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Allen Haagensen opublikował 5 miesięcy, 2 tygodnie temu
α/β-Tubulin inhibitors that alter microtubule (MT) dynamics are commonly used in cancer therapy, however, these inhibitors also cause severe side effects such as peripheral neuropathy. γ-Tubulin is a possible target as antitumor drugs with low side effects, but the antitumor effect of γ-tubulin inhibitors has not been reported yet. In this study, we verified the antitumor activity of gatastatin, a γ-tubulin specific inhibitor. The cytotoxicity of gatastatin was relatively weak compared with that of the conventional MT inhibitors, paclitaxel and vinblastine. To improve the cytotoxicity, we screened the chemicals that improve the effects of gatastatin and found that BI 2536, a Plk1 inhibitor, greatly increases the cytotoxicity of gatastatin. Co-treatment with gatastatin and BI 2536 arrested cell cycle progression at mitosis with abnormal spindles. Moreover, mitotic cell death induced by the combined treatment was suppressed by the Mps1 inhibitor, reversine. These findings suggest that co-treatment with Plk1 and γ-tubulin inhibitors causes spindle assembly checkpoint-dependent mitotic cell death by impairing centrosome functions. These results raise the possibility of Plk1 and γ-tubulin inhibitor co-treatment as a novel cancer chemotherapy.Ischemia-reperfusion (I/R) could cause heart irreversible damage, which is tightly combined with glucose metabolism disorder. It is demonstrated that GLUT4 (glucose transporter 4) translocation is critical for glucose metabolism in the cardiomyocytes under I/R injury. Moreover, DRD4 (dopamine receptor D4) modulate glucose metabolism, and protect neurocytes from anoxia/reoxygenation (A/R) injury. Thus, DRD4 might regulate myocardial I/R injury in association with GLUT4-mediated glucose metabolism. However, the effects and mechanisms are largely unknown. In the present study, the effect of DRD4 in heart I/R injury were studied ex vivo and in vitro. For I/R injury ex vivo, DRD4 agonist (PD168077) was perfused by Langendorff system in the isolated rat heart. DRD4 activated by PD168077 improved cardiac function in the I/R-injured heart as determined by the left ventricular developed pressure (LVDP), +dp/dt, and left ventricular end diastolic pressure (LVEDP), and reduced heart damage evidenced by infarct size, the release of troponin T (TNT) and lactate dehydrogenase (LDH). DRD4 activation diminished I/R injury induced apoptosis and enhanced cell viability impaired by I/R injury in cardiomyocyte, showed by TUNEL staining, flow cytometer and CCK8 assay. Furthermore, DRD4 activation did not change total GULT4 protein expression level but increased the membrane GULT4 localization determined by western blot. In terms of mechanism, DRD4 activation increased pPI3K/p-AKT but not the total PI3K/AKT during anoxia/reoxygenation (A/R) injury in vitro. Interestingly, PI3K inhibitor, Wortmannin, blocked PI3K/AKT pathway and depleted the membrane GULT4, and further promoted apoptosis showed by TUNEL staining, flow cytometer, western blot of cleaved caspase 3, BAX and BCL2 expression. Thus, DRD4 activation exerted a protective effect against I/R injury by promoting GLUT4 translocation depended on PI3K/AKT pathway, which enhanced the ability of glucose uptake, and ultimately reduced the apoptosis in cardiomyocytes.Glia-mediated inflammatory processes are crucial in the pathogenesis of Parkinson’s disease (PD). As the most abundant cells of the brain and active participants in neuroinflammatory responses, astrocytes largely propagate inflammatory signals and amplify neuronal loss. Hence, intensive control of astrocytic activation is necessary to prevent neurodegeneration. In this study, we report that the astrocytic kir6.2, as a abnormal response after inflammatory stimuli, promotes the reactivity of A1 neurotoxic astrocytes. Using kir6.2 knockout (KO) mice, we find reversal effects of kir6.2 deficiency on A1-like astrocyte activation and death of dopaminergic neurons in lipopolysaccharide (LPS)-induced mouse models for PD. Further in vitro experiments show that aberrant kir6.2 expression induced by inflammatory irritants in astrocytes mediates the dynamin-related protein 1 (Drp1)-dependent excessive mitochondrial fragmentation and results in mitochondrial malfunctions. By deleting kir6.2, astrocytic activation is reduced and astrocytes-derived neuronal injury is prevented. We therefore conclude that astrocytic kir6.2 can potentially elucidate the pathology of PD and promote the development of therapeutic strategies for PD.The NLR family pyrin domain containing 3 (NLRP3) inflammasome was reported to be regulated by autophagy and activated during inflammatory procession of Parkinson’s disease (PD). Berberine (BBR) is well-studied to play an important role in promoting anti-inflammatory response to mediate the autophagy activity. However, the effect of Berberine on NLRP3 inflammasome in PD and its potential mechanisms remain unclear. Hence, in this study, we investigated the effects of BBR on 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD mice, by evaluating their behavioral changes, dopaminergic (DA) neurons loss, neuroinflammation, NLRP3 inflammasome and autophagic activity. BBR was also applied in BV2 cells treated with 1-methyl-4-pehnyl-pyridine (MPP+). The autophagy inhibitor 3-Methyladenine (3-MA) was administrated to block autophagy activity both in vivo and in vitro. In our in vivo studies, compared to MPTP group, mice in MPTP + BBR group showed significant amelioration of behavioral disorders, mitigation of neurotoxicity and NLRP3-associated neuroinflammation, enhancement of the autophagic process in substantia nigra (SN). In vitro, compared to MPP+ group, BBR significantly decreased the level of NLRP3 inflammasome including the expressions of NLRP3, PYD and CARD domain containing (PYCARD), cleaved caspase 1 (CASP1), and mature interleukin 1 beta (IL1B), via enhancing autophagic activity. Furthermore, BBR treatment increased the formation of autophagosomes in MPP+-treated BV2 cells. Taken together, our data indicated that BBR prevents NLRP3 inflammasome activation and restores autophagic activity to protect DA neurons against degeneration in vivo and in vitro, suggesting that BBR may be a potential therapeutic to treat PD.Age-related macular degeneration (AMD) is a complex multifactorial degenerative disease that leads to irreversible blindness. AMD affects the macula, the central part of the retina responsible for sharp central vision. Retinal pigment epithelium (RPE) is the main cellular type affected in dry AMD. RPE cells form a monolayer between the choroid and the neuroretina and are in close functional relationship with photoreceptors; moreover, RPE cells are part of the blood retina barrier that is disrupted in ocular diseases such as AMD. During ocular inflammation lymphocytes and macrophages are recruited, contact RPE and produce pro-inflammatory cytokines, which play an important role in AMD pathogenesis. The interaction between RPE and immune cells is mediated by leukocyte integrins, heterodimeric transmembrane receptors, and adhesion molecules, including VCAM-1 and ICAM-1. Within this frame, this study aimed to characterize RPE-leukocytes interaction and to investigate any potentially beneficial effects induced by teraction with immune cells recruited to the retina. Overall, the leukocyte integrin antagonists employed in the present study may represent a novel opportunity to develop new drugs to fight dry AMD.Osteoarthritis (OA), the most common form of arthritis, is a very common joint disease that often affects middle-aged to elderly people. However, current treatment options for OA are predominantly palliative. Thus, understanding its pathological process and exploring its potential therapeutic approaches are of great importance. Rat chondrocytes were isolated and exposed to hydrogen peroxide (H2O2) to mimic OA. The effects of H2O2 on ubiquitin-specific protease 7 (USP7) expression, reactive oxygen species (ROS) levels, proliferation, inflammatory cytokine release, and pyroptosis were measured. USP7 was knocked down (KD) or overexpressed to investigate the role of USP7 in OA. Co-immunoprecipitation (Co-IP) was used to study the interaction between USP7 and NAD(P)H oxidases (NOX)4 as well as NOX4 ubiquitination. NOX4 inhibitor was applied to study the involvement of NOX4 in USP7-mediated OA development. USP7 inhibitor was given to OA animals to further investigate the role of USP7 in OA in vivo. Moreover, H2O2 treatment significantly increased USP7 expression, enhanced ROS levels, and inhibited proliferation in rat chondrocytes. The overexpression of USP7 enhanced pyroptosis, ROS production, interleukin (IL)-1β and IL-18 levels, and the expression level of NLRP3, GSDMD-N, active caspase-1, pro-caspase-1, matrix metalloproteinases (MMP) 1, and MMP13, which was abolished by ROS inhibition. The USP7 KD protected rat chondrocytes against H2O2-induced injury. Co-IP results showed that USP7 interacted with NOX4, and USP7 KD enhanced NOX4 ubiquitinylation. The inhibition of NOX4 blocked the pro-OA effect of USP7. Moreover, the USP7 inhibitor given to OA animals suppressed OA in vivo. USP7 inhibited NOX4 ubiquitination for degradation which leads to elevated ROS production. ROS subsequently activates NLPR3 inflammasome, leading to enhanced production of IL-1β and IL-18, GSDMD-N-dependent pyroptosis, and extracellular matrix remodeling. Thus, UPS7 contributes to the progression of OA via NOX4/ROS/NLPR3 axis.The tumor microenvironment plays a major role in the ability of the tumor cells to undergo metastasis. A major player of tumors gaining metastatic property is the inflammatory protein, cyclooxygenase 2 (COX-2). Several tumors show upregulation of this protein, which has been implicated in mediating metastasis in various cancer types such as of colon, breast and lung. In this report, we show that the concentration of extracellular ATP (eATP) is increased in response to cell death mediated by chemotherapeutic agents such as doxorubicin. By using three different cell-lines-HeLa (cervical), IMR-32 (neuronal) and MCF-7 (breast)-we show that this eATP goes on to act on purinergic (P2) receptors. Among the various P2 receptors expressed in these cells we identified P2X7, in IMR-32 and MCF-7 cells, and P2Y12, in HeLa cells, as important in modulating cell migration and invasion. Downstream of the P2 receptor activation, both p42/44 mitogen-activated protein kinase (MAPK) and the p38 MAPK are activated in these cells. These result in an increase in the expression of COX-2 mRNA and protein. We also observe an increase in the activity of matrix metalloproteinase 2 (MMP-2) enzyme in these cells. Blocking the P2 receptors not only blocks migration and invasion, but also COX-2 synthesis and MMP-2 activity. Our results show the link between purinergic receptors and COX-2 expression. Increased levels of ATP in the tumor microenvironment, therefore, leads to increased COX-2 expression, which, in turn, affords migratory and invasive properties to the tumor. This provides P2 receptor-based anti-inflammatory drugs (PBAIDs) a potential opportunity to be explored as cancer therapeutics.Combination antiretroviral therapy (cART) suppresses HIV-1 replication, improves immune function, and prolongs the life of people living with HIV (PLWH). However, cART also induces neurotoxicity that could complicate HIV-induced neurodegeneration while reduce its therapeutic efficacy in treating HIV/AIDS. Triumeq is a first-line cART regimen, which is co-formulated by three antiretroviral drugs (ARVs), lamivudine (3TC), abcavir (ABC), and dolutegravir (DTG). Little is known about potential side effects of ARVs on the brain (including those co-formulating Triumeq), and their mechanisms impacting neuronal activity. We assessed acute (in vitro) and chronic (in vivo) effects of Triumeq and co-formulating ARVs on pyramidal neurons in rat brain slices containing the medial prefrontal cortex (mPFC) using patch-clamp recording approaches. We found that acute Triumeq or 3TC in vitro significantly increased firing of mPFC neurons in a concentration- and time-dependent manner. This neuronal hyperactivity was associated with enhanced Ca2+ influx through voltage-gated Ca2+ channels (VGCCs).