Overproduction of angiotensinogen from adipose tissue induces adipose inflammation, glucose intolerance, and insulin resistance

Although obesity is associated with overactivation of the white adipose tissue (WAT) renin-angiotensin system (RAS), a causal link between the latter and systemic insulin resistance is not established. We tested the hypothesis that overexpression of angiotensinogen (Agt) from WAT causes systemic insulin resistance via modulation of adipose inflammation. Glucose tolerance, systemic insulin sensitivity, and WAT inflammatory markers were analyzed in mice overexpressing Agt in the WAT (aP2-Agt mice). Proteomic studies and in vitro studies using 3T3-L1 adipocytes were performed to build a mechanistic framework. Male aP2-Agt mice exhibited glucose intolerance, insulin resistance, and lower insulin-stimulated glucose uptake by the skeletal muscle. The difference in glucose tolerance between genotypes was normalized by high-fat (HF) feeding, and was significantly improved by treatment with angiotensin-converting enzyme (ACE) inhibitor captopril. aP2-Agt mice also had higher monocyte chemotactic protein-1 (MCP-1) and lower interleukin-10 (IL-10) in the WAT, indicating adipose inflammation. Proteomic studies in WAT showed that they also had higher monoglyceride lipase (MGL) and glycerol-3-phosphate dehydrogenase levels. Treatment with angiotensin II (Ang II) increased MCP-1 and resistin secretion from adipocytes, which was prevented by cotreating with inhibitors of the nuclear factor-κB (NF-κB) pathway or nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. In conclusion, we show for the first time that adipose RAS overactivation causes glucose intolerance and systemic insulin resistance. The mechanisms appear to be via reduced skeletal muscle glucose uptake, at least in part due to Ang II-induced, NADPH oxidase and NFκB-dependent increases in WAT inflammation.     

Oxidative stress induces an ATM-independent senescence pathway through p38 MAPK-mediated lamin B1 accumulation

We report crosstalk between three senescence-inducing conditions, DNA damage response (DDR) defects, oxidative stress (OS) and nuclear shape alterations. The recessive autosomal genetic disorder Ataxia telangiectasia (A-T) is associated with DDR defects, endogenous OS and premature ageing. Here, we find frequent nuclear shape alterations in A-T cells, as well as accumulation of the key nuclear architecture component lamin B1. Lamin B1 overexpression is sufficient to induce nuclear shape alterations and senescence in wild-type cells, and normalizing lamin B1 levels in A-T cells reciprocally reduces both nuclear shape alterations and senescence. We further show that OS increases lamin B1 levels through p38 Mitogen Activated Protein kinase activation. Lamin B1 accumulation and nuclear shape alterations also occur during stress-induced senescence and oncogene-induced senescence (OIS), two canonical senescence situations. These data reveal lamin B1 as a general molecular mediator that controls OS-induced senescence, independent of established Ataxia Telangiectasia Mutated (ATM) roles in OIS.     

Phosphorylation of liver X receptor alpha selectively regulates target gene expression in macrophages

Dysregulation of liver X receptor alpha (LXRalpha) activity has been linked to cardiovascular and metabolic diseases. Here, we show that LXRalpha target gene selectivity is achieved by modulation of LXRalpha phosphorylation. Under basal conditions, LXRalpha is phosphorylated at S198; phosphorylation is enhanced by LXR ligands and reduced both by casein kinase 2 (CK2) inhibitors and by activation of its heterodimeric partner RXR with 9-cis-retinoic acid (9cRA). Expression of some (AIM and LPL), but not other (ABCA1 or SREBPc1) established LXR target genes is increased in RAW 264.7 cells expressing the LXRalpha S198A phosphorylation-deficient mutant compared to those with WT receptors. Surprisingly, a gene normally not expressed in macrophages, the chemokine CCL24, is activated specifically in cells expressing LXRalpha S198A. Furthermore, inhibition of S198 phosphorylation by 9cRA or by a CK2 inhibitor similarly promotes CCL24 expression, thereby phenocopying the S198A mutation. Thus, our findings reveal a previously unrecognized role for phosphorylation in restricting the repertoire of LXRalpha-responsive genes.     

Functional analysis of a subset of canine olfactory receptor genes

In this paper, we explored the level complexity of the combinatorial olfactory code that allows mammals with a repertoire of about thousand putatively active olfactory receptors encoded in their genomes to recognize and identify a much larger repertoire of odorant molecules. To that end, we cloned 38 canine OR genes belonging to the same OR gene family and transiently expressed them in a subclone of embryonic human kidney cells (HEK293) permanently expressing the G(olf) subunit. Using a Ca(2+) imaging approach, we established for example that as many as 26 out of the 38 cloned OR elicited a Ca(2+) response when exposed to octanal, whereas 10 responded to nonanal, other aldehydes providing intermediate responses. Altogether, these results demonstrated that the combinatorial code is quite complex in support to the highly developed sense of olfaction demonstrated by dogs.     

Assessment of Phytochemical Analysis,Nutritional Composition and Antimicrobial Activity of<i> Moringa oleifera</i>

Moringa oleifera is a miracle plant rich in nutrients, antioxidants, and antibiotic properties. Present study was designed to evaluate various biochemical attributes of leaves and flowers of M. oleifera. Plant parts (leaves, flowers) of M. oleifera, collected from different roadsides of Multan district, Punjab, Pakistan, were used as experimental material. Result indicates that alkaloids, saponin, carbohydrates, fats, and protein had a high value in the aqueous extract of both leaves and flowers of M. oleifera. Whereas phenol content was high in methanolic leaves extract and the phenol contents were high in aqueous extract of flowers. The extract yield of M. oleifera leaves and flowers both showed a higher percentage in aqueous extract (57.5%), followed by methanol extract and lowest in ethyl acetate extract. Flavonoids contents were higher in ethyl acetate extract of leaves (33.67%) and aqueous extract of flowers (53.71%). While crude fiber was high in methanolic extract of leaves (12.40%) and in flowers crude fiber was high in ethyl acetate extract (15.86%). The moisture contents were higher in leaves (8.87%) than flowers (7.3%) and similarly, ash percentage in flowers (52.60%) than leaves (41.84%). Ethyl acetate extracts of M. oleifera leaves show antibacterial activity against Pseudomonas aeruginosa while methanolic extract of M. oleifera flowers shows antibacterial activity against Xanthomonas sp. Maximum growth inhibits show in all extracts of leaves against Aspergillus flavus, F. oxysporum, and P. glabrum except for the concentrated aqueous extract of leaves. While in flowers maximum growth inhibits all extracts against P. glabrum, A. niger, and A. flavus except the diluted ethyl acetate extract. Phytochemicals present in different parts of moringa have significant edible and commercial potential. Moringa extracts exhibited significant antimicrobial activity, therefore have applications in pharmaceuticals.     

Kidney Dysfunction in Adult Offspring Exposed In Utero to Type 1 Diabetes Is Associated with Alterations in Genome-Wide DNA Methylation

Background

Fetal exposure to hyperglycemia impacts negatively kidney development and function.

Objective

Our objective was to determine whether fetal exposure to moderate hyperglycemia is associated with epigenetic alterations in DNA methylation in peripheral blood cells and whether those alterations are related to impaired kidney function in adult offspring.

Design

Twenty nine adult, non-diabetic offspring of mothers with type 1 diabetes (T1D) (case group) were matched with 28 offspring of T1D fathers (control group) for the study of their leukocyte genome-wide DNA methylation profile (27,578 CpG sites, Human Methylation 27 BeadChip, Illumina Infinium). In a subset of 19 cases and 18 controls, we assessed renal vascular development by measuring Glomerular Filtration Rate (GFR) and Effective Renal Plasma Flow (ERPF) at baseline and during vasodilatation produced by amino acid infusion.

Results

Globally, DNA was under-methylated in cases vs. controls. Among the 87 CpG sites differently methylated, 74 sites were less methylated and 13 sites more methylated in cases vs. controls. None of these CpG sites were located on a gene known to be directly involved in kidney development and/or function. However, the gene encoding DNA methyltransferase 1 (DNMT1)—a key enzyme involved in gene expression during early development–was under-methylated in cases. The average methylation of the 74 under-methylated sites differently correlated with GFR in cases and controls.

Conclusion

Alterations in methylation profile imprinted by the hyperglycemic milieu of T1D mothers during fetal development may impact kidney function in adult offspring. The involved pathways seem to be a nonspecific imprinting process rather than specific to kidney development or function.     

The fatty acid content of the Bordetella pertussis endotoxin

The fatty acid content of Bordetella pertussis endotoxin has been estimated by several methods. Expressed as 3-hydroxytetradecanoic acid, it was 0.74 mumol (mg lyophilized material)-1, 0.38 mumol being ester-bound, and 0.32 mumol in amide linkage. Reported molar ratios of ester-bound to amide-bound fatty acids in endotoxins of various bacterial species range from 2.4 to 2 in B. pertussis, to 5 to 2 in Salmonella minnesota; according to these figures large differences must exist in the degree of substitution, and the substitution pattern of the glucosaminyl-beta-1,6-glucosamine unit present in the hydrophobic region of endotoxins. When fatty acids, released by acid and alkaline hydrolyses of the B. pertussis endotoxin, were extracted into chloroform, unidentified chromogenic substances appearing in the extract interfered with their colorimetric estimation; no interference was observed when hexane was used instead of chloroform.