Expression Of FABP4 Research Articles

Concentration and composition of circulating vesicles of adipocytic origin in patients with colon polyps and colorectal cancer

Extracellular vesicles (EVs) are a heterogeneous population of membrane particles less than 1 μm in size, secreted by various cell types. Most EVs circulating in human blood are particles of platelet, leukocyte, erythrocyte and endothelial origin. The composition of circulating adipocyte EVs in various pathological conditions has been virtually unknown. Small EVs from the blood plasma of patients with colorectal cancer (CRC) and colon polyps with obesity or metabolic syndrome were isolated by ultrafiltration with double ultracentrifugation. To study the composition of adipocyte EVs, immunoprecipitation in combination with Western blotting and flow cytometry were used. Vesicle fractions (FABP4- and CD11b-immunoprecipitated EVs, as well as EVs contained in the supernatant after removal of CD11b-positive EVs) contained a complex of adipocyte markers (FABP4, PPAR-γ and perilipin 1). EVs of monocyte-macrophage origin precipitated on CD11b-coated particles in CRC patients without obesity were characterized by combined overexpression of FABP4 and perilipin 1, while such overexpression was not typical for CRC patients with metabolic syndrome or obesity. The fraction of truly adipocyte vesicles (supernatant after removal of CD11b-positive EVs) was characterized by the presence in all patients of a complex of adipocyte markers with predominant expression of FABP4 in both patients with metabolic syndrome/metabolically healthy obesity and patients without metabolic disorders. To correctly characterize circulating EVs of patients without obesity, it is first necessary to remove the fraction of CD11b-positive monocyte-macrophage EVs from EV preparations by immunoprecipitation or similar methods, and in the supernatant after removal/sorption of precipitated EVs, the composition of adipocyte vesicles can be studied using a set of markers (FABP4, PPAR-γ, perilipin 1, etc.). Moreover, in patients with metabolic disorders, taking into account the insignificant expression of FABP4 in CD11b-immunoprecipitated EVs, preliminary depletion of vesicle preparations is apparently not so necessary.

Abstract 4115669: Single-cell and Spatial Transcriptomics Identified Fatty Acid-binding Proteins Controlling Endothelial Glycolytic and Arterial Programming in Pulmonary Hypertension

We are seeking to elucidate the endothelial fatty acid metabolism role for obstructive vascular remodeling in the pathogenesis of PAH. In this study, we bred a severe mouse model of PH Egln1 Tie2Cre mice with Fabp45 -/- mice to generate Egln1 Tie2Cre / Fabp45 -/- mice. We applied single-cell RNA sequencing (scRNA-seq) to profile the pulmonary cells in Egln1 Tie2Cre mice and Egln1 Tie2Cre / Fabp45 -/- mice. Human hPAEC from idiopathic PAH patients and healthy donors were used to measure fatty acid-binding protein 4 and 5 (FABP4 and FABP5) expression via sc-RNA seq and spatial transcriptomics. siRNA-mediated knockdown of FABP4 and FABP5 and lentivirus-mediated FABP4 and 5 overexpression were performed to study cell proliferation, apoptosis, and glycolysis. Our scRNA-seq analysis demonstrated that both FABP4 and 5 were highly induced in the ECs of Egln1 Tie2Cre mice. PAECs from IPAH patients also showed higher expression of FABP4 and 5. Knockdown of FABP4-5 reduced EC proliferation, starvation-induced Caspase 3/7 activity, and glycolysis. Overexpression of FABP4-5 promoted EC glycolysis and proliferation. Genetic deletion of Fabp4 and 5 in Egln1 Tie2Cre mice exhibited a reduction of RVSP, RV hypertrophy, and reduction of EC glycolysis gene programming compared to Egln1 Tie2Cre mice. In conclusion, we found that FABP4 and 5 control EC glycolysis and contribute to the development of PAH.

Induction of a distinct macrophage population and protection from lung injury and fibrosis by Notch2 blockade.

Macrophages are pleiotropic and diverse cells that populate all tissues of the body. Besides tissue-specific resident macrophages such as alveolar macrophages, Kupffer cells, and microglia, multiple organs harbor at least two subtypes of other resident macrophages at steady state. During certain circumstances, like tissue insult, additional subtypes of macrophages are recruited to the tissue from the monocyte pool. Previously, a recruited macrophage population marked by expression of Spp1, Cd9, Gpnmb, Fabp5, and Trem2, has been described in several models of organ injury and cancer, and has been linked to fibrosis in mice and humans. Here, we show that Notch2 blockade, given systemically or locally, leads to an increase in this putative pro-fibrotic macrophage in the lung and that this macrophage state can only be adopted by monocytically derived cells and not resident alveolar macrophages. Using a bleomycin and COVID-19 model of lung injury and fibrosis, we find that the expansion of these macrophages before lung injury does not promote fibrosis but rather appears to ameliorate it. This suggests that these damage-associated macrophages are not, by themselves, drivers of fibrosis in the lung.

Combining single nucleotide polymorphisms and gene expression of LEP, FABP4, STAT5A and DGAT1 genes for improvement of body weight in Holstein calves

The objective of this study was to investigate the possible association of single nucleotide polymorphisms and gene expression of leptin (LEP), fatty acid binding protein (FABP4), signal transducer and activator of transcription 5A (STAT5A) and diacylglycerol acyltransferase (DGAT1) genes with body weight in Holstein calves. For the RNA extraction process, blood samples from 100 Holstein bull calves were taken. According to farm records, the acquired bull calves were weaned at a body weight of roughly 90 kg, with birth weights ranging from 31 to 38 kg and weaning ages ranging from 60 to 100 days. To account for the non-genetic causes, the dairy calves' body weight was changed to their 205-day body weight. Nucleotide sequence changes in the form of SNPs were found in the LEP, FABP4, STAT5A, and DGAT1 genes in the investigated Holstein calves. The identified SNPs and corrected 205-day body weight showed a significant correlation (P < 0.05). According to ΔCT values, a significant relationship between the mRNA levels of the LEP, FABP4, STAT5A, and DGAT1 genes and body weight was also found (P < 0.05). The effectiveness of the LEP, FABP4, STAT5A, and DGAT1 genes as proxies for growth qualities in Holstein dairy calves is highlighted by this study. Therefore, it was possible to select an animal with a high rate of growth.

Histologic Characterization of Tumor-Adjacent Mammary Adipose Tissue in Normal-Weight and Overweight/Obese Patients with Triple-Negative Breast Cancer

Background: Obesity is a risk factor of several types of cancer, including breast cancer. In this study, we aimed to histologically characterize the adipose tissue of the tumor microenvironment (TME) of triple-negative breast cancer (TNBC) in overweight/obese versus normal-weight patients. Methods: TNBC tissue sections from normal-weight (BMI<25) and overweight/obese patients (BMI≥25) were stained with antibodies against CD68, CD163, CD31, CD34, and vimentin. At the invasive tumor front, positive cells were counted in tumor adjacent adipose tissue (AT) and within cancer tissue (CT). Further, the size of the tumor-adjacent and distant mammary adipocytes was determined in perilipin stained sections. Expression of ANGPTL4, CD36 and FABP4, proteins involved in fatty acid metabolism, was analyzed in marginal tumor cells using an immune reactive score. Results: Overweight/obese TNBC patients had significantly larger adipocytes, higher numbers of CD163+ macrophages (BMI<25: 2.80 vs. BMI≥25: 10.45; p = 0.011) and lower numbers of CD31+ (BMI<25: 4.20 vs. BMI≥25: 2.40; p = 0.018) and CD34+ (BMI<25: 14.60 vs. BMI≥25: 5.20; p = 0.045) cells as markers of angiogenesis in the AT as well as a higher frequency of cancer-associated-fibroblast-like cells in the AT and CT (BMI<25: 7.60 vs. BMI≥25: 25.39 in total; p = 0.001). Moreover, expression of CD36 (BMI<25: 2.15 vs. BMI≥25: 2.60; p = 0.041) and ANGPTL4 (BMI<25: 6.00 vs. BMI≥25: 9.80; p = 0.026) was elevated in the TNBC cells of overweight/obese patients. Conclusions: Our data suggest BMI-related changes in the TME of overweight/obese TNBC patients, including hypertrophied adipocytes, reduced vascularization, more M2-like macrophages and CAF-like cells, and an increase in the expression of fatty acid metabolizing proteins in marginal tumor cells, all contributing to a more tumor-promoting, immunosuppressive environment.

Expression Profiles of Fatty Acid Transporters and the Role of n-3 and n-6 Polyunsaturated Fatty Acids in the Porcine Endometrium.

Fatty acids (FAs) are important for cell membrane composition, eicosanoid synthesis, and metabolic processes. Membrane proteins that facilitate FA transport into cells include FA translocase (also known as CD36) and FA transporter proteins (encoded by SLC27A genes). The present study aimed to examine expression profiles of FA transporters in the endometrium of cyclic and early pregnant gilts on days 3 to 20 after estrus and the possible regulation by conceptus signals and polyunsaturated FAs (PUFAs). The effect of PUFAs on prostaglandin (PG) synthesis and transcript abundance of genes related to FA action and metabolism, angiogenesis, and immune response was also determined. Day after estrus and reproductive status of animals affected FA transporter expression, with greater levels of CD36, SLC27A1, and SLC27A4 observed in pregnant than in cyclic gilts. Conceptus-conditioned medium and/or estradiol-17β stimulated SLC27A1 and CD36 expression. Among PUFAs, linoleic acid decreased SLC27A1 and SLC27A6 mRNA expression, while arachidonic, docosahexaenoic, and eicosapentaenoic acids increased SLC27A4 transcript abundance. Moreover, arachidonic acid stimulated ACOX1, CPT1A, and IL1B expression and increased PGE2 and PGI2 secretion. In turn, α-linolenic acid up-regulated VEGFA, FGF2, FABP4, and PPARG mRNA expression. These results indicate the presence of an active transport of FAs in the porcine endometrium and the role of PUFAs as modulators of the uterine activity during conceptus implantation.

FSH increases lipid droplet content by regulating the expression of genes related to lipid storage in Rat Sertoli cells

Sertoli cells (SCs) are essential for appropriate spermatogenesis. From a metabolic standpoint, they catabolize glucose and provide germ cells with lactate, which is their main energy source. SCs also oxidize fatty acids (FAs), which are stored as triacylglycerides (TAGs) within lipid droplets (LDs), to fulfill their own energy requirements. On the other hand, it has been demonstrated that FSH regulates some of SCs functions, but little is known about its effect on lipid metabolism. In the present study, we aimed to analyze FSH-mediated regulation of (1) lipid storage in LDs and (2) the expression of genes involved in FAs activation and TAG synthesis and storage in SCs. SCs obtained from 20-day-old rats were cultured for different incubation periods with FSH (100 ng/ml). It was observed that FSH increased LD content and TAG levels in SCs. There were also increments in the expression of Plin1, Fabp5, Acsl1, Acsl4, Gpat3, and Dgat1, which suggests that these proteins may mediate the increase in TAGs and LDs elicited by FSH. Regarding the signaling involved in FSH actions, it was observed that dbcAMP increased LD, and H89, a PKA inhibitor, inhibited FSH stimulus. Also, dbcAMP increased Plin2, Fabp5, Acsl1, Acsl4, and Dgat1 mRNA levels, confirming a role of the cAMP/PKA pathway in the regulation of lipid storage in SCs. Altogether, these results suggest that FSH, via the cAMP/PKA pathway, regulates lipid storage in SCs ensuring the availability of substrates to satisfy their energy requirements.

The molecular regulated mechanism of METTL3 and FTO in lipid metabolism of Hu sheep

BackgroundBalanced lipid metabolism can improve the growth performance and meat quality of livestock. The m6A methylation-related genes METTL3 and FTO play important roles in animal lipid metabolism; however, the mechanism through which they regulate lipid metabolism in sheep is unclear. ResultsWe established lipid deposition models of hepatocytes and preadipocytes in Hu sheep. In the hepatocyte lipid deposition model, the genes expression levels of FABP4, Accα, ATGL and METTL3, METTL14, and FTO—were significantly up-regulated after lipid deposition (P < 0.05). Transcriptomic and metabolomic analyses showed that lipid deposition had a significant effect on MAPK, steroid biosynthesis, and glycerophospholipid metabolism pathway in hepatocytes. The m6A methylation level decreased but the difference was not significant after METTL3 interference, and the expression levels of FABP4 and ATGL increased significantly (P < 0.05); the m6A methylation level significantly increased following METTL3 overexpression, and LPL and ATGL expression levels significantly decreased (P < 0.05), indicating that overexpression of METTL3 inhibited the expression of lipid deposition-related genes in a m6A-dependent manner. The m6A methylation level was significantly increased, ATGL expression was significantly decreased (P < 0.05), and LPL, FABP4, and Accα expression was not significantly changed following FTO interference (P > 0.05); the m6A methylation level was significantly decreased after FTO overexpression, and LPL, FABP4, and ATGL expression was significantly increased (P < 0.05), indicating that FTO overexpression increased the expression of lipid deposition-related genes in a m6A-dependent manner. Transcriptomic and metabolomic analyses showed that m6A methylation modification mainly regulated lipid metabolism through triglyceride metabolism, adipocytokine signaling, MAPK signaling, and fat digestion and absorption in hepatocytes. In the lipid deposition model of preadipocytes, the regulation of gene expression is the same as that in hepatocytes. ConclusionsMETTL3 significantly inhibited the expression of lipid deposition-related genes, whereas FTO overexpression promoted lipid deposition. Our study provides a theoretical basis and reference for accurately regulating animal lipid deposition by mastering METTL3 and FTO genes to promote high-quality animal husbandry.

Effect of Ritanserin and Duloxetine on the Gene Expression of Primary Aniridia and Healthy Human Limbal Stromal Cells, In Vitro.

In congenital aniridia caused by mutations in paired box 6 (PAX6), PAX6 influences the migration and differentiation of limbal epithelial cells (LECs), thereby playing a pivotal role in aniridia-associated keratopathy. The antidepressants ritanserin and duloxetine affect PAX6 expression in LECs. Limbal stromal cells, which support limbal epithelial stem cells, are crucial in the limbal stem cell niche. This study explores how ritanserin and duloxetine influence gene expression in primary human limbal stromal cells from subjects with congenital aniridia and from healthy subjects, in vitro. Primary human limbal stromal cells from corneas affected by aniridia (AN-LSCs) (n = 8) and from healthy corneas (LSCs) (n = 8) were isolated and cultured in either low-glucose serum-free (LGSF) or normal-glucose serum-containing (NGSC) media. Cells were treated with 4µM ritanserin or duloxetine for 24h. Quantitative PCR (qPCR) and western blot were used to assess the expression of PAX6, FOSL2, TGF-β1, ACTA2A1, LUM, COL1A1, COL5A1, DSG1, FABP5 and ADH7. In AN-LSCs with LGSF-medium, ritanserin increased PAX6 messenger RNA (mRNA) (p = 0.007) and decreased TGF-β1 and FOSL2 mRNA levels (P = 0.005, P = 0.038). In addition, TGF-β1 protein levels decreased with both treatments (P = 0.02, P = 0.007), and FABP5 protein level increased, using ritanserin (P = 0.019). In LSCs with LGSF-medium, ACTA2A1 mRNA levels decreased using ritanserin and duloxetine (P = 0.028; P = 0.031), while FABP5 mRNA levels increased with ritanserin treatment (P = 0.003). Also, duloxetine use reduced α-SMA protein (P = 0.013) and increased FABP5 protein levels (P = 0.029). In LSCs with NGSC-medium, ritanserin elevated LUM, FABP5 and ADH7 mRNA and protein levels (P = 0.025, P = 0.003, P = 0.047, P = 0.024, P = 0.013, P = 0.039). The results of our study confirmed that the antipsychotropic drugs ritanserin and duloxetine alter PAX6 and TGF-β1 gene expression in AN-LSCs cultured in LGSF-medium. These drugs were found to have an impact on retinoic acid signaling pathways and keratocyte characteristic markers both in LSCs and AN-LSCs, using different culture media.

Single-cell RNA-sequencing reveals a unique landscape of the tumor microenvironment in obesity-associated breast cancer

As two diseases with rapidly increasing incidence, the molecular linkages between obesity and breast cancer (BC) are intriguing. Overall, obesity may be a negative prognostic factor for BC. Single-cell RNA-sequencing (scRNA-seq) was performed on tumor tissues from 6 obese and non-obese BC patients. With 48,033 cells analyzed, we found heterogeneous tumor epithelium and microenvironment in these obese and lean BC patients. Interestingly, the obesity-associated epithelial cells exhibited specific expression signatures which linked tumor growth and hormone metabolism in BC. Notably, one population of obesity-specific macrophage up-regulated the nuclear receptor subfamily 1 group H member 3 (NR1H3), which acted a transcription factor and regulated FABP4 expression through its interaction with the DNA of SREBP1, and further increased the proliferation of tumor cells in BC. Using single-cell signatures, our study illustrate cell diversity and transcriptomic differences in tumors from obese and non-obese BC patients, and sheds light on potential molecular link between lipid metabolism and BC.

PSVII-19 Effects of silage particle size on beef quality and muscle lipogenesis of finishing Nellore heifers

Abstract The objective of this study was to evaluate the effect of corn silage particle size on beef quality and expression of gluconeogenic and lipogenic genes in feedlot-finished Nellore heifers. Nellore heifers (n = 94), with an initial body weight (BW) of 249.71 ± 34.62, were allotted into 32 pens (three animals per pen) in a completely randomized design, with 2 treatments and 16 repetitions. The treatments were corn silage with a particle size of 13 mm (short) or 24 mm (long). The feeding period lasted 101 d, with the first 15 d for diet adaptation. After slaughter, samples of the longissimus thoracis muscle (LT) from the left side of the half carcass and liver were taken for beef quality and gene expression analyses. The chemical composition of the beef was analyzed using near infrared according to the AOAC method 2007-04, using the FoodScanTM equipment (AOAC method: 2007-04; FOSS, Hillerod, Denmark). RT-qPCR analyses of each gene investigated were carried out using cDNA from 16 biological replicates per treatment (1 heifer chosen randomly in each pen), with each biological replicate subjected to 2 technical replicates. Relative gene expression analyses were calculated using the delta delta ct method and the reference genes used were ACTB and GAPDH. The normality of all experimental data was checked using the Shapiro-Wilk test in SAS software. When the data did not present a normal distribution, transformation was performed using PROC RANK. The model included particle size as a fixed effect and pen as a random effect. There was no treatment effect on collagen, moisture, and mineral content (P &amp;gt; 0.10), but muscles from heifers fed short particle sizes tended to have greater protein content (23.3 versus 22.9; P = 0.098), while muscles from heifers fed with long particles had greater intramuscular fat content (2.62 versus 3.28; P = 0.05). For liver gene expression, heifers fed short particle sizes tended to have greater expression of the PC gene (1.00 versus 0.82; P = 0.06), while PEPCK2 had higher expression in heifers fed long particles (1.00 versus 1.18; P = 0.04). In addition, the long particle size of corn silage affected the expression of PPARA (P = 0.001), and there was no effect of diets (P &amp;gt; 0.05) on PPARG and SREBF1 expressions (Table 1). Expression of LPL, FABP4, SCD1, CPT2 (P &amp;lt; 0.001), and ACACA (P = 0.017) genes increased in the muscle of heifers fed long particle size. Therefore, it is concluded that the use of corn silage with long particle size in feedlot diets has the potential to increase the expression of genes involved in lipogenesis and then increase intramuscular fat in Nellore heifers.

FABP1 induces lipogenesis by regulating the processing of SREBP1 in hepatocytes of large yellow croaker (Larimichthys crocea).

Fatty acid-binding protein 1 (FABP1) plays an important role in regulating fatty acid metabolism in liver, which is a potential therapeutic target for diseases such as non-alcoholic fatty liver disease (NAFLD). However, the underlying mechanisms are not well defined. Using complementary experimental models, we discovered FABP1 induction in hepatocytes as a primary mediator of lipogenesis when exposed to fatty acids, especially saturated fatty acids (SFAs). In the feeding trial, palm oil led to excess lipid accumulation in the liver of large yellow croaker (Larimichthys crocea), accompanied by significant induction of FABP1. In cultured cells, palmitic acid (PA), a kind of SFA, triggered the fabp1 expression and increased triglyceride (TG) contents. Knockdown of FABP1 dampened PA-induced TG accumulation through mitigated lipogenesis. The overexpression of FABP1 showed the opposite result. Furthermore, the inactivation of FABP1 led to induction in insulin-induced gene 1 (INSIG1) expression, which attenuated the processing of sterol regulatory element-binding protein 1 (SREBP1) by down-regulating the nuclear-localized SREBP1. These results revealed a previously unrecognized function of FABP1 in response to PA, providing additional evidence for targeting FABP1 in the treatment of NAFLD caused by SFA.

Perioperative systemic IL-6 and immune-adipose- metabolism transcription in tumour and tumour adjacent breast cancer.

Surgical resection is the primary treatment approach for patients with breast cancer. Despite optimal multimodal treatment, metastatic recurrence remains a risk. Surgery-mediated systemic inflammation and local tissue inflammation generate an immunosuppressive and wound-healing environment that may accelerate cancer recurrence and metastasis post-operatively. Investigating the impact of surgery on local and systemic inflammation may provide knowledge for improvement of patient prognosis and treatment opportunities. Systemic cytokines were quantified in the blood plasma of patients with breast cancer pre-operatively, early post-operatively, and late post-operatively. Early post-operative levels of IL-6 were significantly elevated in patients who underwent mastectomy compared with wide local excision. Post-operative IL-6 levels correlate with clinicopathological features (age and BMI). The transcriptomes of local matched tumour and normal tumour adjacent (normal) breast tissue, from patients with breast cancer, were analysed by RNA-Seq. Elevated gene expressions of IL6, ADIPOQ, FABP4, LPL, PPARG, and CD36 in normal tissue were associated with worse overall survival of patients with ER-positive breast cancer. In tissue with higher expression of IL6 and ADIPOQ, a higher abundance of M2-like macrophage gene expression was identified. This study revealed perioperative systemic dynamics of inflammatory mediators and identified local immune-adipose-metabolism gene expression in tumour-adjacent tissue associated with pro-tumour function.

The Effects of trans-10, cis-12 Conjugated Linoleic Acid on the Production Performance of Dairy Cows and the Expression and Transcription Regulation of Lipid Metabolism-Related Genes in Bovine Mammary Epithelial Cells.

Dietary fatty acids (FAs) determine the quality of dairy products. The trans-10, cis-12 conjugated linoleic acid (t10c12-CLA) is commonly considered an FA factor leading to milk fat depression syndrome (MFDs) in dairy cow. However, its effect on dairy cow performance and involvement in milk fat metabolism have been insufficiently explored. This study administered 136.17 g/day of rumen-protected CLA (RP-CLA) to dairy cows and found a diminution in milk fat percentage and a trend of increasing milk protein percentage on day 21 postpartum. Lactose content, milk yield, and net energy for lactation were unaffected. In the cell experiments, Oil Red O staining showed a notable increase in lipid droplets. Gene and protein expression analysis showed that 300 μM t10c12-CLA upregulated the expression of CD36, DGAT2, and ADRP, while downregulating the expression of ACACA, FASN, SREBP1, FABP3, FATP3, ACSL4, LPIN1, DGAT1, BTN1A1, XDH, SNAP23, and VAMP4. This provides a possible mechanistic pathway for the contradictory phenomenon of t10c12-CLA reducing milk fat while increasing lipid droplets. Overall, t10c12-CLA, as a long-chain fatty acid, can promote lipid droplet synthesis but may reduce milk fat by inhibiting lipid droplet fusion and secretion, FAs de novo synthesis, and triglyceride biosynthesis.

SIRT3/AMPK Signaling Pathway Regulates Lipid Metabolism and Improves Vulnerability to Atrial Fibrillation in Dahl Salt-Sensitive Rats.

Hypertension may result in atrial fibrillation (AF) and lipid metabolism disorders. The Sirtuins3 (SIRT3)/AMP-activated protein kinase (AMPK) signaling pathway has the capacity to regulate lipid metabolism disorders and the onset of AF. We hypothesize that the SIRT3/AMPK signaling pathway suppresses lipid metabolism disorders, thereby mitigating salt-sensitive hypertension (SSHT)-induced susceptibility to AF. The study involved 7-week-old male Dahl salt-sensitive that were fed either a high-salt diet (8% NaCl; DSH group) or a normal diet (0.3% NaCl; DSN group). Then DSH group was administered either oral metformin (MET, an AMPK agonist) or intraperitoneal injection of Honokiol (HK, a SIRT3 agonist). This experimental model allowed for the measurement of Systolic blood pressure (SBP), the expression levels of lipid metabolism-related biomarkers, pathological examination of atrial fibrosis, and lipid accumulation, as well as AF inducibility and AF duration. DSH decrease SIRT3, phosphorylation-AMPK, and very long-chain acyl-CoA dehydrogenase, (VLCAD) expression, increased FASN and FABP4 expression and concentrations of free fatty acid and triglyceride, atrial fibrosis and lipid accumulation in atrial tissue, enhanced level of SBP, promoted AF induction rate and prolonged AF duration, which are blocked by MET and HK. Our results also showed that the degree of atrial fibrosis was negatively correlated with VLCAD expression, but positively correlated with the expression of FASN and FABP4. We have confirmed that a high-salt diet can result in hypertension, and associated atrial tissue lipid metabolism dysfunction. This condition is linked to the inhibition of the SIRT3/AMPK signaling pathway, which plays a significant role in the progression of susceptibility to AF in SSHT rats.

Hypericum perforatum-derived exosomes-like nanovesicles for adipose tissue photodynamic therapy

BackgroundRecent investigations underscore the capacity of photodynamic therapy (PDT) to induce adipocyte apoptosis, thereby mitigating obesity. Nonetheless, extant synthetic photosensitizers manifest limitations that hinder their clinical viability. PurposeIn the current study, we used Hypericum perforatum-derived exosomes-like nanovesicles (HPExos) as a novel photosensitizer, and investigated its PDT effects in adipose tissue during obesity. MethodHPExos-were administered to high fat diet mice via intraperitoneal injection, followed by targeted irradiation with specialized LED lights. Mass spectrometric analysis was analyzed in adipose tissues. CCK8 assay and Oil Red O staining were used to investigate lipid accumulation in 3T3-L1 cells to clarify adipocyte differentiation. The expression levels of related markers associated with adipogenesis and lipogenesis were assessed by RT-PCR. Apoptosis analysis was performed by TUNEL staining of and western blotting. ResultsHPExos combined with PDT accumulated in visceral white adipose tissues results in a reduced body weight and improved insulin sensitivity. HPExos combined with PDT induced apoptosis by driving high levels of ROS. In addition, HPExos combined with PDT significantly downregulated the expression of transcription factors, PPARγ, C/EBPα, and SREBP and lipogenesis protein FABP4 both in vitro and in vivo, associated with a decreased FFA levels. ConclusionThese findings suggest that HPExos could act as an effective photosensitizer in regulating glucose hemostasis by inhibiting adipocyte differentiation and lipogenesis, offering a promising approach for obesity treatment.

Integrator complex subunit 6 promotes hepatocellular steatosis via β-catenin-PPARγ axis

Hepatic adipogenesis has common mechanisms with adipocyte differentiation such as PPARγ involvement and the induction of adipose tissue-specific molecules. A previous report demonstrated that integrator complex subunit 6 (INTS6) is required for adipocyte differentiation. This study aimed to investigate INTS6 expression and its role in hepatic steatosis progression. The expression of INTS6 and PPARγ was examined in the liver of a mouse model of steatohepatitis and in paired liver biopsy samples from 11 patients with severe obesity and histologically proven metabolic dysfunction associated steatohepatitis (MASH) before and one year after bariatric surgery. To induce hepatocellular steatosis in vitro, an immortalized human hepatocyte cell line Hc3716 was treated with free fatty acids. In the steatohepatitis mouse model, we observed hepatic induction of INTS6, PPARγ, and adipocyte-specific genes. In contrast, β-catenin which negatively regulates PPARγ was reduced. Biopsied human livers demonstrated a strong positive correlation (r2 = 0.8755) between INTS6 and PPARγ mRNA levels. After bariatric surgery, gene expressions of PPARγ, FABP4, and CD36 were mostly downregulated. In our in vitro experiments, we observed a concentration-dependent increase in Oil Red O staining in Hc3716 cells after treatment with the free fatty acids. Alongside this change, the expression of INTS6, PPARγ, and adipocyte-specific genes was induced. INTS6 knockdown using siRNA significantly suppressed cellular lipid accumulation together with induction of β-catenin and PPARγ downregulation. Collectively, INTS6 expression closely correlates with PPARγ. INTS6 suppression significantly reduced hepatocyte steatosis via β-catenin-PPARγ axis, indicating that INTS6 could be a novel therapeutic target for treating MASH.

The Concept of Stroma AReactive Invasion Front Areas (SARIFA) as a new prognostic biomarker for lipid-driven cancers holds true in pancreatic ductal adenocarcinoma

BackgroundPancreatic ductal adenocarcinoma (PDAC) is a ‘difficult-to-treat’ entity. To forecast its prognosis, we introduced a new biomarker, SARIFA (stroma areactive invasion front areas), which are areas at the tumour invasion front lacking desmoplastic stroma reaction upon malignant invasion in the surrounding tissue, leading to direct contact between tumour cells and adipocytes. SARIFA showed its significance in gastric and colorectal carcinoma, revealing lipid metabolism alternations that promote tumour progression.MethodsWe reviewed the SARIFA status of 166 PDAC cases on all available H&E-stained tumour slides from archival Whipple-resection specimens. SARIFA positivity was defined as SARIFA detection in at least 66% of the available slides. To investigate alterations in tumour metabolism and microenvironment, we performed immunohistochemical staining for FABP4, CD36 and CD68. To verify and quantify a supposed delipidation of adipocytes, adipose tissue was digitally morphometrised.ResultsIn total, 53 cases (32%) were classified as SARIFA positive and 113 (68%) as SARIFA negative. Patients with SARIFA-positive PDAC showed a significantly worse overall survival compared with SARIFA-negative cases (median overall survival: 11.0 months vs. 22.0 months, HR: 1.570 (1.082–2.278), 95% CI, p = 0.018), which was independent from other prognostic markers (p = 0.014). At the invasion front of SARIFA-positive PDAC, we observed significantly higher expression of FABP4 (p < 0.0001) and higher concentrations of CD68+ macrophages (p = 0.031) related to a higher risk of tumour progression. CD36 staining showed no significant expression differences. The adipocyte areas at the invasion front were significantly smaller, with mean values of 4021 ± 1058 µm2 and 1812 ± 1008 µm2 for the SARIFA-negative and -positive cases, respectively (p < 0.001).ConclusionsSARIFA is a promising prognostic biomarker for PDAC. Its assessment is characterised by simplicity and low effort. The mechanisms behind SARIFA suggest a tumour-promoting increased lipid metabolism and altered immune background, both showing new therapeutic avenues.

Luteolin Ameliorates Non-alcoholic Fatty Liver Disease via Regulation of Hepatic Lipid Uptake, Autophagy, and Apoptosis in WD/CCl4-induced Mice

Background and Purpose Nonalcoholic fatty liver disease (NAFLD) is a worldwide health problem with high prevalence and morbidity associated with obesity, insulin resistance, type 2 diabetes mellitus (T2DM), and dyslipidemia. Luteolin is a natural flavonoid with various activities. We aimed to investigate whether luteolin can alleviate NAFLD and its possible mechanism. Materials and Methods A mouse model with NAFLD was induced by Western diet (WD) and carbon tetrachloride (CCl4) injection. Twenty-four mice were distributed into three groups randomly: Normal diet group (CON, n = 8), NAFLD group (NAF, n = 8), and luteolin group (LUT, n = 8). NAFLD model was induced by feeding mice in NAF and LUT groups with WD and injecting CCl4. CON group were fed with a normal diet in the same period. The LUT group was administered orally with luteolin (20 mg/kg) every day, starting from the 1st day of the 5th week for 8 weeks, while the CON group was treated with a vehicle. Throughout the experiment, body weight, lipid profile, glucose tolerance test, and the hepatic expressions of CD36/FABP1/LC3B/Bcl-2 were measured beside the histopathological examination. Results Luteolin treatment effectively prevents the body from weight gain in mice with NAFLD (NAF vs. LUT: 36.0 g vs. 32.4 g, p &lt; 0.05). Serum total cholesterol and triglyceride levels are both significantly increased in the NAF group ( p &lt; 0.01) and reduced to some extent in the LUT group ( p &lt; 0.05). Oral glucose tolerance test (OGTT) test results show that luteolin could improve the impaired glucose tolerance and downregulate the elevated fasting blood glucose in mice with NAFLD ( p &lt; 0.05). Histopathological results demonstrate luteolin reduces hepatic steatosis and hepatic fibrosis in NAFLD mice. The possible mechanisms may include that luteolin decreases hepatic CD36 and FABP1 expression, and increases levels of autophagy marker LC3B and antiapoptotic protein Bcl-2. Conclusion Luteolin could reduce hepatic steatosis and fibrosis, hyperglycemia, body weight, and serum lipid levels in NAFLD mice, which exhibits huge potential in the treatment of metabolic disorders related to NAFLD.

Regulation of PPARγ2 Stability and Activity by SHP-1.

The protein tyrosine phosphatase Src homology region 2 domain-containing phosphatase-1 (SHP-1) plays an important role in modulating glucose and lipid homeostasis. We previously suggested a potential role of SHP-1 in the regulation of peroxisome proliferator-activated receptor γ2 (PPARγ2) expression and activity but the mechanisms were unexplored. PPARγ2 is the master regulator of adipogenesis, but how its activity is regulated by tyrosine phosphorylation is largely unknown. Here, we found that SHP-1 binds to PPARγ2 primarily via its N-terminal SH2-domain. We confirmed the phosphorylation of PPARγ2 on tyrosine-residue 78 (Y78), which was reduced by SHP-1 invitro resulting in decreased PPARγ2 stability. Loss of SHP-1 led to elevated, agonist-induced expression of the classical PPARγ2 targets FABP4 and CD36, concomitant with increased lipid content in cells expressing PPARγ2, an effect blunted by abrogation of PPARγ2 phosphorylation. Collectively, we discovered that SHP-1 affects the stability of PPARγ2 through dephosphorylation thereby influencing adipogenesis.