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Background: Fatty acid metabolism in the hypothalamus has an important role in food intake, but its specific role in AgRP neurons is poorly understood. Here, we examined whether carnitinea palmitoyltransferase 1A (CPT1A), a key enzyme in mitochondrial fatty acid oxidation, affects energy balance. Methods: To obtain Cpt1aKO mice and their control littermates, Cpt1a(flox/flox) mice were crossed with tamoxifen-inducible AgRPCreERT2 mice. Food intake and body weight were analyzed weekly in both males and females. At 12 weeks of age, metabolic flexibility was determined by ghrelin-induced food intake and fasting–refeeding satiety tests. Energy expenditure was analyzed by calorimetric system and thermogenic activity of brown adipose tissue. To study fluid balance the analysis of urine and water intake volumes; osmolality of urine and plasma; as well as serum levels of angiotensin and components of RAAS (renin–angiotensin–aldosterone system) were measured. At the central level, changes in AgRP neurons were determined by: (1) analyzing specific AgRP gene expression in RiboTag–Cpt1aKO mice obtained by crossing Cpt1aKO mice with RiboTag mice; (2) measuring presynaptic terminal formation in the AgRP neurons with the injection of the AAV1-EF1a-DIO-synaptophysin-GFP in the arcuate nucleus of the hypothalamus; (3) analyzing AgRP neuronal viability and spine formations by the injection AAV9-EF1a-DIO-mCherry in the arcuate nucleus of the hypothalamus; (4) analyzing in situ the specific AgRP mitochondria in the ZsGreen-Cpt1aKO obtained by breeding ZsGreen mice with Cpt1aKO mice. Two-way ANOVA analyses were performed to determine the contributions of the effect of lack of CPT1A in AgRP neurons in the sex. Results: Changes in food intake were just seen in male Cpt1aKO mice while only female Cpt1aKO mice increased energy expenditure. The lack of Cpt1a in the AgRP neurons enhanced brown adipose tissue activity, mainly in females, and induced a substantial reduction in fat deposits and body weight. Strikingly, both male and female Cpt1aKO mice showed polydipsia and polyuria, with more reduced serum vasopressin levels in females and without osmolality alterations, indicating a direct involvement of Cpt1a in AgRP neurons in fluid balance. AgRP neurons from Cpt1aKO mice showed a sex-dependent gene expression pattern, reduced mitochondria and decreased presynaptic innervation to the paraventricular nucleus, without neuronal viability alterations. Conclusions: Our results highlight that fatty acid metabolism and CPT1A in AgRP neurons show marked sex differences and play a relevant role in the neuronal processes necessary for the maintenance of whole-body fluid and energy balance. Highlights: Fatty acid metabolism and CPT1A in AgRP neurons show marked sex-dependent differences in the control of feeding. Cpt1a gene deletion in AgRP neurons increases energy expenditure in females but not in males. CPT1A in AgRP neurons is involved in the control of thirst and fluid homeostasis. Cpt1a gene deletion in AgRP neurons induces morphological, mitochondrial, and gene expression alterations in a sex-dependent manner. [ABSTRACT FROM AUTHOR]

Background: Histologically, cytoplasmic deposits of lipids and glycogen are common in clear cell renal cell carcinoma (ccRCC). Owing to the significance of lipid deposition in ccRCC, numerous trials targeting lipid metabolism have shown certain therapeutic potential. The agonism of peroxisome proliferator-activated receptor-α (PPARα) via ligands, including WY-14,643, has been considered a promising intervention for cancers. Methods: First, the effects of WY-14,643 on malignant behaviors were investigated in ccRCC in vitro. After RNA sequencing, the changes in lipid metabolism, especially neutral lipids and glycerol, were further evaluated. Finally, the underlying mechanisms were revealed. Results: Phenotypically, the proliferation and migration of ccRCC cells treated with WY-14,643 were significantly inhibited in vitro. A theoretical functional mechanism was proposed in ccRCC: WY-14,643 mediates lipid consumption by recognizing carnitine palmitoyltransferase 1 A (CPT1A). Activation of PPARα using WY-14,643 reduces lipid deposition by increasing the CPT1A level, which also suppresses the NF-κB signaling pathway. Spatially, WY-14,643 binds and activates PPARα by targeting Gly335. Conclusion: Overall, WY-14,643 suppresses the biological behaviors of ccRCC in terms of cell proliferation, migration, and cell cycle arrest. Furthermore, its anticancer properties are mediated by the inhibition of lipid accumulation, at least in part, through the PPARα/CPT1A axis by targeting Gly335, as part of the process, NF-κB signaling is also suppressed. Pharmacological activation of PPARα might offer a new treatment option for ccRCC. [ABSTRACT FROM AUTHOR]

Background: Fatty acid oxidation plays an important role in a variety of developing and mature organ systems. However, the role of this metabolic pathway in different stages of testis development remains unknown. Here, we elucidate the mechanisms by which fatty acid oxidation regulates the maintenance and differentiation of gonocytes and spermatogonial stem cells. Results: During E13.5-E15.5, male germ cells gradually enter the mitotic arrest phase, while the expression of CPT1A, a rate-limiting enzyme for fatty acid oxidation, gradually increases. Therefore, we treated pregnant mice (E13.5 to E15.5) with etomoxir, which is an inhibitor of CPT1A. Etomoxir-treated mice showed no difference in embryonic morphology; however, etomoxir-treated male gonocytes exited mitotic arrest, and cells of the gonad underwent apoptosis. In addition, etomoxir-treated mice at P7 displayed impaired homing of spermatogonia and increased cell apoptosis. We further demonstrated that inhibition of fatty acid oxidation in gonads was associated with gonocyte differentiation events and the histone modification H3K27ac. Conclusions: Inhibiting fatty acid oxidation can specifically reduce the level of H3K27ac in the reproductive crest, which may be the cause of the down-regulation of male differentiation-specific gene expression, which ultimately leads to the male primordial germ cells exited from mitotic arrest. Our work uncovers metabolic reprogramming during male gonadal development, revealing that it plays an important role in the maintenance of gonocytes in a differentiated and quiescent state during foetal testis development. [ABSTRACT FROM AUTHOR]

Background: Human placenta-derived mesenchymal stem cells (PD-MSCs) are powerful sources for cell therapy in regenerative medicine. However, a limited lifespan by senescence through mechanisms that are well unknown is the greatest obstacle. In the present study, we first demonstrated the characterization of replicative senescent PD-MSCs and their possible mitochondrial functional alterations. Methods: Human PD-MSCs were cultured to senescent cells for a long period of time. The cells of before passage number 8 were early cells and after passage number 14 were late cells. Also, immortalized cells of PD-MSCs (overexpressed hTERT gene into PD-MSCs) after passage number 14 were positive control of non-senescent cells. The characterization and mitochondria analysis of PD-MSCs were explored with long-term cultivation. Results: Long-term cultivation of PD-MSCs exhibited increases of senescent markers such as SA-β-gal and p21 including apoptotic factor, and decreases of proliferation, differentiation potential, and survival factor. Mitochondrial dysfunction was also observed in membrane potential and metabolic flexibility with enlarged mitochondrial mass. Interestingly, we founded that fatty acid oxidation (FAO) is an important metabolism in PD-MSCs, and carnitine palmitoyltransferase1A (CPT1A) overexpressed in senescent PD-MSCs. The inhibition of CPT1A induced a change of energy metabolism and reversed senescence of PD-MSCs. Conclusions: These findings suggest that alteration of FAO by increased CPT1A plays an important role in mitochondrial dysfunction and senescence of PD-MSCs during long-term cultivation. [ABSTRACT FROM AUTHOR]

Background: Macrophage are specialized cells that contributes to the removal of detrimental contents via phagocytosis. Lipid accumulation in macrophages, whether from phagocytosis of dying cells or from circulating oxidized low-density lipoproteins, alters macrophage biology and functionality. It is known that carnitine palmitoyl transferase 1-a (CPT1a) gene encodes an enzyme involved in fatty acid oxidation and, therefore, lipid content. However, the potential of CPT1a to activate macrophage phagocytic function have not been elucidated. Methods: Using a murine macrophage cell line, RAW264.7, we determine if intracellular accumulation of 7-ketocholesterol (7-KC) modulates macrophage phagocytic function through CPT1a gene expression. In addition, the effects of CPT1a genetic modification on macrophage phenotype and phagocytosis has been studied. Results: Our results revealed that CPT1a gene expression decreased by the accumulation of 7-KC at the higher dose of 7-KC. This was concomitant with an impair ability to phagocytize bioparticles and an inflammatory phenotype. GW3965 treatment, which have shown to facilitate the efflux of cholesterol, eliminated the intracellular lipid droplets of 7-KC-laden macrophages, increased the gene expression of CPT1a, diminished the gene expression of the inflammatory marker iNOS and restored macrophage phagocytosis. Furthermore, CPT1a Knockdown per se was detrimental for macrophage phagocytosis whereas transcriptional activation of CPT1a heightened the uptake of bioparticles. Conclusions: Altogether, our findings indicate that downregulation of CPT1a by lipid content modulates macrophage phagocytosis and inflammatory phenotype. [ABSTRACT FROM AUTHOR]

Background: Altered cellular metabolism is a hallmark of cancer but the association between utilisation of particular metabolic pathways in tumours and patient outcome is poorly understood. We sought to investigate the association between fatty acid metabolism and outcome in breast and other cancers.Methods: Cox regression analysis and Gene Set Enrichment Analysis (GSEA) of a gene expression dataset from primary breast tumours with well annotated clinical and survival information was used to identify genesets associated with outcome. A geneset representing fatty acid oxidation (FAO) was then examined in other datasets. A doxycycline-inducible breast cancer cell line model overexpressing the rate-limiting enzyme in FAO, carnitine palmitoyl transferase 1A (CPT1A) was generated and analysed to confirm the association between FAO and cancer-associated characteristics in vitro.Results: We identified a gene expression signature composed of 19 genes associated with fatty acid oxidation (FAO) that was significantly associated with patient outcome. We validated this observation in eight independent breast cancer datasets, and also observed the FAO signature to be prognostic in other cancer types. Furthermore, the FAO signature expression was significantly downregulated in tumours, compared to normal tissues from a variety of anatomic origins. In breast cancer, the expression of CPT1A was higher in oestrogen receptor (ER)-positive, compared to ER-negative tumours and cell lines. Importantly, overexpression of CPT1A significantly decreased the proliferation and wound healing migration rates of MDA-MB231 breast cancer cells, compared to basal expression control.Conclusions: Our findings suggest that FAO is downregulated in multiple tumour types, and activation of this pathway may lower cancer cell proliferation, and is associated with improved outcomes in some cancers. [ABSTRACT FROM AUTHOR]

Background Lipid accumulation is the primary evidence of non-alcoholic fatty liver disease (NAFLD). Ginkgo biloba extract (GBE) and its flavonoid ingredients (quercetin, kaempferol, and isorhamnetin) could lessen the lipid accumulation associated with up-regulation of the rate-limiting enzyme, carnitine palmitoyltransferase 1A (CPT1A), in the β-oxidation of long-chain fatty acids. In this study, we investigated the mechanisms by which GBE and its flavonoids induced expression of CPT1A. Results CPT1A inhibition with RNAi resulted in triglyceride accumulation in HepG2 cells. Through deletion and mutation analysis of CPT1A's promoter combined with electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP) experiments, the CPT1A promoter region (-50 to -5 nt) was determined to contain two putative Sp1 binding sites, namely Sp1a and Sp1b, which might act as the GBE regulation response DNA element. Sp1 might be induced to transfer from cytoplasma to nucleus to bind the promoter region of -50 to -5 nt by GBE. The regulatory effects of GBE on CPT1A were also verified on the flavonoid ingredients quercetin, kaempferol, and isorhamnetin. Conclusion Sp1 was crucial in regulating CPT1A expression with GBE and its flavonoid ingredients, and the -50 to -5 nt region of CPT1A promoter played important roles in Sp1 binding. [ABSTRACT FROM AUTHOR]