Loss of Nlrp3 Does Not Protect Mice from Western Diet-Induced Adipose Tissue Inflammation and Glucose Intolerance.

We tested the hypothesis that loss of Nlrp3 would protect mice from Western diet-induced adipose tissue (AT) inflammation and associated glucose intolerance and cardiovascular complications. Five-week old C57BL6J wild-type (WT) and Nlrp3 knockout (Nlrp3-/-) mice were randomized to either a control diet (10% kcal from fat) or Western diet (45% kcal from fat and 1% cholesterol) for 24 weeks (n = 8/group). Contrary to our hypothesis that obesity-mediated white AT inflammation is Nlrp3-dependent, we found that Western diet-induced expression of AT inflammatory markers (i.e., Cd68, Cd11c, Emr1, Itgam, Lgals, Il18, Mcp1, Tnf, Ccr2, Ccl5 mRNAs, and Mac-2 protein) were not accompanied by increased caspase-1 cleavage, a hallmark feature of NLRP3 inflammasome activation. Furthermore, Nlrp3 null mice were not protected from Western diet-induced white or brown AT inflammation. Although Western diet promoted glucose intolerance in both WT and Nlrp3-/- mice, Nlrp3-/- mice were protected from Western diet-induced aortic stiffening. Additionally, Nlrp3-/- mice exhibited smaller cardiomyocytes and reduced cardiac fibrosis, independent of diet. Collectively, these findings suggest that presence of the Nlrp3 gene is not required for Western diet-induced AT inflammation and/or glucose intolerance; yet Nlrp3 appears to play a role in potentiating arterial stiffening, cardiac hypertrophy and fibrosis

Transdermal Delivery of High Molecular Weight Antibiotics to Deep Tissue Infections via Droplette Micromist Technology Device (DMTD)

Wound infection by multidrug-resistant (MDR) bacteria is a major disease burden. Systemic administration of broad-spectrum antibiotics colistin methanesulfonate (CMS) and vancomycin are the last lines of defense against deep wound infections by MDR bacteria. However, systemic administration of CMS and vancomycin are linked to life-threatening vital organ damage. Currently there are no effective topical application strategies to deliver these high molecular weight antibiotics across the stratum corneum. To overcome this difficulty, we tested if high molecular weight antibiotics delivered by Droplette micromist technology device (DMTD), a transdermal delivery device that generates a micromist capable of packaging large molecules, could attenuate deep skin tissue infections. Using green fluorescent protein-tagged E. coli and live tissue imaging, we show that (1) the extent of attenuation of deep-skin E. coli infection was similar when treated with topical DMTD- or systemic IP (intraperitoneal)-delivered CMS; (2) DMTD-delivered micromist did not spread the infection deeper; (3) topical DMTD delivery and IP delivery resulted in similar levels of vancomycin in the skin after a 2 h washout period; and (4) IP-delivered vancomycin was about 1000-fold higher in kidney and plasma than DMTD-delivered vancomycin indicating systemic toxicity. Thus, topical DMTD delivery of these antibiotics is a safe treatment for the difficult-to-treat deep skin tissue infections by MDR bacteria

Animal characteristics.

<p>Animal characteristics.</p

Aortic stiffness and cardiac characterization in WT and <i>Nlrp3</i>^-/- mice fed a control diet versus Western diet.

<p>(A) Aortic pulse wave velocity; (B) representative histological cardiac 10X images stained for trichrome blue (arrows point to trichrome blue positive-stained regions); (C) cardiomyocyte diameter; (D) cardiac fibrosis (quantification of trichrome blue positive-stained area). Data are expressed as means ± SE. WT, wild-type; KO, <i>Nlrp3</i> knockout, CD, control diet; WD, Western diet; D, main effect of diet; G, main effect of genotype; DxG, diet by genotype interaction. Significant p values (<0.05) are highlighted in bold.</p

Visceral white AT characterization in WT and <i>Nlrp3</i>^-/- mice fed a control diet versus Western diet.

<p>(A) Representative immunohistochemical 10X images of retroperitoneal white AT stained for Mac-2; (B) gene expression in stromal vascular cells isolated from epididymal white AT; (C) average adipocyte size in retroperitoneal white AT; (D) Mac-2 positive immunostained area in retroperitoneal white AT; (E) protein content of Mac-2 via Western blotting in retroperitoneal white AT; (F) protein content of pro-caspase-1 via Western blotting in retroperitoneal white AT; (G) protein content of p10 caspase-1 (cleavage) via Western blotting in retroperitoneal white AT; (H) representative Western blot bans. Data are expressed as means ± SE. WT, wild-type; KO, <i>Nlrp3</i> knockout, CD, control diet; WD, Western diet; D, main effect of diet; G, main effect of genotype; DxG, diet by genotype interaction. Significant p values (<0.05) are highlighted in bold. *denotes p<0.05 in panel B.</p

Body weight and composition in WT and <i>Nlrp3</i>^-/- mice fed a control diet versus Western diet.

<p>(A) Weekly body weights; (B) final body weight; (C) final % body fat. Data are expressed as means ± SE. WT, wild-type; KO, <i>Nlrp3</i> knockout, CD, control diet; WD, Western diet; D, main effect of diet; G, main effect of genotype; DxG, diet by genotype interaction. Significant p values (<0.05) are highlighted in bold.</p