Project description:Alzheimer’s disease (AD) is a chronic neurodegenerative disease needing effective therapeutics urgently. Sildenafil, one of the approved phosphodiesterase-5 inhibitors, has been implicated as having potential beneficial effect in AD. We showed that sildenafil usage is associated with reduced likelihood of AD across four new drug compactor cohorts, including bumetanide, furosemide, spironolactone, and nifedipine. For instance, sildenafil usage is associated with a 54% reduced prevalence of AD in MarketScan® (hazard ratio [HR] = 0.46, 95% CI 0.32-0.66) and a 30% reduced prevalence of AD in Clinformatics® (HR = 0.70, 95% CI 0.49-1.00) compared to spironolactone. We found that sildenafil treatment significantly reduced tau hyper-phosphorylation (pTau181, pTau205) in a dose-dependent manner in both familial and sporadic AD patient derived neurons. Further RNA-seq data analysis of sildenafil-treated AD patient iPSC-derived neurons revealed that sildenafil specifically targeting AD related genes and molecular pathways involved in axon guidance, AD-presenilin, neurogenesis, neurodegeneration, synaptic dysregulation, vascular smooth muscle contraction (VSMC) and cyclic guanosine monophosphate (cGMP)-protein kinase G (PKG) signaling pathway, mechanistically supporting the potential beneficial effect of sildenafil in AD. These real-world patient data validation and mechanistic observations from patient iPSC-derived neurons further suggested that sildenafil is a potential repurposable drug for AD. However, randomized clinical trials are required to validate sildenafil as a potential treatment of AD.
Project description:Differential expression in the presence and absence of sildenafil following romidepsin We performed cDNA microarray analysis using an GeneChip® Human Gene 2.0 ST Array to identify cellular genes that may be differentially expressed in the presence and absence of sildenafil following romidepsin treatment in SNK6
Project description:The only validated treatment to prevent brain damage associated with hypoxia-ischemia (HI) encephalopathy of the newborn is controlled hypothermia with limited benefits. Additional putative neuroprotective drug candidates include sildenafil citrate, a phosphodiesterase-type 5 inhibitor. The main objective of this preclinical study is to assess its ability to reduce HI-induced neuroinflammation, in particular through its potential effect on microglial activation. HI was induced in P10 Sprague–Dawley rats by unilateral carotid permanent artery occlusion and hypoxia (HI), and treated by either hypothermia (HT) alone, Sildenafil (Sild) alone or combined treatment (SildHT). Lesion size, glial activation were analyzed by immunohistochemistry, qRT-PCR and proteomic analyses performed at P13. Exposure to any treatment was not associated with significant reduction in lesions size both in cerebral cortex and hippocampus, 72h after HI. Significant reductions in either Iba1+ (within the ipsilateral hemisphere) or GFAP+ cells (within the ipsilateral hippocampus) were observed in SildHT group, but not in the other treatment groups. In microglia sorted cells, pro-inflammatory markers, ie. Il1b, Il6, Nos2, and CD86 were significantly downregulated in SildHT treatment group only. These changes were restricted to ipsilateral hemisphere, were not evidenced in sorted astrocytes, and were not sex-dependent. Proteomic analyses in sorted microglia refined the pro-inflammatory effect of HI and confirmed a biologically relevant impact of SildHT on specific molecular pathways including notably genes related to neutrophilic functions. Our findings demonstrate that Sildenafil combined with controlled hypothermia confers maximum effect to mitigate microglial activation induced by HI through complex proteomic regulation. The reduction of neuroinflammation induced by Sildenafil may represent an interesting therapeutic strategy for neonatal neuroprotection.
Project description:Recently, it is reported that sildenafil suppresses maturation of PO-induced miRNAs. However, the mechanism of how sildenafil coupled NO-cGMP-PKG signaling affects this maturation was not unraveled. Here, we show that PERK-mediated suppression of miRNAs by sildenafil is vital to keep mitochondrial homeostasis, using cardiac-specific PERK knockout (cko) mice.
Project description:Citrate is demonstrated to be an indispensable secondary metabolite in citrus fruit. Citrus citrate content is affected by accumulation, degradation, usage, transport and storage. The detail mechanisms of citrate accumulation are complicated in citrus fruit and there are other regulating pathways that have yet to be discovered. In this study, we utilized genomic expression investigation to gain a deep insight into the citrate-accumulation-related biological processes in sweet orange.
Project description:TLR activation induces inflammatory responses in macrophages by activating temporally defined transcriptional cascades within the first hours after stimulation. Whether concurrent changes in the cellular metabolism that occur upon TLR activation influence the quality of the transcriptional responses remain unknown. Here we investigated how macrophages adopt their metabolism early after activation to regulate TLR-inducible gene induction. Macrophages increase glucose metabolism and adopt fluxes through the TCA cycle to foster Citrate synthesis. We concomitantly observe activation of ATP-Citrate Lyase (Acly), resulting in augmented acetyl-CoA synthesis and histone acetylation. To investigate which genes and genes classes require ATP-citrate lyase activity for induction we stimulated bone marrow derived macrophages with LPS after ATP-citrate lyase inhibition.
Project description:Organic acids and anthocyanins are the most important compounds for the flavor and nutritional quality of citrus fruit. In this study, a comparative transcriptome analysis was conducted to elucidate the genes and pathways involved in the accumulation of citrate and anthocyanins in postharvest citrus fruit using ‘Tarocco’ blood orange (TBO) and ‘Bingtangcheng’ sweet orange (BTSO). About 2397, 2677, 3067, 3131 and 2960 differentially expressed genes (DEGs) between two materials were identified at 0, 15, 30, 60, and 90 DAS (days after storage) respectively. A robust core set of 825 DEGs temporally associated with the citrate and anthocyanin accumulation throughout the storage period. Further function enrichment revealed the up-regulated DEGs in TBO were mainly related to UV protection, flavonoid biosynthesis process and transcription factors (TFs). And the down-regulated DEGs were mainly related to inositol biosynthesis process, carboxylic acid/organic acid transmembrane transport and transporters. Moreover, co-expression network and correlation analysis revealed that 23 differentially expressed TFs may be responsible for the simultaneously positively regulation of citrate and anthocyanin accumulation. And 19 differentially expressed transporters may be involved in citrate metabolism and negatively correlated with citrate content. These results suggesting that the high anthocyanis and citrate levels in TBO compared with BTSO were porbably attributed to the highly active of a group of core TFs and lowly active of transporters, which will accordingly provide novel insights into the molecular mechanisms underlying the difference accumulation of citrate and anthocyanin content in TBO and BTSO.
Project description:Autophagy is a cellular and energy homeostatic mechanism that contributes to maintain the number of primordial follicles, germ cell survival, and anti-ovarian aging. However, it remains unknown whether autophagy in granulosa cells affects the oocyte maturation. Here, we show a clear tendency of reduced autophagy level in human granulosa cell from women of advanced maternal age, implying a potential negative correlation between autophagy level and oocyte quality. We therefore established a co-culture system and show that either pharmacological inhibition or genetic ablation of autophagy in granulosa cells negatively affect the oocyte quality and fertilization ability. Moreover, our metabolomics analysis indicates that the adverse impact of autophagy impairment on oocyte quality is mediated by downregulated citrate levels, while exogenous supplementation of citrate can significantly restore the oocyte maturation. In molecular level, we found ATP citrate lyase (Acly), which is a crucial enzyme catalyzing the cleavage of citrate, was preferentially associated with K63-linked ubiquitin chains and recognized by the autophagy receptor protein SQSTM1/p62 for the selective autophagic degradation. In human follicles, autophagy levels in granulosa cells was downregulated with maternal aging, accompanied by decreased citrate in the follicular fluid, implying a potential correlation between citrate metabolism and oocyte quality. We also show that elevated citrate levels in porcine follicular fluid promote oocyte maturation. Collectively, our data reveal that autophagy in granulosa cells is a beneficial mechanism to maintain a certain degree of citrate by selectively targeting Acly during oocyte maturation.