Inhibition of C3 Convertase Activity by Hepatitis C Virus as an Additional Lesion in the Regulation of Complement Components

We have previously reported that in vitro HCV infection of cells of hepatocyte origin attenuates complement system at multiple steps, and attenuation also occurs in chronically HCV infected liver, irrespective of the disease stage. However, none of these regulations alone completely impaired complement pathways. Modulation of the upstream proteins involved in proteolytic processing of the complement cascade prior to convertase formation is critical in promoting the function of the complement system in response to infection. Here, we examined the regulation of C2 complement expression in hepatoma cells infected in vitro with cell culture grown virus, and validated our observations using randomly selected chronically HCV infected patient liver biopsy specimens. C2 mRNA expression was significantly inhibited, and classical C3 convertase (C4b2a) decreased. In separate experiments for C3 convertase function, C3b deposition onto bacterial membrane was reduced using HCV infected patient sera as compared to uninfected control, suggesting impaired C3 convertase. Further, iC3b level, a proteolytically inactive form of C3b, was lower in HCV infected patient sera, reflecting impairment of both C3 convertase and Factor I activity. The expression level of Factor I was significantly reduced in HCV infected liver biopsy specimens, while Factor H level remained unchanged or enhanced. Together, these results suggested that inhibition of C3 convertase activity is an additional cumulative effect for attenuation of complement system adopted by HCV for weakening innate immune response.     

Stage-dependent changes in localization of a germ cell-specific lamin during mammalian spermatogenesis

We had earlier identified a 110/120-kDa protein specific to nuclear matrix of rat pachytene spermatocytes (Behal, A., Prakash, K., and Rao, M.R.S. (1987) J. Biol. Chem. 262, 10898-10902). This protein is now shown to be a disulfide-linked homodimer of a 60-kDa polypeptide. Indirect immunofluorescence and Western blot analyses using anti-120-kDa polyclonal antibodies have shown that this protein is a component of the pore-complex lamina structure of spermatogonia. As germ cells enter meiotic prophase and the lamina structure disassembles, this polypeptide is redistributed in the nucleus and can be isolated as a component of synaptonemal complexes. Following meiotic division, this 60-kDa protein is relocalized in the lamina, then representing the sole major component of the lamina structure of round spermatids. The identity of the 60-kDa protein in the pore-complex lamina fraction and synaptonemal complexes was further confirmed by two-dimensional analysis of iodinated tryptic peptides. Such an analysis has also shown that the germ cell-specific 60-kDa protein is related but not identical to somatic lamin B.     

Selective extraction of 22 kDa and 10 kDa polypeptides from Photosystem II without removal of 23 kDa and 17 kDa extrinsic proteins

Selective solubilization of Photosystem II membranes with the non-ionic detergent octyl thioglucopyranoside has allowed the isolation of a PS II system which has been depleted of the 22 and 10 kDa polypeptides but retains all three extrinsic proteins (33, 23 and 17 kDa). The PS II membranes which have been depleted of the 22 and 10 kDa species show high rates of oxygen evolution activity, external calcium is not required for activity and the manganese complex is not destroyed by exogenous reductants. When we compared this system to control PS II membranes, we observed a minor modification of the reducing side, and a conversion of the high-potential to the low-potential form of cytochrome b ₅₅₉.Abbreviations Chl- chlorophyll - DCBQ- 2,5-dichloro-p-benzoquinone - DCMU- 3-(3,4-dichlorophenyl)-1,1-dimethylurea - ESR- electron spin resonance - MES- 2-(N-morpholino)ethanesulfonic acid - OTG- octyl--d-thioglucopyranoside - PS II- Photosystem II - PEG- polyethylene glycol, M_r=6000 - Tris- 2-amino-2-hydroxyethylpropane-1,3-diol     

Effect of phenolic compounds on abscisic acid-induced stomatal movement: Structure – activity relationship

Application of abscisic acid (ABA) brings about stomatal closure within 30 min in epidermal peels of Vicia faba . A number of phenolic compounds antagonise the effect of ABA. Derivatives of benzoic acid, cinnamic acid, coumarin and flavonoids have been studied in order to establish structure – activity relationship. Derivatives of benzoic acid reverse the ABA effects. Coumarin, esculetin and three hydro derivatives of cinnamic acid fail to show the anti-ABA activity. Thus, the presence of parahydroxyl group and double bond in the side chain is necessary for anti-ABA activity.     

Blocked 5′ Termini in Brome Mosaic Virus RNA

All four components of brome mosaic virus RNA have m(7)G(5') ppp (5')Gp as their 5' terminus. The m(7)G can be removed by beta-elimination, resulting in the conversion to pppGp.     

HLA class II SNP interactions and the association with type 1 diabetes mellitus in Bengali speaking patients of Eastern India

Background

Several studies have demonstrated a fundamental role for the HLA in the susceptibility of, or protection to, type 1 diabetes mellitus (T1DM). However, this has not been adequately studied in Asian Indian populations. To assess the frequency of HLA class II (DPA1, DPB1, DQA1, DQB1 and DRB1) associated to susceptibility or protection toT1DM in a Bengali population of India with diabetes.

Results

Single nucleotide polymorphism study. The HLA genotyping was performed by a polymerase chain reaction followed by their HLA-DP, DQ, and DRB1 genotypes and haplotypes by sequencing method. The results are studied by Plink software. The χ² tests were used for the inferential statistics. To our knowledge, this study is the first of a kind which has attempted to check the HLA association with T1DM by SNPs analysis. The study recruited 151 patients with T1DM and same number of ethno-linguistic, sex matched non-diabetic controls. The present study found a significant SNP rs7990 of HLA-DQA1 (p = 0.009) negative correlation, again indicating that risk from HLA is considerably more with T1DM.

Conclusions

This study demonstrates that the HLA class-II alleles play a major role in genetic basis of T1DM.     

Characterization of the Vaginal Microbiota among Sexual Risk Behavior Groups of Women with Bacterial Vaginosis

Background

The pathogenesis of bacterial vaginosis (BV) remains elusive. BV may be more common among women who have sex with women (WSW). The objective of this study was to use 454 pyrosequencing to investigate the vaginal microbiome of WSW, women who have sex with women and men (WSWM), and women who have sex with men (WSM) with BV to determine if there are differences in organism composition between groups that may inform new hypotheses regarding the pathogenesis of BV.

Methods

Vaginal swab specimens from eligible women with BV at the Mississippi State Department of Health STD Clinic were used. After DNA extraction, 454 pyrosequencing of PCR-amplified 16S rRNA gene sequences was performed. Sequence data was classified using the Ribosomal Database Program classifer. Complete linkage clustering analysis was performed to compare bacterial community composition among samples. Differences in operational taxonomic units with an abundance of ≥2% between risk behavior groups were determined. Alpha and beta diversity were measured using Shannon’s Index implemented in QIIME and Unifrac analysis, respectively.

Results

33 WSW, 35 WSWM, and 44 WSM were included. The vaginal bacterial communities of all women clustered into four taxonomic groups with the dominant taxonomic group in each being Lactobacillus, Lachnospiraceae, Prevotella, and Sneathia. Regarding differences in organism composition between risk behavior groups, the abundance of Atopobium (relative ratio (RR)=0.24; 95%CI 0.11-0.54) and Parvimonas (RR=0.33; 95%CI 0.11-0.93) were significantly lower in WSW than WSM, the abundance of Prevotella was significantly higher in WSW than WSWM (RR=1.77; 95%CI 1.10-2.86), and the abundance of Atopobium (RR=0.41; 95%CI 0.18-0.88) was significantly lower in WSWM than WSM. Overall, WSM had the highest diversity of bacterial taxa.

Conclusion

The microbiology of BV among women in different risk behavior groups is heterogeneous. WSM in this study had the highest diversity of bacterial taxa. Additional studies are needed to better understand these differences.     

Evaluation of effects of arsenic on carbon, nitrogen, and sulfur metabolism in two contrasting varieties of Brassica juncea

This study evaluated the effects of arsenic (As) exposure on carbon, nitrogen, and sulfur (CNS) metabolism in Brassica juncea. Two contrasting, tolerant (TPM-1) and sensitive (TM-4), varieties of B. Juncea were selected and grown either in control sand (150 g) or in sand containing 10 mg of arsenate. Harvesting was performed at 7 and 15 days and various metabolites and enzymes of CNS as well as γ-aminobutyric acid (GABA) metabolism were analyzed. At 7 days, TM-4 showed significantly higher As accumulation and stressed phenotype with increase in superoxide radicals, malondialdehyde, and cell death, as compared with TPM-1. However, the level of hydrogen peroxide was higher in TPM-1 than in TM-4. The level of GABA and the activity of glutamate decarboxylase increased in both roots and shoots of TPM-1, but not in TM-4. The level of nitrate and sulfate increased and decreased in shoots of TPM-1 and TM-4, respectively. The supply of fumarate and succinate was maintained in both shoots and roots of TPM-1 while it was only in shoots of TM-4. There was significant alteration in the profile of amino acids and in sulfur and nitrogen metabolism. However, at 15 days, As accumulation of both varieties was found to be similar along with an increase in GABA, nitrate, and sulfate in both shoots and roots except sulfate in TM-4. Supply of fumarate and succinate was also maintained and other responses were found to be similar in TPM-1 and TM-4. The study demonstrates that responses of CNS metabolism differ in varietal and time-dependent manner.