UVB irradiation as a tool to assess ROS-induced damage in human spermatozoa

One of the consequences of oxygen metabolism is the production of reactive oxygen species (ROS) which in a situation of imbalance with antioxidants can damage several biomolecules, compromise cell function and even lead to cellular death. The particularities of the sperm cell make it particularly vulnerable to ROS attack compromising its functionality, mirrored in terms of fertility outcome and making the study of the origin of sperm ROS, as well as the alterations they cause very important. In the present work, we used UVB irradiation, an easy experimental approach known as a potent inducer of ROS formation, to better understand the origin of ROS damage without any confounding effects that usually exist in disease models in which ROS are reported to play a role. To address these issues we evaluated sperm mitochondrial ROS production using the Mitosox Red Probe, mitochondrial membrane potential using the JC-1 probe, lipid peroxidation through BODIPY probe and vitality using PI. We observed that UVB irradiation leads to an increase in sperm mitochondrial ROS production and lipid peroxidation that occur previously to an observable mitochondrial dysfunction. We concluded that sperm UVB irradiation appears to be a good and easily manipulated in vitro model system to study mitochondria-induced oxidative stress in spermatozoa and its consequences, which may be relevant in terms of dissecting the action pathways of many other pathologies, drugs and contaminants, including endocrine disruptors.S.A. is the recipient of a FCT fellowship (SFRH/BPD/ 63190/2009). Centre for Neuroscience and Cell Biology (CNC) funding is supported by FCT (PEst-C/SAU/LA0001/2011)

Spinal Cord Injury Causes Sustained Disruption of the Blood-Testis Barrier in the Rat

There is a high incidence of infertility in males following traumatic spinal cord injury (SCI). Quality of semen is frequently poor in these patients, but the pathophysiological mechanism(s) causing this are not known. Blood-testis barrier (BTB) integrity following SCI has not previously been examined. The objective of this study was to characterize the effects of spinal contusion injury on the BTB in the rat. 63 adult, male Sprague Dawley rats received SCI (n = 28), laminectomy only (n = 7) or served as uninjured, age-matched controls (n = 28). Using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), BTB permeability to the vascular contrast agent gadopentate dimeglumine (Gd) was assessed at either 72 hours-, or 10 months post-SCI. DCE-MRI data revealed that BTB permeability to Gd was greater than controls at both 72 h and 10 mo post-SCI. Histological evaluation of testis tissue showed increased BTB permeability to immunoglobulin G at both 72 hours- and 10 months post-SCI, compared to age-matched sham-operated and uninjured controls. Tight junctional integrity within the seminiferous epithelium was assessed; at 72 hours post-SCI, decreased expression of the tight junction protein occludin was observed. Presence of inflammation in the testes was also examined. High expression of the proinflammatory cytokine interleukin-1 beta was detected in testis tissue. CD68+ immune cell infiltrate and mast cells were also detected within the seminiferous epithelium of both acute and chronic SCI groups but not in controls. In addition, extensive germ cell apoptosis was observed at 72 h post-SCI. Based on these results, we conclude that SCI is followed by compromised BTB integrity by as early as 72 hours post-injury in rats and is accompanied by a substantial immune response within the testis. Furthermore, our results indicate that the BTB remains compromised and testis immune cell infiltration persists for months after the initial injury

Investigating the Glycating Effects of Glucose, Glyoxal and Methylglyoxal on Human Sperm

Glycation is the non-enzymatic reaction between reducing sugars, such as glucose, and proteins, lipids or nucleic acids, producing Advanced Glycation End (AGE) products. AGEs, produced during natural senescence as well as through lifestyle factors such as diet and smoking, are key pathogenic compounds in the initiation and progression of diabetes. Importantly, many of these factors and conditions also have influence on male fertility, affecting sperm count and semen quality, contributing to the decreasing trend in male fertility. This study investigated the impact of AGEs on sperm damage. In vitro sperm glycation assays were used to determine the levels and localization of the potent AGE compound, carboxymethyl-lysine (CML) in response to treatment with the glycating compounds glucose, glyoxal and methylglyoxal. Sperm function assays were then used to assess the effects of glycation on motility and hyaluronan binding, and levels of oxidative DNA damage were analyzed through measurement of the marker, 8-oxoguanine. Results showed that glyoxal, but not glucose or methylglyoxal, induced significant increases in CML levels on sperm and this correlated with an increase in 8-oxoguanine. Immunocytochemistry revealed that AGEs were located on all parts of the sperm cell and most prominently on the head region. Sperm motility and hyaluronidase activity were not adversely affected by glycation. Together, the observed detrimental effects of the increased levels of AGE on DNA integrity, without an effect on motility and hyaluronidase activity, suggest that sperm may retain some fertilizing capacity under these adverse conditions

Breast cancer management pathways during the COVID-19 pandemic: outcomes from the UK ‘Alert Level 4’ phase of the B-MaP-C study

Abstract: Background: The B-MaP-C study aimed to determine alterations to breast cancer (BC) management during the peak transmission period of the UK COVID-19 pandemic and the potential impact of these treatment decisions. Methods: This was a national cohort study of patients with early BC undergoing multidisciplinary team (MDT)-guided treatment recommendations during the pandemic, designated ‘standard’ or ‘COVID-altered’, in the preoperative, operative and post-operative setting. Findings: Of 3776 patients (from 64 UK units) in the study, 2246 (59%) had ‘COVID-altered’ management. ‘Bridging’ endocrine therapy was used (n = 951) where theatre capacity was reduced. There was increasing access to COVID-19 low-risk theatres during the study period (59%). In line with national guidance, immediate breast reconstruction was avoided (n = 299). Where adjuvant chemotherapy was omitted (n = 81), the median benefit was only 3% (IQR 2–9%) using ‘NHS Predict’. There was the rapid adoption of new evidence-based hypofractionated radiotherapy (n = 781, from 46 units). Only 14 patients (1%) tested positive for SARS-CoV-2 during their treatment journey. Conclusions: The majority of ‘COVID-altered’ management decisions were largely in line with pre-COVID evidence-based guidelines, implying that breast cancer survival outcomes are unlikely to be negatively impacted by the pandemic. However, in this study, the potential impact of delays to BC presentation or diagnosis remains unknown