Free fatty acids and peripheral blood mononuclear cells (PBMC) are correlated with chronic inflammation in obesity.

Obesity-related chronic inflammation is closely related to the ability of immune cells to adapt to the body's needs, research has shown that excess FAs can further activate pro-inflammatory transcription factors in the nucleus by interacting with various receptors such as CD36 and TLR4, thereby affecting the inflammatory state of cells. However, how the profile of various fatty acids in the blood of obese individuals is associated with chronic inflammation remains unclear. OBJECTIVE: The biomarkers associated with obesity were identified from 40 fatty acids (FAs) in the blood, and analyze the relationship between the biomarkers and chronic inflammation. Furthermore, by analyzing the difference in the expression of CD36, TLR4 and NF-κB p65 in peripheral blood mononuclear cells (PBMC) between obese and standard weight people, understand that immunophenotype PBMC is associated with chronic inflammation. METHODS: This study is a cross-sectional study. Participants were recruited from the Yangzhou Lipan weight loss training camp from May 2020 to July 2020. The sample size was 52 individuals, including 25 in the normal weight group and 27 in the obesity group. Individuals with obesity and controls of normal weight were recruited to identify biomarkers associated with obesity from 40 fatty acids in the blood; correlation analysis was conducted between the screened potential biomarkers FAs and the chronic inflammation index hs-CRP to identify FA biomarkers associated with chronic inflammation. Changes in the fatty acid receptor CD36, inflammatory receptor TLR4, and inflammatory nuclear transcription factor NF-κB p65 in PBMC subsets were used to further test the relationship between fatty acids and the inflammatory state in individuals with obesity. RESULTS: 23 potential FA biomarkers for obesity were screened, eleven of the potential obesity biomarkers were also significantly related to hs-CRP. Compared to the control group, in monocytes the obesity group expressed higher TLR4, CD36, and NF-κB p65 in lymphocytes, the obesity group expressed higher TLR4 and CD36; and in granulocytes the obesity group expressed higher CD36. CONCLUSION: Blood FAs are associated with obesity and are associated with chronic inflammation through increased CD36, TLR4, and NF-κB p65 in monocytes.

Laurolitsine ameliorates type 2 diabetes by regulating the hepatic LKB1-AMPK pathway and gut microbiota.

BACKGROUND: Type 2 diabetes mellitus (DM) is a highly prevalent chronic metabolic disease. Effective antidiabetic drugs are needed to improve and expand the available treatments. Using the ob/ob diabetic mouse model, we previously demonstrated that the alkaloid-rich extract from Litsea glutinosa bark (CG) has potent antidiabetic effects and that laurolitsine (LL) is the richest alkaloid in CG. PURPOSE: We conducted a systematic investigation of the antidiabetic effects and potential mechanisms of LL in vitro and in vivo. METHODS: The antidiabetic effects of LL and its mechanisms of action were explored in HL-7702 hepatocytes in vitro and in db/db mice in vivo by a series of experiments, including cellular toxicity analysis, glucose consumption analysis, serum/liver biochemical analysis, pathological examinations, Western blots, RNA-seq analysis, and gut microbiota analysis. RESULTS: LL stimulated glucose consumption and activated AMP-activated protein kinase (AMPK) without inducing lactic acid production or cytotoxicity in vitro. LL had potent antidiabetic effects with hypoglycemic activity in vivo. It improved insulin resistance, glucose tolerance and lipid metabolism; protected liver, renal and pancreatic functions; and promoted weight loss in db/db mice. Transcriptomic analysis suggested that the antidiabetic effects of LL involved the regulation of mitochondrial oxidative phosphorylation. We further demonstrated that LL effectively activated the hepatic liver kinase B1 (LKB1)/AMPK pathway by regulating the ADP/ATP ratio. Simultaneously, LL significantly modulated the gut microbial community, specifically decreasing the abundances of Mucispirillum schaedleri and Anaerotruncus_sp_G3_2012, which might also contribute to its antidiabetic effects. CONCLUSION: These results suggest that LL is a promising antidiabetic drug candidate that may improve glucolipid metabolism via modulation of the hepatic LKB1/AMPK pathway and the gut microbiota.

Adipo-specific chemerin knockout alters the metabolomic profile of adipose tissue under normal and high-fat diet conditions: Application of an untargeted liquid chromatography-tandem mass spectrometry metabolomics method.

To explore the metabolic effect of chemerin, adipose-specific chemerin knockout (adipo-chemerin-/- ) male mice were established and fed with 5-week normal diet (ND) or high-fat diet (HFD), and then the glycolipid metabolism index was measured and epididymal adipose tissue metabolomics detected using untargeted LC-tandem mass spectrometry (LC-MS/MS). Under HFD, adipo-chemerin-/- mice showed improved glycolipid metabolism (decreased total cholesterol, low-density lipoprotein-cholesterol, insulin and Homeostasis Model Assessment of Insulin Resistance) compared with flox (control) mice. Furthermore, orthogonal partial least squares-discriminant analysis score plots identified separation of metabolites between adipo-chemerin-/- mice and flox mice fed ND and HFD. Under HFD, 28 metabolites were significantly enhanced in adipo-chemerin-/- mice, and pathway enrichment analysis suggested strong relationship of the differential metabolites with arginine and proline metabolism, phenylalanine metabolism, and phenylalanine, tyrosine and tryptophan biosynthesis, which were directly or indirectly related to lipid metabolism, inflammation and oxidative stress. Under ND, taurine was increased in adipo-chemerin-/- mice, resulting in taurine and hypotaurine metabolism and primary bile acid biosynthesis. In conclusion, the improved effect of chemerin knockdown on the glycolipid metabolism of HFD-feeding male mice might be associated with the increases in differential metabolites and metabolic pathways involved in lipid metabolism, inflammation and oxidative stress, which provided insights into the mechanism of chemerin from a metabolomics aspect.

Vaccination with a potent DNA vaccine targeting B-cell epitopes of hGRP induces prophylactic and therapeutic antitumor activity in vivo.

Gastrin-releasing peptide (GRP), a bombesin-like peptide, is an autocrine or paracrine growth factor that can stimulate the growth of various cancer cells, making it an ideal target antigen to develop vaccines against cancer. In this study, we developed a novel DNA vaccine that encodes six tandem repeats of B-cell epitope GRP(18-27) (GRP6) flanked by HSP65 as carrier and four tandem repeats of mycobacterial HSP70(407-426) (M4) as helper T-cell epitopes for enhancement of immunogenicity. When intramuscularly immunized to mice, this anti-GRP DNA vaccine-induced GRP-specific antibody (Ab) responses that were at least 10-fold higher in magnitude compared with HSP65-GRP6 protein vaccine. Both prophylactic and therapeutic antitumor immunities induced by vaccination significantly suppressed the growth of GRP-dependent prostate carcinoma RM-1 in vivo and prolonged the survival of tumor-inoculated mice. Out results also showed that the immune sera with high titer of GRP-specific Abs effectively inhibited the growth of tumor in mice and dose dependently inhibited proliferation of cultured RM-1 cells in vitro, suggesting that the GRP neutralizing Ab is responsible for the protective and therapeutic antitumor activity of vaccination. These findings may be of great importance in the further exploration of the applications of growth factors identified in human in cancer therapy.

Study on preparation and unique properties of a novel insulin analogue with N-terminal Arg-4, Pro-3, Lys-2, Pro-1extension at insulin B-chain.

A novel insulin analog, PIns, with N-terminal Arg-4, Pro-3, Lys-2, Pro-1extension at human regular insulin B-chain was acquired through gene engineering. Preproinsulin for PIns was cloned and expressed using a bacterial expression system at a high level (72.1%) as fusion protein carrying a modified thioredoxin N-terminal region (1-21) linked to N-terminus of proinsulin by a lysine residue. Purified fusion protein was refolded and converted into PIns by a single enzymatic reaction. After PIns was purified, the homogeneity of it was characterized by sodium dodecyl sulfate polyacrylamide gel electrophoresis, isoelectronic focusing electrophoresis, amino acid composition analysis and mass spectrometry methods. A decreased tendency of self-association of PIns as compared with regular insulin was demonstrated by the size exclusion HPLC analysis. When subcutaneously administrated into normal rats, the PIns showed a faster rate of onset of action and a shorter duration of action compared with regular insulin, similar to the pharmacokinetic characteristics of insulin Lispro. These results showed that PIns is a rapid insulin analog. Furthermore, the N-terminal Arg-4, Pro-3, Lys-2, Pro-1extension at insulin B-chain can be excised by DPPIV and recombinant peptidase with DPPIV-like activities. It is suggested that PIns serves as an artificial insulin precursor and can be transformed to regular insulin in vivo due to the truncation of N-terminal sequence of PIns B-chain by DPPIV.