Biology subjects

Rubino, F.

Publications and source records attributed to Rubino, F..

3 recordsLinked to original sources

bioRxiv2025

Vitamin D receptor is necessary for metabolic health after sleeve gastrectomy

BackgroundThe vitamin D receptor (VDR) regulates insulin sensitivity. Metabolic bariatric surgery (MBS) remains the most effective treatment for obesity and T2D. However, whether its metabolic effects are VDR-dependent is unknown. Here, we assessed VDR role in the metabolic response to sleeve gastrectomy (SG). MethodsWhole body VDR knockout (KO) and wild type (WT) C57BL/6J mice with diet-induced obesity (DIO) were assigned to either SG or sham procedure. Postoperatively, animals underwent glucose and insulin tolerance tests. On sacrifice, serum, white adipose tissue (WAT), liver and colonic contents were collected for further biochemical, histological and bile acid analysis. Separately, human VDR gene expression was assessed in subcutaneous adipose tissue (SAT) biopsies collected from patients with/without MBS history. ResultsKO SG mice exhibited delayed glucose utilization after an oral challenge and progressive loss of insulin sensitivity, despite the same magnitude of surgery-induced weight change between the two genotypes. WAT in KO SG mice had lower mass, smaller adipocytes and increased inflammation. SG had a differential effect on colonic levels of the glucoregulatory cholic acid 7-sulfate (CA7S): increasing CA7S concentration in the WT mice but decreasing it in the KO mice. Finally, patients with MBS history had higher VDR expression in SAT as compared to those without MBS history. ConclusionVDR is necessary for metabolic health after SG in DIO mice due to its role in WAT function, insulin sensitivity and inflammatory response after surgery. Increased expression of VDR in patients post-MBS suggests that it may also contribute to metabolic responses in humans. HighlightsO_LIVDR KO results in delayed glucose utilization following SG in DIO mice C_LIO_LIVDR KO results in progressive loss of improved insulin sensitivity after SG C_LIO_LIVDR KO results in white adipose tissue inflammation and remodeling after SG C_LIO_LIVDR expression increases in human subcutaneous adipose tissue after bariatric surgery C_LI

physiology↗

bioRxiv2023

Integrating microbial abundance time series with fermentation dynamics of the rumen microbiome via mathematical modelling

The rumen represents a dynamic microbial ecosystem where fermentation metabolites and microbial concentrations change over time in response to dietary changes. The integration of microbial genomic knowledge and dynamic modelling can enhance our system-level understanding of rumen ecosystems function. However, such an integration between dynamic models and rumen microbiota data is lacking. The objective of this work was to integrate rumen microbiota time series determined by 16S rRNA gene amplicon sequencing into a dynamic modelling framework to link microbial data to the dynamics of the volatile fatty acids (VFA) production during fermentation. For that, we used the theory of state observers to develop a model that estimates the dynamics of VFA from the data of microbial functional proxies associated with the specific production of each VFA. We determined the microbial proxies using CowPi to infer the functional potential of the rumen microbiota and extrapolate their functional modules from KEGG (Kyoto Encyclopedia of Genes and Genomes). The approach was challenged using data from an in vitro RUSITEC experiment and from an in vivo experiment with four cows. The model performance was evaluated by the coefficient of variation of the root mean square error (CRMSE). For the in vitro case study, the mean CVRMSE were 9.8% for acetate, 14% for butyrate and 14.5% for propionate. For the in vivo case study, the mean CVRMSE were 16.4% for acetate, 15.8% for butyrate and 19.8% for propionate. The mean CVRMSE for the VFA molar fractions were 3.1% for acetate, 3.8% for butyrate and 8.9% for propionate. Ours results show the promising application of state observers integrated with microbiota time series data for predicting rumen microbial metabolism.

systems biology↗

bioRxiv2020

Microbiomes attached to fresh perennial ryegrass- are temporally resilient and adapt to changing ecological niches

Gut microbiomes, such as the rumen, greatly influence host nutrition due to their feed energy-harvesting capacity. We investigated temporal ecological interactions facilitating energy-harvesting at the fresh perennial ryegrass (PRG)-biofilm interface in the rumen using an in sacco approach and prokaryotic metatranscriptomic profiling. Network analysis identified two distinct sub-microbiomes primarily representing primary ([≤]4h) and secondary ([≥]4h) colonisation phases and the most transcriptionally active bacterial families (i.e Fibrobacteriaceae, Selemondaceae and Methanobacteriaceae) did not interact with either sub-microbiome, indicating non-cooperative behaviour. Conversely, Prevotellaceae had most transcriptional activity within the primary sub-microbiome (focussed on protein metabolism) and Lachnospiraceae within the secondary sub-microbiome (focussed on carbohydrate degradation). Putative keystone taxa, with low transcriptional activity, were identified within both sub-microbiomes, highlighting the important synergistic role of minor bacterial families, however, we hypothesise that they may be cheating in order to capitalise on the energy-harvesting capacity of other microbes. In terms of chemical cues underlying transition from primary to secondary colonisation phases, we suggest that AI-2 based quorum sensing plays a role, based on LuxS gene expression data, coupled with changes in PRG chemistry. In summary, this study provides the first major insight into the complex temporal ecological interactions occurring at the plant-biofilm interface within the rumen.

microbiology↗