fully elucidated. This study examined the role of β-arrestin1 (ARRB1) in wild-type (WT) and ARRB1-knockout (ARRB1-KO) mouse models of ALI induced by lipopolysaccharide (LPS), and ARRB1-KO mice exhibited more severe inflammatory injury and liver macrophage activation compared to WT mice. We found that LPS treatment reduced the expression level of ARRB1 in Raw264.7 and THP-1 cell lines, and mouse primary hepatic macrophages. Overexpression of ARRB1 in Raw264.7 and THP-1 cell lines significantly attenuated LPS-induced liver macrophage activation, such as transformation in cell morphology and enhanced expression of proinflammatory cytokines (tumor necrosis factor-α, interleukin-1β, and interleukin-6), while downregulation of ARRB1 by small interfering RNA and ARRB1 deficiency in primary hepatic macrophages both aggravated macrophage activation. Moreover, overexpression of ARRB1 suppressed LPS-induced endoplasmic reticulum (ER) stress in liver macrophages, and inhibition of ER stress impeded excessive hepatic macrophage activation induced by downregulation of ARRB1. Our data demonstrate that ARRB1 relieves LPS-induced ALI through the ER stress pathway to regulate hepatic macrophage activation and that ARRB1 may be a potential therapeutic target for ALI.

Lipopolysaccharide/D-galactosamine-induced acute liver injury could be attenuated by dopamine receptor agonist rotigotine via regulating NF-κB signaling pathway

The pathological of lipopolysaccharide (LPS)/D-galactosamine (D-Gal)-induced acute liver injury is similar to what is seen clinically, and be mediated by the release of pro-inflammatory mediators. A growing body of studies have shown that dopamine (DA) and DA receptor agonist are associated with inflammation and immune response. Rotigotine, a non-ergoline dopamine receptor agonist, is a drug for the treatment of Parkinson's disease. Rotigotine-loaded microspheres (RoMS) is an intramuscular extended-release agent, which can steadily release rotigotine for more than 7 days after a single administration. The present study aimed to investigate the effects of rotigotine and RoMS on inflammation and acute liver injury induced by LPS/D-Gal in mice. The LPS/D-Gal-induced liver injury was evidenced by increases of serum aminotransferases activities and liver histological lesions. Pretreatment with rotigotine or RoMS not only ameliorated the liver histologic lesions, but also reduced the activities of serum aminotransferases and the production of TNF-α. It also showed that rotigotine and RoMS increased DA receptor 2 (DRD2) expression in LPS/D-Gal-exposed mice. Rotigotine and RoMS activated β-arrestin 2, inhibited the phosphorylation of Akt, IκB and the transposition of NF-κB. In line with the above findings, the protective effects of rotigotine and RoMS were abrogated by haloperidol, a DA receptor antagonist. In conclusion, dopamine receptor agonist can regulate NF-κB inflammatory signaling pathway and exert protective effects in LPS/D-Gal-induced liver injury.

Susceptibility of Asialoglycoprotein Receptor-Deficient Mice to Lps/Galactosamine Liver Injury and Protection by Betaine Administration

BACKGROUND

Work from our laboratory has shown that the ethanol-induced increase in apoptotic hepatocellular death is closely related to the impairment in the ability of the asialoglycoprotein receptor (ASGP-R) to remove neighboring apoptotic cells. In this study, we assessed the role of ASGP-R in fulminant liver failure and investigated whether prior treatment with betaine (a naturally occurring tertiary amine) is protective.

METHODS

Lipopolysaccharide (LPS; 50 μg/kg BW) and galactosamine (GalN; 350 mg/kg BW) were injected together to wild-type and ASGP-R-deficient mice that were treated for two weeks prior with or without 2% betaine in drinking water. The mice were sacrificed 1.5, 3, or 4.5 h post-injection, and tissue samples were collected.

RESULTS

LPS/GalN injection generate distinct molecular processes, which includes increased production of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), thus causing apoptosis as evident by increased caspase-3 activity. ASGP-R deficient animals showed increased liver caspase activities, serum TNF-α and IL-6 levels, as well as more pronounced liver damage compared with the wild-type control animals after intraperitoneal injection of LPS/GalN. In addition, prior administration of betaine was found to significantly attenuate the LPS/GalN-induced increases in liver injury parameters.

CONCLUSION

Our work underscores the importance of normal functioning of ASGP-R in preventing severe liver damage and signifies a therapeutic role of betaine in prevention of liver injuries from toxin-induced fulminant liver failure.

Standardized Olea europaea L. leaf extract exhibits protective activity in carbon tetrachloride-induced acute liver injury in rats: the insight into potential mechanisms

The protective activity of dry olive leaf extract (DOLE) in carbon tetrachloride (CCl₄)-induced liver damage and possible mechanisms involved in this protection were investigated in rats. Acute CCl₄ intoxication resulted in a massive hepatic necrosis, in increased serum transaminases, and in a perturbation of oxidative stress parameters in liver tissue [malondyaldehide, glutathione (GSH), catalase]. CCl₄ did not affect the expression of caspase-3 and cytochrome c as markers of apoptosis; however, CCl₄ increased the AMP-activated protein kinase (AMPK) activity and the expression of autophagy-related protein LC3II and decreased the expression of p62 protein. The pre-treatment with DOLE significantly improved serum markers of liver damage, liver catalase activity, and GSH concentration, suggesting that antioxidative mechanism is responsible for hepatoprotection. Oral administration of DOLE did not influence LC3II conversion and p62 degradation in liver, but AMPK activity was significantly decreased, suggesting the energy balance perturbation as an additional potential mechanism of DOLE hepatoprotective effect.

Gap Junction Intercellular Communication Negatively Regulates Cadmium-Induced Autophagy and Inhibition of Autophagic Flux in Buffalo Rat Liver 3A Cells

Cadmium is an important environmental pollutant that poses a serious threat to the health of humans and animals. A large number of studies have shown that the liver is one of the important target organs of cadmium. Stimulation of cells can lead to rapid changes in gap junction intercellular communication (GJIC) and autophagy. Previous studies have shown that cadmium can inhibit GJIC and induce autophagy. In order to understand the dynamic changes of GJIC and autophagy in the process of cadmium-induced hepatotoxic injury and the effects of GJIC on autophagy, a time-gradient model of cadmium cytotoxicity was established. The results showed that within 24 h of cadmium exposure, 5 μmol/L cadmium inhibited GJIC by down regulating the expression levels of connexin 43 (Cx43) and disturbing the localization of Cx43 in Buffalo rat liver 3A (BRL 3A) cells. In addition, cadmium induced autophagy and then inhibited autophagic flux in the later stage. During this process, inhibiting of GJIC could exacerbate the cytotoxic damage of cadmium and induce autophagy, but further blocked autophagic flux, promoting GJIC in order to obtain the opposite results.

Selenium mitigates cadmium-induced crosstalk between autophagy and endoplasmic reticulum stress via regulating calcium homeostasis in avian leghorn male hepatoma (LMH) cells

Cadmium (Cd) is a toxic heavy metal and widespread in environment and food, which is adverse to human and animal health. Food intervention is a hot topic because it has no side effects. Selenium (Se) is an essential trace element, found in various fruits and vegetables. Many previous papers have described that Se showed ameliorative effects against Cd. However, the underlying mechanism of antagonistic effect of Se against Cd-induced cytotoxicity in avian leghorn male hepatoma (LMH) cells is unknown, the molecular mechanism of Se antagonistic effect on Cd-induced and calcium (Ca²⁺) homeostasis disorder and crosstalk of ER stress and autophagy remain to be explored. In order to confirm the antagonistic effect of Se on Cd-induced LMH cell toxicity, LMH cells were treated with CdCl₂ (2.5 μM) and Na₂SeO₃ (1.25 and 2.5 μM) for 24 h. In this study, Cd exposure induced cell death, disrupted intracellular Ca²⁺ homeostasis and Ca²⁺ homeostasis related regulatory factors, interfered with the cycle of cadherin (CNX)/calreticulin (CRT), and triggered ER stress and autophagy. Se intervention inhibited Cd-induced LDH release and crosstalk of ER stress and autophagy via regulating intracellular Ca²⁺ homeostasis. Moreover, Se mitigated Cd-induced Intracellular Ca²⁺ overload by Ca²⁺/calmodulin (CaM)/calmodulin kinase IV (CaMK-IV) signaling pathway. Herein, CNX/CRT cycle played a critical role for the protective effect of Se on Cd-induced hepatotoxicity. Based on these findings, we demonstrated that the application of Se is beneficial for prevention and alleviation of Cd toxicity.

Melatonin alleviates LPS-induced endoplasmic reticulum stress and inflammation in spermatogonial stem cells

Orchitis is one of the leading causes of male animal infertility and is associated with inflammatory reactions caused by the bacterium. It has been reported that there is a mutual coupling effect between endoplasmic reticulum stress (ERS) and inflammatory response. Our studies showed that lipopolysaccharide (LPS) could cause testicular damages, apoptosis, ERS, and inflammatory responses in spermatogonial stem cells (SSCs); ERS-related apoptosis proteins were activated and the expression of ERS genes was significantly upregulated; meanwhile, the expression of Toll-like receptor 4 and inflammation factors was apparently increased with LPS treatment. Moreover, melatonin (MEL) could rescue testicular damage, and significantly inhibited the expression of ERS-related apoptosis genes, ERS markers, and inflammatory factors in SSCs and MEL played repairing and anti-infection roles in LPS-induced testicular damage. Therefore, MEL may be used as a drug to prevent and control bacterial infections in male reproductive systems. However, the specific molecular mechanism of MEL to resist ERS and inflammatory response remains to be further studied.

Asiatic acid ameliorates acute hepatic injury by reducing endoplasmic reticulum stress and triggering hepatocyte autophagy

Endoplasmic reticulum stress (ERS), mutual crosstalk between autophagy and apoptosis-related signaling pathway, plays an important role in the process of acute liver injury (ALI). The present study was to investigate the effects and underlying mechanisms of Asiatic acid from Potentilla chinensis (AAPC) on ALI. The model of ALI in mice was induced by administration with Lipopolysaccharide/D-Galactosamine (LPS/D-GalN). The effects of AAPC on hepatic pathology and hepatocyte apoptosis were observed by hematoxylin-eosin (H&E) staining and TUNEL staining. Serum transaminases activities were measured using an automated biochemical analyzer. Moreover, ERS and autophagy were induced in LO2 cells, respectively. Cell cycle and apoptosis were analyzed using flow cytometry. In addition, ERS and autophagy-related pathways were detected in vivo and in vitro. The results showed that AAPC significantly ameliorated LPS/D-GalN-induced ALI in mice, as evidenced by the improvement of liver pathology and the decrease in serum alanine aminotransferase (ALT) and aspartate transaminase (AST) activities. Moreover, AAPC pre-treatment markedly inhibited thapsigargin-induced cell apoptosis, accompanied by cell cycle arrest at S/G1 phase in LO2 cells. AAPC notably inhibited the activation of the PERK/ATF6 and IRE1 pathway, alleviating the extent of ERS. Additionally, AAPC significantly promoted autophagy, as evidenced by the increase in the formation of autophagic vacuoles and the number of autophagosomes as well as the increased expressions of LC3II/I, Beclin-1, Atg5 and Atg7. In summary, our results indicate that AAPC significantly ameliorates ALI by inhibiting the ERS pathway and promoting hepatocyte autophagy.

Therapeutic effect of human umbilical cord blood mesenchymal stem cells combined with G-CSF on rats with acute liver failure

Human umbilical cord blood mesenchymal stem cells (hUCB-MSCs) have been used to facilitate healing in animal models of liver injury, while granulocyte colony-stimulating factor (G-CSF) has been shown to stimulate stem cell mobilization and these cells may contribute to liver repair. hUCB-MSCs were characterized by flow cytometry, and transplanted into rats with d-galactosamine (D-GalN)/lipopolysaccharides (LPS)-induced acute liver failure (ALF) together with granulocyte colony-stimulating factor (G-CSF). Liver function, oxidative stress and pro-inflammatory cytokines expressions were examined using enzyme-linked immunosorbent assay (ELISA). Hematoxylin-eosin (HE) staining was used to observe the morphological changes. Apoptosis was investigated by terminal dUTP nick end labeling (TUNEL) staining. Bromodeoxyuridine (BrdU) cell proliferation assay was analyzed by immunofluorescence and immunohistochemistry. In the results, cultured hUCB-MSCs displayed proliferation and adipogenic and osteogenic differentiation potentials. hUCB-MSCs in combination with G-CSF significantly attenuated ALF-induced liver function injury. Furthermore, hUCB-MSCs and G-CSF treatment remarkably suppressed the secretions of pro-inflammatory cytokines and MDA activation induced by ALF. In addition, inflammation, lesions and cell apoptosis in liver tissues were obviously ameliorated by application of hUCB-MSCs and G-CSF. In conclusion, hUCB-MSCs, alone or co-treatment with G-CSF could ameliorate ALF in rats by inhibiting liver function injury, production of pro-inflammatory cytokines, oxidative stress, and liver cell apoptosis.

Endoplasmic reticulum stress is involved in lipopolysaccharide-induced inflammatory response and apoptosis in goat endometrial stromal cells

Endoplasmic reticulum (ER) stress is involved in regulating cell metabolism, apoptosis, autophagy, and survival. However, there is not enough information about the role of ER stress in lipopolysaccharide (LPS)-induced apoptosis and inflammatory cytokine secretion in the uterus. In this study, we found that LPS induced apoptosis and inflammation in goat endometrial stromal cells (ESCs). LPS treatment inhibited cell viability and cell proliferation. In addition, the genes associated with proliferation, such as proliferating cell nuclear antigen and MKI67, were affected by LPS treatment. Moreover, LPS increased the secretion of interleukin (IL)-1β and IL-8, promoting the levels of MYD88, caspase1, and TRL4. The 4-phenylbutyric acid pretreatment inhibited the expression of unfolded protein response proteins and the secretion of inflammatory cytokines in LPS-treated cells. However, blockage of inositol-requiring enzyme 1 and activating transcription factor 6 did not significantly reduce apoptosis and inflammatory cytokine secretion. Collectively, ER stress involved in LPS-induced apoptosis and inflammatory cytokine increased in goat ESCs. This study provides new insight into the function of ER stress in the pathological process.

Diverse Functions of Autophagy in Liver Physiology and Liver Diseases

Autophagy is a catabolic process by which eukaryotic cells eliminate cytosolic materials through vacuole-mediated sequestration and subsequent delivery to lysosomes for degradation, thus maintaining cellular homeostasis and the integrity of organelles. Autophagy has emerged as playing a critical role in the regulation of liver physiology and the balancing of liver metabolism. Conversely, numerous recent studies have indicated that autophagy may disease-dependently participate in the pathogenesis of liver diseases, such as liver hepatitis, steatosis, fibrosis, cirrhosis, and hepatocellular carcinoma. This review summarizes the current knowledge on the functions of autophagy in hepatic metabolism and the contribution of autophagy to the pathophysiology of liver-related diseases. Moreover, the impacts of autophagy modulation on the amelioration of the development and progression of liver diseases are also discussed.