Src Kinase Inhibitor Research Articles

The inhibition of rutin on Src kinase blocks high glucose-induced EGFR/ERK transactivation in diabetic nephropathy by integrative approach of network pharmacology and experimental verification

BackgroundAlthough clinical strategies for diabetic nephropathy (DN) therapy include stringent blood pressure control through blockade of the renin-angiotensin system and management of hyperglycemia, the condition is still observed to progress relentlessly. PurposeTo elucidate the protective effects of rutin on podocytes in db/db mice with integrative approach of network pharmacology and experimental verification. MethodsThe study employs network pharmacology to identify common targets between rutin and DN, constructs a potential protein-protein interaction (PPI) network, and conducts Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. Molecular docking is utilized to evaluate the interaction between rutin and protein targets. Additionally, experimental validation is performed using db/db mice and human podocyte cell models. ResultsRutin has been found to have a significant renoprotective effect, reducing blood glucose, proteinuria, and improving renal function in db/db mice. Rutin's inhibition of Src kinase reduces the phosphorylation levels of EGFR and ERK, which may mitigate podocyte injury. Additionally, rutin exhibits antioxidant properties, capable of lowering the levels of reactive oxygen species (ROS) in kidney tissue and increasing the activity of antioxidant enzymes like superoxide dismutase (SOD). These effects help protect podocytes from oxidative stress, further supporting the potential application of rutin in the treatment of DN. ConclusionsThe inhibition of rutin on Src kinase blocks high glucose-induced EGFR/ERK transactivation and protects podocyte injury in DN, indicating it might serve as a promising therapeutic agent for podocyte-targeted therapies.

SKI-606, a Src inhibitor, ameliorates benzene-induced hematotoxicity via blocking ROS/Src kinase-mediated p38 and Akt signaling pathways

Exposure to benzene causes acute myelosuppression and other hematologic disorders. However, the detailed mechanism by which benzene exerts its severe hematotoxicity and potential treatments still require further deciphering and exploration. Herein, we found that hydroquinone (HQ), a main benzene metabolite, significantly increased intracellular reactive oxygen species (ROS) formation and subsequently caused damage to DNA, leading to impaired colony formation capacity and induction of apoptosis in human hematopoietic stem/progenitor cells (HSPCs) in vitro. The effects were mediated by activation of Src kinase, which subsequently activated the p38 signaling pathway while inhibiting the Akt signaling pathway. The mechanism was further verified by pre-treatment with a Src kinase inhibitor SKI-606, which effectively reversed the dampened self-renewal capacity and increased apoptosis of HSPCs induced by HQ in vitro. Furthermore, administration of SKI-606 partially reversed benzene-induced hematotoxicity and prolonged the survival time in benzene-poisoned mice. Taken together, these findings highlight that HQ-induced hematotoxicity in HSPCs is attributed to the Src kinase-mediated activation of p38 signaling pathway and repression of Akt signaling pathway. Notably, SKI-606 as a tyrosine kinase inhibitor may be a promising and potential agent for alleviating benzene-induced hematotoxicity.

Stretching the structural envelope of imatinib to reduce β-amyloid production by modulating both β- and γ-secretase cleavages of APP.

We previously showed that the anticancer drug imatinib mesylate (IMT, trade name: Gleevec) and a chemically distinct compound, DV2-103 (a kinase-inactive derivative of the potent Abl and Src kinase inhibitor, PD173955) lower Aβ levels at low micromolar concentrations primarily through a lysosome-dependent mechanism that renders APP less susceptible to proteolysis by BACE1 without directly inhibiting BACE1 enzymatic activity, or broadly inhibiting the processing of other BACE1 substrates. Additionally, IMT indirectly inhibits γ-secretase and stimulates autophagy, and thus may decrease Aβ levels through multiple pathways. In two recent studies we demonstrated similar effects on APP metabolism caused by derivatives of IMT and DV2-103. In the present study, we synthesized and tested radically altered IMT isomers (IMTi's) that possess medium structural similarity to IMT. Independent of structural similarity, these isomers manifest widely differing potencies in altering APP metabolism. These will enable us to choose the most potent isomers for further derivatization.

Mu-Opioid Receptor (MOR) Dependence of Pain in Chemotherapy-Induced Peripheral Neuropathy.

We recently demonstrated that transient attenuation of Toll-like receptor 4 (TLR4) in dorsal root ganglion (DRG) neurons, can both prevent and reverse pain associated with chemotherapy-induced peripheral neuropathy (CIPN), a severe side effect of cancer chemotherapy, for which treatment options are limited. Given the reduced efficacy of opioid analgesics to treat neuropathic, compared to inflammatory, pain, the crosstalk between nociceptor TLR4 and mu-opioid receptors (MOR), and that MOR and TLR4 agonists induce hyperalgesic priming (priming), which also occurs in CIPN, we determined, using male rats, whether: i ) antisense knockdown of nociceptor MOR attenuates CIPN, ii ) and attenuates the priming associated with CIPN, and iii ) CIPN also produces opioid-induced hyperalgesia (OIH). We found that intrathecal MOR antisense prevents and reverses hyperalgesia induced by oxaliplatin and paclitaxel, two common clinical chemotherapy agents. Oxaliplatin induced-priming was also markedly attenuated by MOR antisense. Additionally, intradermal morphine, at a dose that does not affect nociceptive threshold in controls, exacerbates mechanical hyperalgesia (OIH) in rats with CIPN, suggesting the presence of OIH. This OIH associated with CIPN is inhibited by interventions that reverse Type II priming (the combination of an inhibitor of Src and mitogen-activated protein kinase (MAPK)), a MOR antagonist, as well as a TLR4 antagonist. Our findings support a role of nociceptor MOR in oxaliplatin-induced pain and priming. We propose that priming and OIH are central to the symptom burden in CIPN, contributing to its chronicity and the limited efficacy of opioid analgesics to treat neuropathic pain.Significance Statement It remains unknown why opioid analgesics are less effective against neuropathic pain, including that induced by cancer chemotherapy. Here we demonstrate a crucial role of nociceptor mu-opioid receptors (MOR) in chemotherapy-induced peripheral neuropathy (CIPN) pain and hyperalgesic priming (priming), the latter a mechanism involved in the transition from acute to chronic pain. In addition to neuropathic pain and priming, opioid-induced hyperalgesia (OIH) also develops in chemotherapy-treated rats, which is reversed by inhibitors of second messengers that also reverse Type II priming, as well as by MOR and TLR4 antagonists. Taken together our results support the suggestion that priming and OIH contribute to CIPN and its limited responsiveness to opioid analgesics.

Vascular smooth muscle BK channels limit ouabain-induced vasocontraction: Dual role of the Na/K-ATPase as a hub for Src-kinase and the Na/Ca-exchanger.

Large-conductance, calcium-activated potassium channels (BK channels) and the Na/K-ATPase are expressed universally in vascular smooth muscle. The Na/K-ATPase may act via changes in the intracellular Ca2+ concentration mediated by the Na/Ca exchanger (NCX) and via Src kinase. Both pathways are known to regulate BK channels. Whether BK channels functionally interact in vascular smooth muscle cells with the Na/K-ATPase remains to be elucidated. Thus, this study addressed the hypothesis that BK channels limit ouabain-induced vasocontraction. Rat mesenteric arteries were studied using isometric myography, FURA-2 fluorimetry and proximity ligation assay. The BK channel blocker iberiotoxin potentiated methoxamine-induced contractions. The cardiotonic steroid, ouabain (10-5 M), induced a contractile effect of IBTX at basal tension prior to methoxamine administration and enhanced the pro-contractile effect of IBTX on methoxamine-induced contractions. These facilitating effects of ouabain were prevented by the inhibition of either NCX or Src kinase. Furthermore, inhibition of NCX or Src kinase reduced the BK channel-mediated negative feedback regulation of arterial contraction. The effects of NCX and Src kinase inhibition were independent of each other. Co-localization of the Na/K-ATPase and the BK channel was evident. Our data suggest that BK channels limit ouabain-induced vasocontraction by a dual mechanism involving the NCX and Src kinase signaling. The data propose that the NCX and the Src kinase pathways, mediating the ouabain-induced activation of the BK channel, act in an independent manner.

Multiaction Pt(IV) Prodrugs Releasing Cisplatin and Dasatinib Are Potent Anticancer and Anti-Invasive Agents Displaying Synergism between the Two Drugs.

Herein, we describe the general design, synthesis, characterization, and biological activity of new multitargeting Pt(IV) prodrugs that combine antitumor cisplatin and dasatinib, a potent inhibitor of Src kinase. These prodrugs exhibit impressive antiproliferative and anti-invasive activities in tumor cell lines in both two-dimensional (2D) monolayers of cell cultures and three-dimensional (3D) spheroids. We show that the cisplatin moiety and dasatinib in the investigated Pt(IV) complexes are both involved in the mechanism of action in MCF7 breast cancer cells and act synergistically. Thus, combining dasatinib and cisplatin into one molecule, compared to using individual components in a mix, may bring several advantages, such as significantly higher activity in cancer cell lines and higher selectivity for tumor cells. Most importantly, Pt(IV)-dasatinib complexes hold significant promise for potential anticancer therapies by targeting epithelial-mesenchymal transition, thus preventing the spread and metastasis of tumors, a value unachievable by a simple combination of both individual components.

Opposite effects of acute and chronic IGF1 on rat dorsal root ganglion neuron excitability.

Insulin-like growth factor-1 (IGF-1) is a polypeptide hormone with a ubiquitous distribution in numerous tissues and with various functions in both neuronal and non-neuronal cells. IGF-1 provides trophic support for many neurons of both the central and peripheral nervous systems. In the central nervous system (CNS), IGF-1R signaling regulates brain development, increases neuronal firing and modulates synaptic transmission. IGF-1 and IGF-IR are not only expressed in CNS neurons but also in sensory dorsal root ganglion (DRG) nociceptive neurons that convey pain signals. DRG nociceptive neurons express a variety of receptors and ion channels that are essential players of neuronal excitability, notably the ligand-gated cation channel TRPV1 and the voltage-gated M-type K+ channel, which, respectively, triggers and dampens sensory neuron excitability. Although many lines of evidence suggest that IGF-IR signaling contributes to pain sensitivity, its possible modulation of TRPV1 and M-type K+ channel remains largely unexplored. In this study, we examined the impact of IGF-1R signaling on DRG neuron excitability and its modulation of TRPV1 and M-type K+ channel activities in cultured rat DRG neurons. Acute application of IGF-1 to DRG neurons triggered hyper-excitability by inducing spontaneous firing or by increasing the frequency of spikes evoked by depolarizing current injection. These effects were prevented by the IGF-1R antagonist NVP-AEW541 and by the PI3Kinase blocker wortmannin. Surprisingly, acute exposure to IGF-1 profoundly inhibited both the TRPV1 current and the spike burst evoked by capsaicin. The Src kinase inhibitor PP2 potently depressed the capsaicin-evoked spike burst but did not alter the IGF-1 inhibition of the hyperexcitability triggered by capsaicin. Chronic IGF-1 treatment (24 h) reduced the spike firing evoked by depolarizing current injection and upregulated the M-current density. In contrast, chronic IGF-1 markedly increased the spike burst evoked by capsaicin. In all, our data suggest that IGF-1 exerts complex effects on DRG neuron excitability as revealed by its dual and opposite actions upon acute and chronic exposures.

IL-17A Aggravated Blood-Brain Barrier Disruption via Activating Src Signaling in Epilepsy Mice.

Inflammation is an important pathogenic driving force in the genesis and development of epilepsy. The latest researches demonstrated that IL-17A mediated blood-brain barrier (BBB) dysfunction through disruption of tight junction protein expression. To investigate whether IL-17A is involved in BBB disruption after acute seizure attack, the pilocarpine model was established with C57BL/6J (wild type, WT) and IL-17R-deficient mice in vivo and with primary cultured rat brain microvascular endothelial cells in vitro. The mortality rate and brain water content were evaluated at 24h after status epilepticus, and IL-17A concentration, endothelial tight junction, adherens junction proteins, and albumin leakage were assessed at 0h, 4h, 12h, and 24h after status epilepticus (SE). IL-17R-deficient mice showed lessen severity of epilepsy than WT mice, accompanied by less albumin leakage, reduced brain water content, decreased IL-17A, and upregulated expression of target proteins (ZO-1, Occludin and VE-cadherin). IL-17R knockout abrogated abnormal upregulation of Src kinase and phosphorylated Src kinase in the setting of SE, and Src kinase inhibitor PP1 abrogated IL-17A-induced SE related endothelial injury in vitro. In conclusion, IL-17A inhibition might be a promising therapeutic option to attenuate endothelial cell injury and further BBB disruption by reducing Src kinase activation.

Abstract B020: Development of novel Src-targeting strategies to block bladder cancer invasive progression

Abstract Background: Treatment of muscle-invasive bladder cancer remains challenging and, BCG, one of the few treatments that prevents progression of high-risk non-muscle invasive tumors to invasive metastatic disease, is difficult to obtain. Thus, development of new treatment approaches to block progression to muscle invasive disease is essential. We find that TRIM29 (tripartite motif containing 29, also known as ATDC), drives bladder cancer invasive progression through modulation of focal adhesions containing FAK and c-Src (Src). Despite this, literature has reported conflicting effects of Src knockdown and Src kinase inhibition on migration, perhaps due to separable pro- and anti-invasive functions of Src in bladder cancer. Hypothesis: Src drives bladder cancer invasive progression specifically through its tyrosine kinase activity within focal adhesions. Methods: We used 2D live cell migration assays and 3D spheroid invasion assays to test dasatinib, highly specific, novel conformation inhibitors of Src, a novel Src PROTAC, and siRNA against Src on bladder cancer migration and invasion. Results: Dasatinib and our novel conformation-specific inhibitors inhibited Src kinase activity and both siRNA and the novel PROTAC reduced total Src expression in vitro. Neither dasatinib, conformation inhibitors, siRNA, nor the PROTAC impacted bladder cancer cell viability in UM-UC5, UM-UC9 or UM-UC14 cell lines. Interestingly, we found that inhibiting Src’s kinase activity with either dasatinib or conformation-specific inhibitors abrogated bladder cancer migration. Conclusion: These results point to the selective importance of Src in regulating bladder cancer migration and invasion. They also suggest that novel Src targeting agents have potential clinical utility in the prevention of bladder cancer invasive progression. Citation Format: Nicole A. Jerome, Yin Wang, Marian L. Henderson, Luke Broses, Kathleen C. Day, Mark L. Day, Matthew B. Soellner, Phillip L. Palmbos. Development of novel Src-targeting strategies to block bladder cancer invasive progression [abstract]. In: Proceedings of the AACR Special Conference on Bladder Cancer: Transforming the Field; 2024 May 17-20; Charlotte, NC. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(10_Suppl):Abstract nr B020.

Extra-nuclear TERT counteracts oxidative stress and promotes progression in papillary thyroid carcinoma

The reactivation of TERT is associated with poor outcome in papillary thyroid cancer (PTC). Extra-telomeric functions of TERT were reported, with a protective role against oxidative stress (OS). The aim of the present study was to explore the extra-nuclear TERT localization in PTC and its role in cancer progression.TERT nuclear export under OS were analyzed in K1 PTC cell line. We investigated the role of different TERT localizations using specific TERT constructs that limit its localization to the nucleus or to the mitochondria. The effect of SRC kinase inhibitor PP2, which reduces TERT nuclear export, was investigated as well. Moreover, TERT localization was analyzed in 39 PTC tissues and correlated with the genetic profile and the level of OS, DNA damage and apoptosis in the tumors and with the clinical characteristics of the patients.We demonstrated that TERT is exported from the nucleus in response to OS induced either from H2O2 or the BRAF inhibitor PLX4720. We proved that extra-nuclear TERT reduces mitochondrial OS and induces mitochondrial fragmentation. Moreover, limiting mitochondrial TERT localization reduced proliferation, migration, AKT phosphorylation and glycolysis and increased DNA damage and p21 expression. Finally, in PTC tissues the fraction of mitochondrial/nuclear TERT resulted inversely correlated with OS and p21 expression and associated with tumor persistence.In conclusion, our data indicate that extra-nuclear TERT is involved in reducing the effect of excessive OS, thus promoting cancer cell survival. Extra-nuclear TERT may thus represent a marker of cancer progression and a possible therapeutic target in PTC.

Bosutinib Stimulates Macrophage Survival, Phagocytosis, and Intracellular Killing of Bacteria.

Host-acting compounds are emerging as potential alternatives to combating antibiotic resistance. Here, we show that bosutinib, an FDA-approved chemotherapeutic for treating chronic myelogenous leukemia, does not possess any antibiotic activity but enhances macrophage responses to bacterial infection. In vitro, bosutinib stimulates murine and human macrophages to kill bacteria more effectively. In a murine wound infection with vancomycin-resistant Enterococcus faecalis, a single intraperitoneal bosutinib injection or multiple topical applications on the wound reduce the bacterial load by approximately 10-fold, which is abolished by macrophage depletion. Mechanistically, bosutinib stimulates macrophage phagocytosis of bacteria by upregulating surface expression of bacterial uptake markers Dectin-1 and CD14 and promoting actin remodeling. Bosutinib also stimulates bacterial killing by elevating the intracellular levels of reactive oxygen species. Moreover, bosutinib drives NF-κB activation, which protects infected macrophages from dying. Other Src kinase inhibitors such as DMAT and tirbanibulin also upregulate expression of bacterial uptake markers in macrophages and enhance intracellular bacterial killing. Finally, cotreatment with bosutinib and mitoxantrone, another chemotherapeutic in clinical use, results in an additive effect on bacterial clearance in vitro and in vivo. These results show that bosutinib stimulates macrophage clearance of bacterial infections through multiple mechanisms and could be used to boost the host innate immunity to combat drug-resistant bacterial infections.

Concurrent inhibition of ALK and SRC kinases disrupts the ALK lung tumor cell proteome

Precision oncology has revolutionized the treatment of ALK-positive lung cancer with targeted therapies. However, an unmet clinical need still to address is the treatment of refractory tumors that contain drug-induced resistant mutations in the driver oncogene or exhibit resistance through the activation of diverse mechanisms. In this study, we established mouse tumor-derived cell models representing the two most prevalent EML4-ALK variants in human lung adenocarcinomas and characterized their proteomic profiles to gain insights into the underlying resistance mechanisms. We showed that Eml4-Alk variant 3 confers a worse response to ALK inhibitors, suggesting its role in promoting resistance to targeted therapy. In addition, proteomic analysis of brigatinib-treated cells revealed the upregulation of SRC kinase, a protein frequently activated in cancer. Co-targeting of ALK and SRC showed remarkable inhibitory effects in both ALK-driven murine and ALK-patient-derived lung tumor cells. This combination induced cell death through a multifaceted mechanism characterized by profound perturbation of the (phospho)proteomic landscape and a synergistic suppressive effect on the mTOR pathway. Our study demonstrates that the simultaneous inhibition of ALK and SRC can potentially overcome resistance mechanisms and enhance clinical outcomes in ALK-positive lung cancer patients. One Sentence SummaryCo-targeting ALK and SRC enhances ALK inhibitor response in lung cancer by affecting the proteomic profile, offering hope for overcoming resistance and improving clinical outcomes.

Characterization of gastric cancer-stimulated signaling pathways and function of CTGF in cancer-associated fibroblasts

BackgroundCancer-associated fibroblasts (CAFs) are key components of the tumor microenvironment (TME) that play an important role in cancer progression. Although the mechanism by which CAFs promote tumorigenesis has been well investigated, the underlying mechanism of CAFs activation by neighboring cancer cells remains elusive. In this study, we aim to investigate the signaling pathways involved in CAFs activation by gastric cancer cells (GC) and to provide insights into the therapeutic targeting of CAFs for overcoming GC.MethodsAlteration of receptor tyrosine kinase (RTK) activity in CAFs was analyzed using phospho-RTK array. The expression of CAFs effector genes was determined by RT-qPCR or ELISA. The migration and invasion of GC cells co-cultured with CAFs were examined by transwell migration/invasion assay.ResultsWe found that conditioned media (CM) from GC cells could activate multiple receptor tyrosine kinase signaling pathways, including ERK, AKT, and STAT3. Phospho-RTK array analysis showed that CM from GC cells activated PDGFR tyrosine phosphorylation, but only AKT activation was PDGFR-dependent. Furthermore, we found that connective tissue growth factor (CTGF), a member of the CCN family, was the most pronouncedly induced CAFs effector gene by GC cells. Knockdown of CTGF impaired the ability of CAFs to promote GC cell migration and invasion. Although the PDGFR-AKT pathway was pronouncedly activated in CAFs stimulated by GC cells, its pharmacological inhibition affected neither CTGF induction nor CAFs-induced GC cell migration. Unexpectedly, the knockdown of SRC and SRC-family kinase inhibitors, dasatinib and saracatinib, significantly impaired CTGF induction in activated CAFs and the migration of GC cells co-cultured with CAFs. SRC inhibitors restored the reduced expression of epithelial markers, E-cadherin and Zonula Occludens-1 (ZO-1), in GC cells co-cultured with CAFs, as well as CAFs-induced aggregate formation in a 3D tumor spheroid model.ConclusionsThis study provides a characterization of the signaling pathways and effector genes involved in CAFs activation, and strategies that could effectively inhibit it in the context of GC.DC5ErEG73tsyg3F8WfE1xiVideo

Retraction: Developing and Testing Methylated Nano-Structured Dipeptides that Inhibit Src Kinase Activity <em>In Vitro</em> for Anti-Cancer Applications

Retraction: Developing and Testing Methylated Nano-Structured Dipeptides that Inhibit Src Kinase Activity <em>In Vitro</em> for Anti-Cancer Applications

Functionalized 2-Amino-4H-1-Benzopyran-4-yl Phosphonate Scaffolds: Synthesis, Anticancer Evaluation and Computational Studies

Prostate, breast, and lung cancers are various human cancers that have been associated with SRC kinase mutations. Therefore, the development of potent and selective SRC kinase inhibitors is an exciting area of interest for researchers. In this study, we synthesized a series of 2-amino-4H-1-benzopyran-4-yl phosphonate derivatives through a one-pot reaction involving appropriately substituted salicylaldehydes, malononitrile, and diethyl phosphite, with meglumine as the catalyst. We conducted in vitro screening of these compounds for their anticancer activity against human prostate cancer (DU-145), breast cancer (MCF-7), and lung cancer (A549) cell lines using the MTT assay. Notably, compounds 4a, 4j, 4k, and 4l exhibited promising anticancer activity. Molecular docking studies of these compounds supported their potential as therapeutic agents for SRC kinase inhibition. Specifically, compounds 4a, 4b, 4c, 4d, and 4e demonstrated strong ΔG binding affinities ranging from −7.9 to −7.4 kcal/mol. These findings suggest that these molecules hold promise for cancer treatment.

The effects of Src tyrosine kinase inhibitor, saracatinib, on the markers of epileptogenesis in a mixed-sex cohort of adult rats in the kainic acid model of epilepsy.

Neurodegeneration and neuroinflammation are key processes of epileptogenesis in temporal lobe epilepsy (TLE). A considerable number (∼30%) of patients with epilepsy are resistant to currently available antiseizure drugs and thus there is a need to develop adjunct therapies to modify disease progression. A vast majority of interventional strategies to treat TLE have utilized males which limits the translational nature of the studies. In this study, we investigated the effects of repeated low-dose kainic acid (KA) injection on the initial status epilepticus (SE) and the effects of Src kinase inhibitor, saracatinib (SAR/AZD0530; 20 mg/kg, oral, daily for 7 days), in a mixed-sex cohort of adult Sprague Dawley rats during early epileptogenesis. There were no sex differences in response to KA-induced SE, and neither did the stage of estrus influence SE severity. KA-induced SE caused significant astrogliosis and microgliosis across the hippocampus, piriform cortex, and amygdala. SAR treatment resulted in a significant reduction of microgliosis across brain regions. Microglial morphometrics such as branch length and the endpoints strongly correlated with CD68 expression in the vehicle-treated group but not in the SAR-treated group, indicating mitigation by SAR. KA-induced SE caused significant neuronal loss, including parvalbumin-positive inhibitory neurons, in both vehicle (VEH) and SAR-treated groups. SAR treatment significantly mitigated FJB-positive neuronal counts as compared to the VEH group. There was an increase in C3-positive reactive astrocytes in the VEH-treated group, and SAR treatment significantly reduced the increase in the piriform cortex. C3-positive astrogliosis significantly correlated with CD68 expression in the amygdala (AMY) of VEH-treated rats, and SAR treatment mitigated this relationship. There was a significant increase of pSrc(Y419)-positive microglia in both KA-treated groups with a statistically insignificant reduction by SAR. KA-induced SE caused the development of classical glial scars in the piriform cortex (PIR) in both KA-treated groups, while SAR treatment led to a 42.17% reduction in the size of glial scars. We did not observe sex differences in any of the parameters in this study. SAR, at the dose tested in the rat kainate model for a week in this study mitigated some of the markers of epileptogenesis in both sexes.

MUC16 C terminal fragment activates YAP1 through Src signaling to promote gallbladder cancer growth

AbstractThe Hippo pathway is crucial to organ size control and its dysregulation contributes to tumorigenesis. The aberrant activation of YAP1 was identified in gallbladder cancer (GBC). However, the underlying mechanism and role in GBC remains unclear. The C terminal fragment of Mucin16, also known as carbohydrate antigen 125 (CA125) encoded product, MUC16c, plays extensive roles in tumor initiation and development. Our study showed that MUC16c binding with 14‐3‐3ε disrupted the interaction of 14‐3‐3ε and phosphorylated yes‐associated protein 1 (YAP1), which led to the activation of YAP1 in GBC. Furthermore, MUC16c decreased the phosphorylation of YAP1 at serine 397 (ser397) by inhibiting LATS1, which upregulated YAP1 protein stability. Interestingly, there was a potential Src kinase site in the MUC16c fragment. The MUC16c_del15Y polypeptides with the deletion of the Src kinase site promoted the interaction of YAP1 with 14‐3‐3ε and downregulated the YAP1 protein levels. Consistently, SU6656, a Src kinase inhibitor also blocked the activation of YAP1 by MUC16c. The MUC16c_del15Y polypeptides decreased GBC cell proliferation in vitro and the growth of xenograft tumors in vivo. Our study revealed the underlying mechanism of the activation of MUC16c on YAP1 mediated by Src signaling and the antitumor effect of MUC16c_del15Y, providing a potential target for GBC therapy.

Adiposomes from Obese-Diabetic Individuals Promote Endothelial Dysfunction and Loss of Surface Caveolae.

Glycosphingolipids (GSLs) are products of lipid glycosylation that have been implicated in the development of cardiovascular diseases. In diabetes, the adipocyte microenvironment is characterized by hyperglycemia and inflammation, resulting in high levels of GSLs. Therefore, we sought to assess the GSL content in extracellular vesicles derived from the adipose tissues (adiposomes) of obese-diabetic (OB-T2D) subjects and their impact on endothelial cell function. To this end, endothelial cells were exposed to adiposomes isolated from OB-T2D versus healthy subjects. Cells were assessed for caveolar integrity and related signaling, such as Src-kinase and caveolin-1 (cav-1) phosphorylation, and functional pathways, such as endothelial nitric oxide synthase (eNOS) activity. Compared with adiposomes from healthy subjects, OB-T2D adiposomes had higher levels of GSLs, especially LacCer and GM3; they promoted cav-1 phosphorylation coupled to an obvious loss of endothelial surface caveolae and induced eNOS-uncoupling, peroxynitrite generation, and cav-1 nitrosylation. These effects were abolished by Src kinase inhibition and were not observed in GSL-depleted adiposomes. At the functional levels, OB-T2D adiposomes reduced nitric oxide production, shear response, and albumin intake in endothelial cells and impaired flow-induced dilation in healthy arterioles. In conclusion, OB-T2D adiposomes carried a detrimental GSL cargo that disturbed endothelial caveolae and the associated signaling.

SRC and TKS5 mediated podosome formation in fibroblasts promotes extracellular matrix invasion and pulmonary fibrosis

The activation and accumulation of lung fibroblasts resulting in aberrant deposition of extracellular matrix components, is a pathogenic hallmark of Idiopathic Pulmonary Fibrosis, a lethal and incurable disease. In this report, increased expression of TKS5, a scaffold protein essential for the formation of podosomes, was detected in the lung tissue of Idiopathic Pulmonary Fibrosis patients and bleomycin-treated mice. Τhe profibrotic milieu is found to induce TKS5 expression and the formation of prominent podosome rosettes in lung fibroblasts, that are retained ex vivo, culminating in increased extracellular matrix invasion. Tks5+/- mice are found resistant to bleomycin-induced pulmonary fibrosis, largely attributed to diminished podosome formation in fibroblasts and decreased extracellular matrix invasion. As computationally predicted, inhibition of src kinase is shown to potently attenuate podosome formation in lung fibroblasts and extracellular matrix invasion, and bleomycin-induced pulmonary fibrosis, suggesting pharmacological targeting of podosomes as a very promising therapeutic option in pulmonary fibrosis.

SNX17 Mediates Dendritic Spine Maturation via p140Cap.

Sorting nexin17 (SNX17) is a member of the sorting nexin family, which plays a crucial role in endosomal trafficking. Previous research has shown that SNX17 is involved in the recycling or degradation of various proteins associated with neurodevelopmental and neurological diseases in cell models. However, the significance of SNX17 in neurological function in the mouse brain has not been thoroughly investigated. In this study, we generated Snx17 knockout mice and observed that the homozygous deletion of Snx17 (Snx17-/-) resulted in lethality. On the other hand, heterozygous mutant mice (Snx17+/-) exhibited anxiety-like behavior with a reduced preference for social novelty. Furthermore, Snx17 haploinsufficiency led to impaired synaptic transmission and reduced maturation of dendritic spines. Through GST pulldown and interactome analysis, we identified the SRC kinase inhibitor, p140Cap, as a potential downstream target of SNX17. We also demonstrated that the interaction between p140Cap and SNX17 is crucial for dendritic spine maturation. Together, this study provides the first in vivo evidence highlighting the important role of SNX17 in maintaining neuronal function, as well as regulating social novelty and anxiety-like behaviors.