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:New chemical entity KF1601 metabolism study data by 5 species liver microsomes. For metabolic stability, CYP phenotyping, comparative metabolism.
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.
Project description:Exhausted T cells (TEX) in cancer and chronic viral infections undergo metabolic and epigenetic remodeling, impairing protective capabilities. However, the impact of nutrient metabolism on epigenetic modifications that control TEX differentiation remains unclear. Our study reveals that TEX cells shift from acetate to citrate metabolism by downregulating acetyl-CoA synthetase 2 (ACSS2) while maintaining ATP-citrate lyase (ACLY) activity. This metabolic switch increases citrate-dependent histone acetylation, mediated by histone acetyltransferase KAT2A-ACLY interactions, at TEX signature-genes while reducing acetate-dependent histone acetylation, dependent on p300-ACSS2 complexes, at effector and memory T cell genes. Nuclear ACSS2 overexpression or ACLY inhibition prevents TEX differentiation and enhances tumor-specific T cell responses. These findings unveil a nutrient-driven histone code governing CD8+ T cell differentiation, with implications for metabolic- and epigenetic-based T cell therapies
Project description:We conducted a study involving 12 individuals with retinal dystrophy, neurological impairment and skeletal abnormalities placing special focus on GPATCH11, a lesser-known G-patch domain-containing protein regulator of RNA metabolism. To elucidate its role, we employed fibroblasts from unaffected individuals and patients carrying the recurring c.328+1G>T mutation, which specifically removes the main part of the G-patch domain while preserving the other domains. Additionally, we generated a mouse model replicating the patient's phenotyping defects, including retinal dystrophy and behavioral abnormalities. Our results revealed a subcellular localization characterized by a diffuse presence in the nucleoplasm, as well as centrosomal localization, suggesting roles in RNA and cilia metabolism. Transcriptomic analysis performed on mouse retina detected dysregulation in both gene expression and spliceosome activity, impacting key processes such as photoreceptor light responses, RNA regulation, and primary cilia-associated metabolism. Proteomic analysis of mouse retina confirms the roles GPATCH11 plays in RNA processing, splicing, and transcription regulation, while also suggesting additional functions in synaptic plasticity and nuclear stress response. Our research provides insights into the diverse roles of GPATCH11 whose mutations are responsible for a new described syndrome.