Integrated Proteomics and Metabolomics Analysis of Perirenal Adipose Tissue in Obese Rabbits Treated with a Restricted Diet

The potential mechanisms underlying the modulating effect of perirenal adipose tissue on hypertension: Physical compression, paracrine, and neurogenic regulation

Hypertension, a prevalent global cardiovascular disease, affects approximately 45.4 % of adults worldwide. Despite advances in therapy, hypertension continues to pose a significant health risk due to inadequate management. It has been established that excessive adiposity contributes majorly to hypertension, accounting for 65 to 75 % of primary cases. Fat depots can be categorised into subcutaneous and visceral adipose tissue based on anatomical and physiological characteristics. The metabolic impact and the risk of hypertension are determined more significantly by visceral fat. Perirenal adipose tissue (PRAT), a viscera enveloping the kidney, is known for its superior vascularisation and abundant innervation. Although traditionally deemed as a mechanical support tissue, recent studies have indicated its contributing potential to hypertension. Hypertensive patients tend to have increased PRAT thickness compared to those without, and there is a positive correlation between PRAT thickness and elevated systolic blood pressure. This review encapsulates the anatomical characteristics and biogenesis of PRAT. We provide an overview of the potential mechanisms where PRAT may modulate blood pressure, including physical compression, paracrine effects, and neurogenic regulation. PRAT has become a promising target for hypertension management, and continuous effort is required to further explore the underlying mechanisms.

Alternation of the gut microbiota in metabolically healthy obesity: An integrated multiomics analysis

BACKGROUND

Although the gut microbiota may be involved in obesity onset and progression, the exact association of the gut microbiota in metabolically healthy obesity (MHO) remains largely unknown.

METHODS

An integrated paired-sample metagenomic analysis was conducted to investigate the gut microbial network and biomarkers of microbial species from the MHO and healthy non-obese subjects in the GMrepo database. Further explorations were performed in the MHO mice model using a multiomics analysis to detect changes in the composition and function of the intestinal microbiome and associated metabolites.

RESULTS

In the human study, 314 matched metagenomic data were qualified for the final analysis. We identified seven significantly changed species possibly involved in MHO pathogenesis (MHO-enriched: Bacteroides vulgatus, Megamonas sp; MHO-depleted: Butyrivibrio crossotus, Faecalibacterium prausnitzii, Bacteroides cellulosilyticus; Eubacterium siraeum; Bacteroides massiliensis). In the murine study, we found 79 significantly-changed species which may have possible associations with the MHO phenotype. The depletion of Bacteroides cellulosilyticus was commonly recognized in the human and murine MHO phenotype. Consistent with the metagenomic data, liquid chromatography-mass spectrometry (LC/MS) revealed significantly changed gut metabolites, which may promote MHO pathogenesis by altering the amino acids and lipid metabolic pathways. In the microbe-metabolites interaction analysis, we identified certain fatty acids (Dodecanedioic acid, Arachidic Acid, Mevalonic acid, etc.) that were significantly correlated with the MHO-enriched or depleted species.

CONCLUSION

This study provides insights into identifying specific microbes and metabolites that may involve in the development of obesity without metabolic disorders. Future modalities for MHO intervention may be further validated by targeting these bacteria and metabolites.

N6-Acetyl-L-Lysine and p-Cresol as Key Metabolites in the Pathogenesis of COVID-19 in Obese Patients

Despite the growing number of the vaccinated population, COVID-19, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), remains a global health burden. Obesity, a metabolic syndrome affecting one-third of the population, has proven to be a major risk factor for COVID-19 severe complications. Several studies have identified metabolic signatures and disrupted metabolic pathways associated with COVID-19, however there are no reports evaluating the role of obesity in the COVID-19 metabolic regulation. In this study we highlight the involvement of obesity metabolically in affecting SARS-CoV-2 infection and the consequent health complications, mainly cardiovascular disease. We measured one hundred and forty-four (144) metabolites using ultra high-performance liquid chromatography-quadrupole time of flight mass spectrometry (UHPLC-QTOF-MS) to identify metabolic changes in response to SARS-CoV-2 infection, in lean and obese COVID-19 positive (n=82) and COVID-19 negative (n=24) patients. The identified metabolites are found to be mainly correlating with glucose, energy and steroid metabolisms. Further data analysis indicated twelve (12) significantly yet differentially abundant metabolites associated with viral infection and health complications, in COVID-19 obese patients. Two of the detected metabolites, n6-acetyl-l-lysine and p-cresol, are detected only among the COVID-19 cohort, exhibiting significantly higher levels in COVID-19 obese patients when compared to COVID-19 lean patients. These metabolites have important roles in viral entry and could explain the increased susceptibility of obese patients. On the same note, a set of six metabolites associated with antiviral and anti-inflammatory functions displayed significantly lower abundance in COVID-19 obese patients. In conclusion, this report highlights the plasma metabolome of COVID-19 obese patients as a metabolic feature and signature to help improve clinical outcomes. We propose n6-acetyl-l-lysine and p-cresol as potential metabolic markers which warrant further investigations to better understand their involvement in different metabolic pathways in COVID-19.