PRO-INFLAMMATORY CYTOKINES ELICIT INFLAMMATORY RESPONSE IN BLOOD LEUKOCYTES OF POST DIALYTIC CHRONIC RENAL PATIENTS THROUGH HEME OXYGENASE-1 ACTIVATION

Objective: Inflammation is common in patients with chronic renal failure and has beenassociated with the increased production of pro-inflammatory cytokines. Theaim of the investigation is to assess the levels of the pro-inflammatory cytokines,TGF-β,IL-1βand TNF-α and correlate it with HO-1 expression in the leukocytes of renal failurepatients.Methods: Cytokine profile was analyzed in53South Indianpatients suffering from ESRD under post dialysis condition (2 hrs after dialysis).Results: Augmented production of TGF-β,IL-1βand TNF-α was observed in the peripheral bloodleukocytes of the patient population.Anincrease in the expression of HO-1 in the leukocytes was demonstrated from our earlier studies.Conclusion: Thus,our study hypothesized that the inflammatory reaction in the leukocytes of the post dialytic renalfailure cases might be due to the elevation in HO-1 levels brought about by altered pro-inflammatory cytokine level

High-Frequency Three-Dimensional Lumen Volume Ultrasound Is a Sensitive Method to Detect Early Aneurysmal Change in Elastase-Induced Murine Abdominal Aortic Aneurysm

Objective The aim of this study was to investigate the reproducibility of anterior–posterior diameter (APdmax) and three-dimensional lumen volume (3DLV) measurements of abdominal aortic aneurysms (AAA) in a classical murine AAA model. We also compared the magnitude of change in the aortic size detected with each method of assessment. Methods Periadventitial application of porcine pancreatic elastase (PPE AAA) or sham surgery was performed in two cohorts of mice. Cohort 1 was used to assess for observer variability with the APdmax and 3DLV measurements. Cohort 2 highlighted the relationship between APdmax and 3DLV and changes in AAA detected. Results There was no significant observer variability detected with APdmax measurement. Similarly, no significant intraobserver variability was evident with 3DLV; however, a small but significant interobserver difference was present. APdmax and 3DLV measurements of PPE AAA significantly correlated. However, changes in the AAA morphology were detected earlier with 3DLV. Conclusion APdmax and 3DLV are both reliable methods for measuring an AAA. Both these methods correlate with each other. However, changes in AAA morphology were detected earlier with 3DLV, which is important to detect subtle but important changes to aortic geometry in a laboratory setting. 3DLV measurement of AAA is a simple, reproducible, and comprehensive method for assessing changes in disease morphology

Photocatalytic Degradation of p-Cresol by Zinc Oxide under UV Irradiation

Photocatalytic degradation of p-cresol was carried out using ZnO under UV irradiation. The amount of photocatalyst, concentration of p-cresol and pH were studied as variables. The residual concentration and mineralization of p-cresol was monitored using a UV-visible spectrophotometer and total organic carbon (TOC) analyzer, respectively. The intermediates were detected by ultra high pressure liquid chromatography (UPLC). The highest photodegradation of p-cresol was observed at 2.5 g/L of ZnO and 100 ppm of p-cresol. P-cresol photocatalytic degradation was favorable in the pH range of 6–9. The detected intermediates were 4-hydroxy-benzaldehyde and 4-methyl-1,2-benzodiol. TOC studies show that 93% of total organic carbon was removed from solution during irradiation time. Reusability shows no significant reduction in photocatalytic performance in photodegrading p-cresol

Targeting pathological vascular smooth muscle cell remodelling to develop new therapeutics for abdominal aortic aneurysm

Abdominal aortic aneurysm (AAA) is a silent but progressive disease with no pharmacological treatment. Available treatment options – open surgical and endovascular repair carry significant risks. We hypothesize that vascular smooth muscle cell (VSMC) remodelling driven by platelet derived growth factor (PDGF) may contribute to AAA pathogenesis which could be targeted for pharmacological therapy. We used transgenic models to understand this pathological VSMC remodelling in aortic disease. We demonstrated SMC (spatial) and tamoxifen-inducibility (temporal) specificity of the Cre-recombination in our transgenic lines and set-up the porcine pancreatic elastase (PPE)-AAA model in our animal facility. Lineage tracing studies in PPE-AAA showed an increase in lineage traced SMC number and reduced expression of classical SMC markers indicating VSMC dedifferentiation with subsequent re-differentiation and healing. SM22CrePDGFRβD849V mice developed generalised aortopathy from 4 weeks. Transcriptomic analysis of aortic tissue showed 2721 differentially expressed genes mapped to important signalling pathways and cellular processes including extracellular matrix homeostasis and inflammation. Using quantitative RT-PCR, we confirmed the upregulation of key AAA-related genes Mmp2, Mmp12, Timp1, Clec3b, and Spp1 and inflammation-related genes Bmp2 and Ccr5 in SM22CrePDGFRβD849V aorta. While the (inducible) SM-MHCCreERT2PDGFRβD849V mice did not develop any major aortic phenotype, following PPE application, AAA development was similar at 14 days but then became significantly larger and progressive compared to SM-MHCCreERT2PDGFRβWT littermates. Store-operated calcium entry (SOCE) was enhanced in PDGFRβD849V VSMC compared to littermate controls and inhibited by the small molecule Orai1 inhibitor, JPIII. In vivo administration of JPIII failed to alter the progression of PPE-AAA in SM-MHCCreERT2PDGFRβD849V mice. However, Orai1 genetic deletion in SM22CrePDGFRβD849V mice partially rescued the aortic dilatation. In conclusion, these data suggest VSMC remodelling driven by PDGFR is involved in AAA development and progression and Orai1/SOCE may be a potential downstream target for therapeutics

Purification, Crystallization, and Preliminary Crystallographic Studies of Human As(III) S-Adenosylmethionine Methyltransferase (hAS3MT).

Exposure to environmental arsenic is associated with serious of health issues such as cancer, diabetes and developmental delays in infants and children. In human liver, As(III) S-adenosylmethionine methyl transferase (hAS3MT) (EC 2.1.1.137) was proposed to be an detoxification process by methylation of inorganic arsenite into pentavalent methyl MAs(V) and dimethyl arsenite DMAs(V). More recently the first product was shown to be highly toxic and potentially carcinogenic trivalent methylarsenite (MAs(III)). Our studies are designed to elucidate the mechanism of AS3MT and its contribution to arsenic-related diseases. Here, we report the first crystallization and preliminary X-ray diffraction analysis of the human AS3MT enzyme. The crystals belong to the monoclinic P1211 space group with unit cell parameters of a = 135.03 Å, b = 260.44 Å, c = 279.03 Å, α = 90.00°, β = 93.36°, γ = 90.00°

Reorientation of the Methyl Group in MAs(III) is the Rate-Limiting Step in the ArsM As(III) S-Adenosylmethionine Methyltransferase Reaction.

The most common biotransformation of trivalent inorganic arsenic (As(III)) is methylation to mono-, di-, and trimethylated species. Methylation is catalyzed by As(III) S-adenosylmethionine (SAM) methyltransferase (termed ArsM in microbes and AS3MT in animals). Methylarsenite (MAs(III)) is both the product of the first methylation step and the substrate of the second methylation step. When the rate of the overall methylation reaction was determined with As(III) as the substrate, the first methylation step was rapid, whereas the second methylation step was slow. In contrast, when MAs(III) was used as the substrate, the rate of methylation was as fast as the first methylation step when As(III) was used as the substrate. These results indicate that there is a slow conformational change between the first and second methylation steps. The structure of CmArsM from the thermophilic alga Cyanidioschyzon merolae sp. 5508 was determined with bound MAs(III) at 2.27 Å resolution. The methyl group is facing the solvent, as would be expected when MAs(III) is bound as the substrate rather than facing the SAM-binding site, as would be expected for MAs(III) as a product. We propose that the rate-limiting step in arsenic methylation is slow reorientation of the methyl group from the SAM-binding site to the solvent, which is linked to the conformation of the side chain of a conserved residue Tyr70

Reorientation of the Methyl Group in MAs(III) is the Rate-Limiting Step in the ArsM As(III) SAdenosylmethionine Methyltransferase Reaction

The most common biotransformation of trivalent inorganic arsenic (As(III)) is methylation to mono-, di-, and trimethylated species. Methylation is catalyzed by As(III) S-adenosylmethionine (SAM) methyltransferase (termed ArsM in microbes and AS3MT in animals). Methylarsenite (MAs(III)) is both the product of the first methylation step and the substrate of the second methylation step. When the rate of the overall methylation reaction was determined with As(III) as the substrate, the first methylation step was rapid, whereas the second methylation step was slow. In contrast, when MAs(III) was used as the substrate, the rate of methylation was as fast as the first methylation step when As(III) was used as the substrate. These results indicate that there is a slow conformational change between the first and second methylation steps. The structure of CmArsM from the thermophilic alga Cyanidioschyzon merolae sp. 5508 was determined with bound MAs(III) at 2.27 Å resolution. The methyl group is facing the solvent, as would be expected when MAs(III) is bound as the substrate rather than facing the SAM-binding site, as would be expected for MAs(III) as a product. We propose that the rate-limiting step in arsenic methylation is slow reorientation of the methyl group from the SAM-binding site to the solvent, which is linked to the conformation of the side chain of a conserved residue Tyr70

Photocatalysed reaction of meso-tetraphenylporphyrin on mesoporous TiMCM-41 molecular sieves

A preliminary study involving 254 nm irradiation of dichloromethane suspension containing TiMCM-41 catalyst and meso-tetraphenylporphyrin (TPP) was carried out at pH 5.0. The rate of the photoreaction was considerably increased in the presence of the catalyst. Increasing the amount of the catalyst at a fixed TPP concentration enhances the rate, indicating its catalytic role in the reaction. The effect of pH, TPP concentration and calcination temperature of the catalyst on the photoreaction was also investigated. (C) 2000

Reorientation of the Methyl Group in MAs(III) is the Rate-Limiting Step in the ArsM As(III) S-Adenosylmethionine Methyltransferase Reaction.

The most common biotransformation of trivalent inorganic arsenic (As(III)) is methylation to mono-, di-, and trimethylated species. Methylation is catalyzed by As(III) S-adenosylmethionine (SAM) methyltransferase (termed ArsM in microbes and AS3MT in animals). Methylarsenite (MAs(III)) is both the product of the first methylation step and the substrate of the second methylation step. When the rate of the overall methylation reaction was determined with As(III) as the substrate, the first methylation step was rapid, whereas the second methylation step was slow. In contrast, when MAs(III) was used as the substrate, the rate of methylation was as fast as the first methylation step when As(III) was used as the substrate. These results indicate that there is a slow conformational change between the first and second methylation steps. The structure of CmArsM from the thermophilic alga Cyanidioschyzon merolae sp. 5508 was determined with bound MAs(III) at 2.27 Å resolution. The methyl group is facing the solvent, as would be expected when MAs(III) is bound as the substrate rather than facing the SAM-binding site, as would be expected for MAs(III) as a product. We propose that the rate-limiting step in arsenic methylation is slow reorientation of the methyl group from the SAM-binding site to the solvent, which is linked to the conformation of the side chain of a conserved residue Tyr70