Chemotherapeutic drugs induced female reproductive toxicity and treatment strategies

Increase in success of cancer treatment with advancement in the screening, prognosis and diagnosis protocols have significantly improved the rate of cancer survivorship. With the declining cancer mortality, however, the cancer survivors are also subjected to the adverse consequences of chemotherapy, particularly in the female reproductive system. Recent studies have shown the sensitivity of the ovarian tissue to the chemotherapeutic drugs-induced toxicity. Several in vitro and in vivo studies have assessed the toxic effects of chemotherapeutic drugs. The most frequently used chemotherapeutic drugs such as doxorubicin, cyclophosphamide, cisplatin and paclitaxel have been reported to cause ovarian damage, diminution of follicular pool reserve, premature ovarian failure and early menopause, resulting into declining fertility potential among females. The chemotherapy often employs combination of drug regimen to increase the efficacy of the treatment. However, the literature mostly consists of clinical data regarding the gonadotoxicity caused by anticancer drugs but there lacks the understanding of toxicity mechanism. Therefore, understanding of the different toxicity mechanisms will be helpful in development of possible therapeutic interventions for preservation of declining female fertility among cancer survivors. The current review comprehends the underlying mechanisms of female reproductive toxicity induced by the most commonly used chemotherapeutic drugs. In addition, the review also summarizes the recent findings related to the use of various protectants to diminish or at least in managing the toxicity induced by different chemotherapeutic drugs in females.     

Membrane ruffles capture C3bi-opsonized particles in activated macrophages

A widespread belief in phagocyte biology is that FcγR-mediated phagocytosis utilizes membrane pseudopods, whereas Mac-1–mediated phagocytosis does not involve elaborate plasma membrane extensions. Here we report that dynamic membrane ruffles in activated macrophages promote binding of C3bi-opsonized particles. We identify these ruffles as components of the macropinocytosis machinery in both PMA- and LPS-stimulated macrophages. C3bi-particle capture is facilitated by enrichment of high-affinity Mac-1 and the integrin-regulating protein talin in membrane ruffles. Membrane ruffle formation and C3bi-particle binding are cytoskeleton dependent events, having a strong requirement for F-actin and microtubules (MTs). MT disruption blunts ruffle formation and PMA- and LPS-induced up-regulation of surface Mac-1 expression. Furthermore, the MT motor, kinesin participates in ruffle formation implicating a requirement for intracellular membrane delivery to active membrane regions during Mac-1–mediated phagocytosis. We observed colocalization of Rab11-positive vesicles with CLIP-170, a MT plus-end binding protein, at sites of particle adherence using TIRF imaging. Rab11 has been implicated in recycling endosome dynamics and mutant Rab11 expression inhibits both membrane ruffle formation and C3bi-sRBC adherence to macrophages. Collectively these findings represent a novel membrane ruffle “capture” mechanism for C3bi-particle binding during Mac-1–mediated phagocytosis. Importantly, this work also demonstrates a strong functional link between integrin activation, macropinocytosis and phagocytosis in macrophages.     

Estimating the conditional probability of developing human papilloma virus related oropharyngeal cancer by combining machine learning and inverse Bayesian modelling

The epidemic increase in the incidence of Human Papilloma Virus (HPV) related Oropharyngeal Squamous Cell Carcinomas (OPSCCs) in several countries worldwide represents a significant public health concern. Although gender neutral HPV vaccination programmes are expected to cause a reduction in the incidence rates of OPSCCs, these effects will not be evident in the foreseeable future. Secondary prevention strategies are currently not feasible due to an incomplete understanding of the natural history of oral HPV infections in OPSCCs. The key parameters that govern natural history models remain largely ill-defined for HPV related OPSCCs and cannot be easily inferred from experimental data. Mathematical models have been used to estimate some of these ill-defined parameters in cervical cancer, another HPV related cancer leading to successful implementation of cancer prevention strategies. We outline a “double-Bayesian” mathematical modelling approach, whereby, a Bayesian machine learning model first estimates the probability of an individual having an oral HPV infection, given OPSCC and other covariate information. The model is then inverted using Bayes’ theorem to reverse the probability relationship. We use data from the Surveillance, Epidemiology, and End Results (SEER) cancer registry, SEER Head and Neck with HPV Database and the National Health and Nutrition Examination Surveys (NHANES), representing the adult population in the United States to derive our model. The model contains 8,106 OPSCC patients of which 73.0% had an oral HPV infection. When stratified by age, sex, marital status and race/ethnicity, the model estimated a higher conditional probability for developing OPSCCs given an oral HPV infection in non-Hispanic White males and females compared to other races/ethnicities. The proposed Bayesian model represents a proof-of-concept of a natural history model of HPV driven OPSCCs and outlines a strategy for estimating the conditional probability of an individual’s risk of developing OPSCC following an oral HPV infection.     

The long unstructured region of Bcl‐xl modulates its structural dynamics

Bcl‐xl protein has a long unstructured loop attached to its structured region which joins two helices. The necessity to have this unstructured segment in Bcl‐xl is not yet well understood. To what extent the unstructured segment can influence the dynamics of the structured region of protein, with potential to influence the function, has been investigated in this work. Molecular dynamics simulation and principal component analysis show how the loop affects the internal motions of the protein, particularly its ligand binding pocket. Generally an unstructured region in the structure would promote flexibility resulting entropic stability but in contrary, here it narrows down the conformational space of the structured region of protein that could be hypothesized to impact the functional precision. Effects of the loop propagate to the binding pocket through structural rearrangements of polar side chains. The immediate suspicion of possible impact of phosphorylation to modulate the function of the protein is proven to be a fact, as the phosphorylated S49 and S62 located on the large unstructured region are seen to perturb the electrostatic network of the structure; an observation that validates and clarifies the role of loop as a modulator through biophysical and biochemical mechanisms. Proteins 2017; 85:1567–1579. © 2017 Wiley Periodicals, Inc.     

microRNA (miRNA) speciation in Alzheimer’s disease (AD) cerebrospinal fluid (CSF) and extracellular fluid (ECF)

Human cerebrospinal fluid (CSF), produced by the choroid plexus and secreted into the brain ventricles and subarachnoid space, plays critical roles in intra-cerebral transport and the biophysical and immune protection of the brain. CSF composition provides valuable insight into soluble pathogenic bio-markers that may be diagnostic for brain disease. In these experiments we analyzed amyloid beta (Aβ) peptide and micro RNA (miRNA) abundance in CSF and in short post-mortem interval (PMI <2.1 hr) brain tissue-derived extracellular fluid (ECF) from Alzheimer’s disease (AD) and age-matched control neocortex. There was a trend for decreased abundance of Aβ42 in the CSF and ECF in AD but it did not reach statistical significance (mean age ~72 yr; N=12; p~0.06, ANOVA). The most abundant nucleic acids in AD CSF and ECF were miRNAs, and their speciation and inducibility were studied further. Fluorescent miRNA-array-based analysis indicated significant increases in miRNA-9, miRNA-125b, miRNA-146a, miRNA-155 in AD CSF and ECF (N=12; p<0.01, ANOVA). Primary human neuronal-glial (HNG) cell co-cultures stressed with AD-derived ECF also displayed an up-regulation of these miRNAs, an effect that was quenched using the anti-NF-кB agents caffeic acid phenethyl ester (CAPE) or 1-fluoro-2-[2-(4-methoxy-phenyl)-ethenyl]-benzene (CAY10512). Increases in miRNAs were confirmed independently using a highly sensitive LED-Northern dot-blot assay. Several of these NF-кB-sensitive miRNAs are known to be up-regulated in AD brain, and associate with the progressive spreading of inflammatory neurodegeneration. The results indicate that miRNA-9, miRNA-125b, miRNA-146a and miRNA-155 are CSF- and ECF-abundant, NF-кB-sensitive pro-inflammatory miRNAs, and their enrichment in circulating CSF and ECF suggest that they may be involved in the modulation or proliferation of miRNA-triggered pathogenic signaling throughout the brain and central nervous system (CNS).     

Induction of cytokines in a macrophage cell line by proteins of Clostridium difficile

Clostridium difficile is a major cause of nosocomial diarrhoea. The toxins produced by C. difficile are responsible for the characteristic pathology observed in C. difficile disease, but several surface-associated proteins of C. difficile are also recognized by the immune system and could modulate the immune response in infection. The aim of this study was to assess the induction of cytokines in a macrophage cell line in response to different antigens prepared from five C. difficile strains: the hypervirulent ribotype 027, ribotypes 001 and 106 and reference strains VPI 10463 and 630 (ribotype 012). PMA-activated THP-1 cells were challenged with surface-layer proteins, flagella, heat-shock proteins induced at 42 and 60 °C and culture supernatants of the five C. difficile strains. The production of the pro-inflammatory cytokines such as TNF-α, IL-1β, IL-6, IL-8 and IL-12p70 was observed in response to the surface-associated proteins, and high levels of TNF-α, IL-1β and IL-8 were detected in response to challenge with culture supernatants. The immune response triggered by the surface-associated proteins was independent of the strain from which the antigens were derived, suggesting that these proteins might not be related to the varying virulence of the hypervirulent ribotype 027 or ribotypes 001 and 106. There was no interstrain difference observed in response to the culture supernatants of the tested C. difficile strains, but this was perhaps due to toxicity induced in the macrophages by large amounts of toxin A and toxin B.     

Chronic Disfiguring Facial Lesions in an Immunocompetent Patient Due to Exophiala spinifera: A Case Report and Review of Literature

Exophiala spinifera is a rare fungus causing chromoblastomycosis or different types of phaeohyphomycosis (cutaneous, subcutaneous, disseminated and cyst phaeohyphomycosis). We report a case of a young male with phaeohyphomycosis due to E. spinifera, who had multiple itchy painful papular lesions disfiguring his face for 4?years. His diagnosis was delayed and had received antibacterial and antileishmanial therapy elsewhere without any improvement. While he reported to our hospital, the histopathology of the biopsy collected from the lesion demonstrated acute on chronic inflammation with granuloma formation and darkly pigmented fungal elements. The isolate grown on culture was identified as E. spinifera on the basis of morphological characters. The identification of the isolate was further confirmed by sequencing of the ITS region of ribosomal DNA. After treatment with oral itraconazole, he had marked clinical improvement.     

News & Notes: Sorption and Desorption of Cobalt by Oscillatoria anguistissima

Oscillatoria anguistissima rapidly adsorbs appreciable amounts of cobalt from the aqueous solutions within 15 min of initial contact with the metal solution. O. anguistissima showed a high sequestration of cobalt at low equilibrium concentrations, and it followed the Freundlich model of adsorption. The adsorption is a strongly pH-dependent and temperature-independent phenomenon. The presence of Mg²⁺ and Ca²⁺ (100–200 ppm) resulted in decline in Co²⁺ adsorption capacity of Oscillatoria biomass. Sulphate and nitrate (0.75–10 mM) drastically reduced the extent of Co²⁺ biosorption. The biosorption of cobalt is an ion-exchange process as the Co²⁺ binding was accompanied by release of a large amounts of Mg²⁺ ions. Na₂CO₃ (1.0 mM) resulted in about 76% desorption of Co²⁺ from the loaded biomass. Received: 30 January 1999 / Accepted: 3 March 1999