Publications by authors named "Kassem Makki"

Background: This research investigates the determinants of circulating FGF21 levels in a cohort reflecting metabolic disease progression, examining the associations of circulating FGF21 with morphology and function of adipose tissue (AT), and with metabolic adjustments following metabolic surgery.

Methods: We measured serum FGF21 in 678 individuals cross-sectionally and in 189 undergoing metabolic surgery longitudinally. Relationships between FGF21 levels, AT histology, transcriptomes and proteomes, cardiometabolic risk factors, and post-surgery metabolic adjustments were assessed using univariate and multivariate analyses, causal mediation analysis, and network integration of AT transcriptomes and proteomes.

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Alterations in gut microbiota composition are suggested to contribute to cardiometabolic diseases, in part by producing bioactive molecules. Some of the metabolites are produced by very low abundant bacterial taxa, which largely have been neglected due to limits of detection. However, the concentration of microbially produced metabolites from these taxa can still reach high levels and have substantial impact on host physiology.

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Understanding the neurobiology of complex behaviors requires measurement of activity in the discrete population of active neurons, neuronal ensembles, which control the behavior. Conventional neuroimaging techniques ineffectively measure neuronal ensemble activity in the brain because they assess the average regional neuronal activity instead of the specific activity of the neuronal ensemble that mediates the behavior. Our functional molecular photoacoustic tomography (FM-PAT) system allows direct imaging of Fos-dependent neuronal ensemble activation in Fos-LacZ transgenic rats in vivo.

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Mice with deletion of Cyp2c70 have a human-like bile acid composition, display age- and sex-dependent signs of hepatobiliary disease and can be used as a model to study interactions between bile acids and the gut microbiota in cholestatic liver disease. In the present study, we rederived Cyp2c70-/- mice as germ-free (GF) and colonized them with a human or a mouse microbiota to investigate whether the presence of a microbiota can be protective in cholangiopathic liver disease associated with Cyp2c70-deficiency. GF Cyp2c70-/- mice showed reduced neonatal survival, liver fibrosis, and distinct cholangiocyte proliferation.

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The intestinal microbiota is known to influence postnatal growth. We previously found that a strain of (strain Lp) buffers the adverse effects of chronic undernutrition on the growth of juvenile germ-free mice. Here, we report that Lp sustains the postnatal growth of malnourished conventional animals and supports both insulin-like growth factor-1 (IGF-1) and insulin production and activity.

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Objective: Dietary fibres are essential for maintaining microbial diversity and the gut microbiota can modulate host physiology by metabolising the fibres. Here, we investigated whether the soluble dietary fibre oligofructose improves host metabolism by modulating bacterial transformation of secondary bile acids in mice fed western-style diet.

Design: To assess the impact of dietary fibre supplementation on bile acid transformation by gut bacteria, we fed conventional wild-type and TGR5 knockout mice western-style diet enriched or not with cellulose or oligofructose.

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Measuring neuroactivity underlying complex behaviors facilitates understanding the microcircuitry that supports these behaviors. We have developed a functional and molecular photoacoustic tomography (F/M-PAT) system which allows direct imaging of Fos-expressing neuronal ensembles in Fos-LacZ transgenic rats with a large field-of-view and high spatial resolution. F/M-PAT measures the beta-galactosidase catalyzed enzymatic product of exogenous chromophore X-gal within ensemble neurons.

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Although the mechanism of action of the antidiabetic drug metformin is still a matter of discussions, it is well accepted that the gut plays an important role. To gain more insights into the mechanisms occurring in the different regions of the intestine, adult male mice were fed a high-fat-high sucrose (HFS) diet for 8 days and treated with metformin by gavage (300 mg/day/kg body weight) during the HFS diet. Metformin counteracted HFS diet-induced overexpression of a network of genes involved in the transport of glucose and fatty acids in the different regions of the small intestine.

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Background And Aim: Maternal dyslipidemia is recognized as a risk factor for the development of arterial hypertension (AH) and cardiovascular dysfunction in offspring. Here we evaluated the effects of probiotic administration of a specific strain of Lactiplantibacillus plantarum (WJL) during pregnancy and lactation on gut microbiota and metabolic profile in dams fed with a high-fat and high-cholesterol (HFHC) diet and its long-term effects on the cardiovascular function in male rat offspring.

Methods And Results: Pregnant Wistar rats were allocated into three groups: dams fed a control diet (CTL = 5), dams fed a HFHC diet (DLP = 5) and dams fed a HFHC diet and receiving L.

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Food is a primordial need for our survival and well-being. However, diet is not only essential to maintain human growth, reproduction, and health, but it also modulates and supports the symbiotic microbial communities that colonize the digestive tract-the gut microbiota. Type, quality, and origin of our food shape our gut microbes and affect their composition and function, impacting host-microbe interactions.

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In most animal species, juvenile growth is marked by an exponential gain in body weight and size. Here we show that the microbiota of infant mice sustains both weight gain and longitudinal growth when mice are fed a standard laboratory mouse diet or a nutritionally depleted diet. We found that the intestinal microbiota interacts with the somatotropic hormone axis to drive systemic growth.

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The "mechanistic target of rapamycin" (mTOR) is a central controller of growth, proliferation and/or motility of various cell-types ranging from adipocytes to immune cells, thereby linking metabolism and immunity. mTOR signaling is overactivated in obesity, promoting inflammation and insulin resistance. Therefore, great interest exists in the development of mTOR inhibitors as therapeutic drugs for obesity or diabetes.

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Adipose tissue is a complex organ that comprises a wide range of cell types with diverse energy storage, metabolic regulation, and neuroendocrine and immune functions. Because it contains various immune cells, either adaptive (B and T lymphocytes; such as regulatory T cells) or innate (mostly macrophages and, more recently identified, myeloid-derived suppressor cells), the adipose tissue is now considered as a bona fide immune organ, at the cross-road between metabolism and immunity. Adipose tissue disorders, such as those encountered in obesity and lipodystrophy, cause alterations to adipose tissue distribution and function with broad effects on cytokine, chemokine, and hormone expression, on lipid storage, and on the composition of adipose-resident immune cell populations.

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Unlabelled: We performed a review of public microarray data that revealed a significant down-regulation of Rnd3 expression in hepatocellular carcinoma (HCC), as compared to nontumor liver. Rnd3/RhoE is an atypical RhoGTPase family member because it is always under its active GTP-bound conformation and not sensitive to classical regulators. Rnd3 down-regulation was validated by quantitative real-time polymerase chain reaction in 120 independent tumors.

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