JAK2/STAT3 pathway is involved in the protective effects of epidermal growth factor receptor activation against cerebral ischemia/reperfusion injury in rats. Neurosci Lett. 2018;662:219-226. [PMID: 29061394 DOI: 10.1016/j.neulet.2017.10.037]

Evaluation of neuropathy in epidermal growth factor administered patients diagnosed with diabetic foot

AIM

This study was conducted to evaluate the effect of epidermal growth factor administered to patients diagnosed with diabetic foot on neuropathy. Secondarily, the effect of EGF on foot ulcer and neuropathic pain has also been evaluated.

MATERIALS AND METHODS

The study is an analytical type study with a single-group pretest-posttest quasi-experimental design. It was conducted with 30 patients diagnosed with Type 1 and Type 2 Diabetes who applied to the wound care unit and cardiovascular surgery outpatient clinic at Pamukkale University Hospitals between March 2021 and November 2022. By not using the sampling method, all patients who received EGF in the units were reached. Data were collected by "structured patient information form", "SINBAD classification", and "LANSS pain scale." Data were obtained as a "pretest" before the administration of epidermal growth factor (EGF), and as a "posttest" applied one month after the completion of EGF administration. Data were analyzed with Wilcoxon, Mann-Whitney U, Kruskal-Wallis H, Spearman's Rank Correlation, Mc Nemar, and Chi-Square Tests.

FINDINGS

It was observed that the average age of individuals with diabetic foot ulcer was 60.1 ± 12.9, 40 % were obese/morbidly obese, 83.3 % were male, and 43.3 % were treated with insulin + oral antidiabetic. It was determined that the number of years with diabetes was 17.37 ± 10.93 years, and the duration of diabetic foot ulcer was 218.83 ± 279.04 days. 46.7 % of the participants were determined to have a previous foot wound, and 33.3 % had a history of amputation in the past. Neuropathy was present in 100 % of the participants in the pre-test, while it was found to be 56.7 % in the post-test. The participants with neuropathy were observed to have a significantly higher SINBAD classification and LANSS pain scale scores: (p = 0,01; p = .00). HbA1c, SINBAD, and LANSS scores decreased significantly after EGF (p = 0,00; p = .01; p = .01). EGF administration was observed to have a statistically significant positive effect on neuropathy (p < .01).

RESULTS

EGF administration was observed to have a positive effect on the healing of foot ulcers, the reduction of neuropathic pain, and on neuropathy in patients diagnosed with diabetic foot.

Electro-acupuncture Suppresses Ferroptosis to Alleviate Cerebral Ischemia-Reperfusion Injury Through KAT3B-Mediated Succinylation of ACSL4

Electro-acupuncture (EA) is identified as an effective therapeutic method for cerebral ischemia/reperfusion injury (CIRI), which is a combination of Chinese traditional acupuncture and modern electro-therapy. However, the downstream molecular mechanisms of EA in CIRI process remains largely unknown. The purpose of the present study is to unveil the therapeutic effect of EA on CIRI rat and its regulatory mechanisms. At first, we constructed middle cerebral artery occlusion (MCAO) rat models and then treated them with EA to observe the pathological changes. The results indicated that EA decreased the infarct volume (43.81 ± 3.34 vs 15.96 ± 2.22) and the neurological scores (3.33 ± 0.52 vs 1.67 ± 0.52) and suppressed the apoptosis in MCAO model rats. For ferroptosis analysis, EA decreased the Fe2 + (0.08 ± 0.01 vs 0.06 ± 0.01), MDA (36.61 ± 4.29 vs 21.72 ± 2.79), and LPS (5.25 ± 0.69 vs 2.89 ± 0.42) contents and increased the GSH (4.94 ± 1.04 vs 11.69 ± 1.88) content in MCAO model rats. We next detected whether succinylation mediated EA-treated I/R injury. According to immunoprecipitation and western blot analysis, EA treatment could lower both levels of succinylation and KAT3B in MCAO rats. Moreover, mechanism experiments unveiled that KAT3B promoted the succinylation of the ferroptosis-related protein ACSL4 at K661 site and thus stabilizing ACSL4. Finally, EA-treated MCAO rats were further injected with KAT3B expression vector. The results showed that KAT3B overexpression increased the infarct volume (31.44 ± 3.92 vs 7.94 ± 2.84) and the neurological scores (2.67 ± 0.51 vs 1.33 ± 0.51) and promoted the apoptosis in EA treated MCAO model rats. For ferroptosis analysis, KAT3B overexpression increased the Fe2 + (0.08 ± 0.01 vs 0.05 ± 0.01), MDA (29.24 ± 4.30 vs 22.06 ± 1.89), and LPO (5.07 ± 0.45 vs 2.88 ± 0.49) contents and decreased the GSH (7.86 ± 1.09 vs 11.06 ± 1.76) content in EA treated MCAO model rats. Collectively, our study demonstrates that EA plays a therapeutic role in CIRI through suppressing KAT3B-induced stabilization of ACSL4 to inhibit ferroptosis. These findings contribute to our understanding of the molecular mechanisms underlying the neuroprotective effects of EA and open new avenues for the development of innovative therapeutic strategies for CIRI.

Molecular network mechanism in cerebral ischemia-reperfusion rats treated with human urine stem cells

Objective

To explore the effect of human urine-derived stem cells (husc) in improving the neurological function of rats with cerebral ischemia-reperfusion (CIR), and report new molecular network by bioinformatics, combined with experiment validation.

Methods

After CIR model was established, and husc were transplanted into the lateral ventricle of rats，neurological severe score (NSS) andgene network analysis were performed. Firstly, we input the keywords "Cerebral reperfusion" and "human urine stem cells" into Genecard database and merged data with findings from PubMed so as to get their targets genes, and downloaded them to make Venny intersection plot. Then, Gene ontology (GO) analysis, kyoto encyclopedia of genes and genomes (KEGG) pathway analysis and protein-protein interaction (PPI) were performed to construct molecular network of core genes. Lastly, the expressional level of core genes was validated via quantitative real-time polymerase chain reaction (qRT-PCR), and localized by immunofluorescence.

Results

Compared with the Sham group, the neurological function of CIR rats was significantly improved after the injection of husc into the lateral ventricle; at 14 days, P = 0.028, which was statistically significant. There were 258 overlapping genes between CIR and husc, and integrated with 252 genes screened from PubMed and CNKI. GO enrichment analysis were mainly involved neutrophil degranulation, neutrophil activation in immune response and platelet positive regulation of degranulation, Hemostasis, blood coagulation, coagulation, etc. KEGG pathway analysis was mainly involved in complement and coagulation cascades, ECM-receptor. Hub genes screened by Cytoscape consist ofCD44, ACTB, FN1, ITGB1, PLG, CASP3, ALB, HSP90AA1, EGF, GAPDH. Lastly, qRT-PCR results showed statistic significance (P < 0.05) in ALB, CD44 and EGF before and after treatment, and EGF immunostaining was localized in neuron of cortex.

Conclusion

husc transplantation showed a positive effect in improving neural function of CIR rats, and underlying mechanism is involved in CD44, ALB, and EGF network.

IL-22 relieves hepatic ischemia-reperfusion injury by inhibiting mitochondrial apoptosis based on the activation of STAT3

INTRODUCTION

Interleukin-22 (IL-22) has been proven to exhibit a protective role in hepatic ischemia-reperfusion injury (HIRI). This study aimed to explore the change of IL-22 and IL-22 receptor 1 (IL-22R1) axis in HIRI and its role in mitochondrial apoptosis associated with STAT3 activation.

MATERIALS AND METHODS

I/R mice were examined for the expression of IL-22, IL-22R1 and IL-22BP. The roles of IL-22 in hepatic histopathology and oxidative stress injuries (ALT, MDA and SOD) were determined. Oxidative stress damages of AML-12 cells were induced by H2O2, and were indicated by apoptosis, Ca2+ concentration, and mitochondrial function. The effects of IL-22 on p-STAT3Try705 were analyzed.

RESULTS

We found that the expression of IL-22, IL-22R1, and IL-22BP was elevated 24 h after I/R induction, while decreased 48 h after I/R induction. Furthermore, we also discovered that IL-22 rescued the morphological damages and dysfunction of hepatocytes induced by H2O2, which were antagonized by IL-22BP, an endogenous antagonist of IL-22. Additionally, increased levels of Ca2+ concentration, MDA, ROS, apoptosis and mitochondrial dysfunction were noticed in H2O2-treated hepatocytes. However, IL-22 ameliorated the effects of I/R or H2O2. The protective effects of IL-22 were reversed by AG490, a specific antagonist of STAT3.

CONCLUSIONS

In conclusion, our results indicated that IL-22 inhibited I/R-induced oxidative stress injury, Ca2+ overload, and mitochondrial apoptosis via STAT3 activation.

Delayed recanalization reduced neuronal apoptosis and neurological deficits by enhancing liver-derived trefoil factor 3-mediated neuroprotection via LINGO2/EGFR/Src signaling pathway after middle cerebral artery occlusion in rats

Delayed recanalization at days or weeks beyond the therapeutic window was shown to improve functional outcomes in acute ischemic stroke (AIS) patients. However, the underlying mechanisms remain unclear. Previous preclinical study reported that trefoil factor 3 (TFF3) was secreted by liver after cerebral ischemia and acted a distant neuroprotective factor. Here, we investigated the liver-derived TFF3-mediated neuroprotective mechanism enhanced by delayed recanalization after AIS. A total of 327 male Sprague-Dawley rats and the model of middle cerebral artery occlusion (MCAO) with permanent occlusion (pMCAO) or with delayed recanalization at 3 d post-occlusion (rMCAO) were used. Partial hepatectomy was performed within 5 min after MCAO. Leucine-rich repeat and immunoglobulin-like domain-containing nogo receptor-interacting protein 2 (LINGO2) siRNA was administered intracerebroventricularly at 48 h after MCAO. Recombinant rat TFF3 (rr-TFF3, 30 μg/Kg) or recombinant rat epidermal growth factor (rr-EGF, 100 μg/Kg) was administered intranasally at 1 h after recanalization, and EGFR inhibitor Gefitinib (75 mg/Kg) was administered intranasally at 30 min before recanalization. The evaluation of outcomes included neurobehavior, ELISA, western blot and immunofluorescence staining. TFF3 in hepatocytes and serum were upregulated in a similar time-dependent manner after MCAO. Compared to pMCAO, delayed recanalization increased brain TFF3 levels and attenuated brain damage with the reduction in neuronal apoptosis, infarct volume and neurological deficits. Partial hepatectomy reduced TFF3 levels in serum and ipsilateral brain hemisphere, and abolished the benefits of delayed recanalization on neuronal apoptosis and neurobehavioral deficits in rMCAO rats. Intranasal rrTFF3 treatment reversed the changes associated with partial hepatectomy. Delayed recanalization after MCAO increased the co-immunoprecipitation of TFF3 and LINGO2, as well as expressions of p-EGFR, p-Src and Bcl-2 in the brain. LINGO2 siRNA knockdown or EGFR inhibitor reversed the effects of delayed recanalization on apoptosis and brain expressions of LINGO2, p-EGFR, p-Src and Bcl-2 in rMCAO rats. EGFR activator abolished the deleterious effects of LINGO2 siRNA. In conclusion, our investigation demonstrated for the first time that delayed recanalization may enhance the entry of liver-derived TFF3 into ischemic brain upon restoring blood flow after MCAO, which attenuated neuronal apoptosis and neurological deficits at least in part via activating LINGO2/EGFR/Src pathway.

Procyanidins Alleviated Cerebral Ischemia/Reperfusion Injury by Inhibiting Ferroptosis via the Nrf2/HO-1 Signaling Pathway

Procyanidins (PCs), which are organic antioxidants, suppress oxidative stress, exhibit anti-apoptotic properties, and chelate metal ions. The potential defense mechanism of PCs against cerebral ischemia/reperfusion injury (CIRI) was investigated in this study. Pre-administration for 7 days of a PC enhanced nerve function and decreased cerebellar infarct volume in a mouse middle cerebral artery embolization paradigm. In addition, mitochondrial ferroptosis was enhanced, exhibited by mitochondrial shrinkage and roundness, increased membrane density, and reduced or absent ridges. The level of Fe²⁺ and lipid peroxidation that cause ferroptosis was significantly reduced by PC administration. According to the Western blot findings, PCs altered the expression of proteins associated with ferroptosis, promoting the expression of GPX4 and SLC7A11 while reducing the expression of TFR1, hence inhibiting ferroptosis. Moreover, the treatment of PCs markedly elevated the expression of HO-1 and Nuclear-Nrf2. The PCs' ability to prevent ferroptosis due to CIRI was decreased by the Nrf2 inhibitor ML385. Our findings showed that the protective effect of PCs may be achieved via activation of the Nrf2/HO-1 pathway and inhibiting ferroptosis. This study provides a new perspective on the treatment of CIRI with PCs.

Network pharmacology-based prediction and validation of the active ingredients and potential mechanisms of the Huangxiong formula for treating ischemic stroke

ETHNOPHARMACOLOGICAL RELEVANCE

Huangxiong Formula (HXF) is composed of four herbs: Rheum palmatum L., Ligusticum striatum DC., Curcuma aromatica Salisb., and Acorus gramineus Aiton. HXF is clinically used for the treatment of ischemic stroke (IS). However, its molecular mechanism remains unclear.

AIM OF THE STUDY

A network pharmacology-based strategy combined with experimental study in vivo and in vitro to were used to investigate the bioactive components, potential targets, and molecular mechanisms of HXF in the treatment of IS.

MATERIALS AND METHODS

The components of HXF were detected by ultra-performance liquid chromatography (UPLC). The potential active ingredients of HXF were acquired from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP) and literature, and corresponding targets were discerned through the Swiss TargetPrediction database. IS-related targets were obtained from Genecards, Online Mendelian Inheritance in Man (OMIM), Therapeutic Target Database (TTD), and DisGeNET. The intersection of ingredient and disease targets was screened, and a herbal-compound-target network was constructed. A protein-protein interaction (PPI) network was created, and Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed. Based on these analyses, we established a compound-target-pathway (C-T-P) network. A cerebral ischemia-reperfusion (I/R) animal model was established, and the cerebral protective effect of HXF was assessed. The accuracy of the predicted targets was verified by real-time quantitative polymerase chain reaction (RT-qPCR). Hippocampal neuronal injury cell model induced by oxygen-glucose deprivation and reperfusion (OGD/R) was used to evaluate the protective effect of α-Asarone. Furthermore, molecular docking, drug affinity responsive target stability (DARTS) assay, and cellular thermal shift assay (CETSA) were performed to verify whether α-Asarone can bind to PI3K.

RESULTS

A total of 44 active ingredients and 795 gene targets were identified through network pharmacology. Network analysis showed that naringenin, eupatin, kaempferol, and α-Asarone were possible drug candidates. SRC, AKT1, TP53, MAPK3, STAT3, HRAS, CTNNB1, EGFR, VEGFA, PIK3R1 could serve as potential drug targets. KEGG analysis implied that the PI3K/AKT signaling pathway might play an important role in treating IS by HXF. Moreover, HXF significantly reduced neurological impairment, cerebral infarct volume, brain index, and brain histopathological damage in I/R rats. The mRNA expression of the top 10 potential targets was verified in the brain tissue. The C-T-P network and UPLC analysis suggested that α-Asarone might be an important component of HXF and can inhibit oxidative stress and apoptosis in HT22 cells by activating the PI3K/AKT signaling pathway. Molecular docking, DARTS, and CETSA assay analysis confirmed that there were direct interactions between α-Asarone and PI3K.

CONCLUSION

HXF had a therapeutic effect in IS with multi-component, multi-target, and multi-approach features. α-Asarone, identified as one of the major active components of HXF, could alleviate oxidative stress and apoptosis by targeting PI3K/AKT pathway.

Pterostilbene Ameliorates Fumonisin B1-Induced Cytotoxic Effect by Interfering in the Activation of JAK/STAT Pathway

Fumonisin B1 (FB1) is a mycotoxin that poses a great threat to agricultural production and the health of humans and animals. Pterostilbene (PTE) is a natural plant polyphenolic compound with good anti-inflammatory, antioxidant and cell regeneration effects, yet its effectiveness in treating FB1-induced cytotoxicity remains to be explored. In this study, we used porcine alveolar macrophages (3D4/21) as a model to characterize the cytotoxicity induced by FB1, and to investigate the potential alleviating effect of PTE on FB1-induced cytotoxicity. We demonstrate that FB1 induces cytotoxicity, apoptosis, pro-inflammatory cytokine production and mitochondrial damage, which can be largely recovered by PTE treatment, suggesting the promising application of PTE to treat FB1-induced damage. Mechanistically, FB1 activates the JAK/STAT signaling pathway, while PTE attenuates FB1-induced cytotoxicity through the inhibition of key JAK/STAT genes such as JAK2 and STAT3. Overall, our study characterized the molecular mechanism for FB1-induced cytotoxicity and found PTE to be a promising component which can alleviate FB1-induced cytotoxicity by interfering in the activation of JAK/STAT pathway.

Pathological Changes and Expression of JAK-STAT Signaling Pathway Hallmark Proteins in Rat Retinas at Different Time Points After Retinal Ischemia Reperfusion Injury

Retinal ischemia reperfusion injury (RIRI) is a conventional pathological process in various retinal vascular diseases. Many studies select only one specific time point to apply drugs and then assess the therapeutic effect of drugs; however, the baselines are not the same at different time points, which may cause variation in the judgement. Therefore, further investigation is needed. Accordingly, this study aimed to investigate the pathological changes of retinal structure, expression of JAK-STAT signaling pathway hallmark proteins, and apoptosis at different time points after retinal ischemia reperfusion injury in rats. Sixty-six male SPF Sprague-Dawley rats were randomly divided into six groups: control group, RIRI 0, 6-, 24-, 72-, and 144-h groups. RIRI models were induced by perfusing equilibrium solution into the right eye anterior chamber to increase intraocular pressure to 110 mmHg for 60 min. Rats were sacrificed at different time points after reperfusion. Then hematoxylin-eosin staining, transmission electron microscope, immunohistochemistry, western blot, and TUNEL were used. Hematoxylin-eosin showed the pathological changes while transmission electron microscope revealed the ultra-structure changes of retina after RIRI. Immunohistochemistry showed that JAK2, STAT3, p-JAK2, p-STAT3, Bax, and Bcl-2 proteins mainly located in ganglion cell layer and inner nuclear layer, the relative expression of former five proteins had significant differences vs. control group (p < 0.05), while Bcl-2 had no significant difference. In western blot, the protein expressing of JAK2, STAT3, p-JAK2, p-STAT3, p-Akt, and Bax had significant differences vs. control group (p < 0.05), while Akt and Bcl-2 had no significant differences. TUNEL staining showed the number of apoptosis positive cells rose initially but declined later, with a peak value at RIRI 24 h group. The dynamic changes of hallmark proteins at different time points after RIRI indicate that JAK-STAT signaling pathway activates rapidly but weakens later and plays a vital role in RIRI, and apoptosis is involved in RIRI with a peak value at 24 h in the process, suggesting a potential therapeutic direction and time window for treating RIRI.

Role of Phytoconstituents as PPAR Agonists: Implications for Neurodegenerative Disorders

Peroxisome proliferator-activated receptors (PPAR-γ, PPAR-α, and PPAR-β/δ) are ligand-dependent nuclear receptors that play a critical role in the regulation of hundreds of genes through their activation. Their expression and targeted activation play an important role in the treatment of a variety of diseases, including neurodegenerative, cardiovascular, diabetes, and cancer. In recent years, several reviews have been published describing the therapeutic potential of PPAR agonists (natural or synthetic) in the disorders listed above; however, no comprehensive report defining the role of naturally derived phytoconstituents as PPAR agonists targeting neurodegenerative diseases has been published. This review will focus on the role of phytoconstituents as PPAR agonists and the relevant preclinical studies and mechanistic insights into their neuroprotective effects. Exemplary research includes flavonoids, fatty acids, cannabinoids, curcumin, genistein, capsaicin, and piperine, all of which have been shown to be PPAR agonists either directly or indirectly. Additionally, a few studies have demonstrated the use of clinical samples in in vitro investigations. The role of the fruit fly Drosophila melanogaster as a potential model for studying neurodegenerative diseases has also been highlighted.

Genistein-3'-sodium sulfonate ameliorates cerebral ischemia injuries by blocking neuroinflammation through the α7nAChR-JAK2/STAT3 signaling pathway in rats

BACKGROUND

Neuroinflammation plays a pivotal role in the acute progression of cerebral ischemia/reperfusion injury (I/RI). We previously reported that genistein-3'-sodium sulfonate (GSS), a derivative from the extract of the phytoestrogen genistein (Gen), protects cortical neurons against focal cerebral ischemia. However, the molecular mechanism underlying the neuroprotective effects exerted by GSS remains unclear.

PURPOSE

The present study focused on the anti-inflammatory effects of GSS following I/RI in rats.

STUDY DESIGN

Randomized controlled trial.

METHODS

The tMCAO rat model and LPS-stimulated BV2 in vitro model were used. Longa's scare was used to observe neurological function. TTC staining and Nissl staining were used to evaluate brain injury. ELISA, qRT-PCR, Western blotting and immunofluorescent staining methods were used to detect cytokine concentration, mRNA level, protein expression and location.

RESULTS

GSS treatment improves neurological function, reduces the volume of cerebral infarction, attenuates proinflammatory cytokines and inactivates the phosphorylation of JAK2 and STAT3 in I/RI rats. Furthermore, GSS increased the expression of α7nAChR. More importantly, the neuroprotective, anti-inflammatory and inhibiting JAK2/STAT3 signaling pathway effects of GSS were counteracted in the presence of alpha-bungarotoxin (α-BTX), an α7nAChR inhibitor, suggesting that α7nAChR is a potential target associated with the anti-inflammatory effects of GSS in the I/RI rats. GSS also inhibited BV2 cells from releasing IL-1β via the α7nAChR pathway after LPS stimulation.

CONCLUSION

GSS protects against cerebral I/RI through the expression of α7nAChR and inhibition of the JAK2/STAT3 pathway. Our findings provide evidence for the role of the cholinergic anti-inflammatory pathway in neuroinflammation and uncover a potential novel mechanism for GSS treatment in ischemic stroke. The downstream signals of GSS, α7nAChR- JAK2/STAT3 could also be potential targets for the treatment of I/RI.

The in ovo injection of methionine improves intestinal cell proliferation and differentiation in chick embryos by activating the JAK2/STAT3 signaling pathway

The intestinal health of chick embryos is vital for their life-long growth, and exogenous nutrition intervention may provide sufficient nutrition for embryonic development. In the present study, we investigated the effect of in ovo injection of L-methionine (L-Met) on the intestinal structure and barrier function of chick embryos. There were 4 groups of treatments: the control (CON) group injected with phosphate-buffered saline (PBS) and the other 3 groups injected with 5, 10, and 20 mg L-Met/egg, respectively. The injection was performed on embryonic day 9 (E9), and intestinal samples were collected on the day of hatching for analysis. The results showed that, compared with the CON group, the groups administered an in ovo injection of L-Met increased relative weights of the duodenum, jejunum, and ileum (P < 0.05). Hematoxylin and eosin (H&E) staining showed that the groups injected with 5, 10, and 20 mg L-Met significantly increased villus height and crypt depth (P < 0.05). Moreover, in ovo injection of 10 mg L-Met also increased the transepithelial electrical resistance (TEER) of the jejunum (P < 0.05). Injection with 10 and 20 mg L-Met increased the expression of the tight junction proteins (ZO-1 and claudin-1) and the fluorescence signal intensity of Ki67 and villin proteins (P < 0.05). Further, the protein expression of phospho-Janus kinase 2 (p-JAK2) and phospho-signal transducer and activator of transcription 3 (p-STAT3) was significantly increased by 10 or 20 mg L-Met injection (P < 0.05). In conclusion, the injection of L-Met, especially at a dose of 10 mg, showed beneficial effects on the intestinal integrity of chick embryos due to the activation of the JAK2/STAT3 signaling pathway. Our results may provide new insights for regulating the intestinal development of embryonic chicks and the rapid growth of chicks after hatching.

Effect of combination therapy with neural stem cell transplantation and teramethylpyrazine in rats following acute spinal cord injury

OBJECTIVES

This study was to explore the effects of teramethylpyrazine (TMP) administered in conjunction with neural stem cell transplantation on motor function, pathological lesions and the Janus kinase (JAK)2/signal transducer and activator of transcription 3 signal transduction pathway in rats following acute spinal cord injury (SCI).

METHODS

Female Sprague-Dawley rats were randomly divided into sham, model, neural stem cells (NSCs) and NSCs+TMP groups. Motor function was evaluated using the Basso, Beattie, Bresnahan scale. Spinal cord neuropathies and neuron apoptosis were observed by HE and TUNEL staining. The brain-derived neurotrophic factor (BDNF), Nogo-A, JAK2 and p-JAK2 protein levels were measured by western blot analysis.

RESULTS

NSCs+TMP significantly improved rat motor function, attenuated impaired spinal cords, and decreased cellular apoptosis, compared with NSCs therapy alone (P < 0.05). In addition, expression of BDNF protein was significantly higher in NSCs+TMP rats compared with other groups regardless of time postinjury (P < 0.05). The highest expression levels of Nogo-A protein were observed in the model group. The expression of p-JAK2 in the NSCs+TMP group was relatively lower than the model and NSCs groups (P < 0.05).

CONCLUSIONS

In rats with SCI, NSCs+TMP effectively improved motor function and offered spinal cord protection by increasing BDNF and decreasing Nogo-A levels, as well as inhibiting the JAK2/STAT3 signal transduction pathway, suggesting that TMP could be a useful agent in NSCs transplantation in the treatment of SCI.

circ_CHFR regulates ox-LDL-mediated cell proliferation, apoptosis, and EndoMT by miR-15a-5p/EGFR axis in human brain microvessel endothelial cells

Oxidized low-density lipoprotein (ox-LDL) is a significant risk factor for various brain vascular diseases. Circular RNA (circRNA) is involved in the pathogenesis of brain vascular diseases. This study revealed the roles of circ_CHFR in ox-LDL-mediated cell proliferation, apoptosis, and endothelial-to-mesenchymal transition (EndoMT). Our results showed that circ_CHFR and EGFR expressions were dramatically upregulated, while miR-15a-5p expression was downregulated in ox-LDL-induced human brain microvessel endothelial cells (HBMECs) relative to control groups. circ_CHFR knockdown hindered the effects of ox-LDL exposure on cell proliferation, cell cycle, apoptosis, and EndoMT in HBMECs, whereas these impacts were abolished by miR-15a-5p inhibitor. In addition, circ_CHFR functioned as a sponge of miR-15a-5p and miR-15a-5p bound to EGFR. Thus, we concluded that circ_CHFR silencing hindered ox-LDL-mediated cell proliferation, apoptosis, and EndoMT by downregulating EGFR expression through sponging miR-15a-5p in HBMECs. Our findings provide a new mechanism for studying circRNA-directed therapy in ox-LDL-induced human brain vascular diseases.

Icariin enhance mild hypothermia-induced neuroprotection via inhibiting the activation of NF-κB in experimental ischemic stroke

Therapeutic hypothermia (TH) is a promising neuroprotective agent for treating stroke. However, its clinical application was limited by the impractical duration. Icariin (ICA) were reported to have therapeutic effect on cerebral ischemia. In this research, our aim was to investigate whether the combination of TH and ICA had better neuroprotective effects on ischemic stroke. An ischemia-reperfusion rat model was established and treated with mild hypothermia, ICA or JSH-23 (inhibitor of NF-κB). Thermistor probe, 2'3'5'-triphenyl tetrazolium chloride (TTC), 5/12-score system, and ELISA were used to detect temperature (rectum, cortex, striatum), infarct volume, neurological deficit, and cerebral cell death of these rats. The expressions of tumor necrosis factor (TNF)-α, Interleukin- 6 (IL-6), nuclear factor-kappa B (NF-κB), nuclear factor erythroid2-related factor (Nrf2), peroxisome proliferator activated receptor gamma (PPARα), PPARγ, Janus kinase 2 (JAK2), p-JAK2, signal transducers and activators of transduction-3 (STAT3), and p-STAT3 were detected by Western blot or q-PCR. Mild hypothermia, ICA, and JSH-23 reduced the cerebral infarct volume, neurological deficit, cerebral cell death of rats, downregulated the expressions of TNF-α, IL-6, C-Caspase 3 and Bax, and the activation of PPARs/Nrf2/NF-κB and JAK2/STAT3 pathways, but elevated the expression of Bcl-2. ICA promoted the effect of mild hypothermia on infarct volume, neurological deficit, and cerebral cell death. Moreover, ICA also enhanced the regulatory effect of mild hypothermia on apoptosis/inflammation factors expressions and activation of PPARs/Nrf2/NF-κB and JAK2/STAT3 pathways. ICA could promote mild hypothermia-induced neuroprotection by inhibiting the activation of NF-κB through the PPARs/Nrf2/NF-κB and JAK2/STAT3/NF-κB pathways in experimental stroke.

microRNA-1906 protects cerebral ischemic injury through activating Janus kinase 2/signal transducer and activator of transcription 3 pathway in rats

This study aimed to investigate the effects of miR-1906 on cerebral ischemic injury and its underlying mechanisms. After 24 h of reperfusion, neurological deficit scores, brain water content and infarct volume were measured. Neuronal apoptosis was detected by using terminal dexynucleotidyl transferase-mediated dUTP nick end labeling assay. Hematoxylin-eosin staining was used to evaluate the histopathological damage of neurons. The expression of miR-1906 was detected by qRT-PCR. And the expressions of Bax, Bcl-2, caspase-3, Janus kinase 2 (JAK2), p-JAK2, signal transducer and activator of transcription 3 (STAT3) and p-STAT3 were measured by western blot. Furthermore, the levels of tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β) and IL-6 were measured by ELISA. We found that miR-1906 expression was significantly decreased in the cerebral ischemia injury rats. miR-1906 decreased neurological score, infarct volume, brain water content, neuronal apoptosis and inflammatory factors (TNF-α, IL-6 and IL-1β) expression. In addition, miR-1906 promoted the phosphorylation of JAK2 and STAT3. After treating with JAK2/STAT3 pathway inhibitor AG490, the phosphorylation of JAK2 and STAT3 was inhibited and the effects of miR-1906 on neurological score, infarct volume, brain water content, neuronal apoptosis and inflammatory factors were reversed. miR-1906 could protect cerebral ischemic injury through activating the JAK2/STAT3 pathway in rats.

The bidirectional role of the JAK2/STAT3 signaling pathway and related mechanisms in cerebral ischemia-reperfusion injury

The Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) signaling pathway, a well-conserved and basic intracellular signaling cascade, is mostly inactivated under basal conditions, although it can be phosphorylated under extracellular stimulation; in addition, it can influence the transcription and expression of multiple genes involved in biological processes such as cellular growth, metabolism, differentiation, degradation and angiogenesis. The inflammatory response, apoptosis, oxidative stress and angiogenesis are the main factors involved in the pathogenesis of ischemic stroke. Numerous studies have confirmed that the JAK2/STAT3 axis can be activated rapidly by ischemic stress, which is closely related to the regulation of these important pathological processes. However, different opinions on the specific role of this signaling pathway remain. In this paper, we review and summarize previous studies on the JAK2/STAT3 pathway in ischemic stroke.

Neuroprotective potential of imatinib in global ischemia-reperfusion-induced cerebral injury: possible role of Janus-activated kinase 2/signal transducer and activator of transcription 3 and connexin 43

The present study was aimed to explore the neuroprotective role of imatinib in global ischemia-reperfusion-induced cerebral injury along with possible mechanisms. Global ischemia was induced in mice by bilateral carotid artery occlusion for 20 min, which was followed by reperfusion for 24 h by restoring the blood flow to the brain. The extent of cerebral injury was assessed after 24 h of global ischemia by measuring the locomotor activity (actophotometer test), motor coordination (inclined beam walking test), neurological severity score, learning and memory (object recognition test) and cerebral infarction (triphenyl tetrazolium chloride stain). Ischemia-reperfusion injury produced significant cerebral infarction, impaired the behavioral parameters and decreased the expression of connexin 43 and phosphorylated signal transducer and activator of transcription 3 (p-STAT3) in the brain. A single dose administration of imatinib (20 and 40 mg/kg) attenuated ischemia-reperfusion-induced behavioral deficits and the extent of cerebral infarction along with the restoration of connexin 43 and p-STAT3 levels. However, administration of AG490, a selective Janus-activated kinase 2 (JAK2)/STAT3 inhibitor, abolished the neuroprotective actions of imatinib and decreased the expression of connexin 43 and p-STAT3. It is concluded that imatinib has the potential of attenuating global ischemia-reperfusion-induced cerebral injury, which may be possibly attributed to activation of JAK2/STAT3 signaling pathway along with the increase in the expression of connexin 43.

Folic Acid Deficiency Enhances the Tyr705 and Ser727 Phosphorylation of Mitochondrial STAT3 in In Vivo and In Vitro Models of Ischemic Stroke

Ischemic stroke remains one of the most common causes of death and disability worldwide. The stroke patients with an inadequate intake of folic acid tend to have increased brain injury and poorer prognosis. However, the precise mechanisms underlying the harmful effects of folic acid deficiency (FD) in ischemic stroke is still elusive. Here, we aimed to test the hypothesis that mitochondrial localized STAT3 (mitoSTAT3) expression may be involved in the process of neuronal damage induced by FD in in vivo and in vitro models of ischemic stroke. Our results exhibited that FD increased infarct size and aggravated the damage of mitochondrial ultrastructure in ischemic brains. Meanwhile, FD upregulated the phosphorylation levels of mitoSTAT3 at Tyr705 (Y705) and Ser727 (S727) sites in the rat middle cerebral artery occlusion/reperfusion (MCAO/R) model and oxygen-glucose deprivation followed by reperfusion (OGD/R) N2a cells. Furthermore, the inhibition of JAK2 by AG490 led to a significant decrease in FD-induced phosphorylation of Y705, while S727 phosphorylation was unaffected. Conversely, U0126 and LY294002, which respectively inhibited phosphorylation of ERK1/2 and Akt, partially prevented S727 phosphorylation, but had limited effects on the level of pY705, suggesting that phosphorylation of Y705 and S727 is regulated via independent mechanisms in FD-treated brains.

Combined inhibition of JAK1/2 and DNMT1 by newly identified small-molecule compounds synergistically suppresses the survival and proliferation of cervical cancer cells

Despite substantial advances in treating cervical cancer (CC) with surgery, radiation and chemotherapy, patients with advanced CC still have poor prognosis and significantly variable clinical outcomes due to tumor recurrence and metastasis. Therefore, to develop more efficacious and specific treatments for CC remains an unmet clinical need. In this study, by virtual screening the SPECS database, we identified multiple novel JAK inhibitor candidates and validated their antitumor drug efficacies that were particularly high against CC cell lines. AH057, the best JAK inhibitor identified, effectively blocked the JAK/STAT pathways by directly inhibiting JAK1/2 kinase activities, and led to compromised cell proliferation and invasion, increased apoptosis, arrested cell cycles, and impaired tumor progression in vitro and in vivo. Next, by screening the Selleck chemical library, we identified SGI-1027, a DNMT1 inhibitor, as the compound that displayed the highest synergy with AH057. By acting on a same set of downstream effector molecules that are dually controlled by JAK1/2 and DNMT1, the combination of AH057 with SGI-1027 potently and synergistically impaired CC cell propagation via dramatically increasing apoptotic cell death and cell-cycle arrest. These findings establish a preclinical proof of concept for combating CC by dual targeting of JAK1/2 and DNMT1, and provide support for launching a clinical trial to evaluate the efficacy and safety of this drug combination in patients with CC and other malignant tumors.

Melatonin Plays a Protective Role by Regulating miR-26a-5p-NRSF and JAK2-STAT3 Pathway to Improve Autophagy, Inflammation and Oxidative Stress of Cerebral Ischemia-Reperfusion Injury

Background

Melatonin (MT) has potential protective effect on cerebral ischemia-reperfusion injury (CIRI), but its underlying regulatory mechanism has not been identified.

Purpose

This study aimed to explore the role of miR-26a-5p-neuron-restrictive silencing factor (NRSF/REST), Janus kinase-2 (JAK2)-signal transducer and activator of transcription-3 (STAT3) pathway in the protection mechanism of MT against CIRI in vivo and in vitro.

Methods

Sprague Dawley rats were induced with ischemia-reperfusion (IR) in vivo model; PC12 cells were induced with oxygen-glucose deprivation/reperfusion (OGD/R) in vitro model; and MT intervention was conducted before the model was established. The effect of MT on autophagy factors (LC3II/LC3I, P62), inflammatory factors (TNF-α, IL-6, IL-10) and oxidative stress indexes (MDA, GSHPx, SOD) was explored, and then the above three indexes were determined by real-time quantitative PCR, ELISA, and detection kit corresponding to oxidative stress indexes. The neuroprotective effect of MT pretreatment on brain IR injury was evaluated by neurological deficit scores and TUNEL method. The levels of miR-26a-5p and NRSF were detected by real-time quantitative PCR and Western blot, and the interaction between them was evaluated by dual luciferase report. The role of JAK2-STAT3 pathway in MT protection mechanism was verified by pathway blocker (AG490) and Western blot.

Results

MT pretreatment can significantly reduce neurological deficit score and neuronal apoptosis, inhibit CIRI autophagy, inflammation and oxidative stress in vivo and in vitro, reduce LC3II/LC3I, TNF-α, IL-6, MDA and increase P62, IL-10, GSHPx, SOD. Further analysis identifies that downregulating miR-26a-5p or upregulating NRSF can eliminate the protective effect of MT, and NRSF is the direct target of miR-26a-5p. The protective effect of MT can also be eliminated under AG490 intervention.

Conclusion

MT plays a protective role by regulating miR-26a-5p-NRSF and JAK2-STAT3 pathway to improve CIRI autophagy, inflammation and oxidative stress.

Overexpression of HIF-1α protects PC12 cells against OGD/R-evoked injury by reducing miR-134 expression

Nowadays, searching for new therapeutic targets for cerebral stroke treatment are still in urgent need. Our study explored the influences and mechanisms of HIF-1α on OGD/R-evoked injury. OGD/R treatment was conducted on PC12 cells to simulate ischemic injury. CCK-8, flow cytometry and qRT-PCR were conducted to determine the variations of cell viability, apoptosis and gene expression, respectively. Cell transfections were conducted to overexpress HIF-1α and miR-134. Variations of protein levels were evaluated by employing western blot. Results showed that OGD/R treatment induced cell injury through reducing viability, while enhancing apoptosis that was validated by the elevated ratios of C/P-PARP and C/P-caspase-3. HIF-1α expression was markedly increased by OGD/R treatment. HIF-1α overexpression attenuated OGD/R-evoked injury in PC12 cells and remarkably reversed OGD/R-triggered inhibitory effects on ERK1/2 and JAK1/STAT3 pathways. Besides, miR-134 was also down-regulated by HIF-1α overexpression in PC12 cells. Up-regulation of miR-134 notably counteracted HIF-1α overexpression-triggered neuro-protective impacts on OGD/R-evoked injury and ERK1/2 and JAK1/STAT3 pathways. Our present study reported that HIF-1α overexpression protected PC12 cells against OGD/R-evoked injury via down-regulation of miR-134, which making HIF-1α and miR-134 to be promising targets for cerebral stroke therapy.

Intraventricular Medium B Treatment Benefits an Ischemic Stroke Rodent Model via Enhancement of Neurogenesis and Anti-apoptosis

Enhancement of endogenous neurogenesis after ischemic stroke may improve functional recovery. We previously demonstrated that medium B, which is a combination with epidermal growth factor (EGF) and fibronectin, can promote neural stem/progenitor cell (NSPC) proliferation and migration. Here, we showed that medium B promoted proliferation and migration of cultured NSPCs onto various 3-dimentional structures. When rat cortical neurons with oxygen glucose deprivation (OGD) were co-cultured with NSPCs, medium B treatment increased neuronal viability and reduced cell apoptosis. In a rat model with transient middle cerebral artery occlusion (MCAO), post-insult intraventricular medium B treatment enhanced proliferation, migration, and neuronal differentiation of NSPCs and diminished cell apoptosis in the infarct brain. In cultured post-OGD neuronal cells and the infarct brain from MCAO rats, medium B treatment increased protein levels of Bcl-xL, Bcl-2, phospho-Akt, phospho-GSK-3β, and β-catenin and decreased the cleaved caspase-3 level, which may be associated with the effects of anti-apoptosis. Notably, intraventricular medium B treatment increased neuronal density, improved motor function and reduced infarct size in MCAO rats. In summary, medium B treatment results in less neuronal death and better functional outcome in both cellular and rodent models of ischemic stroke, probably via promotion of neurogenesis and reduction of apoptosis.

Mild Hypothermia Attenuates Hepatic Ischemia-Reperfusion Injury through Regulating the JAK2/STAT3-CPT1a-Dependent Fatty Acid β-Oxidation

Hepatic ischemia–reperfusion (IR) injury is a clinical issue that can result in poor outcome and lacks effective therapies at present. Mild hypothermia (32–35°C) is a physiotherapy that has been reported to significantly alleviate IR injury, while its protective effects are attributed to multiple mechanisms, one of which may be the regulation of fatty acid β-oxidation (FAO). The aim of the present study was to investigate the role and underlying mechanisms of FAO in the protective effects of mild hypothermia. We used male mice to establish the experimental models as previously described. In brief, before exposure to in situ ischemia for 1 h and reperfusion for 6 h, mice received pretreatment with mild hypothermia for 2 h and etomoxir (inhibitor of FAO) or leptin (activator of FAO) for 1 h, respectively. Then, tissue and blood samples were collected to evaluate the liver injury, oxidative stress, and changes in hepatic FAO. We found that mild hypothermia significantly reduced the hepatic enzyme levels and the score of hepatic pathological injury, hepatocyte apoptosis, oxidative stress, and mitochondrial injury. In addition, the expression of the rate-limiting enzyme (CPT1a) of hepatic FAO was downregulated almost twofold by IR, while this inhibition could be significantly reversed by mild hypothermia. Experiments with leptin and etomoxir confirmed that activation of FAO could also reduce the hepatic enzyme levels and the score of hepatic pathological injury, hepatocyte apoptosis, oxidative stress, and mitochondrial injury induced by IR, which had the similar effects to mild hypothermia, while inhibition of FAO had negative effects. Furthermore, mild hypothermia and leptin could promote the phosphorylation of JAK2/STAT3 and upregulate the ratio of BCL-2/BAX to suppress hepatocyte apoptosis. Thus, we concluded that FAO played an important role in hepatic IR injury and mild hypothermia attenuated hepatic IR injury mainly via the regulation of JAK2/STAT3-CPT1a-dependent FAO.

Granulocyte colony-stimulating factor attenuates myocardial remodeling and ventricular arrhythmia susceptibility via the JAK2-STAT3 pathway in a rabbit model of coronary microembolization

Background

Coronary microembolization (CME) has a poor prognosis, with ventricular arrhythmia being the most serious consequence. Understanding the underlying mechanisms could improve its management. We investigated the effects of granulocyte colony-stimulating factor (G-CSF) on connexin-43 (Cx43) expression and ventricular arrhythmia susceptibility after CME.

Methods

Forty male rabbits were randomized into four groups (n = 10 each): Sham, CME, G-CSF, and AG490 (a JAK2 selective inhibitor). Rabbits in the CME, G-CSF, and AG490 groups underwent left anterior descending (LAD) artery catheterization and CME. Animals in the G-CSF and AG490 groups received intraperitoneal injection of G-CSF and G-CSF + AG490, respectively. The ventricular structure was assessed by echocardiography. Ventricular electrical properties were analyzed using cardiac electrophysiology. The myocardial interstitial collagen content and morphologic characteristics were evaluated using Masson and hematoxylin-eosin staining, respectively.

Results

Western blot and immunohistochemistry were employed to analyze the expressions of Cx43, G-CSF receptor (G-CSFR), JAK2, and STAT3. The ventricular effective refractory period (VERP), VERP dispersion, and inducibility and lethality of ventricular tachycardia/fibrillation were lower in the G-CSF than in the CME group (P < 0.01), indicating less severe myocardial damage and arrhythmias. The G-CSF group showed higher phosphorylated-Cx43 expression (P < 0.01 vs. CME). Those G-CSF-induced changes were reversed by A490, indicating the involvement of JAK2. G-CSFR, phosphorylated-JAK2, and phosphorylated-STAT3 protein levels were higher in the G-CSF group than in the AG490 (P < 0.01) and Sham (P < 0.05) groups.

Conclusion

G-CSF might attenuate myocardial remodeling via JAK2-STAT3 signaling and thereby reduce ventricular arrhythmia susceptibility after CME.

The effects of epidermal growth factor on early burn-wound progression in rats

After burns, protecting tissues by medicines in the zone of stasis reduces the width and depth of injury. This study's goal was to reduce burned tissue damage in the zone of stasis using epidermal growth factor (EGF). Forty-eight Wistar rats were separated into three groups. In all groups, the burn procedure was applied following the comb burn model. In Group 1, no postburn treatment was administered. In Group 2, physiological saline solution (0.3 cc) was injected intradermally and in Group 3, EGF (0.3 cc) was injected intradermally into stasis zone tissues after the burn procedure. Surviving tissue rates were 24.0% in Group 1, 25.3% in Group 2, and 70.2% in Group 3. The average numbers of cells stained with Nrf2, HO-1, and the number of apoptotic cells were 230, 150, and 17.5 in Group 1, 230, 145, and 15.0 in Group 2, and 370, 230, and 0 in Group 3, respectively. Values in Group 3 were found to be statistically significantly different than those of Groups 1 and 2; there was no difference between Groups 1 and 2. This study shows that EGF protects zone of stasis tissue from burn damage.

Identification of Hub Genes and Pathways in a Rat Model of Renal Ischemia-Reperfusion Injury Using Bioinformatics Analysis of the Gene Expression Omnibus (GEO) Dataset and Integration of Gene Expression Profiles

Background

This study aimed to identify hub genes and pathways in a rat model of renal ischemia-reperfusion injury (IRI) using bioinformatics analysis of the Gene Expression Omnibus (GEO) microarray dataset and integration of gene expression profiles.

Material/Methods

GEO software and the GEO2R calculation method were used to analyze two mRNA profiles, including GSE 39548 and GSE 108195. The co-expression of differentially expressed genes (DEGs) were identified and searched in the DAVID and STRING databases for pathway and protein-protein interaction (PPI) analysis. Cytoscape was used to draw the PPI network. DEGs were also analyzed using the Molecular Complex Detection (MCODE) algorithm. Cytoscape and cytoHubba were used to analyze the hub genes and visualize the molecular interaction networks. Rats (n=20) included the IRI model group (n=10) and a control group (n=10). Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was used to measure and compare the expression of the identified genes in rat renal tissue in the IRI model and the control group.

Results

Ten hub genes were identified, STAT3, CD44, ITGAM, CCL2, TIMP1, MYC, THBS1, IGF1, SOCS3, and CD14. Apart from IGF1, qRT-PCR showed that expression of these genes was significantly increased in renal tissue in the rat model of IRI. The HIF-1α signaling pathway was involved in IRI in the rat model, which was supported by MCODE analysis.

Conclusions

In a rat model of renal IRI, bioinformatics analysis of the GEO dataset and integration of gene expression profiles identified involvement of HIF-1α signaling and the STAT3 hub gene.

How does Helicobacter pylori cause gastric cancer through connexins: An opinion review

Helicobacter pylori (H. pylori) is a Gram-negative bacterium with a number of virulence factors, such as cytotoxin-associated gene A, vacuolating cytotoxin A, its pathogenicity island, and lipopolysaccharide, which cause gastrointestinal diseases. Connexins function in gap junctional homeostasis, and their downregulation is closely related to gastric carcinogenesis. Investigations into H. pylori infection and the fine-tuning of connexins in cells or tissues have been reported in previous studies. Therefore, in this review, the potential mechanisms of H. pylori-induced gastric cancer through connexins are summarized in detail.

The mechanism and tumor inhibitory study of Lagopsis supine ethanol extract on colorectal cancer in nude mice

Background

This study was aimed to determination the tumor inhibitory effect and explore the potential mechanisms of Lagopsis supine ethanol extract (Ls) on colorectal cancer.

Methods

The cell growth inhibition experiment of Ls in colorectal cancer cell lines was determined by MTT method in the time course of 24, 48 and 72 h in four gradient drug concentrations. The protein expression levels of pSTAT3, pJAK2, STAT3, JAK2, Bcl-2 and caspase 3 were measured by Western blot method. The mRNA levels of the downstream genes of STAT3 were detected through semi-quantitative RT PCR. Sixty Balb/c-nude mice were xenograft with HCT116 colorectal cancer cells through subcutaneously. The xenografts were divided into five groups: model group, positive group (capecitabine 300 mg/kg) and three dosages of Ls treated groups (75, 150 and 300 mg/kg). Tumor size and tumor weight were calculated for evaluation the anti-tumor effects. H & E staining and immunohistochemical analysis were used to determine the histopathological changes and the levels of pSTAT3 and pJAK2 in the tumor tissues.

Results

Ls exhibited a significant anti-proliferation effect in HCT116 and SW480 cells in vitro. The protein levels of pSTAT3, pJAK2 and Bcl-2, and the mRNA levels of Bcl-2 and Bak notably reduced with a dose-dependent manner. While the protein levels of caspase 3, and mRNA levels of Bax and caspase-3 remarkably increased in the gradient dosage of Ls in HCT116 cells. HCT116 in vivo xenografts experiment showed that the growth of the tumors significantly inhibited by Ls administration, which with no any significant body weight changes in each experiment group. The histopathology analysis displayed that Ls significantly reduced the inflammatory cells in tumor tissue. Furthermore, Ls also significantly down-regulate the protein levels of pSTAT3 and pJAK2 in the tumor tissues, compared with the model group.

Conclusions

This work shows that Ls inhibited the cell proliferation of colorectal cancer in vitro and significantly reduced the tumor growth in HCT116 xenografts in vivo, which is probably related with the JAK/STAT signal pathway.

Aflatoxin B1 Induces Immunotoxicity through the DNA Methyltransferase-Mediated JAK2/STAT3 Pathway in 3D4/21 Cells

As the most toxic mycotoxin of all of the fungal toxins, aflatoxin B₁ (AFB₁) has carcinogenesis, heptotoxicity, and immunotoxicity. DNA methylation plays a critical role in gene expression regulation of the pathological process. However, the relationship between DNA methylation and AFB₁-induced immunotoxicity was not yet reported. Therefore, the objectives of this study were to verify AFB₁-induced immunotoxicity and investigate the potential role of the DNA methyltransferase (DNMT) family in AFB₁-induced immunotoxicity and the pathway mechanism in 3D4/21 cells. The results showed that AFB₁ could induce cytotoxicity, apoptosis, pro-inflammatory cytokine expression, DNA damage, and oxidative stress and decrease phagocytotic capacity. Meanwhile, the levels of DNMT1 and DNMT3a were significantly increased in 0.04 and 0.08 μg/mL AFB₁ compared to the control. Inhibition of DNMT1 and DNMT3a by 5-Aza-2dc could reverse changes of the above parameters. Further, the JAK2/STAT3 pathway was significantly activated in 0.04 μg/mL AFB₁. Inhibition of p-JAK2 and p-STAT3 by AG490 could alleviate AFB₁-induced immunotoxicity. Moreover, inhibition of DNMT1 and DNMT3a by 5-Aza-2dc could suppress the phosphorylation of JAK2 and STAT3. Taken together, AFB₁-induced immunotoxicity is related to the JAK2/STAT3 pathway mediated by DNMTs in 3D4/21 cells.

Anti-inflammatory effect of afatinib (an EGFR-TKI) on OGD-induced neuroinflammation

Activated epidermal growth factor receptor (EGFR) has been proposed in the pathophysiology of neurodegenerative diseases. In the present study, the anti-inflammatory effect of afatinib, an EGFR-tyrosine kinase inhibitor (EGFR-TKIs) was investigated using CTX-TNA2 cells and primary cultured astrocytes subjected to oxygen/glucose deprivation (OGD). We found that OGD induced EGFR phosphorylation and activated subsequent signaling pathways, including phosphorylation of AKT and extracellular signal-regulated kinases (ERK). Afatinib blocked OGD-induced phosphorylation of EGFR, AKT and ERK. At the same time, afatinib attenuated OGD-induced elevations in glial fibrillary acidic protein (a biomarker of activated astrocytes) and proliferating cell nuclear antigen expression (a cell proliferating biomarker) as well as hypoxia-induced migratory ability. Furthermore, afatinib decreased OGD-induced increases in cyclooxygenase-II and inducible nitric oxide synthase expression of the treated astrocytes as well as NO content in the culture medium. Moreover, afatinib attenuated OGD-induced caspase 1 activation (a biomarker of inflammasome activation) and interleukin-1β levels (a pro-inflammatory cytokine). Collectively, afatinib could block OGD-induced EGFR activation and its downstream signaling pathways in astrocytes. Moreover, afatinib attenuated OGD-induced astrocyte activation, proliferation and inflammasome activation. These data support the involvement of EGFR activation in neuroinflammation. Furthermore, EGFR-TKIs may be promising in inhibiting neuroinflammation in the CNS neurodegenerative diseases.

Neuroprotective effect of Notch pathway inhibitor DAPT against focal cerebral ischemia/reperfusion 3 hours before model establishment

As an inhibitor of the Notch signaling pathway, N-[N-(3,5-difluorohenacetyl)-l-alanyl]-S-phenylglycine tert-butyl ester (DAPT) may protect brain tissue from serious ischemic injury. This study aimed to explore neuroprotection by DAPT after cerebral ischemia/reperfusion (I/R) injury. DAPT was intraperitoneally injected 3 hours before the establishment of a focal cerebral I/R model in the right middle cerebral artery of obstructed mice. Longa scores were used to assess neurological changes of mice. Nissl staining and TdT-mediated dUTP-biotin nick-end labeling staining were used to examine neuronal damage and cell apoptosis in the right prefrontal cortex, while immunofluorescence staining was used to detect glial fibrillary acidic protein- and Notch1-positive cells. Protein expression levels of Hes1 and Hes5 were detected by western blot assay in the right prefrontal cortex. Our results demonstrated that DAPT significantly improved neurobehavioral scores and relieved neuronal morphological damage. DAPT decreased the number of glial fibrillary acidic protein- and Notch1-positive cells in the right prefrontal cortex, while also reducing the number of apoptotic cells and decreasing interleukin-6 and tumor necrosis factor-α contents, and simultaneously downregulating Hes1 and Hes5 protein expression. These findings verify that DAPT alleviates pathological lesions and strengthens the anti-inflammatory response after cerebral I/R injury. Thus, DAPT might be developed as an effective drug for the prevention of cerebral I/R injury.

Inhibition of Connexin43 hemichannels with Gap19 protects cerebral ischemia/reperfusion injury via the JAK2/STAT3 pathway in mice

Functional disruption of the neurovascular unit may lead to aggravation of ischemic cerebral injury. Connexin43 (Cx43)-dependent gap junctional channels (GJCs) are critical in maintaining brain homeostasis. However, excessive opening of hemichannels (HCs) after cerebral ischemia may cause apoptosis and finally lead to amplification of ischemic injury. Previous studies indicated that Cx43 mimetic peptides Gap26 and Gap27 may protect cerebral ischemic injury, but the latest studies showed they also inhibit the opening of GJCs, which are beneficial for neuroprotection. Recent studies showed that Gap19 is a new specific inhibitor of Cx43 HCs. We investigated the role of Gap19 on cerebral ischemia/reperfusion (I/R) injury in a mouse model of middle cerebral artery occlusion (MCAO). Ventricle-injected Gap19 significantly alleviated infarct volume, neuronal cell damage and neurological deficits after ischemia, the neuroprotective effect of Gap19 was significant stronger than Gap26. Post-treatment with TAT-Gap19 still provided neuroprotection when it was administered intraperitoneally at 4 h after reperfusion. In addition, we found that Gap19 decreased the levels of cleaved caspase-3 and Bax and increased the level of Bcl-2, suggesting the anti-apoptotic activity of specifically blocking the Cx43 HCs. Furthermore, our data indicate that Gap19 treatment increased the levels of phosphorylated JAK2 and STAT3 both in vivo and in vitro. Gap19 inhibited hemichannel activity assessed by dye uptake in astrocytes. And we detected that pSTAT3 co-localized with Cx43 together in astrocytes after oxygen glucose deprivation (OGD) injury. Finally, AG490, a blocker of the JAK2/STAT3 pathway, could reverse the neuroprotective effects of Gap19 both in vivo and in vitro. Our experiment investigated the anti-apoptotic activity of Gap19, the specific inhibitor of Cx43 HCs, and the potential mechanisms. Our results demonstrated that Gap19 plays an anti-apoptotic role via activating the JAK2/STAT3 pathway after cerebral I/R injury, indicating that specific blocking of Cx43 HCs is a potential target for ischemic stroke.

Pretreatment With Diazoxide Attenuates Spinal Cord Ischemia-Reperfusion Injury Through Signaling Transducer and Activator of Transcription 3 Pathway

BACKGROUND

Delayed paraplegia remains a feared complication of thoracoabdominal aortic intervention. Pharmacologic preconditioning with diazoxide (DZ), an adenosine 5'-triphosphate-sensitive potassium channel opener, results in neuroprotection against ischemic insult. However, the effects of DZ in spinal cord ischemia-reperfusion injury have not been fully elucidated. We hypothesized that DZ attenuates spinal cord ischemia-reperfusion injury through the signaling transducer and activator of transcription (STAT) 3 pathway.

METHODS

Adult male C57/BL6 mice received DZ (20 mg/kg) by oral gavage. Spinal cords were harvested at 0, 12, 24, 36, 48, and 60 hours after administration of DZ. The expression of phosphorylated STAT3 was assessed by Western blot analysis. Five groups were studied: DZ (DZ pretreatment, n = 8), ischemic control (phosphate-buffered saline pretreatment, n = 11), DZ + STAT3 inhibitor LY5 (DZ pretreatment + LY5, n = 8), LY5 (phosphate-buffered saline pretreatment + LY5, n = 8), and sham (without cross-clamping, n = 5). Spinal cord ischemia was induced by 4 minutes of thoracic aortic cross-clamp. Functional scoring (Basso Mouse Score) was done at 12-hour intervals until 48 hours, and spinal cords were harvested for the evaluation of B-cell lymphoma 2 expression and histologic changes.

RESULTS

The expression of phosphorylated STAT3 was significantly upregulated 36 hours after the administration of DZ. The motor function in the DZ group was significantly preserved compared with all other groups. The expression of B-cell lymphoma 2 in the DZ group was significantly higher than in the ischemic control, DZ + LY5, and LY5 groups 48 hours after reperfusion.

CONCLUSIONS

DZ preserves motor function in spinal cord ischemia-reperfusion injury by the STAT3 pathway. DZ may be beneficial clinically for use in spinal protection in aortic intervention.