Protective effects of SOCS3 overexpression in high glucose‑induced lung epithelial cell injury through the JAK2/STAT3 pathway

Wogonin upregulates SOCS3 to alleviate the injury in Diabetic Nephropathy by inhibiting TLR4-mediated JAK/STAT/AIM2 signaling pathway

BACKGROUND

Diabetic nephropathy (DN) is a life-threatening renal disease and needs urgent therapies. Wogonin is renoprotective in DN. This study aimed to explore the mechanism of how wogonin regulated high glucose (HG)-induced renal cell injury.

METHODS

Diabetic mice (db/db), control db/m mice, and normal glucose (NG)- or HG-treated human tubule epithelial cells (HK-2) were used to evaluate the levels of suppressor of cytokine signaling 3 (SOCS3), Toll-like receptor 4 (TLR4), inflammation and fibrosis. Lentivirus was used to regulate SOCS3 and TLR4 expressions. After oral gavage of wogonin (10 mg/kg) or vehicle in db/db mice, histological morphologies, blood glucose, urinary protein, serum creatinine values (Scr), blood urea nitrogen (BUN), superoxide dismutase (SOD), glutathione (GSH), and reactive oxygen species (ROS) were assessed. RT-qPCR and Western blot evaluated inflammation and fibrosis-related molecules.

RESULTS

HG exposure induced high blood glucose, severe renal injuries, high serumal Src and BUN, low SOD and GSH, and increased ROS. HG downregulated SOCS3 but upregulated TLR4 and JAK/STAT, fibrosis, and inflammasome-related proteins. Wogonin alleviated HG-induced renal injuries by decreasing cytokines, ROS, Src, and MDA and increasing SOD and GSH. Meanwhile, wogonin upregulated SOCS3 and downregulated TLR4 under HG conditions. Wogonin-induced SOCS3 overexpression directly decreased TLR4 levels and attenuated JAK/STAT signaling pathway-related inflammation and fibrosis, but SOCS3 knockdown significantly antagonized the protective effects of wogonin. However, TLR4 knockdown diminished SOCS3 knockdown-induced renal injuries.

CONCLUSION

Wogonin attenuates renal inflammation and fibrosis by upregulating SOCS3 to inhibit TLR4 and JAK/STAT pathway.

Non-apoptotic programmed cell deaths in diabetic pulmonary dysfunction: the new side of advanced glycation end products

Diabetes mellitus (DM) is a chronic metabolic disorder that affects multiple organs and systems, including the pulmonary system. Pulmonary dysfunction in DM patients has been observed and studied for years, but the underlying mechanisms have not been fully understood. In addition to traditional mechanisms such as the production and accumulation of advanced glycation end products (AGEs), angiopathy, tissue glycation, oxidative stress, and systemic inflammation, recent studies have focused on programmed cell deaths (PCDs), especially the non-apoptotic ones, in diabetic pulmonary dysfunction. Non-apoptotic PCDs (NAPCDs) including autophagic cell death, necroptosis, pyroptosis, ferroptosis, and copper-induced cell death have been found to have certain correlations with diabetes and relevant complications. The AGE-AGE receptor (RAGE) axis not only plays an important role in the traditional pathogenesis of diabetes lung disease but also plays an important role in non-apoptotic cell death. In this review, we summarize novel studies about the roles of non-apoptotic PCDs in diabetic pulmonary dysfunction and focus on their interactions with the AGE-RAGE axis.

DNA methylation at the suppressor of cytokine signaling 3 (SOCS3) gene influences height in childhood

Human height is strongly influenced by genetics but the contribution of modifiable epigenetic factors is under-explored, particularly in low and middle-income countries (LMIC). We investigate links between blood DNA methylation and child height in four LMIC cohorts (n = 1927) and identify a robust association at three CpGs in the suppressor of cytokine signaling 3 (SOCS3) gene which replicates in a high-income country cohort (n = 879). SOCS3 methylation (SOCS3m)-height associations are independent of genetic effects. Mendelian randomization analysis confirms a causal effect of SOCS3m on height. In longitudinal analysis, SOCS3m explains a maximum 9.5% of height variance in mid-childhood while the variance explained by height polygenic risk score increases from birth to 21 years. Children's SOCS3m is associated with prenatal maternal folate and socio-economic status. In-vitro characterization confirms a regulatory effect of SOCS3m on gene expression. Our findings suggest epigenetic modifications may play an important role in driving child height in LMIC.

Chlorinated Organophosphate Flame Retardants Impair the Lung Function via the IL-6/JAK/STAT Signaling Pathway

Toxicological studies have revealed the adverse impacts of organophosphate flame retardants (OPFRs) on the respiratory system, while there is a lack of epidemiological evidence, and information for risk assessment remains insufficient. Herein, we investigated the associations of urinary metabolites of OPFRs with the lung function in 987 adults participating in the U.S. National Health and Nutrition Examination Survey 2011-2012. The elevation of three primary metabolites of chlorinated OPFRs [bis(1,3-dichloro-2-propyl) phosphate (BDCIPP), bis(2-chloroethyl) phosphate (BCEP), and bis(1-chloro-2-propyl) phosphate (BCIPP)] was related to pulmonary dysfunction in a sample-weighted regression model. Each one-unit increase in the log-transformed levels of BDCIPP and BCEP was related to 91.52 and 79.34 mL reductions in the forced vital capacity (FVC). Each one-unit elevation in BCIPP was correlated with 130.86, 153.56, 302.26, and 148.24 mL reductions in forced expiratory volume 1st second (FEV₁), FVC, peak expiratory flow rate (PEF), and forced expiratory flow at 25-75% of FVC (FEF_25-75%), respectively. Then, an adverse outcome pathway (AOP) framework was constructed using the Comparative Toxicogenomics Database, the Toxicity Forecaster, and the GeneCards database. Based on the weight of the evidence, BDCIPP, BCEP, BCIPP, and their parent compounds (TDCIPP, TCEP, and TCIPP) may affect the IL-6/Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway, induce airway remodeling, and impair the lung function. Additionally, tobacco smoke exposure may modify the effects of BDCIPP on the lung function (P_int < 0.05) and affect the IL-6-mediated AOP. These results suggested that chlorinated OPFRs were associated with pulmonary dysfunction via the IL-6/JAK/STAT pathway.

Astaxanthin ameliorates lipopolysaccharide-induced acute lung injury via inhibition of inflammatory reactions and modulation of the SOCS3/JAK2/STAT3 signaling pathways in mice

The results showed that astaxanthin had a protective effect on LPS-induced acute lung injury in mice, and its protective mechanism was through activating the SOCS3/JAK2/STAT3 signaling pathway.

Protective effect of exosomes derived from bone marrow mesenchymal stem cells on rats with diabetic nephropathy and its possible mechanism

OBJECTIVE

To investigate the effect of exosomes derived from bone marrow mesenchymal stem cells (BMMSC-Exos) on diabetic nephropathy (DN) rats and its possible mechanism.

METHODS

Thirty rats were divided into the following three groups of 10 rats each: the NC group (normal rats), the DN group (rats with DN), and the BM group (DN rats injected with BMMSC-Exo). Blood glucose level, renal function, blood lipid level, and plasma viscosity of the rats were detected. Renal tissue morphology was observed using hematoxylin-eosin staining. Expression levels of JAK2 and STAT3 in rats' kidneys were measured by RT-PCR and western blot.

RESULTS

The rats in the DN group had higher levels of blood glucose, blood lipids, and blood viscosity, worse renal function, and lower body weight than those in the NC group (all P<0.05). After treatment with BMMSC-Exos, rats in the BM group had markedly decreased levels of blood glucose, blood lipids, and blood viscosity, improved renal function, and higher body weight compared to those in the DN group (all P<0.05). The renal tissues in the NC group had intact structure, and no hyperplastic or hypertrophic cells were observed. In the DN group, the renal glomerulus and mesangial matrix were abnormal, and the capillary lumen and renal tubule lumen were depressed and blocked, accompanied by interstitial edema. Pathologic changes in the renal glomerulus and tubule in the BM group were less severe than those in the DN group. The DN rats had higher expression levels of JAK2 and STAT3 than normal rats, and the rats treated with BMMSC-Exos had lower levels of JAK2 and STAT3 compared to the DN rats (all P<0.05).

CONCLUSION

BMMSC-Exo can achieve a good therapeutic effect in DN, which may be due to its ability to lower the blood glucose level, improve renal function, and inhibit JAK2/STAT3 expression.

Interleukin-24 as a Pulmonary Target Cytokine in Bronchopulmonary Dysplasia

The proliferation of fetal alveolar type II cells (FATIICs) was impaired in bronchopulmonary dysplasia (BPD), which is modulated by hyperoxia and inflammatory response. Interleukin 24 (IL-24), a cytokine produced by certain cell types, plays an essential role in inflammation and host protection against infection. However, the ability of FATIICs to produce IL-24 remains unclear, and the role of IL-24 in BPD progression is yet to be determined. With reverse transcription quantitative polymerase chain reaction (RT-qPCR) and enzyme-linked immunosorbent assay, the authors evaluated whether FATIICs produce IL-24 in physiological conditions. The authors quantified IL-24 expression in the lungs of newborn rat pups exposed to hyperoxia (70% oxygen) and in FATIICs isolated on embryonic day 19 that were exposed to 95% oxygen or lipopolysaccharide (LPS). The role of IL-24 in FATIICs, cell proliferation, cell apoptosis, and cell cycle were further evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and flow cytometric analysis. Also, they assessed caspase-3 and SOCS3 mRNA in IL-24 siRNA-treated cells by using RT-qPCR. During culture, IL-24 mRNA and protein levels in FATIICs gradually decreased with FATIIC differentiation. IL-24 expression increased significantly in rat lungs exposed to hyperoxia and FATIICs exposed to oxygen or LPS. Recombinant IL-24 enhanced cell proliferation by decreasing the proportion of apoptotic cells and increasing the proportion of cells in the S phase. The IL-24 siRNA-treated cells expressed more caspase-3 mRNA. Furthermore, suppressor of cytokine signaling 3 (SOCS3) mRNA was significantly decreased in rats and FATIICs exposed to oxygen, whereas it dramatically increased in FATIICs exposed to LPS. The IL-24 siRNA-treated cells expressed more SOCS3 mRNA. These studies suggest IL-24 is a pulmonary target cytokine in BPD, and may possibly regulate SOCS3 in oxidative stress and inflammation of the lung.

Quercetin attenuates high glucose-induced injury in human retinal pigment epithelial cell line ARPE-19 by up-regulation of miR-29b

Quercetin is a kind of distinctive bioactive flavonoid that has potent anti-oxidant, anti-inflammatory and anti-diabetic properties. The present article was designed to check the effect of quercetin on diabetic retinopathy. Adult retinal pigment epithelial cell line (ARPE)-19 cells were pre-treated with quercetin and then stimulated by high glucose. Cell damage was evaluated by CCK-8 assay, flow cytometer, quantitative reverse transcriptase polymerase chain reaction (qRT-PCR), enzyme-linked immunosorbent assay, 2,7-dichlorofluorescein diacetate probe and western blot. The association between quercetin and miR-29b expression as well as the downstream pathways was studied by qRT-PCR and western blot. Pre-treating ARPE-19 cells with quercetin clearly attenuated high glucose-induced viability loss, apoptosis, MCP-1 and IL-6 overproduction and reactive oxygen species (ROS) generation. Quercetin down-regulated p53, Bax and cleaved-caspase-3 expression, while up-regulated CyclinD1, CDK4 and Bcl-2. miR-29b was low expressed in high glucose-treated cell, but quercetin elevated its expression. Moreover, the protective action of quercetin towards ARPE-19 cells was attenuated when miR-29b was suppressed. Also, quercetin promoted PTEN/AKT pathway, while inhibited NF-κB pathway via a miR-29b-dependent way. These data illustrated quercetin possibly possess the anti-diabetic retinopathy potential, as quercetin clearly attenuated high glucose-evoked damage in ARPE-19 cells. The protective action of quercetin may due to its regulation on miR-29b expression as well as PTEN/AKT and NF-κB pathways.

SOCS3-microtubule interaction via CLIP-170 and CLASP2 is critical for modulation of endothelial inflammation and lung injury

Proinflammatory cytokines such as IL-6 induce endothelial cell (EC) barrier disruption and trigger an inflammatory response in part by activating the Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway. The protein suppressor of cytokine signaling-3 (SOCS3) is a negative regulator of JAK-STAT, but its role in modulation of lung EC barrier dysfunction caused by bacterial pathogens has not been investigated. Using human lung ECs and EC-specific SOCS3 knockout mice, we tested the hypothesis that SOCS3 confers microtubule (MT)-mediated protection against endothelial dysfunction. SOCS3 knockdown in cultured ECs or EC-specific SOCS3 knockout in mice resulted in exacerbated lung injury characterized by increased permeability and inflammation in response to IL-6 or heat-killed Staphylococcus aureus (HKSA). Ectopic expression of SOCS3 attenuated HKSA-induced EC dysfunction, and this effect required assembled MTs. SOCS3 was enriched in the MT fractions, and treatment with HKSA disrupted SOCS3-MT association. We discovered that-in addition to its known partners gp130 and JAK2-SOCS3 interacts with MT plus-end binding proteins CLIP-170 and CLASP2 via its N-terminal domain. The resulting SOCS3-CLIP-170/CLASP2 complex was essential for maximal SOCS3 anti-inflammatory effects. Both IL-6 and HKSA promoted MT disassembly and disrupted SOCS3 interaction with CLIP-170 and CLASP2. Moreover, knockdown of CLIP-170 or CLASP2 impaired SOCS3-JAK2 interaction and abolished the anti-inflammatory effects of SOCS3. Together, these findings demonstrate for the first time an interaction between SOCS3 and CLIP-170/CLASP2 and reveal that this interaction is essential to the protective effects of SOCS3 in lung endothelium.

Suppressors of cytokine signaling (SOCS) proteins in inflammatory bone disorders

Suppressor of cytokine signaling (SOCS) proteins are significant regulators of cellular immune responses. Therefore, the role of SOCS in bone-inflammatory disorders, including arthritis and periodontitis, has been investigated in experimental and clinical conditions. Recent evidence shows that SOCS proteins are expressed in major bone-related cells, including osteoblasts, osteoclasts, chondrocytes and synoviocytes, although their direct role in these cells is not fully described. These signaling molecules, especially SOCS1, 2 and 3, were shown to play critical roles in the control of bone resorption associated to inflammation. This review focuses on the involvement of SOCS proteins in inflammatory bone remodeling, including their direct and indirect role in the control of osteoclast hyperactivation, during arthritis and periodontitis. The description of the roles of SOCS proteins in inflammatory bone diseases highlights the pathways involved in the pathophysiology of these conditions and, thus, may contribute to the development and improvement of potential therapeutic interventions.

Adoptive transfer of bone marrow-derived dendritic cells (BMDCs) alleviates OVA-induced allergic airway inflammation in asthmatic mice

Airway dendritic cells (DCs) are recognized as important factors in the mechanisms of allergic inflammatory diseases. Suppressor of cytokine signaling 3 (SOCS3) is involved in regulating the functions of T cells and macrophages, but the roles of SOCS3-expressing DCs in the pathogeneses of allergic inflammatory diseases are still controversial. We compared the effects of adoptively transferred SOCS3-/- and SOCS3+/+ bone marrow-derived DCs (BMDCs) on airway inflammation in ovalbumin (OVA)-sensitized asthmatic mice. Adoptive transfer of mature DCs (lipopolysaccharide [LPS]-induced DCs, DClps) with or without SOCS3 gene expression significantly ameliorated allergic airway inflammation. SOCS3-/- DCs slightly attenuated BMDC-induced immunogenic tolerance. DClps migrated to OVA-sensitized lungs with higher efficiency than immature DCs (DCim). DClps with or without SOCS3 greatly improved lung pathology scores and alleviated airway inflammatory cell infiltration after adoptive transfer into mice; they also increased interleukin-10 (IL-10) and transforming growth factor-β (TGF-β) production and inhibited signal transducer and activator of transcription (STAT) 4 and STAT6 signaling in the lungs after OVA sensitization. In conclusion, the BMDC adoptive transfer-induced immunogenic tolerance in OVA-sensitized mice might not be due to SOCS3 gene depletion. BMDC adoptive transfer may be developed into a new approach that alleviates asthma by modulating the balance between immune tolerance and inflammation.

Chimeric Peptidomimetics of SOCS 3 Able to Interact with JAK2 as Anti-inflammatory Compounds

The immunomodulatory effects of Suppressor of Cytokine Signaling (SOCS) proteins, that control the JAK/STAT pathway, indicate them as attractive candidates for immunotherapies. Recombinant SOCS3 protein suppresses the effects of inflammation, and its deletion in neurons or in immune cells increases pathological blood vessels growth. Recently, on the basis of the structure of the ternary complex among SOCS3, JAK2, and gp130, we focused on SOCS3 interfacing regions and designed several interfering peptides (IPs) that were able to mimic SOCS3 biological role in triple negative breast cancer (TNBC) models. Herein, to explore other protein regions involved in JAK2 recognition, several new chimeric peptides connecting noncontiguous SOCS3 regions and including a strongly aromatic fragment were investigated. Their ability to recognize the catalytic domain of JAK2 was evaluated through MST (microscale thermophoresis), and the most promising compound, named KIRCONG chim, exhibited a low micromolar value for dissociation constant. The conformational features of chimeric peptides were analyzed through circular dichroism and NMR spectroscopies, and their anti-inflammatory effects were assessed in cell cultures. Overall data suggest the importance of aromatic contribution in the recognition of JAK2 and that SOCS3 peptidomimetics could be endowed with a therapeutic potential in diseases with activated inflammatory cytokines.

Smad3 signalling affects high glucose-induced podocyte injury via regulation of the cytoskeletal protein transgelin

Aim

The aim of the present study was to characterize the role of Smad3 signalling on high glucose‐induced podocyte injury.

Methods

Synchronized conditionally immortalized mouse podocyte cell line (MPC5) cells were treated with either D‐glucose alone or D‐glucose plus the Smad3 inhibitor SIS3. The distribution of F‐actin and transgelin in a high glucose‐induced model of podocyte injury were examined by immunofluorescence. Levels of transgelin and Smad3 signalling proteins in MPC5 cells were determined by Western blot.

Results

A disordered distribution of F‐actin, as well as co‐localization of F‐actin and transgelin, was observed in podocytes exposed to high glucose. Increased levels of transgelin were first observed 10 minutes after treatment with glucose, suggesting that this protein is sensitive to hyperglycaemic injury. Levels of phosphorylated Smad3 and cleaved caspase 3 increased significantly with glucose stimulation. Moreover, expression of the downstream protein c‐Myc, but not JAK1/STAT3, was induced in conditions of high glucose. The Smad3‐specific inhibitor SIS3 prevented the effects of high glucose on Smad3 phosphorylation, expression of transgelin and c‐Myc, caspase 3 cleavage and cytoskeletal organization. Expression of the tumour suppressor protein p15^INK4B increased after podocyte injury but was unaffected by Smad3 inhibition, suggesting that Smad3 regulation of high glucose‐induced podocyte injury occurs through a p15^INK4B‐independent mechanism.

Conclusion

Smad3 signalling plays a critical role in the modulation of hyperglycaemic injury. Targeted inhibition of the Smad3 pathway may offer a novel route for treatment of podocyte damage, especially in cases of diabetic nephropathy.

Podocyte damage is characteristic of diabetic kidney disease. This study showed that inhibition of Smad‐3 signalling using the specific inhibitor SIS3 in vitro, could alleviate podocyte abnormalities induced by high glucose including actin cytoskeletal rearrangement and actviation of cell death pathways.

HIF1α inhibits LPS-mediated induction of IL-6 synthesis via SOCS3-dependent CEBPβ suppression in human dental pulp cells

Hypoxia-inducible factor 1 alpha (HIF1α) is a transcriptional factor that plays a key role in the regulation of various molecules expressed in hypoxic conditions. Ischemic/hypoxic conditions are regarded as a distinct characteristic of dental pulp inflammation due to the encasement of pulp tissue within the rigid tooth structure. This study was performed to examine the role of HIF1α in the regulation of interleukin (IL)-6, a proinflammatory cytokine expressed in inflamed dental pulp, in lipopolysaccharide (LPS)-stimulated human dental pulp cells (hDPCs). LPS stimulation promoted the expression of IL-6 in hDPCs, while HIF1α suppressed the expression of IL-6. Moreover, HIF1α induced suppressor of cytokine signaling 3 (SOCS3) expression in LPS-stimulated hDPCs, and SOCS3 activity led to downregulate expression of CCAAT enhancer-binding protein beta (CEBPβ), an inducer of IL-6. LPS stimulation promoted HIF1α expression in hDPCs and mouse pulp tissue explants cultured under hypoxic conditions. These findings suggest that HIF1α negatively regulates IL-6 synthesis in LPS-stimulated hDPCs via upregulation of SOCS3 and subsequent downregulation of CEBPβ.

Increased expression of STAT3 and SOCS3 in placenta from hyperglycemic rats

Signal transducer and activator of transcription 3 (STAT3) is a transcription factor that is activated by interleukin (IL)-6 and IL-10 that generate nearly opposing responses. The suppressor of cytokine signaling 3 (SOCS3) is the negative regulator of STAT3 and plays an important role in the negative regulation of the inflammatory process. Evidence has shown the importance of STAT3 and SOCS3 during implantation and normal pregnancy. However, little is known about the relationship of both factors under hyperglycemic condition. The aim of this study was to evaluate the placenta regions exhibiting immunopositivity for STAT3 and SOCS3 in hyperglycemic rats, as well as correlate these proteins with IL-10 and IL-6 levels. It was observed increased expression of STAT3 at the labyrinth (approximately 47% of increase compared to control) and junctional zone (approximately 32% of increase compared to control) from hyperglycemic placentas. Similar results were observed to SOCS3 (approximately 71% -labyrinth- and 53% -junctional zone- of increase compared to control). The levels of IL-10 were augmented at hyperglycemic placentas (approximately 1.5 fold of increase) and they were positively correlated with the increase of STAT3 at the labyrinth and SOCS at junctional zone. Therefore, under hyperglycemic conditions, the relation between STAT3 and SOCS3 was changed, leading to unbalance of the cytokine profile.

Gas6/Axl signaling attenuates alveolar inflammation in ischemia-reperfusion-induced acute lung injury by up-regulating SOCS3-mediated pathway

Background

Axl is a cell surface receptor tyrosine kinase, and activation of the Axl attenuates inflammation induced by various stimuli. Growth arrest-specific 6 (Gas6) has high affinity for Axl receptor. The role of Gas6/Axl signaling in ischemia-reperfusion-induced acute lung injury (IR-ALI) has not been explored previously. We hypothesized that Gas6/Axl signaling regulates IR-induced alveolar inflammation via a pathway mediated by suppressor of cytokine signaling 3 (SOCS3).

Methods

IR-ALI was induced by producing 30 min of ischemia followed by 90 min of reperfusion in situ in an isolated and perfused rat lung model. The rats were randomly allotted to a control group and IR groups, which were treated with three different doses of Gas6. Mouse alveolar epithelium MLE-12 cells were cultured in control and hypoxia-reoxygenation (HR) conditions with or without Gas6 and Axl inhibitor R428 pretreatment.

Results

We found that Gas6 attenuated IR-induced lung edema, the production of proinflammatory cytokines in perfusates, and the severity of ALI ex vivo. IR down-regulated SOCS3 expression and up-regulated NF-κB, and Gas6 restored this process. In the model of MLE-12 cells with HR, Gas6 suppressed the activation of TRAF6 and NF-κB by up-regulating SOCS3. Axl expression of alveolar epithelium was suppressed in IR-ALI but Gas6 restored phosphorylation of Axl. The anti-inflammatory effect of Gas6 was antagonized by R428, which highlighted that phosphorylation of Axl mediated the protective role of Gas6 in IR-ALI.

Conclusions

Gas6 up-regulates phosphorylation of Axl on alveolar epithelium in IR-ALI. The Gas6/Axl signaling activates the SOCS3-mediated pathway and attenuates IR-related inflammation and injury.

Nonylphenol attenuates SOCS3 expression and M1 polarization in lipopolysaccharide-treated rat splenic macrophages

Endocrine disruptors interfere with normal sexual and reproductive development of numerous organisms. Widely used in several chemical and manufacturing industries, nonylphenol (NP), a potent xenoestrogen, has the potential to perturb immune system. Using rat splenic macrophages (SMΦ) as the model system, NP-modulation of lipopolysaccharide (LPS)-induced inflammatory response has been investigated. Our results demonstrate that NP (0.1-10 µM) attenuates catalase activity, reactive oxygen species (ROS) generation and nitric oxide (NO) synthesis in LPS-treated SMΦ in vitro. NP inhibition of LPS-induced nuclear factor kappa B (NF-κB) activation and pro-inflammatory cytokine gene expression corroborate well with attenuation of suppressor of cytokine signalling 3 (SOCS3). Besides, elevated expression of anti-inflammatory factors reveals inverse correlation with suppression of endotoxin-induced M1 polarization in NP pre-incubated cells. While LPS promotes, NP prevents ERK1/2 (extracellular-signa1-regulated kinase 1/2) phosphorylation and MEK-inhibitor abrogates SOCS3 expression and NO production suggesting involvement of ERK1/2 in NP inhibition of SOCS3 expression. Further, translational inhibitor cycloheximide prevents LPS-induced NF-κB activation indicating functional importance of de novo synthesis of SOCS3, at least in part, in toll-like receptor 4 (TLR4)-mediated inflammatory response. Collectively, present study provides evidence favouring participation of SOCS3 in NP modulation of inflammatory response in rat SMΦ.

MiR-455-5p ameliorates HG-induced apoptosis, oxidative stress and inflammatory via targeting SOCS3 in retinal pigment epithelial cells

Diabetic retinopathy (DR) remains the leading cause of blindness in adults with diabetes mellitus. Numerous microRNAs (miRNAs) have been identified to modulate the pathogenesis of DR. The main purpose of this study was to evaluate the potential roles of miR-455-5p in high glucose (HG)-treated retinal pigment epithelial (RPE) cells and underlying mechanisms. Our present investigation discovered that the expression of miR-455-5p was apparently downregulated in ARPE-19 cells stimulated with HG. In addition, forced expression of miR-455-5p markedly enhanced cell viability and restrained HG-induced apoptosis accompanied by decreased BCL2-associated X protein (Bax)/B-cell leukemia/lymphoma 2 (Bcl-2) ratio and expression of apoptotic marker cleaved caspase-3 during HG challenged. Subsequently, augmentation of miR-455-5p remarkably alleviated HG-triggered oxidative stress injury as reflected by decreased the production of intracellular reactive oxygen species (ROS) and malondialdehyde (MDA) content as well as NADPH oxidase 4 expression, concomitant with enhanced the activities of superoxide dismutase, catalase, and GPX stimulated with HG. Furthermore, enforced expression of miR-455-5p effectively ameliorated HG-stimulated inflammatory response as exemplified by repressing the secretion of inflammatory cytokines interleukin 1β (IL-1β), IL-6, and tumour necrosis factor-α in ARPE-19 cells challenged by HG. Most importantly, we successfully identified suppressor of cytokine signaling 3 (SOCS3) as a direct target gene of miR-455-5p, and miR-455-5p negatively regulated the expression of SOCS3. Mechanistically, restoration of SOCS3 abrogated the beneficial effects of miR-455-5p on apoptosis, accumulation of ROS, and inflammatory factors production in response to HG. Taken together, these findings demonstrated that miR-455-5p relieved HG-induced damage through repressing apoptosis, oxidant stress, and inflammatory response by targeting SOCS3. The study gives evidence that miR-455-5p may serve as a new potential therapeutic agent for DR treatment.

Systematic analysis of gene expression alterations and clinical outcomes of STAT3 in cancer

Accumulated studies have provided controversial evidences of prognostic value for signal transducer and activator of transcription proteins 3 (STAT3) in cancers. To address this inconsistency, we performed a systematic analysis to determine whether STAT3 can serve as a prognostic marker in human cancers. STAT3 expression was assessed using Oncomine analysis. cBioPortal, Kaplan-Meier Plotter, and Prognoscan were performed to identify the prognostic roles of STAT3 in human cancers. The copy number alteration, mutation, interactive analysis, and visualize the altered networks were performed by cBioPortal. We found that STAT3 was more frequently overexpressed in lung, ovarian, gastric, blood and brain cancers than their normal tissues and its expression might be negatively related with the prognosis. In addition, STAT3 mutation mainly occurred in uterine cancer and existed in a hotspot in SH2 domain. Those findings suggest that STAT3 might serve as a diagnostic and therapeutic target for certain types of cancer, such as lung, ovarian, gastric, blood and brain cancers. However, future research is required to validate our findings and thus promote the clinical utility of STAT3 in those cancers prognosis evaluation.