Mycobacterium species, including Mycobacterium tuberculosis and Mycobacterium leprae, are among the most potent human bacterial pathogens. The discovery of cytosolic mycobacteria challenged the paradigm that these pathogens exclusively localize within the phagosome of host cells. As yet the biological relevance of mycobacterial translocation to the cytosol remained unclear. In this current study we used electron microscopy techniques to establish a clear link between translocation and mycobacterial virulence. Pathogenic, patient‐derived mycobacteria species were found to translocate to the cytosol, while non‐pathogenic species did not. We were further able to link cytosolic translocation with pathogenicity by introducing the ESX‐1 (type VII) secretion system into the non‐virulent, exclusively phagolysosomal Mycobacterium bovis BCG. Furthermore, we show that translocation is dependent on the C‐terminus of the early‐secreted antigen ESAT‐6. The C‐terminal truncation of ESAT‐6 was shown to result in attenuation in mice, again linking translocation to virulence. Together, these data demonstrate the molecular mechanism facilitating translocation of mycobacteria. The ability to translocate from the phagolysosome to the cytosol is with this study proven to be biologically significant as it determines mycobacterial virulence.

There is increasing evidence that chronic inflammation is an important determinant in insulin resistance and in the pathogenesis of type 2 diabetes (T2D). MicroRNAs constitute a newly discovered system of cell regulation and in particular two microRNAs (miR-146a and miR-155) have been described as regulators and biomarkers of inflammation. To determine a putative association between the levels of miR-146a and miR-155 in serum of T2D patients, clinical parameters and serological indicators of inflammation. We performed quantitative Real Time PCR (qPCR) of microRNAs from serum (56 Ecuadorian T2D ambulatory patients and 40 non-diabetic controls). In addition, we evaluated T2D-related serum cytokines.chemokines and growth factors using a commercially available multi-analyte cytometric bead array system. We correlated outcomes to clinical parameters, including BMI, HbA1c and lipid state. The Ecuadorian non-diabetic controls appeared as overweight (BMI>25: patients 85%, controls 82.5%) and as dyslipidemic (hypercholesterolemia: patients 60.7%, controls 67.5%) as the patients. This study shows decreased serum anti-inflammatory miR-146a, increased pro-inflammatory IL-8 and increased HGF (a vascular/insular repair factor) as discriminating markers of failure of glucose control occurring on the background of obesity and dyslipidemia.

There is clinical evidence that des‐acyl ghrelin (DAG) favorably modulates glucose and lipid metabolism, although its mode of action is unknown. A murine model of prediabetes was used to assess possible mechanisms of action for DAG and a newly developed bioactive analog, AZP531. C57BL/6J mice were infused with saline, DAG, or AZP531 continuously for 4 wk, and fed either normal diet (ND) or normal diet for 2 wk followed by a high‐fat diet (HFD) for 2 wk. Compared with mice in the ND group, HFD increased body and fat mass, caused glucose intolerance and insulin resistance, had proinflammatory effects in white adipose tissue, and caused lipid accumulation in brown adipose tissue. DAG and AZP531 treatment prevented HFD‐induced proinflammatory effects, stimulated expression of mitochondrial function markers in brown adipose tissue, and prevented development of a prediabetic metabolic state. AZP531 also prevented a HFD‐induced increase in acyl ghrelin levels. Our data indicate DAG analogs as potential treatment for the prevention of metabolic syndrome.—Delhanty, P. J. D., Huisman, M., Baldeon‐Rojas, L.Y., van den Berge, I., Grefhorst, A., Abribat, T., Leenen, P. J. M., Themmen, A. P. N., van der Lely, A.‐J. Des‐acyl ghrelin analogs prevent high‐fat diet‐induced dysregulation of glucose homeostasis. FASEB J. 27, 1690–1700 (2013). www.fasebj.org

Introduction: Sepsis is a public health problem due to its high prevalence and mortality. Mean platelet volume (MPV), a biomarker reported in routine blood counts, has been investigated and shows promise for determining fatal outcomes in septic patients. Objective: Evaluate whether the mean platelet volume (MPV) and mean platelet volume-to-platelet count (MPV/P) ratio are predictors of clinical severity and mortality in patients with sepsis. Methods: A prospective population cohort of 163 patients aged 18–97 years was recruited at the Intensive Care Unit of Pablo Arturo Hospital, Quito, Ecuador from 2017–2019 and followed up for 28 days. Patients were diagnosed with sepsis based on SEPSIS-3 septic shock criteria; in which the MPV and the MPV/P ratio were measured on days 1, 2, and 3. Sequential organ failure assessment (SOFA) score and presence of septic shock assessed clinical severity. Mortality on day 28 was considered the fatal outcome. Results: The average age of the patients was 61,15 years (SD 20,94) and female sex was predominant. MPV cutoff points at days 1, 2 and 3 were >9,45fL, >8,95fL and >8, 85fL; and (MPV/P) ratio >8, 18, >4, 12 y >3, 95, respectively. MPV at days 2 (9,85fL) and 3 (8,55fL) and (MPV/P) ratio at days 1 (4,42), 2 (4,21), and 3 (8,55), were predictors of clinical severity assessed by septic shock, which reached significance in the ROC curves. MPV and (MPV/P) ratio were also predictors of clinical severity determined by SOFA at days 1, 2, and 3, where higher values were observed in non-survivors reaching significance in all categories. MPV and MPV/P ratio at days 1, 2 and 3 were independent predictor factors of mortality using Cox proportional hazards model (HR 2,31; 95% CI 1,36–3,94), (HR 2,11; 95% CI 1,17–3,82), (HR 2,13; 95% CI 1,07–4,21) and (HR 2,38; 95% CI 1,38–4,12), (HR 2,15; 95% CI 1,14–4,06), (HR 4,43; 95% CI, 1,72–11,37) respectively. Conclusions: MPV and the MPV/P ratio are predictors of clinical severity and mortality in sepsis. The MPV and its coefficient are indicators of the biological behavior of platelets in sepsis. They should be considered as a cost-effective and rapidly available tool that guides the treatment.

In December 2019, a novel coronavirus known as SARS-CoV-2 was first detected in Wuhan, China, causing outbreaks of the coronavirus disease COVID-19 that has now spread globally. For this reason, The World Health Organization (WHO) declared COVID-19 a public health emergency in March 2020. People living with pre-existing conditions such as obesity, cardiovascular diseases, type 2 diabetes (T2D), and chronic kidney and lung diseases, are prone to develop severe forms of disease with fatal outcomes. Metabolic diseases such as obesity and T2D alter the balance of innate and adaptive responses. Both diseases share common features characterized by augmented adiposity associated with a chronic systemic low-grade inflammation, senescence, immunoglobulin glycation, and abnormalities in the number and function of adaptive immune cells. In obese and T2D patients infected by SARS-CoV-2, where immune cells are already hampered, this response appears to be stronger. In this review, we describe the abnormalities of the immune system, and summarize clinical findings of COVID-19 patients with pre-existing conditions such as obesity and T2D as this group is at greater risk of suffering severe and fatal clinical outcomes.

Objective Resection of primary colorectal cancer is associated with enhanced risk of development of liver metastases. It was previously demonstrated that surgery initiated an early inflammatory response resulting in elevated tumour cell adhesion in the liver. Because reactive oxygen species (ROS) are shown to be produced and released during surgery, the effects of ROS on the liver vascular lining and tumour cell adhesion were investigated. Methods Human endothelial cell monolayers (human umbilical vein endothelial cells (HUVECs) and human microvascular endothelial cells of the lung (HMEC-1s)) were exposed to ROS production, after which electrical impedance, cellular integrity and tumour cell adhesion were investigated. Furthermore, surgery-induced tumour cell adhesion as well as the role of ROS and liver macrophages (Kupffer cells) in this process were studied in vivo. Results Production of ROS decreased cellular impedance of endothelial monolayers dramatically. Moreover, formation of intercellular gaps in endothelial monolayers was observed, exposing subendothelial extracellular matrix (ECM) on which colon carcinoma cells adhered via integrin molecules. Endothelial damage was, however, prevented in the presence of ROS-scavenging enzymes. Additionally, surgery induced downregulation of both rat and human liver tight junction molecules. Treatment of rats with the ROS scavenger edaravone prevented surgery-induced tumour cell adhesion and downregulation of tight junction proteins in the liver. Interestingly, depletion of Kupffer cells prior to surgery significantly reduced the numbers of adhered tumour cells and prevented disruption of expression of tight junction proteins. Conclusions In this study it is shown that surgery-induced ROS production by macrophages damages the vascular lining by downregulating tight junction proteins. This leads to exposure of ECM, to which circulating tumour cells bind. In light of this, perioperative therapeutic intervention, preventing surgery-induced inflammatory reactions, may reduce the risk of developing liver metastases, thereby improving the clinical outcome of patients with colorectal cancer.