Carnitine Palmitoyltransferase 1A Research Articles

NQO1/CPT1A promotes the progression of pancreatic adenocarcinoma via fatty acid oxidation.

NQO1, a cytosolic enzyme, is closely related to the progression of cancers and poor outcome of cancer patients. However, the molecular biological mechanism of NQO1 tumorigenicity in pancreatic adenocarcinoma (PAAD) has not been clearly understood. In this study, we demonstrate the molecular mechanism of NQO1 in PAAD proliferation, metastasis and fatty acid oxidation (FAO). Multiple databases and western blot analysis show that NQO1 is overexpressed in PAAD and associated with lymph node metastasis and shorter survival. Furthermore, in vitro and in vivo experiments reveal that overexpression of NQO1 improves tumor growth, metastasis and FAO in PAAD. Mechanistically, NQO1 is able to bind to carnitine palmitoyltransferase 1A (CPT1A), a key enzyme controlling FAO. Therefore, Co-IP and a series of rescue experiments demonstrate that NQO1 promotes PAAD progression via CPT1A-mediated FAO. Our findings identify CPT1A-dependent FAO as an essential metabolic pathway for NQO1 to promote the PAAD process. Targeting the NQO1/CPT1A/FAO axis in PAAD to attenuate proliferation and dissemination is a potential approach to promote a better antitumour effect and improve patient outcomes.

Inhibition of Fatty Acid β-Oxidation by Fatty Acid Binding Protein 4 Induces Ferroptosis in HK2 Cells Under High Glucose Conditions.

Ferroptosis, which is caused by an iron-dependent accumulation of lipid hydroperoxides, is a type of cell death linked to diabetic kidney disease (DKD). Previous research has shown that fatty acid binding protein 4 (FABP4) is involved in the regulation of ferroptosis in diabetic retinopathy. The present study was constructed to explore the role of FABP4 in the regulation of ferroptosis in DKD. We first detected the expression of FABP4 and proteins related to ferroptosis in renal biopsies of patients with DKD. Then, we used a FABP4 inhibitor and small interfering RNA to investigate the role of FABP4 in ferroptosis induced by high glucose in human renal proximal tubular epithelial (HG-HK2) cells. In kidney biopsies of DKD patients, the expression of FABP4 was elevated, whereas carnitine palmitoyltransferase-1A (CP-T1A), glutathione peroxidase 4, ferritin heavy chain, and ferritin light chain showed reduced expression. In HG-HK2 cells, the induction of ferroptosis was accompanied by an increase in FABP4. Inhibition of FABP4 in HG-HK2 cells changed the redox state, sup-pressing the production of reactive oxygen species, ferrous iron (Fe2+), and malondialdehyde, increasing superoxide dismutase, and reversing ferroptosis-associated mitochondrial damage. The inhibition of FABP4 also increased the expression of CPT1A, reversed lipid deposition, and restored impaired fatty acid β-oxidation. In addition, the inhibition of CPT1A could induce ferroptosis in HK2 cells. Our results suggest that FABP4 mediates ferroptosis in HG-HK2 cells by inhibiting fatty acid β-oxidation.

Implantation of CPT1AM-expressing adipocytes reduces obesity and glucose intolerance in mice

Obesity and its associated metabolic comorbidities are a rising global health and social issue, with novel therapeutic approaches urgently needed. Adipose tissue plays a key role in the regulation of energy balance and adipose tissue-derived mesenchymal stem cells (AT-MSCs) have gained great interest in cell therapy. Carnitine palmitoyltransferase 1A (CPT1A) is the gatekeeper enzyme for mitochondrial fatty acid oxidation. Here, we aimed to generate adipocytes expressing a constitutively active CPT1A form (CPT1AM) that can improve the obese phenotype in mice after their implantation. AT-MSCs were differentiated into mature adipocytes, subjected to lentivirus-mediated expression of CPT1AM or the GFP control, and subcutaneously implanted into mice fed a high-fat diet (HFD). CPT1AM-implanted mice showed lower body weight, hepatic steatosis and serum insulin and cholesterol levels alongside improved glucose tolerance. HFD-induced increases in adipose tissue hypertrophy, fibrosis, inflammation, endoplasmic reticulum stress and apoptosis were reduced in CPT1AM-implanted mice. In addition, the expression of mitochondrial respiratory chain complexes was enhanced in the adipose tissue of CPT1AM-implanted mice. Our results demonstrate that implantation of CPT1AM-expressing AT-MSC-derived adipocytes into HFD-fed mice improves the obese metabolic phenotype, supporting the future clinical use of this ex vivo gene therapy approach.

Lysosomal acid lipase regulates bioenergetic process during the cytodifferentiation of human periodontal ligament cells

Lipid metabolism is one of energy metabolic pathways that produce adenosine triphosphate (ATP). In this pathway, lysosomal acid lipase (LAL) encoded by Lipase A (LIPA), plays an important role in catalyzing lipids to fatty acids (FAs), which drive oxidative phosphorylation (OXPHOS) and generate ATP. Previously, we found that a LIPA single nucleotide polymorphism rs143793106, which decreases the LAL activity, suppressed the cytodifferentiation of human periodontal ligament (HPDL) cells. However, the mechanisms underlying that suppression are still not fully clarified. Thus, we aimed to investigate the mechanisms regulating the cytodifferentiation of HPDL cells by LAL in terms of energy metabolism. We performed the osteogenic induction of HPDL cells with or without Lalistat-2, a LAL inhibitor. To visualize lipid droplet (LD) utilization, we performed confocal microscopy on HPDL cells. We also performed real-time PCR to analyze the gene expression of calcification-related and metabolism-related genes. Furthermore, we measured the ATP production rate from two major energy production pathways, OXPHOS and glycolysis, and OXPHOS-related parameters of HPDL cells during their cytodifferentiation. We found that LDs were utilized during the cytodifferentiation of HPDL cells. Alkaline phosphatase (ALPL), collagen type 1 alpha 1 chain (COL1A1), ATP synthase F1 subunit alpha (ATP5F1A), and carnitine palmitoyltransferase 1A (CPT1A) mRNA expressions were upregulated, whereas lactate dehydrogenase A (LDHA) mRNA expression was downregulated. Additionally, total ATP production rate was significantly increased. In contrast, in the presence of Lalistat-2, LD utilization was inhibited and ALPL, COL1A1, and ATP5F1A mRNA expression was downregulated. Additionally, ATP production rate and spare respiratory capacity of the OXPHOS pathway were decreased in HPDL cells during their cytodifferentiation. Collectively, the defect of LAL in HPDL cells decreased LD utilization and OXPHOS capacity, resulting in reduced energy to sustain the adequate ATP production required for the cytodifferentiation of HPDL cells. Thus, LAL is important for periodontal tissue homeostasis as a regulator of bioenergetic process of HPDL cells.

Punicalagin inhibits hepatic lipid deposition in obese mice via AMPK/ACC pathway

Hepatic lipid deposition is one of the basic manifestations of obesity, and nowadays pharmacological treatment is the most important tool. Punicalagin(PU), a polyphenol derived from pomegranate peel, is a potential anti-obesity substance. In this study, 60 C57BL/6J mice were randomly divided into a normal group and a model group. After establishing a model of simple obesity with a high-fat diet for 12 weeks, the successfully established rat models of obesity were then regrouped into a model group, an orlistat group, a PU low-dose group, a PU medium-dose group, and a PU high-dose group. The normal group was kept on routine diet and other groups continued to feed the high-fat diet. The body weight and food intake were measured and recorded weekly. After 8 weeks, the levels of the four lipids in the serum of each group of mice were determined by an automatic biochemical instrument. Oral glucose tole-rance and intraperitoneal insulin sensitivity were tested. Hemoxylin-eosin(HE) staining was applied to observe the hepatic and adipose tissues. The mRNA expression levels of peroxisome proliferators-activated receptor γ(PPARγ) and C/EBPα were determined by real-time quantitative polymerase chain reaction(Q-PCR), and the mRNA and protein expression levels of adenosine 5'-monophosphate-activated protein kinase(AMPK), anterior cingulate cortex(ACC), and carnitine palmitoyltransferase 1A(CPT1A) were determined by Western blot. Finally, the body mass, Lee's index, serum total glyceride(TG), serum total cholesterol(TC), and low-density lipoprotein cholesterol(LDL-C) levels were significantly higher and high-density lipoprotein cholesterol(HDL-C) levels were significantly lower in the model group as compared with the normal group. The fat deposition in the liver was significantly increased. The mRNA expression levels of hepatic PPARγ and C/EBPα and the protein expression level of ACC were increased, while the mRNA and protein expression levels of CPT-1α(CPT1A) and AMPK were decreased. After PU treatment, the above indexes of obese mice were reversed. In conclusion, PU can decrease the body weight of obese mice and control their food intake. It also plays a role in the regulation of lipid metabolism and glycometabolism metabolism, which can significantly improve hepatic fat deposition. Mechanistically, PU may regulate liver lipid deposition in obese mice by down-regulating lipid synthesis and up-regulating lipolysis through activation of the AMPK/ACC pathway.

Short-Term Growth Hormone Administration Mediates Hepatic Fatty Acid Uptake and De Novo Lipogenesis Gene Expression in Obese Rats

Obesity has been linked to metabolic syndrome, type 2 diabetes, and non-alcoholic fatty liver disease (NAFLD). Obesity causes a decrease in growth hormone (GH) levels and an increase in insulin levels. Long-term GH treatment increased lipolytic activity as opposed to decreasing insulin sensitivity. Nonetheless, it is possible that short-term GH administration had no impact on insulin sensitivity. In this study, the effect of short-term GH administration on liver lipid metabolism and the effector molecules of GH and insulin receptors were investigated in diet-induced obesity (DIO) rats. Recombinant human GH (1 mg/kg) was then administered for 3 days. Livers were collected to determine the hepatic mRNA expression and protein levels involved in lipid metabolism. The expression of GH and insulin receptor effector proteins was investigated. In DIO rats, short-term GH administration significantly reduced hepatic fatty acid synthase (FASN) and cluster of differentiation 36 (CD36) mRNA expression while increasing carnitine palmitoyltransferase 1A (CPT1A) mRNA expression. Short-term GH administration reduced hepatic FAS protein levels and downregulated gene transcription of hepatic fatty acid uptake and lipogenesis, while increasing fatty acid oxidation in DIO rats. DIO rats had lower hepatic JAK2 protein levels but higher IRS-1 levels than control rats due to hyperinsulinemia. Our findings suggest that short-term GH supplementation improves liver lipid metabolism and may slow the progression of NAFLD, where GH acts as the transcriptional regulator of related genes.

Mitochondrial CPT1A: Insights into structure, function, and basis for drug development.

Carnitine Palmitoyl-Transferase1A (CPT1A) is the rate-limiting enzyme in the fatty acid β-oxidation, and its deficiency or abnormal regulation can result in diseases like metabolic disorders and various cancers. Therefore, CPT1A is a desirable drug target for clinical therapy. The deep comprehension of human CPT1A is crucial for developing the therapeutic inhibitors like Etomoxir. CPT1A is an appealing druggable target for cancer therapies since it is essential for the survival, proliferation, and drug resistance of cancer cells. It will help to lower the risk of cancer recurrence and metastasis, reduce mortality, and offer prospective therapy options for clinical treatment if the effects of CPT1A on the lipid metabolism of cancer cells are inhibited. Targeted inhibition of CPT1A can be developed as an effective treatment strategy for cancers from a metabolic perspective. However, the pathogenic mechanism and recent progress of CPT1A in diseases have not been systematically summarized. Here we discuss the functions of CPT1A in health and diseases, and prospective therapies targeting CPT1A. This review summarizes the current knowledge of CPT1A, hoping to prompt further understanding of it, and provide foundation for CPT1A-targeting drug development.

Calponin 2 harnesses metabolic reprogramming to determine kidney fibrosis

ObjectiveIn the fibrotic kidneys, the extent of a formed deleterious microenvironment is determined by cellular mechanical forces. This process requires metabolism for energy. However, how cellular mechanics and metabolism are connected remains unclear. MethodsA multi-disciplinary approach was employed: the fibrotic kidney disease models were induced by renal ischemia-reperfusion injury and unilateral ureteral obstruction in Calponin 2 (CNN2) knockdown mice. Proteomics, bioinformatics, and in vivo and in vitro molecular experimental pathology studies were performed. ResultOur proteomics revealed that actin filament binding and cell metabolism are the two most dysregulated events in the fibrotic kidneys. As a prominent actin stabilizer, CNN2 was predominantly expressed in fibroblasts and pericytes. In CKD patients, CNN2 levels was markedly induced in blood. In mice, CNN2 knockdown preserves kidney function and alleviates fibrosis. Global proteomics profiled that CNN2 knockdown enhanced the activities of the key rate-limiting enzymes and regulators of fatty acid oxidation (FAO) in the diseased kidneys. Inhibiting carnitine palmitoyltransferase 1α in the FAO pathway resulted in lipid accumulation and extracellular matrix deposition in the fibrotic kidneys, which were restored after CNN2 knockdown. Bioinformatics and chromatin immunoprecipitation showed that CNN2 interactor, estrogen receptor 2 (ESR2), binds peroxisome proliferator-activated receptor-α (PPARα) to transcriptionally regulate FAO downstream target genes expression amid kidney fibrosis. In vitro, ESR2 knockdown repressed the mRNA levels of PPARα and the key genes in the FAO pathway. Conversely, activation of PPARα reduced CNN2-induced matrix inductions. ConclusionsOur results suggest that balancing cell mechanics and metabolism is crucial to develop therapeutic strategies to halt kidney fibrosis.

Palmitate paves the way to lung metastasis

New findings by Altea-Manzano et al. demonstrate that primary breast tumours or a high-fat diet induce palmitate secretion by alveolar type 2 (AT2) cells to prepare a premetastatic niche that promotes lung metastasis. Palmitate is utilised by cancer cells via carnitine palmitoyltransferase 1a (CPT1a) and lysine acetyltransferase 2a (KAT2a) to acetylate nuclear factor-κB (NF-κB)/p65. Blocking these enzymes reduced metastasis formation in both lean and high-fat diet mice.

Goliath induces inflammation in obese mice by linking fatty acid β-oxidation to glycolysis.

Obesity is associated with metabolic disorders and chronic inflammation. However, the obesity-associated metabolic contribution to inflammatory induction remains elusive. Here, we show that, compared with lean mice, CD4+ T cells from obese mice exhibit elevated basal levels of fatty acid β-oxidation (FAO), which promote T cell glycolysis and thus hyperactivation, leading to enhanced induction of inflammation. Mechanistically, the FAO rate-limiting enzyme carnitine palmitoyltransferase 1a (Cpt1a) stabilizes the mitochondrial E3 ubiquitin ligase Goliath, which mediates deubiquitination of calcineurin and thus enhances activation of NF-AT signaling, thereby promoting glycolysis and hyperactivation of CD4+ T cells in obesity. We also report the specific GOLIATH inhibitor DC-Gonib32, which blocks this FAO-glycolysis metabolic axis in CD4+ T cells of obese mice and reduces the induction of inflammation. Overall, these findings establish a role of a Goliath-bridged FAO-glycolysis axis in mediating CD4+ T cell hyperactivation and thus inflammation in obese mice.

Abstract P6-11-05: Carnitine palmitoyltransferase 1A (CPT1A) mediates therapeutic response to endocrine therapy in estrogen receptor positive breast cancer

Abstract Breast cancer (BC) is the most commonly diagnosed cancer and second leading cause of cancer-related deaths in women in the United States, with more than 70% of the cases are hormone receptor positive (HR+) disease. Endocrine based therapies (ET) are successfully used, however, 30-50% will acquire ET resistance leading to tumor progression. Since the mechanism of acquired resistance remains unknown for ~60% of patients, identifying novel mechanisms of resistance is essential. We recently reported that carnitine palmitoyltransferase 1A (CPT1A), the rate limiting enzyme in fatty acid oxidation, is overexpressed in aggressive HR+ tumors, including ET resistant patients. We propose that CPT1A level and activity changes the tumor microenvironment to enhance tumorigenesis and contribute to ET resistance. To determine the mechanism by which CPT1A is promoting cell proliferation, tumor microenvironment, cellular signaling and ET resistance, we used a series of in vitro studies incorporating a panel of either endogenously or experimentally derived CPT1A-low and CPT1A-high controls, HR+ breast cancer cell lines as well as their ET resistant counterparts. We determined that CPT1A is upregulated in cell lines that acquire ET resistance. Our analyses demonstrated that levels of CPT1A can affect tumor formation ability in both CPT1A-high and adjacent CPT1A-low tumor cells with concurrent changes in both intra- and inter-cellular signaling which may be essential to promote tumor progression and mediate therapeutic response. This represents a promising step in understanding the mechanisms that promote tumorigenesis and ET resistance in HR+ breast cancer. Citation Format: Shaimaa Hussein, Michael L. Gatza, Shridar Ganesan. Carnitine palmitoyltransferase 1A (CPT1A) mediates therapeutic response to endocrine therapy in estrogen receptor positive breast cancer [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P6-11-05.

Long-term dietary DHA intervention prevents telomere attrition and lipid disturbance in telomerase-deficient male mice.

Previous evidence indicated anti-ageing potential of docosahexaenoic acid (DHA), but the underlying mechanism remains unclear. We investigated protective effect of DHA on telomere attrition and lipid disturbance in male mice with premature ageing caused by telomerase deficiency. Wild-type (WT) and fourth-generation telomerase-deficient (G4 Terc-/-, Terc knockout, KO) male mice (C57BL/6, 2months old) were fed control diet (WT-C and KO-C groups) or DHA-enriched diet containing 0.80% DHA by weight (WT-DHA and KO-DHA groups) for 10months. The ageing phenotypes and metabolic level [carbon dioxide emission, oxygen consumption, and respiratory exchange ratio (RER)] were assessed at the end of the experiment. Telomere length in various tissues and the hepatic gene and protein expression for regulating lipid synthesis and lipolysis were measured. Data were tested using one- or two-factor ANOVA. In KO male mice, DHA prevented weight loss, corrected high RER, and reduced fat loss. Telomere shortening was reduced by 22.3%, 25.5%, and 13.5% in heart, liver, and testes of the KO-DHA group compared with those in the KO-C group. The KO-DHA group exhibited higher gene transcription involved in glycerol-3-phosphate pathway [glycerol-3-phosphate acyltransferase (Gpat)], lower gene expression of β-oxidation [carnitine palmitoyltransferase 1a (Cpt1a)], and upregulation of proteins in lipid synthesis [mammalian target of rapamycin complex 1 (mTORC1) and sterol responsive element binding protein 1 (SREBP1)] in liver than the KO-C group. Long-term DHA intervention attenuates telomere attrition and promotes lipid synthesis via the tuberous sclerosis complex 2 (TSC2)-mTORC1-SREBP1 pathway in KO male mice.

Ror1 promotes PPARα-mediated fatty acid metabolism in astrocytes.

Ror1 signaling regulates cell polarity, migration, proliferation, and differentiation during developmental morphogenesis, and plays an important role in regulating neurogenesis in the embryonic neocortices. However, the role of Ror1 signaling in the brains after birth remains largely unknown. Here, we found that expression levels of Ror1 in the mouse neocortices increase during the postnatal period, when astrocytes mature and start expressing GFAP. Indeed, Ror1 is highly expressed in cultured postmitotic mature astrocytes. RNA-Seq analysis revealed that Ror1 expressed in cultured astrocytes mediates upregulated expression of genes related to fatty acid (FA) metabolism, including the gene encoding carnitine palmitoyl-transferase 1a (Cpt1a), the rate-limiting enzyme of mitochondrial fatty acid β-oxidation (FAO). We also found that Ror1 promotes the degradation of lipid droplets (LDs) accumulated in the cytoplasm of cultured astrocytes after oleic acid loading, and that suppressed expression of Ror1 decreases the amount of FAs localized at mitochondria, intracellular ATP levels, and expression levels of peroxisome proliferator-activated receptor α (PPARα) target genes, including Cpt1a. Collectively, these findings indicate that Ror1 signaling promotes PPARα-mediated transcription of FA metabolism-related genes, thereby facilitating the availability of FAs derived from LDs for mitochondrial FAO in the mature astrocytes.

Feeding rumen-protected lysine altered immune and metabolic biomarkers in dairy cows during the transition period

This experiment was conducted to determine the effects of feeding rumen-protected lysine (RPL; AjiPro-L Generation 3, Ajinomoto Health and Nutrition North America Inc.) from -26 ± 4.6 d prepartum (0.54% RPL of dietary dry matter intake) to 28 d postpartum (0.39% RPL of dietary dry matter intake) on immunometabolic status and liver composition in dairy cows. Seventy-five multiparous Holstein cows, blocked by parity, previous 305-d mature-equivalent milk production, expected calving date, and body condition score during the far-off dry period were assigned to 1 of 4 dietary treatments in a randomized, complete block design with a 2 × 2 factorial arrangement of treatments. Treatments prepartum consisted of total mixed ration top dressed with RPL (PRE-L) or without RPL (PRE-C), and postpartum treatments consisted of total mixed ration top dressed PRE-L prepartum and postpartum, PRE-L prepartum and PRE-C postpartum, PRE-C prepartum and PRE-L postpartum, and PRE-C prepartum and postpartum in 300 g of molasses. Blood samples were taken on -7 ± 0.5, 0 ± 0.5, 7 ± 0.9, 14 ± 0.9, and 28 ± 0.5 d relative to calving. Whole blood samples were taken on -14 ± 0.5, -7 ± 0.5, 7 ± 0.9, and 14 ± 0.9 d relative to calving for oxidative burst and phagocytic capacity of monocytes and neutrophils. Liver samples were collected via a biopsy on -12 ± 4.95 and 13 ± 2.62 d relative to calving and analyzed for liver composition (triacylglyceride and carnitine concentrations), mRNA expression of hepatic genes, and protein abundance. Protein abundance was calculated by normalizing intensity bands for a specific protein with glyceraldehyde-3-phosphate dehydrogenase. Concentrations of haptoglobin and glutathione peroxidase activity in plasma were lower at d 0 for cows in PRE-L (102 µg/mL and 339 nmol/min per mL, respectively) compared with cows in PRE-C (165 µg/mL and 405 nmol/min per mL, respectively). Oxidative burst capacity in monocytes tended to be greater on d 7 postpartum for cows in PRE-L (65.6%) than cows in PRE-C (57.5%). Additionally, feeding RPL altered the mRNA expression in liver tissue prepartum [decreased INSR (insulin receptor), CPT1A (carnitine palmitoyltransferase 1A), and IL1B (interleukin 1 β)] and postpartum [increased IL8 (interleukin 8), EHMT2 (euchromatic histone lysine methyltransferase 2), TSPO (translocator protein), and SLC3A2 (solute carrier family 3 member 2); and decreased SLC7A1 (solute carrier family 7 member 1), SOD1 (superoxide dismutase 1), and SAA3 (serum amyloid A 3)] compared with cows not consuming RPL]. Additionally, cows in the PRE-C prepartum and PRE-L postpartum treatment tended to have greater protein abundance of mTOR postpartum compared with the PRE-C prepartum and postpartum treatment. Protein abundance of SLC7A7 (solute carrier family 7 member 7) pre- and postpartum tended to be greater and BBOX1 (gamma-butyrobetaine dioxygenase 1) tended to be less when RPL was consumed prepartum. In conclusion, cows that consumed RPL during the transition period had molecular changes related to liver composition, enhanced liver function indicated by greater total protein and albumin concentrations in plasma, and improved immune status indicated by decreased haptoglobin, glutathione peroxidase activity, and immune related mRNA expression.

Tandem mass tag-based quantitative proteomics analysis reveals the effects of the α-lactalbumin peptides GINY and DQW on lipid deposition and oxidative stress in HepG2 cells

The objective of this study was to investigate the mechanism by which the α-lactalbumin peptides Gly-Ile-Asn-Tyr (GINY) and Asp-Gln-Trp (DQW) ameliorate free fatty acid-induced lipid deposition in HepG2 cells. The results show that GINY and DQW reduced triglyceride, total cholesterol, and free fatty acid levels significantly in free fatty acid-treated HepG2 cells. Based on proteomic analysis, GINY and DQW alleviated lipid deposition and oxidative stress mainly through the peroxisome proliferator-activated receptor (PPAR) pathway, fatty acid metabolism, oxidative phosphorylation, and response to oxidative stress. In vitro experiments confirmed that GINY and DQW upregulated the mRNA and protein expression of fatty acid β-oxidation-related and oxidative stress-related genes, and downregulated the mRNA and protein expression of lipogenesis-related genes by activating peroxisome proliferator-activated receptor α (PPARα). Meanwhile, GINY and DQW reduced free fatty acid-induced lipid droplet accumulation and reactive oxygen species generation, and enhanced the mitochondrial membrane potential and ATP levels. Furthermore, GINY and DQW enhanced carnitine palmitoyl-transferase 1a (CPT-1a) and superoxide dismutase activities, and diminished acetyl-coenzyme A carboxylase 1 (ACC1) and fatty acid synthase (FASN) activities in a PPARα-dependent manner. Interestingly, GW6471 (a PPARα inhibitor) weakened the effects of GINY and DQW on the PPARα pathway. Hence, our findings suggest that GINY and DQW have the potential to alleviate nonalcoholic fatty liver disease by activating the PPARα pathway.

CD4+ T cells expressing CX3CR1, GPR56, with variable CD57 are associated with cardiometabolic diseases in persons with HIV.

Persons with HIV (PWH) on long-term antiretroviral therapy (ART) have a higher incidence and prevalence of cardiometabolic diseases attributed, in part, to persistent inflammation despite viral suppression. In addition to traditional risk factors, immune responses to co-infections such as cytomegalovirus (CMV) may play an unappreciated role in cardiometabolic comorbidities and offer new potential therapeutic targets in a subgroup of individuals. We assessed the relationship of CX3CR1+, GPR56+, and CD57+/- T cells (termed CGC+) with comorbid conditions in a cohort of 134 PWH co-infected with CMV on long-term ART. We found that PWH with cardiometabolic diseases (non-alcoholic fatty liver disease, calcified coronary arteries, or diabetes) had higher circulating CGC+CD4+ T cells compared to metabolically healthy PWH. The traditional risk factor most correlated with CGC+CD4+ T cell frequency was fasting blood glucose, as well as starch/sucrose metabolites. While unstimulated CGC+CD4+ T cells, like other memory T cells, depend on oxidative phosphorylation for energy, they exhibited higher expression of carnitine palmitoyl transferase 1A compared to other CD4+ T cell subsets, suggesting a potentially greater capacity for fatty acid β-oxidation. Lastly, we show that CMV-specific T cells against multiple viral epitopes are predominantly CGC+. Together, this study suggests that among PWH, CGC+ CD4+ T cells are frequently CMV-specific and are associated with diabetes, coronary arterial calcium, and non-alcoholic fatty liver disease. Future studies should assess whether anti-CMV therapies could reduce cardiometabolic disease risk in some individuals.

Is There a Role of Warburg Effect in Prostate Cancer Aggressiveness? Analysis of Expression of Enzymes of Lipidic Metabolism by Immunohistochemistry in Prostate Cancer Patients (DIAMOND Study).

Prostate Cancer (PCa) is still ranked as the first cancer in the male population and evidences have suggested an alteration of glycemic and lipidic metabolism that are related to its progression and prognosis. The aim of the study is to investigate associations between enzymes' expression, especially involved in the lipidic pathway, and PCa aggressiveness. We retrospectively analyzed data from 390 patients with PCa or benign prostatic hyperplasia (BPH) at the Department of Urology, University of Catania. Immunohistochemical slides were evaluated for the expression of proteins related to glucose and lipidic metabolism. A total of 286 were affected by PCa while 104 by BPH. We demonstrated that ATP-lyase (odds ratio [OR]: 1.71; p < 0.01), fatty acid synthase (OR: 4.82; p < 0.01), carnitine palmitoyl transferase-1a (OR: 2.27; p < 0.05) were associated with androgen receptor (AR) expression. We found that steaoryl Co-A desaturase expression in PCa patients with total cholesterol ≥ 200 mg/dL was independently associated with ISUP ≥4 (OR: 4.22; p = 0.049). We found that CPT-1a+ was associated with biochemical recurrence (hazard ratio: 1.94; p = 0.03]). Our results support the evidence that the manipulation of lipidic metabolism could serve in the future to contrast PCa progression.

A palmitate-rich metastatic niche enables metastasis growth via p65 acetylation resulting in pro-metastatic NF-κB signaling.

Metabolic rewiring is often considered an adaptive pressure limiting metastasis formation; however, some nutrients available at distant organs may inherently promote metastatic growth. We find that the lung and liver are lipid-rich environments. Moreover, we observe that pre-metastatic niche formation increases palmitate availability only in the lung, whereas a high-fat diet increases it in both organs. In line with this, targeting palmitate processing inhibits breast cancer-derived lung metastasis formation. Mechanistically, breast cancer cells use palmitate to synthesize acetyl-CoA in a carnitine palmitoyltransferase 1a-dependent manner. Concomitantly, lysine acetyltransferase 2a expression is promoted by palmitate, linking the available acetyl-CoA to the acetylation of the nuclear factor-kappaB subunit p65. Deletion of lysine acetyltransferase 2a or carnitine palmitoyltransferase 1a reduces metastasis formation in lean and high-fat diet mice, and lung and liver metastases from patients with breast cancer show coexpression of both proteins. In conclusion, palmitate-rich environments foster metastases growth by increasing p65 acetylation, resulting in a pro-metastatic nuclear factor-kappaB signaling.

Abstract TMP29: Elevated Levels Of Palmitic Acid Mediate Early Disruption Of Endothelial Barrier Integrity And Promote Behavioral Dysfunction Relevance To Vascular Cognitive Impairment And Dementia (VCID)

Increased consumption of a high-fat diet (HFD) is believed to increase the risk for the development and progression of VCID, but the underlying mechanisms of how HFD leads to cognitive impairment are unclear, partly due to the use of different HFD models in preclinical studies. Palmitic acid (PA), the most common form of saturated fatty acid, found in the human cerebrospinal fluid in obesity, promotes disruption of BBB integrity. We hypothesized that a PA-rich diet mediates early disruption of blood brain barrier (BBB) integrity which leads to progressive neurovascular pathologies and cognitive impairment in VCID. Methods: Experimental design for in vivo studies is depicted in Fig 1. In vitro studies included assessment of endothelial integrity by trans-endothelial electrical resistance (TEER) and FITC measurements, cell viability, and expression levels of tight junction proteins and cell stress markers (Hsp70, Occludin1, Claudin 5, and Carnitine Palmitoyl transferase 1A -CTP1A) in male BMVECs cultured in normal and high PA conditions. Results (Table): Animals that were on the PA-rich diet exhibited risk-taking behavior. BMVECs showed significantly increased permeability of FITC-dextran and decreased TEER measurements. While Hsp70 and CTP1A increased with PA treatment, tight junction protein levels did not change. Conclusion: A special PA-rich diet mediates an anxiety-like behavior as early as 8 weeks without any metabolic effects. Assessments at 22 and 24W will determine whether behavioral dysfunction worsens and progresses to cognitive deficits. In vitro results suggest that initiation of the stress response may be the underlying mechanism of early BBB impairment. Modulation of the endothelial stress response may prevent/attenuate the development/progression of cognitive deficits induced by a PA-rich diet.

Lycopene alleviates lipopolysaccharide-induced testicular injury in rats by activating the PPAR signaling pathway to integrate lipid metabolism and the inflammatory response.

Male fertility can be hampered by systemic and testicular infections and inflammation, which can lead to impaired spermatogenesis that often cannot be reversed by antibiotic treatment. There has been some suggestion that lycopene (LYC) may be useful in the preservation of fertility, although its mechanisms are complex. This current study examined the therapeutic efficacy of LYC on testicular damage and its underlying mechanisms. Lipopolysaccharide (LPS; 5 mg/kg) was injected intraperitoneally to induce inflammation of the testes in mature male rats. The rats in the experimental group were administered 5 mg/kg LYC intragastrically for 4 weeks. The testes were harvested from the euthanized rats for lipidomics, RNA sequencing, and related experimental tests. Laboratory data suggested that LPS-induced systemic inflammation induced cytokine excess and oxidative stress in the testes. Administration of oral LYC inhibited the excess cytokine production and oxidative stress, mitigating damage to the testes. Lipidomic studies identified significant changes to 258 lipids and 5 metabolism pathways. Coupled with RNA sequencing analysis, 1,116 genes were found to be significantly regulated and many lipid metabolism-related signaling pathways were identified. The expression of retinoid X receptor alpha (RXR) in the peroxisome proliferator-activated receptor (PPAR) signaling pathway was significantly upregulated after LYC treatment, which activated the RXR/PPAR easy dimer. The expression of downstream genes such as fatty acid binding protein 3 (FABP3) and carnitine palmitoyltransferase 1A (CPT1A) was increased. These genes are involved in the control of fatty acid metabolism, fatty acid degradation, fatty acid chain elongation, and lipid metabolism, which partially explains the changes in the content and composition of lipids. LYC regulates the lipid metabolism of testes and lipid metabolism-related signaling pathways, such as the PPAR signaling pathway. Furthermore, LYC ameliorated the LPS-induced dysregulation of lipid metabolism in the testes, as well as the LPS-induced inflammatory response. This study offers a new perspective for the investigation of the mechanisms in inflammatory testicular damage and potential therapeutic targets.