The intercalated BSc (Med) Honours/MB ChB and integrated MB ChB/PhD tracks at the University of Cape Town: Models for a national medical student research training programme

The Faculty of Health Sciences at the University of Cape Town is addressing the shortage of clinician-scientists in South Africa by introducing two research training tracks in parallel with the professional MB ChB programme, namely the intercalated BSc (Med) Hons/MB ChB track and the integrated MB ChB/PhD track. The BSc (Med) Hons/MB ChB track is available to MB ChB students who have completed the first two years of study. The track comprises a course in Molecular Medicine given concurrently with the MB ChB third-year curriculum, followed by a BSc (Med) Hons as a ‘year out’ of MB ChB. Subsequently students may enrol into the integrated MB ChB/PhD track that enables them to undertake a PhD concurrently with MB ChB studies, which will be spread over additional years, or alternatively to undertake a PhD after completion of the MB ChB. These tracks, which were launched in 2011, represent an opportunity to train a new cadre of young African clinician-scientists at the undergraduate level.

Exogenous Vimentin Supplementation Transiently Affects Early Steps during HPV16 Pseudovirus Infection

Understanding and modulating the early steps in oncogenic Human Papillomavirus (HPV) infection has great cancer-preventative potential, as this virus is the etiological agent of virtually all cervical cancer cases and is associated with many other anogenital and oropharyngeal cancers. Previous work from our laboratory has identified cell-surface-expressed vimentin as a novel HPV16 pseudovirus (HPV16-PsVs)-binding molecule modulating its infectious potential. To further explore its mode of inhibiting HPV16-PsVs internalisation, we supplemented it with exogenous recombinant human vimentin and show that only the globular form of the molecule (as opposed to the filamentous form) inhibited HPV16-PsVs internalisation in vitro. Further, this inhibitory effect was only transient and not sustained over prolonged incubation times, as demonstrated in vitro and in vivo, possibly due to full-entry molecule engagement by the virions once saturation levels have been reached. The vimentin-mediated delay of HPV16-PsVs internalisation could be narrowed down to affecting multiple steps during the virus’ interaction with the host cell and was found to affect both heparan sulphate proteoglycan (HSPG) binding as well as the subsequent entry receptor complex engagement. Interestingly, decreased pseudovirus internalisation (but not infection) in the presence of vimentin was also demonstrated for oncogenic HPV types 18, 31 and 45. Together, these data demonstrate the potential of vimentin as a modulator of HPV infection which can be used as a tool to study early mechanisms in infectious internalisation. However, further refinement is needed with regard to vimentin’s stabilisation and formulation before its development as an alternative prophylactic means

European-South Africa collaboration on the genetic basis of gonadotropin-releasing hormone deficiency in failure to progress through puberty and infertility

Reproductive capacity, the key element for species survival, depends on a complex organ network involving the hypothalamus, pituitary, gonads, and internal and external genitalia. This system is centrally controlled by incompletely understood neuroendocrine mechanisms integrated at the hypothalamic level, whose elucidation is the research focus. Vertebrate reproduction depends entirely upon the neurosecretion of the decapeptide gonadotropin-releasing hormone (GnRH) from less than 4 000 GnRH neurons in the preoptic area of the hypothalamus.http://www.jemdsa.co.za/index.php/JEMDSAhb201

The Brugia malayi neuropeptide receptor-4 is activated by FMRFamide-like peptides and signals via Gα

Genetic studies undertaken in the model organism Caenorhabditis elegans have demonstrated the importance of neuropeptidergic signalling in nematode physiology. Disruption of this signalling may have deleterious phenotypic consequences, including altered locomotion, feeding behaviour, and reproduction. Neuropeptide G protein-coupled receptors (GPCRs) that transduce many of these signals therefore represent cogent drug targets. Recently published genomic sequencing data for a number of parasitic helminths of medical and veterinary importance has revealed the apparent conservation of a number of neuropeptides, and neuropeptide receptors between parasitic and free-living species, raising the intriguing possibility of developing broad-spectrum anthelmintic therapeutics. Here, we identify and clone a neuropeptide receptor, NPR-4, from the human filarial nematode Brugia malayi and demonstrate its activation in vitro, by FMRFamide-like peptides of the FLP-18 family, and intracellular signalling via G i mediated pathways. These data represent the first example of deorphanisation of a neuropeptide GPCR in any parasitic helminth species.MRC South Africa and the University of Cape Town.http://www.journals.elsevier.com/molecular-and-biochemical-parasitology/hb2014Zoology and EntomologyMammal Research Institut

Kisspeptin regulation of genes involved in cell invasion and angiogenesis in first trimester human trophoblast cells

The precise regulation of extravillous trophoblast invasion of the uterine wall is a key process in successful pregnancies. Kisspeptin (KP) has been shown to inhibit cancer cell metastasis and placental trophoblast cell migration. In this study primary cultures of first trimester human trophoblast cells have been utilized in order to study the regulation of invasion and angiogenesis-related genes by KP. Trophoblast cells were isolated from first trimester placenta and their identity was confirmed by immunostaining for cytokeratin-7. Real-time quantitative RT-PCR demonstrated that primary trophoblast cells express higher levels of GPR54 (KP receptor) and KP mRNA than the trophoblast cell line HTR8Svneo. Furthermore, trophoblast cells also expressed higher GPR54 and KP protein levels. Treating primary trophoblast cells with KP induced ERK1/2 phosphorylation, while co-treating the cells with a KP antagonist almost completely blocked the activation of ERK1/2 and demonstrated that KP through its cognate GPR54 receptor can activate ERK1/2 in trophoblast cells. KP reduced the migratory capability of trophoblast cells in a scratch-migration assay. Real-time quantitative RT-PCR demonstrated that KP treatment reduced the expression of matrix metalloproteinase 1, 2, 3, 7, 9, 10, 14 and VEGF-A, and increased the expression of tissue inhibitors of metalloproteinases 1 and 3. These results suggest that KP can inhibit first trimester trophoblast cells invasion via inhibition of cell migration and down regulation of the metalloproteinase system and VEGF-A.The South African MRC and the University of Cape Town.http://www.plosone.orgam201

The Cytotoxicity of the Ajoene Analogue BisPMB in WHCO1 Oesophageal Cancer Cells Is Mediated by CHOP/GADD153

Garlic is a food and medicinal plant that has been used in folk medicine since ancient times for its beneficial health effects, which include protection against cancer. Crushed garlic cloves contain an array of small sulfur-rich compounds such as ajoene. Ajoene is able to interfere with biological processes and is cytotoxic to cancer cells in the low micromolar range. BisPMB is a synthetic ajoene analogue that has been shown in our laboratory to have superior cytotoxicity to ajoene. In the current study we have performed a DNA microarray analysis of bisPMB-treated WHCO1 oesophageal cancer cells to identify pathways and processes that are affected by bisPMB. The most significantly enriched biological pathways as assessed by gene ontology, KEGG and ingenuity pathway analysis were those involving protein processing in the endoplasmic reticulum (ER) and the unfolded protein response. In support of these pathways, bisPMB was found to inhibit global protein synthesis and lead to increased levels of ubiquitinated proteins. BisPMB also induced alternate splicing of the transcription factor XBP-1; increased the expression of the ER stress sensor GRP78 and induced expression of the ER stress marker CHOP/GADD153. CHOP expression was found to be central to the cytotoxicity of bisPMB as its silencing with siRNA rendered the cells resistant to bisPMB. The MAPK proteins, JNK and ERK1/2 were activated following bisPMB treatment. However JNK activation was not critical in the cytotoxicity of bisPMB, and ERK1/2 activation was found to play a pro-survival role. Overall the ajoene analogue bisPMB appears to induce cytotoxicity in WHCO1 cells by activating the unfolded protein response through CHOP/GADD153.Peer reviewe

Exercise intervention alters HDL subclass distribution and function in obese women

Background Obesity is associated with a change in high-density lipoprotein (HDL) function and subclass. Exercise training reduces cardiovascular risk in obese patients. We aimed to explore the effect of an exercise training stimulus on HDL functionality and subclass in obese women. Methods Thirty-two obese black South African women were randomly assigned to exercise (combined aerobic and resistance exercise) or control (no exercise) conditions for 12-weeks. Pre- and post-testing included venous blood sampling for analysis of lipid profile and HDL functionality, by measuring cellular cholesterol efflux capacity, reduction in endothelial vascular cell adhesion molecule (VCAM) expression (anti-inflammatory function), paraoxonase (PON) (antioxidative function) and platelet activating factor acetylhydrolase (PAF-AH) activities (anti-thrombotic function). PON-1 and PAF-AH expression were determined in serum and in isolated HDL using Western blotting. Levels of large, intermediate and small HDL subclasses were measured using the Lipoprint® system. Results Exercise training resulted in a decrease in body mass index (− 1.0 ± 0.5% vs + 1.2 ± 0.6%, p = 0.010), PON activity (− 8.7 ± 2.4% vs + 1.1 ± 3.0%, p = 0.021), PAF-AH serum expression (− 22.1 ± 8.0% vs + 16.9 ± 9.8, p = 0.002), and the distribution of small HDL subclasses (− 10.1 ± 5.4% vs + 15.7 ± 6.6%, p = 0.004) compared to controls. Exercise did not alter HDL cellular cholesterol efflux capacity and anti-inflammatory function. Conclusions These results demonstrate the potential for exercise training to modify HDL subclass distribution and HDL function in obese women. Trial registration Clinical trials number: PACTR201711002789113

Surfactant protein a impairs genital HPV16 pseudovirus infection by innate immune cell activation in a murine model

Infection by oncogenic human papillomavirus (HPV) is the principle cause of cervical cancer and other anogenital cancers. The majority of cervical cancer cases occur in low- and middle-income countries (LMIC). Prophylactic vaccines exist to combat HPV infection but accessibility to these in LMIC is limited. Alternative preventative measures against HPV infection are therefore also needed to control cervical cancer risk. HPV employs multiple mechanisms to evade the host immune response. Therefore, an approach to promote HPV recognition by the immune system can reduce infection. Surfactant proteins A and D (SP-A and SP-D) are highly effective innate opsonins of pathogens. Their function is primarily understood in the lung, but they are also expressed at other sites of the body, including the female reproductive tract (FRT). We hypothesized that raised levels of SP-A and/or SP-D may enhance immune recognition of HPV and reduce infection. Co-immunoprecipitation and flow cytometry experiments showed that purified human SP-A protein directly bound HPV16 pseudovirions (HPV16-PsVs), and the resulting HPV16-PsVs/SP-A complex enhanced uptake of HPV16-PsVs by RAW264.7 murine macrophages. In contrast, a recombinant fragment of human SP-D bound HPV16-PsVs weakly and had no effect on viral uptake. To assess if SP-A modulates HPV16-PsVs infection in vivo, a murine cervicovaginal challenge model was applied. Surprisingly, neither naïve nor C57BL/6 mice challenged with HPV16-PsVs expressed SP-A in the FRT. However, pre-incubation of HPV16-PsVs with purified human SP-A at a 1:10 (w/w) ratio significantly reduced the level of HPV16-PsV infection. When isolated cells from FRTs of naïve C57BL/6 mice were incubated with HPV16-PsVs and stained for selected innate immune cell populations by flow cytometry, significant increases in HPV16-PsVs uptake by eosinophils, neutrophils, monocytes, and macrophages were observed over time using SP-A-pre-adsorbed virions compared to control particles. This study is the first to describe a biochemical and functional association of HPV16 virions with the innate immune molecule SP-A. We show that SP-A impairs HPV16-PsVs infection and propose that SP-A is a potential candidate for use in topical microbicides which provide protection against new HPV infections

Histidine7.36(305) in the conserved peptide receptor activation domain of the gonadotropin releasing hormone receptor couples peptide binding and receptor activation

Please read abstract in the article.Grants from the South African Medical Research Council, the National Research Foundation, the Korea-South Africa Collaboration Program (2012K1A3A1A09033014) and the MRC program (2010-0029522) of the National Research Foundation of Korea.http://www.elsevier.com/locate/mcehj201