七氟烷上调糖尿病大鼠缺血再灌注肾脏Src和FAK的表达

目的 观察七氟烷预处理对糖尿病大鼠肾脏缺血再灌注(I/R)损伤肾功能及肾组织Src和FAK表达的影响。方法 将糖尿病大鼠分为假手术组、I/R组和七氟烷预处理组。给药后喂养24 h,麻醉大鼠并下腔静脉采血,测定血肌酐(creatinine,Cr)和尿素氮(blood urea nitrogen,BUN),取肾组织使用免疫组织化学方法测定大鼠肾脏组织中Src和FAK的表达。结果 与假手术组比较,I/R组Cr、BUN明显增高,肾组织Src、FAK表达显著降低(P<0.05);与I/R组比较,七氟烷预处理组血清Cr、BUN明显降低,肾组织Src、FAK表达显著升高(P<0.05)。结论 七氟烷预处理能改善糖尿病大鼠肾脏I/R损伤肾功能,上调Src、FAK在肾组织中的表达。     

Src family kinases involved in CXCL12-induced loss of acute morphine analgesia

Functional interactions between the chemokine receptor CXCR4 and opioid receptors have been reported in the brain, leading to a decreased morphine analgesic activity. However the cellular mechanisms responsible for this loss of opioid analgesia are largely unknown. Here we examined whether Src family-kinases (SFK)-linked mechanisms induced by CXCR4 contributed to the loss of acute morphine analgesia and could represent a new physiological anti-opioid signaling pathway. In this way, we showed by immunohistochemistry and western blot that CXCL12 rapidly activated SFK phosphorylation in vitro in primary cultured lumbar rat dorsal root ganglia (DRG) but also in vivo in the DRG and the spinal cord. We showed that SFK activation occurred in a sub population of sensory neurons, in spinal microglia but also in spinal nerve terminals expressing mu-(MOR) and delta-opioid (DOR) receptor. In addition we described that CXCR4 is detected in MOR- and DOR-immunoreactive neurons in the DRG and spinal cord. In vivo, we demonstrated that an intrathecal administration of CXCL12 (1 μg) significantly attenuated the subcutaneous morphine (4 mg/kg) analgesia. Conversely, pretreatment with a potent CXCR4 antagonist (5 μg) significantly enhanced morphine analgesia. Similar effects were obtained after an intrathecal injection of a specific SFK inhibitor, PP2 (10 μg). Furthermore, PP2 abrogated CXCL12-induced decrease in morphine analgesia by suppressing SFK activation in the spinal cord. In conclusion, our data highlight that CXCL12-induced loss of acute morphine analgesia is linked to Src family kinases activation.     

Src family kinases activity is required for transmitting purinergic P2X7 receptor signaling in cortical spreading depression and neuroinflammation

BackgroundPurinergic P2X7 receptor plays an important role in migraine pathophysiology. Yet precise molecular mechanism underlying P2X7R signaling in migraine remains unclear. This study explores the hypothesis that P2X7 receptor transmits signaling to Src family kinases (SFKs) during cortical spreading depression (CSD) and neuroinflammation after CSD.MethodsCSD was recorded using electrophysiology in rats and intrinsic optical imaging in mouse brain slices. Cortical IL-1β and TNFα mRNA levels were detected using qPCR. Glutamate release from mouse brain slices was detected using glutamate assay.ResultsThe data showed that deactivation of SFKs by systemic injection of PP2 reduced cortical susceptibility to CSD in rats and CSD-induced IL-1β and TNF-α gene expression in rat ipsilateral cortices. Consistently, in mouse brain slices, inhibition of SFKs activity by saracatinib and P2X7 receptor by A740003 similarly reduced cortical susceptibility to CSD. When the interaction of P2X7 receptor and SFKs was disrupted by TAT-P2X7, a marked reduction of cortical susceptibility to CSD, IL-1β gene expression and glutamate release after CSD induction were observed in mouse brain slices. The reduced cortical susceptibility to CSD by TAT-P2X7 was restored by NMDA, and disrupting the Fyn-NMDA interaction using TAT-Fyn (39-57) but not disrupting Src-NMDA receptor interaction using TAT-Src (40-49) reduced cortical susceptibility to CSD. Furthermore, activation of P2X7 receptor by BzATP restored the TAT-Fyn (39-57)-reduced cortical susceptibility to CSD.ConclusionThis study reveals that SFKs activity transmits P2X7 receptor signaling to facilitate CSD propagation via glutamatergic pathway and promote neuroinflammation, which is of particular relevance to migraine.     

c‐Src promotes tumor progression through downregulation of microRNA‐129‐1‐3p

MicroRNAs (miRNAs) fine‐tune cellular signaling by regulating expression of signaling proteins, and aberrant expression of miRNAs is observed in many cancers. The tyrosine kinase c‐Src is upregulated in various human cancers, but the molecular mechanisms underlying c‐Src‐mediated tumor progression remain unclear. In previous investigations of miRNA‐mediated control of c‐Src‐related oncogenic pathways, we identified miRNAs that were downregulated in association with c‐Src transformation and uncovered the signaling networks by predicting their target genes, which might act cooperatively to control tumor progression. Here, to further elucidate the process of cell transformation driven by c‐Src, we analyzed the expression profiles of miRNAs in a doxycycline‐inducible Src expression system. We found that miRNA (miR)‐129‐1‐3p was downregulated in the early phase of c‐Src‐induced cell transformation, and that reexpression of miR‐129‐1‐3p disrupted c‐Src‐induced cell transformation. In addition, miR‐129‐1‐3p downregulation was tightly associated with tumor progression in human colon cancer cells/tissues. Expression of miR‐129‐1‐3p in human colon cancer cells caused morphological changes and suppressed tumor growth, cell adhesion, and invasion. We also identified c‐Src and its critical substrate Fer, and c‐Yes, a member of the Src family of kinases, as novel targets of miR‐129‐1‐3p. Furthermore, we found that miR‐129‐1‐3p‐mediated regulation of c‐Src/Fer and c‐Yes is important for controlling cell adhesion and invasion. Downregulation of miR‐129‐1‐3p by early activation of c‐Src increases expression of these target genes and synergistically promotes c‐Src‐related oncogenic signaling. Thus, c‐Src‐miR‐129‐1‐3p circuits serve as critical triggers for tumor progression in many human cancers that harbor upregulation of c‐Src.     

Cx32、Src/FAK信号通路在肝癌组织中的表达及其与肝癌术后患者预后的关系

目的 探讨肝细胞癌（肝癌）组织中连接蛋白Cx32、磷酸化Src(p-Src)Y416、总Src(total Src)、磷酸化局部黏着斑激素（p-FAK）Y925、总FAK(total FAK)蛋白表达水平对肝癌术后患者预后的影响。方法 收集97例接受根治性手术肝癌患者的肝癌组织标本和相应的癌旁组织标本,使用免疫组织化学（免疫组化）染色法测定Cx32、p-Src Y416、total Src、p-FAK Y925和total FAK的蛋白表达水平,并对肝癌患者术后随访5年,采用单因素和多因素Cox回归分析肝癌患者术后死亡的影响因素,并使用Kaplan-Meier法计算生存率。结果 免疫组化染色结果显示肝癌组织中Cx32的阳性表达率低于相应的癌旁组织,而p-Src Y416、total Src、p-FAK Y925、total FAK的蛋白阳性表达率均高于相应的癌旁组织（P均<0.05）。单因素Cox回归分析显示,年龄、肿瘤分化程度、肿瘤直径、Cx32、p-Src、total Src、p-FAK Y925、total FAK是肝癌患者术后死亡的8个可疑影响因素（P均<0.05）...     

The osteoclast: a potential therapeutic target of bone and joint destruction in rheumatoid arthritis

There is accumulating evidence that osteoclasts, the primary cells responsible for bone resorption, are involved in bone and joint destruction in rheumatoid arthritis (RA). Recent progress in bone cell biology has revealed the molecular mechanism of osteoclast differentiation and bone resorption by mature osteoclasts. We here highlight the potential role of RANKL–RANK pathways in bone destruction in RA. We also describe our recent trials on gene therapy of arthritic joint disease targeting osteoclasts by regulating Src kinase activity in the cells.     

Zinc induces protein phosphatase 2A inactivation and tau hyperphosphorylation through Src dependent PP2A (tyrosine 307) phosphorylation

The activity of protein phosphatase (PP) 2A is downregulated and promotes the hyperphosphorylation of tau in the brains of Alzheimer's disease (AD), but the mechanism for PP2A inactivation has not been elucidated. We have reported that PP2A phosphorylation at tyrosine 307 (Y307) is involved in PP2A inactivation. Here, we further studied the upstream mechanisms for PP2A phosphorylation and inactivation. We found that zinc, a heavy metal ion that is widely distributed in the normal brain and accumulated in the susceptible regions of AD brain, could induce PP2A inhibition, phosphorylation of PP2A at Y307 and tau hyperphosphorylation both in rat brains and cultured N2a cells, while zinc chelating prevented these changes completely. Upregulation of PP2A chemically or genetically attenuated zinc-induced tau hyperphosphorylation, whereas mutation of Y307 to phenylalanine abolished the zinc-induced tyrosine phosphorylation and inactivation of PP2A. Zinc could activate Src, while PP2, a specific Src family kinases inhibitor, attenuated zinc-induced PP2A phosphorylation and inactivation, indicating that zinc induces PP2A Y307 phosphorylation and inactivation through Src activation. In human tau transgenic mice, zinc chelator rescued PP2A activity, prevented Src activation, and reduced hyperphosphorylated and insoluble tau levels. We concluded that zinc induces PP2A inactivation and tau hyperphosphorylation through Src-dependent pathway, regulation of zinc homeostasis may be a promising therapeutic for AD and the related tauopathies.     

胶质细胞源性神经生长因子家族成员及其受体介导的胞内信号转导

GDNF家族成员是TGF β生长因子超家族的一个亚家族 ,在神经元的存活 ,生长 ,分化 ,再生 ,轴突生长 ,神经损伤和神经退行性疾病中都有重要作用。神经细胞中存在GDNF的RET依赖性和非RET依赖性两条信号转导途径。本文就GDNF家族成员及其受体介导的胞内信号转导机制研究的最新进展进行简述