miR-548ag promotes DPP4 expression in hepatocytes through activation of TLR(7/8)/NF-κB pathway.

OBJECTIVE: In our previous study, we identified a notable increase in miR-548ag content after obesity, which contributes to the progression of Type 2 diabetes Mellitus(T2DM) through the up-regulation of Dipeptidyl Peptidase-4(DPP4) expression within the liver. However, the precise molecular mechanisms underlying the upregulation of DPP4 by miR-548ag remain elusive. Mature miRNAs rich in GU sequences can activate the TLR(7/8)/NF-κB signalling pathway, which transcriptionally activates DPP4 expression. Notably, the proportion of GU sequences in hsa-miR-548ag was found to be 47.6%. The study proposes a hypothesis suggesting that miR-548ag could potentially increase DPP4 expression in hepatocytes by activating the TLR(7/8)/NF-κB signalling pathway. METHODS: Male C57BL/6J mice were fed normal chow diet (NCD, n = 16) or high-fat diet (HFD, n = 16) for 12 weeks. For a duration of 6 weeks, NCD mice received intraperitoneal injections of a miR-548ag mimic, while HFD mice and db/db mice (n = 16) were administered intraperitoneal injections of a miR-548ag inhibitor. qRT-PCR and Western Blot were used to detect the expression level of miR-548ag, DPP4 and the activation of TLR(7/8)/NF-κB signalling pathway. HepG2 and L02 cells were transfected with miR-548ag mimic, miR-548ag inhibitor, TLR7/8 interfering fragment, and overexpression of miR-548ag while inhibiting TLR7/8, respectively. RESULTS: (1) We observed elevated levels of miR-548ag in the serum, adipose tissue, and liver of obese mice, accompanied by an upregulation of TLR7/8, pivotal protein in the NF-κB pathway, and DPP4 expression in the liver. (2) miR-548ag promotes DPP4 expression in hepatocytes via the TLR(7/8)/NF-κB signalling pathway, resulting in a reduction in the glucose consumption capacity of hepatocytes. (3) The administration of a miR-548ag inhibitor enhanced glucose tolerance and insulin sensitivity in db/db mice. CONCLUSIONS: MiR-548ag promotes the expression of DPP4 in hepatocytes by activating the TLR(7/8)/NF-κB signalling pathway. MiR-548ag may be a potential target for the treatment of T2DM.

Palmitic acid-activated GPRs/KLF7/CCL2 pathway is involved in the crosstalk between bone marrow adipocytes and prostate cancer.

BACKGROUND: Obesity-induced abnormal bone marrow microenvironment is one of the important risk element for bone metastasis in prostate cancer (PCa). The present study aimed to determine whether obesity-induced elevation in palmitic acid (PA), which is the most abundant of the free fatty acids (FFAs), increased CCL2 via the GPRs/KLF7 pathway in bone marrow adipocytes (BMA) to facilitate PCa growth and metastasis. METHODS: We constructed a bone-tumor bearing mouse model with obesity through high-fat diet, and observed the tumor formation ability of PCa cells. In vitro, observe the effect of PA on the expression level of CCL2 in BMA through GPRs/KLF7 signaling pathway. After co-culture of BMA and PCa cells, CCK8 assay and transwell experiment were used to detect the changes in biological behavior of PCa cells stimulated by BMA. RESULTS: The BMA distribution in the bone marrow cavity of BALB/c nude mice fed with the high-fat diet (HFD) was evidently higher than that in the mice fed with the normal diet (ND). Moreover, HFD-induced obesity promoted KLF7/CCL2 expression in BMA and PCa cell growth in the bone marrow cavity of the mice. In the vitro experiment, a conditioned medium with increased CCL2 obtained from the BMA cultured with PA (CM-BMA-PA) was used for culturing the PCa cell lines, which evidently enhanced the proliferation, invasion, and migration ability. KLF7 significantly increased the CCL2 expression and secretion levels in BMA by targeting the promoter region of the CCL2 gene. In addition, GPR40/120 engaged in the PA-induced high KLF7/CCL2 levels in BMA to facilitate the malignant progression of PC-3 cells. CONCLUSIONS: PA-activated GPRs/KLF7/CCL2 pathway in BMA facilitates prostate cancer growth and metastasis.

Association of saturated fatty acids with cancer risk: a systematic review and meta-analysis.

OBJECTIVE: Extensive research has explored the link between saturated fatty acids (SFAs) and cardiovascular diseases, alongside other biological dysfunctions. Yet, their association with cancer risk remains a topic of debate among scholars. The present study aimed to elucidate this association through a robust meta-analysis. METHODS: PubMed, Embase, Cochrane Library, and Web of Science databases were searched systematically to identify relevant studies published until December 2023. The Newcastle-Ottawa Scale was used as the primary metric for evaluating the quality of the included studies. Further, fixed- or random-effects models were adopted to determine the ORs and the associated confidence intervals using the Stata15.1 software. The subsequent subgroup analysis revealed the source of detection and the cancer types, accompanied by sensitivity analyses and publication bias evaluations. RESULTS: The meta-analysis incorporated 55 studies, comprising 38 case-control studies and 17 cohort studies. It revealed a significant positive correlation between elevated levels of total SFAs and the cancer risk (OR of 1.294; 95% CI: 1.182-1.416; P-value less than 0.001). Moreover, elevated levels of C14:0, C16:0, and C18:0 were implicated in the augmentation of the risk of cancer. However, no statistically significant correlation of the risk of cancer was observed with the elevated levels of C4:0, C6:0, C8:0, C10:0, C12:0, C15:0, C17:0, C20:0, C22:0, and C24:0. Subgroup analysis showed a significant relationship between excessive dietary SFA intake, elevated blood SFA levels, and heightened cancer risk. Increased total SFA levels correlated with higher risks of breast, prostate, and colorectal cancers, but not with lung, pancreatic, ovarian, or stomach cancers. CONCLUSION: High total SFA levels were correlated with an increased cancer risk, particularly affecting breast, prostate, and colorectal cancers. Higher levels of specific SFA subtypes (C14:0, C16:0, and C18:0) are also linked to an increased cancer risk. The findings of the present study would assist in providing dietary recommendations for cancer prevention, thereby contributing to the development of potential strategies for clinical trials in which diet-related interventions would be used in combination with immunotherapy to alter the levels of SFAs in patients and thereby improve the outcomes in cancer patients. Nonetheless, further high-quality studies are warranted to confirm these associations.

KLF7 promotes adipocyte inflammation and glucose metabolism disorder by activating the PKCζ/NF-κB pathway.

In the obesity context, inflammatory cytokines secreted by adipocytes lead to insulin resistance and are key to metabolic syndrome development. In our previous study, we found that the transcription factor KLF7 promoted the expression of p-p65 and IL-6 in adipocytes. However, the specific molecular mechanism remained unclear. In the present study, we found that the expression of KLF7, PKCζ, p-IκB, p-p65, and IL-6 in epididymal white adipose tissue (Epi WAT) in mice fed a high-fat diet (HFD) was significantly increased. In contrast, the expression of PKCζ, p-IκB, p-p65, and IL-6 was significantly decreased in Epi WAT of KLF7 fat conditional knockout mice. In 3T3-L1 adipocytes, KLF7 promoted the expression of IL-6 via the PKCζ/NF-κB pathway. In addition, we performed luciferase reporter and chromatin immunoprecipitation assays, which confirmed that KLF7 upregulated the expression of PKCζ transcripts in HEK-293T cells. Collectively, our results show that KLF7 promotes the expression of IL-6 by upregulating PKCζ expression and activating the NF-κB signaling pathway in adipocytes.

Stress-inducible IL-6 is regulated by KLF7 in brown adipocytes.

Stress-inducible interleukin 6 (IL-6) is generated in brown adipocytes via beta-3 adrenergic receptor (ADRB3) signaling, which is necessary in stress hyperglycemia, the kind of metabolic adaptation enabling "fight or flight" response by means of liver gluconeogenesis. Nevertheless, the mechanism of ADRB3 signaling mediates IL-6 in brown adipocytes remains unclear. As a result, it is critical to understand how brown adipocytes produce IL-6 via ADRB3 signaling. We found that the ADRB3 agonist and cold stimulation promoted the expression of KLF7 and IL-6 in brown adipocytes of mice. In parallel to these results in vivo, treatment with ADRB3 agonist promoted the expression of KLF7 and the release of IL-6 in primary brown adipocytes of mice. Notably, we discovered that KLF7 positively controls the expression of IL-6 and downregulated KLF7 largely blunted ADRB3 agonist induced IL-6 expressions in brown adipocytes. Our findings suggest that KLF7 is required for the generation of IL-6 when ADRB3 signaling is activated in brown adipocytes.

Hepatic Glucose Metabolism Disorder Induced by Adipose Tissue-Derived miR-548ag via DPP4 Upregulation.

The present study aimed to explore the molecular mechanism underlying the regulation of glucose metabolism by miR-548ag. For the first time, we found that miR-548ag expression was elevated in the abdominal adipose tissue and serum of subjects with obesity and type 2 diabetes mellitus (T2DM). The conditional knockout of adipose tissue Dicer notably reduced the expression and content of miR-548ag in mouse adipose tissue, serum, and liver tissue. The combined use of RNAseq, an miRNA target gene prediction software, and the dual luciferase reporter assay confirmed that miR-548ag exerts a targeted regulatory effect on DNMT3B and DPP4. miR-548ag and DPP4 expression was increased in the adipose tissue, serum, and liver tissue of diet-induced obese mice, while DNMT3B expression was decreased. It was subsequently confirmed both in vitro and in vivo that adipose tissue-derived miR-548ag impaired glucose tolerance and insulin sensitivity by inhibiting DNMT3B and upregulating DPP4. Moreover, miR-548ag inhibitors significantly improved the adverse metabolic phenotype in both obese mice and db/db mice. These results revealed that the expression of the adipose tissue-derived miR-548ag increased in obese subjects, and that this could upregulate the expression of DPP4 by targeting DNMT3B, ultimately leading to glucose metabolism disorder. Therefore, miR-548ag could be utilized as a potential target in the treatment of T2DM.

miR-548ag functions as an oncogene by suppressing MOB1B in the development of obesity-related endometrial cancer.

Obesity is a high-risk factor in the development of endometrial cancer (EC). Our previous study observed that miR-548ag was significantly overexpressed in the sera of obese individuals. Here, we report the function of miR-548ag and its mechanism in promoting the obesity-related progression of EC. The content of miR-548ag was increased in the serum of obese EC individuals. Bioinformatics analysis indicated that the survival rate of EC patients with a higher expression of miR-548ag was significantly reduced. The Mps One Binder Kinase Activator 1B (MOB1B, the core member of the Hippo signaling pathway) is a direct target gene of miR-548ag, which is inversely correlated with the expression of miR-548ag. The overexpression of miR-548ag enhances the proliferation, invasion, and migration, and inhibits apoptosis by downregulating the expression of MOB1B, leading to the deactivation of the Hippo pathway in EC cell lines and contributing to tumor progression in vivo. Our study has established that miR-548ag functions as an oncogene by suppressing MOB1B in the development of obesity-related EC.

Diallyl trisulfide plays an antifibrotic role by inhibiting the expression of Bcl-2 in hepatic stellate cells.

Hepatic fibrosis is an important early stage in the evolution of liver cirrhosis, and specific medicine and therapeutic measures are unavailable to date. Hepatic stellate cells (HSCs) are the main cells involved in the formation of hepatic fibrosis, and induction of the apoptosis of HSCs is an important strategy for the treatment of hepatic fibrosis. Diallyl trisulfide (DATS) is a natural product and is the main active ingredient in garlic. However, the exact molecular mechanisms underlying HSC apoptosis induced by DATS are not well understood. This study aimed to analyze the efficiency and mechanism of DATS in hepatic fibrosis. Different concentrations (25, 50, 100, and 200 µM) of DATS were used to treat HSCs. Changes in cell morphology and formation of apoptotic bodies were observed under an inverted microscope and an electric microscope. Bcl-2 signaling involving Bax, Caspase-3, Caspase-6, Caspase-8, Caspase-9, p53, Apaf-1, and Cyto-c in fibrosis were examined, which is a critical step in the evaluation of antihepatic fibrosis agents. We also evaluated the effect of DATS on the cellular morphology of HSCs and apoptosis-related factors under different Bcl-2 expression states. Our results suggest that DATS regulates hepatic fibrosis by blocking the Bcl-2 signaling pathway and upregulating the Bax/Bcl-2 ratio.

Obesity-induced elevated palmitic acid promotes inflammation and glucose metabolism disorders through GPRs/NF-κB/KLF7 pathway.

OBJECTIVE: Our previous results have shown that obesity-induced excessive palmitic acid (PA) can promote the expression of KLF7, which plays a vital role in regulation of inflammation, glucose metabolism. But the exact mechanism of PA up-regulating the expression of KLF7 is not clear yet. This study is intend to explore whether PA promoting KLF7 expression through GPRs/NF-κB signaling pathway, causing inflammation and glucose metabolism disorders. METHODS: Cells were blocked GPRs/NF-κB under PA stimulation in vitro to demonstrate the molecular mechanism of PA up-regulates KLF7 expression. The regulatory effect of p65 on KLF7 was detected by luciferase reporter gene assay. Blocking GPRs/NF-κB in diet-induced obesity mice to detect the expression of KLF7, inflammatory cytokines and glucose metabolism related factors, clarifying the effects of GPRs/NF-κB on KLF7 in vivo. RESULTS: In 3T3-L1 adipocytes and HepG2 cells, PA could up-regulate the expression of KLF7 by promoting the GPR40/120-NF-κB signaling pathway, leading to inflammation and reduced glucose consumption (p < 0.05 for both). Luciferase reporter gene assay and ChIP assay showed that p65 could transcriptionally up-regulates the expression of KLF7. In high-fat diet (HFD) mice, after intraperitoneal injection of GPR40 or GPR120 blocker, the levels of p-p65 and KLF7 in epididymal white adipose tissue and liver were significantly decreased (p < 0.05 for both). Pharmacological inhibition of p-p65 significantly attenuated KLF7 expression and improved glucose tolerant and insulin sensitive (p < 0.05 for both). CONCLUSIONS: Our results indicate that obesity-induced elevated palmitic acid promotes inflammation and glucose metabolism disorders through GPRs/NF-κB/KLF7 signaling pathway.

Transcription factor Klf9 controls bile acid reabsorption and enterohepatic circulation in mice via promoting intestinal Asbt expression.

Bile acid (BA) homeostasis is regulated by the extensive cross-talk between liver and intestine. Many bile-acid-activated signaling pathways have become attractive therapeutic targets for the treatment of metabolic disorders. In this study we investigated the regulatory mechanisms of BA in the intestine. We showed that the BA levels in the gallbladder and faeces were significantly increased, whereas serum BA levels decreased in systemic Krüppel-like factor 9 (Klf9) deficiency (Klf9-/-) mice. These phenotypes were also observed in the intestine-specific Klf9-deleted (Klf9vil-/-) mice. In contrast, BA levels in the gallbladder and faeces were reduced, whereas BA levels in the serum were increased in intestinal Klf9 transgenic (Klf9Rosa26+/+) mice. By using a combination of biochemical, molecular and functional assays, we revealed that Klf9 promoted the expression of apical sodium-dependent bile acid transporter (Asbt) in the terminal ileum to enhance BA absorption in the intestine. Reabsorbed BA affected liver BA synthetic enzymes by regulating Fgf15 expression. This study has identified a previously neglected transcriptional pathway that regulates BA homeostasis.

miR-4431 targets TRIP10/PRKD1 and impairs glucose metabolism.

AIM/INTRODUCTION: Obesity is considered an important risk factor for many metabolic disorders, especially type 2 diabetes mellitus, and microRNAs (miRNAs) play a vital role in the development of type 2 diabetes mellitus. Therefore, we conducted this study to investigate the role of miR-4431 in the obesity-associated pathobiology of type 2 diabetes mellitus. MATERIALS AND METHODS: Subjects were divided into normal control (n = 36), obese (n = 36), and type 2 diabetes mellitus (n = 12) groups, and serum miR-4431 levels were analyzed. Adenovirus-vectored miR-4431 mimic or sponge was intraperitoneally injected into the normal diet group and the high-fat diet group (HFD) mice to investigate glucose tolerance, insulin sensitivity, and lipid levels. The downstream target genes of miR-4431 were predicted using bioinformatics, and they were verified in vitro. RESULTS: Serum miR-4431 levels were significantly high in obese and type 2 diabetes mellitus individuals, and positively correlated with the body mass index and fasting plasma glucose levels. In HFD mice, miR-4431 levels in the serum, white adipose tissue, and liver were significantly increased. Moreover, miR-4431 impaired glucose tolerance, insulin sensitivity, and lipid metabolism in mice. Bioinformatic prediction suggested that TRIP10 and PRKD1 could be the downstream target genes of miR-4431. The HFD mice showed a remarkable reduction in the mRNA levels of TRIP10 and PRKD1 in the liver, which were countered by blocking miR-4431. In HepG2 and L02 cells, miR-4431 could downregulate TRIP10 and PRKD1 while blocking glucose uptake. The luciferase reporter assay showed that miR-4431 could bind TRIP10 and PRKD1 3'-UTR. CONCLUSION: miR-4431 targets TRIP10/PRKD1 and impairs glucose metabolism.

PA and OA induce abnormal glucose metabolism by inhibiting KLF15 in adipocytes.

BACKGROUND: Obesity-induced elevated serum free fatty acids (FFAs) levels result in the occurrence of type 2 diabetes mellitus (T2DM). However, the molecular mechanism remains largely enigmatic. This study was to explore the effect and mechanism of KLF15 on FFAs-induced abnormal glucose metabolism. METHODS: Levels of TG, TC, HDL-C, LDL-C, and glucose were measured by different assay kits. qRT-PCR and Western Blot were used to detect the levels of GPR120, GPR40, phosphorylation of p38 MAPK, KLF15, and downstream factors. RESULTS: KLF15 was decreased in visceral adipose tissue of obesity subjects and high-fat diet (HFD) mice. In HFD mice, GPR120 antagonist significantly promoted KLF15 protein expression level and phosphorylation of p38 MAPK, meanwhile reduced the blood glucose levels. While, blocking GPR40 inhibited the KLF15 expression. In 3T3-L1 adipocytes, 1500 µM PA inhibited KLF15 through a GPR120/P-p38 MAPK signal pathway, and 750 µM OA inhibited KLF15 mainly through GPR120 while not dependent on P-p38 MAPK, ultimately resulting in abnormal glucose metabolism. Unfortunately, GPR40 didn't contribute to PA or OA-induced KLF15 reduction. CONCLUSIONS: Both PA and OA inhibit KLF15 expression through GPR120, leading to abnormal glucose metabolism in adipocytes. Notably, the inhibition of KLF15 expression by PA depends on phosphorylation of p38 MAPK.

[RS102895 inhibits the proliferation, invasion, and migration of PC-3 prostate cancer cells by blocking CCL2/CCR2 pathway].

Objective To investigate the effect of RS102895, a specific C-C motif chemokine receptor 2 (CCR2) antagonist, on the biological behavior of prostate cancer (PCa) cells with different degrees of malignancy. Methods Non-androgen-dependent prostate cancer cells PC-3 and androgen-dependent prostate cancer cells 22RV1 were cultured in vitro. A control group, a recombinant C-C motif chemokine ligand 2 (rCCL2) treatment group, and a rCCL2 combined with RS102895 treatment group were established. Cell proliferation ability was detected by CCK-8 assay, cell invasion and migration abilities were detected by TranswellTM assay, mRNA expressions of cell antigen KI-67 (ki67) and matrix metalloproteinase 2 (MMP2) were detected by real-time quantitative PCR, and protein expression levels of ki67 and MMP2 were detected by Western blotting. Results The proliferation, invasion, and migration abilities of PC-3 cells were significantly enhanced by rCCL2, and the proliferation ability of 22RV1 cells was significantly increased as well. Meanwhile, the mRNA and protein expression levels of ki67 and MMP2 in PC-3 cells were significantly up-regulated by rCCL2. After RS102895 treatment, the above effects of rCCL2 were reversed. Conclusion RS102895 can inhibit the proliferation, invasion, and migration of PC-3 prostate cancer cells by specifically blocking the CCL2/CCR2 pathway and down-regulating the expressions of ki67 and MMP2.

Potential biomarker in serum for predicting susceptibility to type 2 diabetes mellitus: Free fatty acid 22:6.

AIMS/INTRODUCTION: Type 2 diabetes mellitus is closely linked to increased levels of free fatty acids (FFAs) in obese individuals, although which FFA is most associated with type 2 diabetes mellitus is unclear. This study aimed to identify the specific FFAs that best predict the occurrence of type 2 diabetes mellitus in obese individuals, and assess their potential application value. MATERIALS AND METHODS: Participants were divided into three groups: a normal weight group (n = 20), an obese group (n = 10) and a type 2 diabetes mellitus group (n = 10). FFAs in serum samples were determined by ultra-high-pressure liquid chromatography-mass spectrometry, and orthogonal partial least squares discriminant analysis models were used to study the FFA profile among the three groups. RESULTS: Compared with the normal weight group, 14 FFAs (C8:0/10:0/14:0/16:1/18:1/20:2/ 20:3 /20:4/ 20:5/ 22:6/7:0/9:0/11:0 and C13:0) were significantly increased in the obese group, and nine FFAs (C14:0, C18:1, C20:1, C 18:2, C20:2, C20:3, C18:3, C20:5 and C22:6) were significantly increased in the type 2 diabetes mellitus group. Subsequently, the Venn diagram results showed that six FFAs (C14:0, C18:1, C20:2, C20:3, C20:5 and C22:6) were significantly increased in both the obese and type 2 diabetes mellitus groups. Among these six, C22:6 was finally identified as an independent risk factor for type 2 diabetes mellitus, and had a great potential to predict the susceptibility to type 2 diabetes mellitus (area under the curve 0.803). CONCLUSIONS: C22:6 can be an independent risk factor for type 2 diabetes mellitus, and it has a great potential to predict the susceptibility to type 2 diabetes mellitus.

Correlation analysis of microribonucleic acid-155 and microribonucleic acid-29 with type 2 diabetes mellitus, and the prediction and verification of target genes.

AIMS/INTRODUCTION: Microribonucleic acid-155 (microRNA155) and microRNA29 are reported to inhibit glucose metabolism in some cell and animal models, but no evidence from susceptible populations that examines the relationship between microRNA155 or microRNA29 and type 2 diabetes mellitus currently exists. Furthermore, target genes regulated by microRNA155 and microRNA29 that affect glucose and lipid metabolism remain unknown. MATERIALS AND METHODS: Human participants were divided into normal weight (n = 72), obesity (n = 120) and type 2 diabetes (n = 59) groups. The contents of microRNA155 and microRNA29 abundance in serum were measured, and candidate genes potentially related to glucose and lipid metabolism targeted by either microRNA155 or microRNA29 were screened. Overexpression of microRNA155 and microRNA29 in HepG2 cells was used to verify candidate gene expression, and measure the effects on glucose and lipid metabolism. RESULTS: Serum levels of microRNA155 and microRNA29 show a significant increase in individuals with obesity and type 2 diabetes compared with normal weight individuals. Identified target genes for microRNA155 were MAPK14, MAP3K10, DUSP14 and PRKAR2B. Identified target genes for microRNA29 were PEX11A and FADS1. Overexpression of microRNA155 or microRNA29 in HepG2 cells was found to downregulate the expression of identified target genes, and result in inhibition of triglyceride synthesis and glucose incorporation. CONCLUSIONS: MicroRNA155 and microRNA29 were significantly higher in type 2 diabetes patients compared with the control patients, their levels were also positively correlated with fasting plasma glucose levels, and over-expression of microRNA155 or microRNA29 were found to downregulate glucose and lipid metabolism target genes, and reduce lipid synthesis and glucose incorporation in HepG2 cells.

Caprylic acid (C8:0) promotes bone metastasis of prostate cancer by dysregulated adipo-osteogenic balance in bone marrow.

Prostate cancer (PCa) continues to be the most common, noncutaneous cancer in men. Bone is the most frequent site of PCa metastases, and up to 90% of patients with advanced PCa develop bone metastases. An altered bone marrow microenvironment, induced by obesity, is a significant mediator for the bone tropism of PCa. However, the specific molecular mechanisms by which obesity causes changes in the bone marrow microenvironment, leading to PCa bone metastasis, are not fully understood. Our results demonstrate that a high-fat diet (HFD) leads to dyslipidemia and changes in bone marrow of nude mice: an increase in the area and number of adipocytes and a reduction in the area and number of osteoblasts. Moreover, a HFD promoted cyclooxygenase 2 (COX2) expression and inhibited osteoprotegerin (OPG) expression in the bone microenvironment. Additionally, the total level of free fatty acids (FFAs) and caprylic acid (C8:0) was significantly higher in PCa patients with bone metastases. In vitro, caprylic acid (C8:0) promoted bone mesenchymal stem cell (MSC)-derived adipocytic differentiation, COX2 expression, and prostaglandin E2 (PGE2) secretion, whereas osteoblastic differentiation and OPG expression were reduced. Furthermore, caprylic acid (C8:0)-treated adipocytes promoted the invasion and migration of PCa cells. Taken together, our findings suggest caprylic acid (C8:0) promotes bone metastasis of PCa by dysregulated adipo-osteogenic balance of bone marrow.

Free Fatty Acids Promote the Development of Prostate Cancer by Upregulating Peroxisome Proliferator-Activated Receptor Gamma.

INTRODUCTION: As one of the most common forms of cancer that threatens men's health, prostate cancer (PCa) is under a trend of increasing morbidity and mortality in most countries. More and more studies have pointed out that obesity is closely linked to the occurrence and development of PCa, although there are still many undiscovered molecular mechanisms between the two. METHODS: In the present study, we compare serum lipid levels in patients with PCa and normal individuals. PCa cells (PC3 and 22RV1) were cultured in vitro, the TC/TG/HDL/GLU assay kit was used to detect the glucose and lipid metabolism level of PCa cells, the flow cytometry technique was used to detect the proliferation ability of PCa cells, and the Transwell was used to detect the invasion and migration ability of PCa cells. Western blot/quantitative real-time PCR was used to detect peroxisome proliferator-activated receptor γ (PPARγ) and vimentin/vascular endothelial growth factor-A (VEGF-A) expression levels, and immunohistochemistry was used to observe tumor-associated gene expression levels in nude mice. All data were analysed using the Independent samples t-test or rank sum test. RESULTS: We found higher levels of FFA in the serum of patients with PCa. In vitro experiments have demonstrated that high levels of FFA can promote the proliferation, migration and invasion of two PCa cells (PC3 and 22RV1) and affect the energy metabolism of PCa cells. The upregulated PPARγ plays a key role in this process, and vimentin may be involved in this signaling pathway. CONCLUSION: We infer that high levels of FFA may promote PCa development by upregulating PPARγ expression.

Serum FFAs profile analysis of Normal weight and obesity individuals of Han and Uygur nationalities in China.

BACKGROUND: Han and Uygur are the two main nationalities living in Xinjiang, China. There are significant differences in the incidence of metabolic diseases for two nationalities, but the specific reasons are not clear. Obesity is an important risk factor for the development of metabolic syndrome, which may be closely related to the increase of serum free fatty acids (FFAs) content. This study aims to use metabolomics to compare the changes of serum FFAs profiles between normal weight (NW) and obese (OB) individuals of two nationalities, screening out the differential FFAs, predicting and evaluating their relationship with diseases. METHODS: Thirty-four kinds of FFAs in serum were detected by ultra-high-pressure liquid chromatography-mass spectrometry (UHPLC-MS) and distinctions in FFAs profiles were evaluated using a metabolomics method while Receiver operating characteristics (ROC) and logistic regression models were used to explore FFAs significant for diagnosing obesity and obesity-associated comorbidities. RESULTS: In the Han nationality, ten kinds of FFAs (C7:0, C8:0, C9:0, C10:0, C11:0, C14:0, C18:2, C20:3, C20:4 and C22:6) showed significant differences between NW and OB individuals. These differential FFAs may be related to hypertension and gestational diabetes mellitus. In the Uygur nationality, C20:3 and C20:5 showed significant differences between NW and OB individuals. C9:0 and C19:0, which were screened out among the female subjects, showed a good ability to predict obesity status in Uygur females (AUC = 0.950). CONCLUSION: In both the Han and Uygur nationalities, the FFAs profiles of NW individuals differed from those of OB individuals. The significantly differential FFAs are closely related to obesity and may be important risk factors for obesity and related metabolic diseases.

High Level of Palmitic Acid Induced Over-Expressed Methyltransferase Inhibits Anti-Inflammation Factor KLF4 Expression in Obese Status.

Our study is based on the establishment of a cohort of human obese omental adipose tissue and the culture of adipocytes in vitro. To observe the effect of high level of free fatty acid (FFA) on the expression of DNA methyltransferases (DNMTs) and the anti-inflammatory factor Kruppel-like factor 4 (KLF4) in adipocytes and evaluate the role of methyltransferases in FFA inhibiting KLF4 expression. A total of 20 normal patients and 20 obese patients were selected for further test. qRT-PCR and western blot were used to detect the mRNA and protein expression levels of DNMT1/DNMT3a/DNMT3b and KLF4 in human adipose tissue and 3T3-L1 adipocytes which stimulated with saturated fatty acid, palmitic acid (PA). Bisulfite sequencing PCR (BSP) detected methylation status of KLF4 gene in human adipose tissue. It was found that the mRNA and protein expression levels of DNMT1 and DNMT3a in the omental tissue of obese individuals were higher than those in normal group, but the expression of KLF4 was decreased. The positive methylation rate of KLF4 promoter region in obese individuals were significantly higher than those in normal individuals, especially at CpG_33 and CpG_34 sites. Meanwhile compared with non-methylated group at CpG_33 and CpG_34 sites of KLF4 promoter region, the DNMT3a mRNA expression in methylated group were significantly increased. A total of 200 µM PA significantly promoted DNMT1, DNMT3a, and DNMT3b and inhibited KLF4 protein expression levels in 3T3-L1 adipocytes. Our findings suggest that under obesity status, the lower expression level of KLF4 of visceral adipose tissue may correlate with palmitic acid promoted DNMTs expression in adipocytes.

Comparative gene expression profile and DNA methylation status in diabetic patients of Kazak and Han people.

We attempted to investigate the mechanism and susceptibility genes for diabetes in Han and Kazak ethnic individuals.The abdominal omental adipose tissues were obtained from diabetic cases and healthy controls. The gene expression and methylation data were produced for Kazak and Han individuals, respectively, and analyzed by bioinformatics analysis.We obtained 921 differentially expressed genes (DEGs) in Han group and 1772 in Kazak group. DEGs in Han group were significantly related with type 2 diabetes mellitus, and biosynthesis of amino acids, while the DEGs specific to Kazak patients were significantly enriched in metabolism-related pathways such as carbon metabolism, propanoate metabolism, and 2-oxocarboxylic acid metabolism. Major facilitator superfamily domain containing 1 (MFSD1) was found to be a methylation associated gene at hypermethylation site of cg16289538 in Han group. Rho guanine nucleotide exchange factor 1 (ARHGEF1) was the susceptible gene corresponding to the methylation sites of cg18800192 and cg00759295 in Kazak group. ARHGEF1 was also a node in protein-protein interaction network and significantly enriched in hsa04270: vascular smooth muscle contraction pathways.The molecular mechanism of diabetes may be different in Han and Kazak patients. MFSD1 and ARHGEF1 may be the diabetes susceptible genes.