GPR124 promotes trophoblast proliferation, migration, and invasion and inhibits trophoblast cell apoptosis and inflammation via JNK and P38 MAPK pathways.

Early-onset preeclampsia, which occurrs before 34 weeks of gestation, is the most dangerous classification of preeclampsia, which is a pregnancy-specific disease that causes 1% of maternal deaths. G protein-coupled receptor 124 (GPR124) is significantly expressed at various stages of the human reproductive process, particularly during embryogenesis and angiogenesis. Our prior investigation demonstrated a notable decrease in GPR124 expression in the placentas of patients with early-onset preeclampsia compared to that in normal pregnancy placentas. However, there is a lack of extensive investigation into the molecular processes that contribute to the role of GPR124 in placenta development. This study aimed to examine the mechanisms by which GPR124 affects the occurrence of early-onset preeclampsia and its function in trophoblast. Proliferative, invasive, migratory, apoptotic, and inflammatory processes were identified in GPR124 knockdown, GPR124 overexpression, and normal HTR8/SVneo cells. The mechanism of GPR124-mediated cell function in GPR124 knockdown HTR8/SVneo cells was examined using inhibitors of the JNK or P38 MAPK pathway. Downregulation of GPR124 was found to significantly inhibit proliferation, invasion and migration, and promote apoptosis of HTR8/SVneo cells when compared to the control and GPR124 overexpression groups. This observation is consistent with the pathological characteristics of preeclampsia. In addition, GPR124 overexpression inhibits the secretion of pro-inflammatory cytokines interleukin (IL)-8 and interferon-γ (IFN-γ) while enhancing the secretion of the anti-inflammatory cytokine interleukin (IL)-4. Furthermore, GPR124 suppresses the activation of P-JNK and P-P38 within the JNK/P38 MAPK pathway. The invasion, apoptosis, and inflammation mediated by GPR124 were partially restored by suppressing the JNK and P38 MAPK pathways in HTR8/SVneo cells. GPR124 plays a crucial role in regulating trophoblast proliferation, invasion, migration, apoptosis, and inflammation via the JNK and P38 MAPK pathways. Furthermore, the effect of GPR124 on trophoblast suggests its involvement in the pathogenesis of early-onset preeclampsia.

The promotion of non-small cell lung cancer progression by collagen and calcium binding EGF domain 1 is mediated through the regulation of ERK/JNK/P38 phosphorylation by reactive oxygen species.

Reactive oxygen species (ROS) are metabolic by-products of cells, and abnormal changes in their levels are often associated with tumor development. Our aim was to determine the role of collagen and calcium binding EGF domain 1 (CCBE1) in oxidative stress and tumorigenesis in non-small cell lung cancer cells (NSCLC). We investigated the tumorigenic potential of CCBE1 in NSCLC using in vitro and in vivo models of CCBE1 overexpression and knockdown. Immunohistochemical staining results showed that the expression of CCBE1 in cancer tissues was significantly higher than that in adjacent tissues. Cell counting Kit 8, clonal formation, wound healing, and transwell experiments showed that CCBE1 gene knockdown significantly inhibited the migration, invasion, and proliferation of NSCLC cell lines. In terms of mechanism, the silencing of CCBE1 can significantly promote the morphological abnormalities of mitochondria, significantly increase the intracellular ROS level, and promote cell apoptosis. This change of oxidative stress can affect cell proliferation, migration, and invasion by regulating the phosphorylation level of ERK/JNK/P38 MAPK. Specifically, the downregulation of CCBE1 inhibits the phosphorylation of ERK/P38 and promotes the phosphorylation of JNK in NSCLC, and this regulation can be reversed by the antioxidant NAC. In vivo experiments confirmed that downregulating CCBE1 gene could inhibit the growth of NSCLC in BALB/c nude mice. Taken together, our results confirm the tumorigenic role of CCBE1 in promoting tumor invasion and migration in NSCLC, and reveal the molecular mechanism by which CCBE1 regulates oxidative stress and the ERK/JNK/P38 MAPK pathway.

Carfilzomib activates ER stress and JNK/p38 MAPK signaling to promote apoptosis in hepatocellular carcinoma cells.

Hepatocellular carcinoma (HCC) is one of the most prevalent and deadly cancers in the world, which is frequently diagnosed at a late stage. HCC patients have a poor prognosis due to the lack of an efficacious therapeutic strategy. Approved drug repurposing is a way for accelerating drug discovery and can significantly reduce the cost of drug development. Carfilzomib (CFZ) is a second-generation proteasome inhibitor, which is highly efficacious against multiple myeloma and has been reported to possess potential antitumor activities against multiple cancers. However, the underlying mechanism of CFZ on HCC is still unclear. Here, we show that CFZ inhibits the proliferation of HCC cells through cell cycle arrest at the G2/M phase and suppresses the migration and invasion of HCC cells by inhibiting epithelial-mesenchymal transition. We also find that CFZ promotes reactive oxygen species production to induce endoplasmic reticulum (ER) stress and activate JNK/p38 MAPK signaling in HCC cells, thus inducing cell death in HCC cells. Moreover, CFZ significantly inhibits HCC cell growth in a xenograft mouse model. Collectively, our study elucidates that CFZ impairs mitochondrial function and activates ER stress and JNK/p38 MAPK signaling, thus inhibiting HCC cell and tumor growth. This indicates that CFZ has the potential as a therapeutic drug for HCC.

Sodium aescinate ameliorates chronic neuropathic pain in male mice via suppressing JNK/p38-mediated microglia activation.

OBJECTIVE: A study confirmed that sodium aescinate (SA) can effectively relieve bone cancer pain, but its role in neuropathic pain (NP) remains confused. METHODS: Eighty male mice were randomly divided into four groups: sham+vehicle, sham+SA (40 µg/L, intrathecal injection), chronic contraction injury (CCI)+vehicle, CCI+SA. Behavioral assessments were used to evaluate the locomotor activity and paw withdrawal threshold (PWT) of mice. At the end of the study, spinal cord tissues were collected for histopathological analysis. The JNK/p38 signaling activation, Iba-1 expression, pro-inflammatory cytokines levels, and microglia subtype were assessed by western blotting, immunohistochemical staining, enzyme-linked immunosorbent assay, and flow cytometry with CD86/CD206, respectively. RESULTS: Early treatment with SA delayed the development of mechanical allodynia in CCI mice. Repeated SA treatment could prominently increase the reduction of PWT induced by CCI, and improve the locomotor activity of CCI mice. Mechanically, CCI surgery induced significant up-regulation of p-JNK and p-p38 protein levels, increased number and M1/M2 ratio of microglia, as well as pro-inflammatory factors in the spinal cords of mice, which could be blocked after SA administration. CONCLUSIONS: SA might suppress the activation of microglia and neuroinflammation by selectively inhibiting the JNK/p38 signaling pathway, thereby alleviating CCI-induced NP in male mice.

Six-Transmembrane Epithelial Antigen of Prostate 3 Promotes Hepatic Insulin Resistance and Steatosis.

Nonalcoholic fatty liver disease (NAFLD) is a clinicopathological syndrome characterized by excessive deposition of fatty acids in the liver. Further deterioration leads to nonalcoholic steatohepatitis, cirrhosis, and hepatocellular carcinoma, creating a heavy burden on human health and the social economy. Currently, there are no effective and specific drugs for the treatment of NAFLD. Therefore, it is important to further investigate the pathogenesis of NAFLD and explore effective therapeutic targets for the prevention and treatment of the disease. Six-transmembrane epithelial antigen of prostate 3 (STEAP3), a STEAP family protein, is a metalloreductase. Studies have shown that it can participate in the regulation of liver ischemia-reperfusion injury, hepatocellular carcinoma, myocardial hypertrophy, and other diseases. In this study, we found that the expression of STEAP3 is upregulated in NAFLD. Deletion of STEAP3 inhibits the development of NAFLD in vivo and in vitro, whereas its overexpression promotes palmitic acid/oleic acid stimulation-induced lipid deposition in hepatocytes. Mechanistically, it interacts with transforming growth factor beta-activated kinase 1 (TAK1) to regulate the progression of NAFLD by promoting TAK1 phosphorylation and activating the TAK1-c-Jun N-terminal kinase/p38 signaling pathway. Taken together, our results provide further insight into the involvement of STEAP3 in liver pathology.

ASK1-K716R reduces neuroinflammation and white matter injury via preserving blood-brain barrier integrity after traumatic brain injury.

BACKGROUND: Traumatic brain injury (TBI) is a significant worldwide public health concern that necessitates attention. Apoptosis signal-regulating kinase 1 (ASK1), a key player in various central nervous system (CNS) diseases, has garnered interest for its potential neuroprotective effects against ischemic stroke and epilepsy when deleted. Nonetheless, the specific impact of ASK1 on TBI and its underlying mechanisms remain elusive. Notably, mutation of ATP-binding sites, such as lysine residues, can lead to catalytic inactivation of ASK1. To address these knowledge gaps, we generated transgenic mice harboring a site-specific mutant ASK1 Map3k5-e (K716R), enabling us to assess its effects and elucidate potential underlying mechanisms following TBI. METHODS: We employed the CRIPR/Cas9 system to generate a transgenic mouse model carrying the ASK1-K716R mutation, aming to investigate the functional implications of this specific mutant. The controlled cortical impact method was utilized to induce TBI. Expression and distribution of ASK1 were detected through Western blotting and immunofluorescence staining, respectively. The ASK1 kinase activity after TBI was detected by a specific ASK1 kinase activity kit. Cerebral microvessels were isolated by gradient centrifugation using dextran. Immunofluorescence staining was performed to evaluate blood-brain barrier (BBB) damage. BBB ultrastructure was visualized using transmission electron microscopy, while the expression levels of endothelial tight junction proteins and ASK1 signaling pathway proteins was detected by Western blotting. To investigate TBI-induced neuroinflammation, we conducted immunofluorescence staining, quantitative real-time polymerase chain reaction (qRT-PCR) and flow cytometry analyses. Additionally, immunofluorescence staining and electrophysiological compound action potentials were conducted to evaluate gray and white matter injury. Finally, sensorimotor function and cognitive function were assessed by a battery of behavioral tests. RESULTS: The activity of ASK1-K716R was significantly decreased following TBI. Western blotting confirmed that ASK1-K716R effectively inhibited the phosphorylation of ASK1, JNKs, and p38 in response to TBI. Additionally, ASK1-K716R demonstrated a protective function in maintaining BBB integrity by suppressing ASK1/JNKs activity in endothelial cells, thereby reducing the degradation of tight junction proteins following TBI. Besides, ASK1-K716R effectively suppressed the infiltration of peripheral immune cells into the brain parenchyma, decreased the number of proinflammatory-like microglia/macrophages, increased the number of anti-inflammatory-like microglia/macrophages, and downregulated expression of several proinflammatory factors. Furthermore, ASK1-K716R attenuated white matter injury and improved the nerve conduction function of both myelinated and unmyelinated fibers after TBI. Finally, our findings demonstrated that ASK1-K716R exhibited favorable long-term functional and histological outcomes in the aftermath of TBI. CONCLUSION: ASK1-K716R preserves BBB integrity by inhibiting ASK1/JNKs pathway in endothelial cells, consequently reducing the degradation of tight junction proteins. Additionally, it alleviates early neuroinflammation by inhibiting the infiltration of peripheral immune cells into the brain parenchyma and modulating the polarization of microglia/macrophages. These beneficial effects of ASK1-K716R subsequently result in a reduction in white matter injury and promote the long-term recovery of neurological function following TBI.

Hydroxychloroquine suppresses anti-GBM nephritis via inhibition of JNK/p38 MAPK signaling.

BACKGROUND: Anti-glomerular basement membrane (anti-GBM) nephritis, characterized by glomerular crescent formation, requires early treatment because of poor prognosis. Hydroxychloroquine (HCQ) is an antimalarial drug with known immunomodulatory, anti-inflammatory, and autophagy inhibitory effects; it is recognized in the treatment of autoimmune diseases such as systemic lupus erythematosus. However, its effect on anti-GBM nephritis remains unknown. In this study, we investigated the effect of HCQ on anti-GBM nephritis in rats. METHODS: Seven-weeks-old male WKY rats were administered anti-GBM serum to induce anti-GBM nephritis. Either HCQ or vehicle control was administered from day 0 to day 7 after the induction of nephritis. Renal function was assessed by measuring serum creatinine, proteinuria, and hematuria. Renal histological changes were assessed by PAS staining and Masson trichrome staining, and infiltration of macrophages was assessed by ED-1 staining. Mitogen-activated protein kinase (MAPK) was evaluated by western blotting, while chemokine and inflammatory cytokines were evaluated by enzyme-linked immunosorbent assay using urine sample. RESULTS: HCQ treatment suppressed the decline in renal function. Histologically, extracapillary and intracapillary proliferations were observed from day 1, while fibrinoid necrosis and ED-1 positive cells were observed from day 3. Rats with anti-GBM nephritis showed high levels of monocyte chemotactic protein-1 and tumor necrosis factor-α. These changes were significantly suppressed following HCQ treatment. In addition, HCQ suppressed JNK/p38 MAPK phosphorylation. CONCLUSION: HCQ attenuates anti-GBM nephritis by exerting its anti-inflammatory effects via the inhibition of JNK/p38 MAPK activation, indicating its therapeutic potential against anti-GBM nephritis.

Echinatin induces reactive oxygen species-mediated apoptosis via JNK/p38 MAPK signaling pathway in colorectal cancer cells.

Colorectal cancer (CRC) is a very common and deadly cancer worldwide, and oxaliplatin is used as first-line chemotherapy. However, resistance usually develops, limiting treatment. Echinatin (Ech) is the main component of licorice and exhibits various therapeutic effects on inflammation-mediated diseases and cancer, ischemia/reperfusion, and liver injuries. The present study elucidated the underlying molecular mechanism of Ech-induced apoptosis in both oxaliplatin-sensitive (HT116 and HT29) and -resistant (HCT116-OxR and HT29-OxR) CRC cells. To evaluate the antiproliferative activities of Ech, we performed MTT and soft agar assays. Ech reduced viability, colony size, and numbers of CRC cells. The underlying molecular mechanisms were explored by various flow cytometry analyses. Ech-induced annexin-V stained cells, reactive oxygen species (ROS) generation, cell cycle arrest, JNK/p38 MAPK activation, endoplasmic reticulum (ER) stress, mitochondrial membrane potential depolarization, and multi-caspase activity. In addition apoptosis-, cell cycle-, and ER stress-related protein levels were confirmed by western blotting. Moreover, we verified ROS-mediated cell death by treatment with inhibitors such as N-acetyl-L-cysteine, SP600125, and SB203580. Taken together, Ech exhibits anticancer activity in oxaliplatin-sensitive and -resistant CRCs by inducing ROS-mediated apoptosis through the JNK/p38 MAPK signaling pathway. This is the first study to show that Ech has the potential to treat drug-resistant CRC, providing new directions for therapeutic strategies targeting drug-resistant CRC.

CircPrkcsh, a circular RNA, contributes to the polarization of microglia towards the M1 phenotype induced by spinal cord injury and acts via the JNK/p38 MAPK pathway.

Spinal cord injury (SCI) is a complex pathological change that includes primary SCI and gradually evolves into secondary SCI. Accumulating evidence demonstrates that circular RNAs (circRNAs) are involved in the pathology of a variety of neurological diseases and injuries. However, the characteristics and function of circRNAs in SCI have yet to be elucidated. Although previous research demonstrated that circPrkcsh induces astrocytes to produce inflammatory factors and chemokines, the precise function and mechanism of circPrkcsh in microglia after SCI remains unknown. In this study, we constructed a mouse model of SCI by applying a SCI impactor. Quantitative Real-time PCR and Fluorescence in situ hybridization analysis revealed that circPrkcsh was upregulated in the microglia of SCI mice when compared to sham-operated mice. Gain- or loss-of-function experiments and in vivo assays further indicated that circPrkcsh promotes microglia M1 polarization both in vivo and in vitro. Furthermore, bioinformatics analysis, dual-luciferase assays, and RNA immunoprecipitation assays, confirmed that circPrkcsh serves as a competing endogenous RNA (ceRNA) to promote the expression of MEKK1 mRNA by sponging miR-488. Double knockout rescue experiments further showed that circPrkcsh regulates the MEKK1/JNK/p38 MAPK pathway via miR-488. Our research provides a better understanding of the mechanism of circPrkcsh in SCI and demonstrates that the circPrkcsh/miR-488/Mekk1 axis is a promising regulatory method for the treatment of SCI.

Midazolam suppresses ischemia/reperfusion-induced cardiomyocyte apoptosis by inhibiting the JNK/p38 MAPK signaling pathway.

Myocardial ischemia/reperfusion (I/R) injury causes irreversible injury to the heart, thereby causing acute myocardial infarction. Midazolam is a benzodiazepine commonly utilized in anesthesia and intensive care. Research has indicated that midazolam plays a critical role in many diseases; however, the function of midazolam in myocardial injury induced by I/R still needs further investigation. The infarct size and damage to the heart tissues were examined through 2,3,5-triphenyl tetrazolium chloride (TTC) staining and hematoxylin and eosin staining. The creatine kinase-myocardial band isoenzyme, lactate dehydrogenase, and aspartate aminotransferase levels were tested using commercial kits. Cell apoptosis was determined through TUNEL staining or flow cytometry assays. Bax, Bcl-2, cleaved caspase-3, phospho-38 (p-p38), p38, p-JNK, JNK, extracellular signal-regulated kinases (ERK), and p-ERK expression was examined through Western blot. In our study, midazolam was shown to suppress the infarct size and heart tissue damage and reduce myocardial enzyme leakage in I/R rats. Additionally, midazolam was found to retard cardiomyocyte apoptosis in I/R rats. The JNK/p38 MAPK signaling pathway in I/R rats was inhibited by midazolam. Our findings demonstrated that in hypoxia/reoxygenation (H/R) - mediated H9C2 cells, anisomycin abolished the suppressive effects of midazolam on the JNK/p38 MAPK signaling pathway. Next, exploration discovered that anisomycin abolished the cytoprotective effects of midazolam on H/R-treated H9C2 cell apoptosis. In conclusion, this work demonstrated that midazolam retarded I/R-induced cardiomyocyte apoptosis by inhibiting the JNK/p38 MAPK signaling pathway. These results may provide new insight into the treatment of myocardial I/R injury.

Mechanism of Action of Flavonoids of Oxytropis falcata on the Alleviation of Myocardial Ischemia-Reperfusion Injury.

Oxytropis falcata Bunge is a plant used in traditional Tibetan medicine, with reported anti-inflammatory and antioxidants effects and alleviation of myocardial ischemia reperfusion injury (MIRI). However, the underlying mechanism against MIRI and the phytochemical composition of O. falcata are vague. One fraction named OFF1 with anti-MIRI activity was obtained from O. falcata, and the chemical constituents were identified by ultra-high-performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS). The potential targets and signaling pathways involved in the action of O. falcata against MIRI were predicted by network pharmacology analysis, and its molecular mechanism on MIRI was determined by in vitro assays. The results revealed that flavonoids are the dominant constituents of OFF1. A total of 92 flavonoids reported in O. falcata targeted 213 potential MIRI-associated factors, including tumor necrosis factor (TNF), prostaglandin-endoperoxide synthase 2 (PTGS2), and the NF-κB signaling pathway. The in vitro assay on H9c2 cardiomyocytes subjected to hypoxia/reoxygenation injury confirmed that the flavonoids in OFF1 reduced myocardial marker levels, apoptotic rate, and the inflammatory response triggered by oxidative stress. Moreover, OFF1 attenuated MIRI by downregulating the ROS-mediated JNK/p38MAPK/NF-κB pathway. Collectively, these findings provide novel insights into the molecular mechanism of O. falcata in alleviating MIRI, being a potential therapeutic candidate.

Circular RNA ciRS-7 promotes tube formation in microvascular endothelial cells through downregulation of miR-26a-5p.

Atherosclerosis is one of the most common and crucial heart diseases involving the heart and brain. At present, atherosclerosis and its major complications comprise the leading causes of death worldwide. Our purpose was to identify the role of ciRS-7 in atherosclerosis. Tubulogenesis of HMEC-1 cell was evaluated utilizing tube formation assay. Cell Counting Kit-8 assay and flow cytometry were utilized to test viability and apoptosis. Migration assay was utilized to determine the migration capacity of experimental cells. Western blot was applied to examine apoptosis and tube formation-associated protein expression. In addition, the above experiments were repeated when silencing ciRS-7, overexpressing ciRS-7, and upregulating miR-26a-5p. HMEC-1 cells formed tube-like structures over time. Silencing ciRS-7 suppressed viability, migration, and tube formation but promoted apoptosis. Oppositely, overexpressing ciRS-7 reversed the effect in HMEC-1 cells. miR-26a-5p expression was elevated by silencing ciRS-7 and reduced by overexpressing ciRS-7. Moreover, overexpressing ciRS-7 facilitated viability, migration, and tube formation via upregulating miR-26a-5p. Conclusively, overexpressing ciRS-7 mobilized phosphoinositide 3-kinase/protein kinase B (PI3K/AKT) pathway and suppressed c-Jun N-terminal kinase (JNK)/p38 pathway. ciRS-7 exerted influence on apoptosis, viability, migration, and tube formation through mediating PI3K/AKT and JNK/p38 pathways by miR-26a-5p downregulation in HMEC-1 cells.

TRAF6-p38/JNK-ATF2 axis promotes microglial inflammatory activation.

Activating transcription factor 2 (ATF2), a member of the alkaline-leucine zipper family, is widely expressed in various tissues, and reportedly involved in inflammatory responses to various irritates, but its role in the central nervous system (CNS) remains unclear. This study aimed to investigate the expression and biological function of ATF2 in CNS inflammation. Utilizing the LPS-induced neuroinflammation model on mice, we first found ATF2 up-regulation and its co-localization with microglia in inflamed mice brain. In vitro, we revealed an increased expression, phosphorylation, and nuclear accumulation of ATF2 in LPS-treated BV2 microglia cells. Inhibiting ATF2 significantly decreased the expression of pro-inflammatory factors in LPS-treated microglia, and alleviated neuronal apoptosis induced by the conditioned medium of activated microglia. Knocking down TRAF6, an important adaptor of the TLR4/MAPK/NF-κB signaling pathway, suppressed the LPS-induced ATF2 expression and phosphorylation, accompanied by the decreased p38/JNK phosphorylation, in microglia. Blocking p38 or JNK signaling pathway by the specific inhibitors reversed the TRAF6-overexpression mediated ATF2 activation. Taken together, our data first proved the pro-inflammatory function of ATF2 in microglia, and suggested that the TRAF6-JNK/p38-ATF2 axis might promote microglial inflammatory activation and thus aggravate neuronal injury in brain, which might become a potential therapeutic target for CNS diseases.

Rifampicin induces clathrin-dependent endocytosis and ubiquitin-proteasome degradation of MRP2 via oxidative stress-activated PKC-ERK/JNK/p38 and PI3K signaling pathways in HepG2 cells.

It was reported that antituberculosis medicines could induce liver damage via oxidative stress. In this study, we investigated the effects of rifampicin (RFP) on the membrane expression of multidrug resistance-associated protein 2 (MRP2) and the relationship between oxidative stress and RFP-induced endocytosis of MRP2 in HepG2 cells. We found that RFP (12.5-50 µM) dose-dependently decreased the expression and membrane localization of MRP2 in HepG2 cells without changing the messenger RNA level. RFP (50 µM) induced oxidative stress responses that further activated the PKC-ERK/JNK/p38 (protein kinase C-extracellular signal-regulated kinase/c-JUN N-terminal kinase/p38) and PI3K (phosphoinositide 3-kinase) signaling pathways in HepG2 cells. Pretreatment with glutathione reduced ethyl ester (2 mM) not only reversed the changes in oxidative stress indicators and signaling molecules but also diminished RFP-induced reduction in green fluorescence intensity of MRP2. We conducted co-immunoprecipitation assays and revealed that a direct interaction existed among MRP2, clathrin, and adaptor protein 2 (AP2) in HepG2 cells, and their expression was clearly affected by the changes in intracellular redox levels. Knockdown of clathrin or AP2 with small interfering RNA attenuated RFP-induced decreases of membrane and total MRP2. We further demonstrated that RFP markedly increased the ubiquitin-proteasome degradation of MRP2 in HepG2 cells, which was mediated by the E3 ubiquitin ligase GP78, but not HRD1 or TEB4. In conclusion, this study demonstrates that RFP-induced oxidative stress activates the PKC-ERK/JNK/p38 and PI3K signaling pathways that leads to clathrin-dependent endocytosis and ubiquitination of MRP2 in HepG2 cells, which provides new insight into the mechanism of RFP-induced cholestasis.

Autophagy inhibits the mesenchymal stem cell aging induced by D-galactose through ROS/JNK/p38 signalling.

Autophagy and cellular senescence are two critical responses of mammalian cells to stress and may have a direct relationship given that they respond to the same set of stimuli, including oxidative stress, DNA damage, and telomere shortening. Mesenchymal stem cells (MSCs) have emerged as reliable cell sources for stem cell transplantation and are currently being tested in numerous clinical trials. However, the effects of autophagy on MSC senescence and corresponding mechanisms have not been fully evaluated. Several studies demonstrated that autophagy level increases in aging MSCs and the downregulation of autophagy can delay MSC senescence, which is inconsistent with most studies that showed autophagy could play a protective role in stem cell senescence. To further study the relationship between autophagy and MSC senescence and explore the effects and mechanisms of premodulated autophagy on MSC senescence, we induced the up- or down-regulation of autophagy by using rapamycin (Rapa) or 3-methyladenine, respectively, before MSC senescence induced by D-galactose (D-gal). Results showed that pretreatment with Rapa for 24 hours remarkably alleviated MSC aging induced by D-gal and inhibited ROS generation. p-Jun N-terminal kinases (JNK) and p-38 expression were also clearly decreased in the Rapa group. Moreover, the protective effect of Rapa on MSC senescence can be abolished by enhancing the level of ROS, and p38 inhibitor can reverse the promoting effect of H2 O2 on MSC senescence. In summary, the present study indicates that autophagy plays a protective role in MSC senescence induced by D-gal, and ROS/JNK/p38 signalling plays an important mediating role in autophagy-delaying MSC senescence.

ß-carotene attenuates weaning-induced apoptosis via inhibition of PERK-CHOP and IRE1-JNK/p38 MAPK signalling pathways in piglet jejunum.

Weaning may cause oxidative injury, immune response impairment, apoptosis and other injuries in piglets. Oxidative and endoplasmic reticulum stress (ERS) can elicit inflammatory responses, and persistent oxidative and ERS also may lead to apoptotic cascades, which is associated with the pathogenesis of multiple diseases. ß-carotene, a natural carotenoid, has potential anti-inflammatory and antioxidant functions. However, the effect of ß-carotene on apoptosis in weaned piglets and the detailed molecular mechanism remain unclear. In this study, we found that ß-carotene decreased malondialdehyde (MDA) levels and increased the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in piglet serum. ß-carotene could inhibit the mRNA levels of caspase-3 significantly, but had no significant inhibitory effect of the mRNA levels of caspase-9 and caspase-12 in the piglet jejunum. In addition, ß-carotene decreased the activation of GRP78, CHOP, and JNK/p38 MAPK and the ratio of Bax/Bcl-2. Furthermore, ß-carotene had a significant influence on the activation of ERS and apoptosis-related signals in TG-induced IPEC-J2. In the present study, ß-carotene pre-treatment attenuated the ratio of Bax/Bcl-2 and prevented TG-induced increases in the level of PERK-CHOP and IRE1-JNK/p38 MAPK pathway activation in a dose-dependent manner. Overall, these findings indicate that ß-carotene may protect weaning-induced apoptosis through inhibiting ERS.

MIP-1α induces inflammatory responses by upregulating chemokine receptor 1/chemokine receptor 5 and activating c-Jun N-terminal kinase and mitogen-activated protein kinase signaling pathways in acute pancreatitis.

OBJECTIVE: We aimed to investigate the association of macrophage inflammatory protein (MIP)-1α (CCL3) expression with the severity of acute pancreatitis (AP). METHODS: The patients with AP were selected and divided into mild AP (MAP), moderately severe AP (MSAP), and severe AP (SAP) groups according to the severity of AP. The pancreatic acinar cell line Ar42 j was treated with cerulein to induce in vitro cell AP model. The expression of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) and the activation of the c-Jun N-terminal kinase (JNK)/p38 mitogen-activated protein kinase (MAPK) signaling pathway in stimulated or transfected Ar42 j cells were detected. RESULTS: We detected that the upregulation of MIP-1α was associated with the severity of AP. Patients with SAP showed the highest MIP-1α contents, followed by MSAP, and, lastly, MAP. In cerulein-stimulated Ar42 j cells, the upregulation of MIP-1α, CCR5, TNF-α, and IL-6 was time dependent. In addition, in human recombinant MIP-1α treated Ar42 j cells, the upregulation of TNF-α and IL-6 was MIP-1α-dose-dependent. In contrast, we detected the inhibition of TNF-α and IL-6 in MIP-1α small interfering RNA (siRNA)-treated cells. Also, the activation of the JNK/p38 MAPK signaling pathway was induced and inhibited by human recombinant MIP-1α and MIP-1α siRNA, respectively. CONCLUSION: These results suggested that MIP-1α might be used as a biomarker for the prognosis of AP severity. The MIP-1α-induced inflammatory responses in AP were mediated by TNF-α and IL-6, which were associated with the activation of the JNK/p38 MAPK signaling pathway.

All-Trans Retinoic Acid Ameliorates the Early Experimental Cerebral Ischemia-Reperfusion Injury in Rats by Inhibiting the Loss of the Blood-Brain Barrier via the JNK/P38MAPK Signaling Pathway.

All-trans retinoic acid (ATRA) influences the outcomes of cerebral ischemic reperfusion (CIR) injury, but the mechanism remains unclear. The present study aimed to investigate the effects of ATRA on loss of the blood brain barrier (BBB) following CIR and to explore the possible mechanisms. Transient middle cerebral artery occlusion was performed on male SD rats to construct an in vivo CIR model. Neurological deficits, BBB permeability, brain edema, MRI and JNK/P38 MAPK proteins were detected at 24 h following CIR. We demonstrated that ATRA pretreatment could alleviate CIR-induced neurological deficits, increase of BBB permeability, infarct volume, degradation of tight junction proteins, inhibit MMP-9 protein expression and activity. ATRA treatment also reduced the p-P38 and p-JNK protein level. However the protective effect of ATRA on CIR could be reversed by administration of retinoic acid alpha receptor antagonist Ro41-5253. SP600125 and SB203580, which is the JNK/P38 pathway inhibitors has the same protective effect as ATRA. These results indicated that ATRA may inhibit the JNK/P38 MAPK pathway to alleviate BBB disruption and improve CIR outcomes.

PI3K/AKT/JNK/p38 signalling pathway-mediated neural apoptosis in the prefrontal cortex of mice is involved in the antidepressant-like effect of pioglitazone.

Numerous studies have reported that inflammation is involved in the pathophysiology of depression. Pioglitazone, a PPAR-γ agonist, has potential anti-inflammatory and antidepressive effects. However, the underlying molecular mechanisms of the antidepressant-like effect of pioglitazone on an inflammation-related mouse model of depression remain to be fully elucidated. Herein, we aimed to explore the effects of pioglitazone on depressive-like behaviours of mice exposed to lipopolysaccharides (LPS), and elucidate the underlying mechanisms. We assessed behaviour changes of mice pretreated with pioglitazone exposed to LPS. Additionally, neural apoptosis, and the expression of apoptosis-related (cleaved caspase-3, Bax, Bcl-2, cyt c) and signalling proteins (AKT, JNK, p38) were assessed in the prefrontal cortex (PFC) of these mice. Furthermore, we assessed the influence of anisomycin, a JNK/p38 agonist, and LY294002, a PI3K/AKT inhibitor, on the antidepressant-like effect of pioglitazone in mice. We show that pioglitazone pretreatment (20 mg/kg, intragastrically) attenuated LPS-induced (10 ng/µL per site) depressive-like behaviours. GW9662, a PPAR-γ antagonist, significantly blocked the antidepressant-like effect of pioglitazone. Furthermore, at the molecular level, pioglitazone significantly reversed, via PPAR-γ-dependent increase in neural apoptosis in the PFC of mice, accompanied by upregulation of the PI3K/AKT pathway and down-regulation of the JNK/p38 pathway. Moreover, both anisomycin and LY294002 abrogated the antidepressant-like effect of pioglitazone.; In conclusion, our results showed that PI3K/AKT/JNK/p38 signalling pathway-mediated neural apoptosis in the PFC of mice may be involved in the antidepressant-like effect of pioglitazone. This provides novel insights into and therapeutic targets for inflammation-related depression.

Structure-Antiplatelet Activity Relationships of Novel Ruthenium (II) Complexes: Investigation of Its Molecular Targets.

The regulation of platelet function by pharmacological agents that modulate platelet signaling has proven to be a positive approach to the prevention of thrombosis. Ruthenium complexes are fascinating for the development of new drugs, as they possess numerous chemical and biological properties. The present study aims to evaluate the structure-activity relationship (SAR) of newly synthesized ruthenium (II) complexes, TQ-1, TQ-2 and TQ-3 in agonists-induced washed human platelets. Silica gel column chromatography, aggregometry, immunoblotting, NMR, and X-ray analyses were performed in this study. Of the three tested compounds, TQ-3 showed a concentration (1-5 µM) dependent inhibitory effect on platelet aggregation induced by collagen (1 µg/mL) and thrombin (0.01 U/mL) in washed human platelets; however, TQ-1 and TQ-2 had no response even at 250 µM of collagen and thrombin-induced aggregation. TQ-3 was effective with inhibiting collagen-induced ATP release, calcium mobilization ([Ca2+]i) and P-selectin expression without cytotoxicity. Moreover, TQ-3 significantly abolished collagen-induced Lyn-Fyn-Syk, Akt-JNK and p38 mitogen-activated protein kinases (p38 MAPKs) phosphorylation. The compound TQ-3 containing an electron donating amino group with two phenyl groups of the quinoline core could be accounted for by its hydrophobicity and this nature might be the reason for the noted antiplatelet effects of TQ-3. The present results provide a molecular basis for the inhibition by TQ-3 in collagen-induced platelet aggregation, through the suppression of multiple machineries of the signaling pathway. These results may suggest that TQ-3 can be considered a potential agent for the treatment of vascular diseases.