Obesity and type 2 diabetes are characterized by subclinical inflammatory process. Changes in composition or modulation of the gut microbiota may play an important role in the obesity-associated inflammatory process. In the current study, we evaluated the effects of probiotics (Lactobacillus rhamnosus, L. acidophilus and Bifidobacterium bifidumi) on gut microbiota, changes in permeability, and insulin sensitivity and signaling in high-fat diet and control animals. More importantly, we investigated the effects of these gut modulations on hypothalamic control of food intake, and insulin and leptin signaling. Swiss mice were submitted to a high-fat diet (HFD) with probiotics or pair-feeding for 5 weeks. Metagenome analyses were performed on DNA samples from mouse feces. Blood was drawn to determine levels of glucose, insulin, LPS, cytokines and GLP-1. Liver, muscle, ileum and hypothalamus tissue proteins were analyzed by Western blotting and real-time polymerase chain reaction. In addition, liver and adipose tissues were analyzed using histology and immunohistochemistry. The HFD induced huge alterations in gut microbiota accompanied by increased intestinal permeability, LPS translocation and systemic low-grade inflammation, resulting in decreased glucose tolerance and hyperphagic behavior. All these obesity-related features were reversed by changes in the gut microbiota profile induced by probiotics. Probiotics also induced an improvement in hypothalamic insulin and leptin resistance. Our data demonstrate that the intestinal microbiome is a key modulator of inflammatory and metabolic pathways in both peripheral and central tissues. These findings shed light on probiotics as an important tool to prevent and treat patients with obesity and insulin resistance.

Production of recombinant B-domaindeleted canine factor VIII (cFVIII-BDD) unexpectedly revealed superior protein yields with 3-fold increased specific activity relative to human FVIII-BDD (hFVIII-BDD). We also determined that activated cFVIII-BDD is more stable than activated hFVIII-BDD. Furthermore, cFVIII-BDD is efficient at inducing hemostasis in human plasma containing FVIII inhibitors. Infusion of cFVIII-BDD in hemophilia IntroductionHemophilia A (HA) is an X-linked bleeding disease resulting from a functional factor VIII (FVIII) deficiency affecting 1 in 5000 males worldwide. For several decades, the HA dog model has been the most extensively used for preclinical studies. 1 Notably, in 2 strains of dogs, the underlying mutation consists of an inversion in intron 22 of the FVIII gene that is analogous to the most common human mutation. 2 This model faithfully replicates the human disease at both genotypic and phenotypic levels. 3,4 To date, there is no characterization of the cFVIII protein resulting from difficulties in purifying large amounts from canine plasma and to the relative poor performance in recombinant FVIII expression systems in general. Although the cFVIII cDNA sequence has a high sequence identity to human FVIII (hFVIII), 5 adult HA dogs develop immune responses on exposure to hFVIII that preclude the assessment of the efficacy and safety of potential novel therapies for HA. Notably, among humans, even small nucleotide changes in the hFVIII gene may predispose to inhibitor formation. 6 To overcome these limitations, we established a heterologous expression system for cFVIII. Our findings uncovered unforeseen enhanced biologic properties of the protein. This work fills an important void for the study of cFVIII biologic properties and immune responses in HA dogs. Methods Production and characterization of recombinant cFVIII-BDDPermission was obtained from the Institutional Animal Care and Use Committee of the University of Pennsylvania and the Children's Hospital of Philadelphia for all studies. cFVIII-BDD 7 and hFVIII-BDD 8 were expressed in baby hamster kidney cells and purified as previously described (supplemental data and supplemental Table 1, available on the Blood website; see the Supplemental Materials link at the top of the online article). [8][9][10][11] Canine and human FVIII-BDD protein concentrations were determined by absorbance at 280 nm using an extinction coefficient (E 280 , 1%) of 1.60 and molecular weight of 160 000; these values, obtained with porcine FVIIIa, were assumed to be the same as canine and human FVIII-BDD. 12 Protein specific activity was determined by activated partial thromboplastin time (aPTT) with minor modifications. 13 Decay of activated FVIII activity was monitored by purified component assay using reconstituted human factor Xase complex and plasma models as previously described. 11 N-terminal sequencing was determined in the laboratory of Dr Alexander Kurosky and Steven Smith at University of Texas Medical Branch (Galveston, TX). Enzymatic cleavage of N-...

Background Our understanding of the pathophysiology of the COVID-19 manifestations and evolution has improved over the past 10 months, but the reasons why evolution is more severe in obese and diabetic patients are not yet completely understood. Main text In the present review we discuss the different mechanisms that may contribute to explain the pathophysiology of COVID-19 including viral entrance, direct viral toxicity, endothelial dysfunction, thromboinflammation, dysregulation of the immune response, and the renin–angiotensin–aldosterone system. Conclusions We show that the viral infection activates an integrated stress response, including activations of serine kinases such as PKR and PERK, which induce IRS-1 serine phosphorylation and insulin resistance. In parallel, we correlate and show the synergy of the insulin resistance of COVID-19 with this hormonal resistance of obesity and diabetes, which increase the severity of the disease. Finally, we discuss the potential beneficial effects of drugs used to treat insulin resistance and diabetes in patients with COVID-19.

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