Growth of HIV-Exposed Uninfected Infants in the First 6 Months of Life in South Africa: The IeDEA-SA Collaboration

BackgroundHIV-exposed uninfected (HEU) infants are a growing population in sub-Saharan Africa especially with the increasing coverage of more effective prevention of mother-to-child transmission (PMTCT) antiretroviral therapy regimens. This study describes the characteristics of South African HEU infants, investigates factors impacting birth weight and assesses their growth within the first 28 weeks of life.MethodsThis is a retrospective cohort based on routine clinical data from two South African PMTCT programmes. Data were collected between 2007 and 2013. Linear regression assessed factors affecting birth weight-for-age z-scores (WAZ) while growth (longitudinal WAZ) was assessed using mixed effects models.ResultsWe assessed the growth of 2621 HEU infants (median birth WAZ was -0.65 (IQR -1.46; 0.0) and 51% were male). The feeding modalities practised were as follows: 0.5% exclusive breastfeeding, 7.9% breastfeeding with unknown exclusivity, 0.08% mixed breastfeeding and 89.2% formula feeding. Mothers with CD4 <200 cells/μl delivered infants with a lower birth WAZ (adjusted ß -0.253 [95% CI -0.043; -0.072], p = 0.006) compared to mothers with aCD4 ≥500 cells/μl. Similarly, mothers who did not receive antiretroviral drugs delivered infants with a lower birth WAZ (adjusted ß -0.39 [95% CI -0.67; -0.11], p = 0.007) compared to mothers who received antenatal antiretrovirals. Infants with a birth weight <2 500g (ß 0.070 [95% CI 0.061; 0.078], p <0.0001) experienced faster growth within the first 28 weeks of life compared to infants with a birth weight ≥2 500g. Infants with any breastfeeding exposure experienced slower longitudinal growth compared to formula fed infants (adjusted ß -0.012 [95% CI 0.021; -0.003], p = 0.011).ConclusionLess severe maternal disease and the use of antiretrovirals positively impacts birth weight in this cohort of South African HEU infants. Formula feeding was common with breastfed infants experiencing marginally slower longitudinal growth.     

Using SRM-MS to quantify nuclear protein abundance differences between adipose tissue depots of insulin-resistant mice

Insulin resistance (IR) underlies metabolic disease. Visceral, but not subcutaneous, white adipose tissue (WAT) has been linked to the development of IR, potentially due to differences in regulatory protein abundance. Here we investigate how protein levels are changed in IR in different WAT depots by developing a targeted proteomics approach to quantitatively compare the abundance of 42 nuclear proteins in subcutaneous and visceral WAT from a commonly used insulin-resistant mouse model, Lepr(db/db), and from C57BL/6J control mice. The most differentially expressed proteins were important in adipogenesis, as confirmed by siRNA-mediated depletion experiments, suggesting a defect in adipogenesis in visceral, but not subcutaneous, insulin-resistant WAT. Furthermore, differentiation of visceral, but not subcutaneous, insulin-resistant stromal vascular cells (SVCs) was impaired. In an in vitro approach to understand the cause of this impaired differentiation, we compared insulin-resistant visceral SVCs to preadipocyte cell culture models made insulin resistant by different stimuli. The insulin-resistant visceral SVC protein abundance profile correlated most with preadipocyte cell culture cells treated with both palmitate and TNFα. Together, our study introduces a method to simultaneously measure and quantitatively compare nuclear protein expression patterns in primary adipose tissue and adipocyte cell cultures, which we show can reveal relationships between differentiation and disease states of different adipocyte tissue types.     

Limitations of variable number of tandem repeat typing identified through whole genome sequencing of Mycobacterium avium subsp. paratuberculosis on a national and herd level

Background

Mycobacterium avium subsp. paratuberculosis (MAP), the causative bacterium of Johne’s disease in dairy cattle, is widespread in the Canadian dairy industry and has significant economic and animal welfare implications. An understanding of the population dynamics of MAP can be used to identify introduction events, improve control efforts and target transmission pathways, although this requires an adequate understanding of MAP diversity and distribution between herds and across the country. Whole genome sequencing (WGS) offers a detailed assessment of the SNP-level diversity and genetic relationship of isolates, whereas several molecular typing techniques used to investigate the molecular epidemiology of MAP, such as variable number of tandem repeat (VNTR) typing, target relatively unstable repetitive elements in the genome that may be too unpredictable to draw accurate conclusions. The objective of this study was to evaluate the diversity of bovine MAP isolates in Canadian dairy herds using WGS and then determine if VNTR typing can distinguish truly related and unrelated isolates.

Results

Phylogenetic analysis based on 3,039 SNPs identified through WGS of 124 MAP isolates identified eight genetically distinct subtypes in dairy herds from seven Canadian provinces, with the dominant type including over 80% of MAP isolates. VNTR typing of 527 MAP isolates identified 12 types, including “bison type” isolates, from seven different herds. At a national level, MAP isolates differed from each other by 1–2 to 239–240 SNPs, regardless of whether they belonged to the same or different VNTR types. A herd-level analysis of MAP isolates demonstrated that VNTR typing may both over-estimate and under-estimate the relatedness of MAP isolates found within a single herd.

Conclusions

The presence of multiple MAP subtypes in Canada suggests multiple introductions into the country including what has now become one dominant type, an important finding for Johne’s disease control. VNTR typing often failed to identify closely and distantly related isolates, limiting the applicability of using this typing scheme to study the molecular epidemiology of MAP at a national and herd-level.     

Complement component 1, q subcomponent binding protein is a marker for proliferation in breast cancer

Complement component 1, q subcomponent binding protein (C1QBP), is a multi-compartmental protein with higher mRNA expression reported in breast cancer tissues. This study evaluated the association between immunohistochemical expression of the C1QBP protein in breast cancer tissue microarrays (TMAs) and clinicopathological parameters, in particular tumor size. In addition, an in vitro study was conducted to substantiate the breast cancer TMA findings. Breast cancer TMAs were constructed from pathological specimens of patients diagnosed with invasive ductal carcinoma. C1QBP protein and proliferating cell nuclear antigen (PCNA) immunohistochemical analyses were subsequently performed in the TMAs. C1QBP immunostaining was detected in 131 out of 132 samples examined. The C1QBP protein was predominantly localized in the cytoplasm of the breast cancer cells. Univariate analysis revealed that a higher C1QBP protein expression was significantly associated with older patients (P = 0.001) and increased tumor size (P = 0.002). Multivariate analysis showed that C1QBP is an independent predictor of tumor size in progesterone-positive tumors. Furthermore, C1QBP was also significantly correlated with expression of PCNA, a known marker of proliferation. Inhibition of C1QBP expression was performed by transfecting C1QBP siRNA into T47D breast cancer cells, a progesterone receptor-positive breast cancer cell line. C1QBP gene expression was analyzed by real-time RT-PCR, and protein expression by Western blot. Cell proliferation assays were also performed by commercially available assays. Down-regulation of C1QBP expression significantly decreased cell proliferation and growth in T47D cells. Taken together, our findings suggest that the C1QBP protein could be a potential proliferative marker in breast cancer.     

The discovery of a potent orally efficacious indole androgen receptor antagonist through in vivo screening

A series of novel 2-(1H-indol-2-yl)-propan-2-ols have been designed, synthesized, and screened for their ability to inhibit testosterone-induced prostate weight increases in immature rats. Through the use of this paradigm, we were able to identify compounds that exhibited in vivo potency equal to that of the marketed antiandrogen Casodex when orally administered.     

Synthesis and identification of novel 11beta-aryl-4',5'-dihydrospiro[estra-4,9-diene-17beta,4'-oxazole] analogs with dissociated antiprogesterone activities

A series of novel 11beta-aryl-4',5'-dihydrospiro[estra-4,9-diene-17beta,4'-oxazole] analogs have been evaluated for their antagonist hormonal properties using the T47D cell-based alkaline phosphatase assay and the A549 cell-based functional assay. Some of the compounds showed highly potent, and more selective antiprogestational activity against antiglucocorticoid activity than mifepristone (RU 486).     

Discovery of novel phosphorus-containing steroids as selective glucocorticoid receptor antagonist

Mifepristone is a non-selective antagonist of 3-oxosteroid receptors with both abortifacient and anti-diabetic activities. For glucocorticoid receptor (GR) program, we sought an unexplored, synthetically accessible phosphorus-containing steroidal mimetic of mifepristone, suitable for parallel synthesis of analogues. One compound 4a, with high oral bioavailability (59%) in rat, exhibited functional antagonism of GR in oral glucose tolerance test (OGTT). Thus this series of compounds might be potentially useful for the treatment of type II diabetes.     

An intracellular serpin regulates necrosis by inhibiting the induction and sequelae of lysosomal injury

Extracellular serpins such as antithrombin and alpha1-antitrypsin are the quintessential regulators of proteolytic pathways. In contrast, the biological functions of the intracellular serpins remain obscure. We now report that the C. elegans intracellular serpin, SRP-6, exhibits a prosurvival function by blocking necrosis. Minutes after hypotonic shock, srp-6 null animals underwent a catastrophic series of events culminating in lysosomal disruption, cytoplasmic proteolysis, and death. This newly defined hypo-osmotic stress lethal (Osl) phenotype was dependent upon calpains and lysosomal cysteine peptidases, two in vitro targets of SRP-6. By protecting against both the induction of and the lethal effects from lysosomal injury, SRP-6 also blocked death induced by heat shock, oxidative stress, hypoxia, and cation channel hyperactivity. These findings suggest that multiple noxious stimuli converge upon a peptidase-driven, core stress response pathway that, in the absence of serpin regulation, triggers a lysosomal-dependent necrotic cell death routine.