Unbalanced production of LTB4/PGE2 driven by diabetes increases susceptibility to cutaneous leishmaniasis

The Role of Melatonin in the Inflammatory Process in Patients with Hyperglycemia and Leishmania Infection

Type 2 diabetes mellitus is a metabolic disorder that causes chronic high blood sugar levels, and diabetic patients are more susceptible to infections. American cutaneous leishmaniasis is an infectious disease caused by a parasite that affects the skin and mucous membranes, leading to one or multiple ulcerative lesions. Chronic inflammation and functional changes in various organs and systems, including the immune system, are the primary causes of both diseases. Melatonin, an essential immunomodulatory, antioxidant, and neuroprotective agent, can benefit many immunological processes and infectious diseases, including leishmaniasis. Although, limited reports are available on diabetic patients with leishmaniasis. The literature suggests that melatonin may play a promising role in inflammatory disorders. This study was designed to assess melatonin levels and inflammatory mediators in diabetic patients affected by leishmaniasis. Blood samples from 25 individuals were analyzed and divided into four groups: a control group (without any diseases), a Leishmania-positive group, patients with type 2 diabetes mellitus, and patients with a combination of both diseases. This study measured the serum levels of melatonin through ELISA, while IL-4 and TNF-α were measured using flow cytometry, and C-reactive protein was measured through turbidimetry. This study found that patients with leishmaniasis significantly increased TNF-α and decreased melatonin levels. However, the group of diabetic patients with leishmaniasis showed higher melatonin levels than the control group. These observations suggest that TNF-α may influence melatonin production in patients with American cutaneous leishmaniasis, potentially contributing to the inflammatory characteristics of both diseases.

Combined therapeutic use of umbilical cord blood serum and amniotic membrane in diabetic wounds

Diabetic wounds are hard-to-heal due to complex multifactorial dysregulation within the micro-environment, necessitating the development of novel regenerative approaches to stimulate healing. This study investigated whether the combined therapeutic application of two novel cellular tissue products, namely a decellularized collagen-rich amniotic membrane (AmR) and growth factor-rich umbilical cord blood serum (UCBS) could have a positive synergistic effect on long-term healing outcomes by stimulating both superficial wound closure and wound bed regeneration. Full thickness excisional wounds were induced on obese diabetic mice (B6.Cg-lepob/J, ob/ob, n = 23) and treated with either: 1) Standard wound care (control); 2) UCBS; 3) AmR or 4) UCBS + AmR. Macroscopic wound closure was assessed on days 0, 3, 7, 10 and 14 post wounding. To determine the potential impact on wound recurrence, endpoint analysis was performed to determine both the overall quality of healing histologically as well as the molecular state of the wounds on day 14 via proteomic analysis. The data demonstrated the presence of both healers and non-healers. Re-epithelization took place in the healers of all treatment groups, but underlying tissue regeneration was far more pronounced following application of the combined treatment (UCBS + AmR), suggesting improved quality of healing and potentially a reduced change of recurrence long term. In non-healers, wounds failed to heal due to excessive slough formation and a reduction in LTB4 expression, suggesting impaired antimicrobial activity. Care should thus be taken since the cellular tissue product therapy could pose an increased risk for infection in some patients.

Diabetes and hypertension in elderly women: interactions between severity and failure to control inflammation

Elderly women are more susceptible to the development of chronic non-communicable diseases. Among these, diabetes mellitus (DM) and systemic arterial hypertension (SAH) stand out. This work aimed to carry out an expanded study on the interactions of anthropometric, biochemical and inflammatory parameters associated with the risk of severity in elderly women with hypertension and diabetes. The study involved the evaluation of 126 elderly women with hypertension and diabetes mellitus. The women were divided according disease severity (low, moderate, high and very high). Anthropometric data were collected by bioimpedance analysis. The inflammatory and biochemical data were obtained from volunteer blood samples. Waist circumference, waist circumference/height ratio, and systolic and diastolic pressures increased with severity. Biochemical marker levels increased with risk of severity, except HDLc. In the very high risk group, there was a higher IL-1β, IFN-γ and TNF-α production, however, lower IL-10 levels were observed. The very high risk group showed change values for the IL-10/IL-1β, IL-10/IL-17 and IL-10/TNF-α ratios. The results showed to be extensively altered in the very high risk group, where the inflammatory profile loses its responsiveness. This is the first study that shows an expanded view of the different parameters evaluated in elderly women with hypertension and diabetes.

Prostaglandin E2/Leukotriene B4 balance and viral load in distinct clinical stages of COVID-19: A cross-sectional study

BACKGROUND

Prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) are eicosanoids involved in modulation of the antiviral immune response. Recent studies have identified increased levels of several eicosanoids in the plasma and bronchoalveolar lavage of patients with coronavirus disease (COVID-19). This study investigated correlations between plasma levels of PGE2 and LTB4 and clinical severity of COVID-19.

METHODS

This cross-sectional study involved non-infected (n = 10) individuals and COVID-19 patients classified as cured (n = 13), oligosymptomatic (n = 29), severe (n = 15) or deceased (n = 11). Levels of D-dimer a, known COVID-19 severity marker, PGE2 and LTB4 were measured by ELISAs and data were analysed with respect to viral load.

RESULTS

PGE2 plasma levels were decreased in COVID-19 patients compared to the non-infected group. Changes in PGE2 and LTB4 levels did not correlate with any particular clinical presentations of COVID-19. However, LTB4 was related to decreased SARS-CoV-2 burden in patients, suggesting that only LTB4 is associated with control of viral load.

CONCLUSIONS

Our data indicate that PGE2/LTB4 plasma levels are not associated with COVID-19 clinical severity. Hospitalized patients with COVID-19 are treated with corticosteroids, which may influence the observed eicosanoid imbalance. Additional analyses are required to fully understand the participation of PGE2 receptors in the pathophysiology of COVID-19.

Leishmania amazonensis infection regulates oxidate stress in hyperglycemia and diabetes impairing macrophage's function and immune response

Leishmaniasis is a group of infectious diseases caused by protozoa of the Leishmania genus and its immunopathogenesis results from an unbalanced immune response during the infection. Diabetes is a chronic disease resulting from dysfunction of the body's production of insulin or the ability to use it properly, leading to hyperglycemia causing tissue damage and impairing the immune system.

AIMS

The objective of this work was to evaluate the effects of hyperglycemia and diabetes during Leishmania amazonensis infection and how these conditions alter the immune response to the parasite.

METHODS

An in vitro hyperglycemic stimulus model using THP-1-derived macrophages and an in vivo experimental diabetes with streptozotocin (STZ) in C57BL/6 mice was employed to investigate the impact of diabetes and hyperglicemia in Leishmania amazonensis infection.

RESULTS

We observed that hyperglycemia impair the leishmanicidal capacity of macrophages derived from THP-1 cells and reverse the resistance profile that C57BL/6 mice have against infection by L. amazonensis, inducing more exacerbated lesions compared to non-diabetic animals. In addition, the hyperglycemic stimulus favored the increase of markers related to the phenotype of M2 macrophages. The induction of experimental diabetes in C57BL/6 mice resulted in a failure in the production of nitric oxide (NO) in the face of infection and macrophages from diabetic animals failed to process and present Leishmania antigens, being unable to activate and induce proliferation of antigen-specific lymphocytes.

CONCLUSION

Together, these data demonstrate that diabetes and hyperglycemia can impair the cellular immune response, mainly of macrophages, against infection by parasites of the genus Leishmania.

Prostaglandin E2 contributes to L. braziliensis survival and therapeutic failure in cutaneous leishmaniasis

Patients with cutaneous leishmaniasis (CL) present an exacerbated inflammatory response associated with tissue damage and ulcer development. In recent years, higher rates of failure to pentavalent antimoniate therapy have been observed, yet the underlying reason remains poorly understood. We hypothesize that the eicosanoid PGE2 favours the establishment of infection by L. braziliensis, which contributes to therapeutic failure. The aim of the present study was to investigate the influence of PGE2 on the survival of L. braziliensis in macrophages and rates of therapeutic failure in CL patients. PGE2, an eicosanoid derived from the metabolism of arachidonic acid by the COX-2 enzyme, plays several roles in immune response. We found that increased PGE2 decreases the microbicidal function of macrophages and is associated with disease severity and therapeutic failure. Additionally, the neutralization of COX-2 by NS398, a selective NSAID, increases the ability of macrophages to kill L. braziliensis and protects against the pathological inflammatory response. Our data suggest that NS398 may serve as an adjunct treatment for CL patients.

The impact of diabetes on cutaneous leishmaniasis: a case-control field assessment

This study aimed to assess the associated-risk determinants for cutaneous leishmaniasis (CL) in patients with diabetes mellitus (DM) compared to patients without DM. This case-control study was performed between 2017 and 2019 in southeastern Iran. Overall, 206 participants were selected from patients with DM without CL (11.2%), patients with CL without DM (6.2%), and DM patients concomitance with CL (27.6%) as case groups and healthy individuals as a control group 64 (76%). These cases were compared for parasitological, immunological, biochemical, and hematological parameters. The findings demonstrated that parasitological factors regarding the number, duration, and size of the lesion in CL patients showed a significant difference among patients with and without DM (p < 0.05). Data analysis showed that six major risk factors, including female (odds ratio (OR) = 3.47, confidence interval (CI) = 1.84-6.53, p < 0.001), total protein in CL group (OR = 4.9, CI = 2.3-10.44, p < 0.001), alanine aminotransferase (ALT) concentration in CL group (OR = 0.87, CI = 0.81-0.93, p < 0.001) and DM co-infected with CL group (OR = 0.8, CI = 0.72-0.88, p < 0.001) than healthy group, aspartate aminotransferase (AST) concentration in DM group (OR = 0.86, CI = 0.76-0.98, p = 0.02), transforming growth factor beta)TGF-β( level in the CL group (OR = 1.03, CI = 1.003-1.05, p = 0.02), and presence of diabetes disease (OR = 2.07, CI = 1.16-3.7, p < 0.05), were significantly linked with the induction of CL lesion. The findings demonstrated a significant relationship between DM and CL in distinct risk determinants. Also, the study revealed that DM enhanced the severity of active CL.

Factors influencing on development of COVID-19 pneumonia and association with oral anti-diabetic drugs in hospitalized patients with diabetes mellitus

BACKGROUND

Diabetes mellitus (DM) increases mortality and morbidity in patients with coronavirus disease (COVID-19). In this study, it was aimed to assess factors influencing on COVID-19 pneumonia in hospitalized patients with diabetes and association with oral anti-diabetic drugs.

MATERIALS AND METHODS

This cross-sectional study included 432 patients with type 2 diabetes mellitus diagnosed with COVID-19. Data regarding clinical characteristics, demographic characteristics, intensive care unit (ICU) rate in patients admitted to ICU, laboratory results on day 1 and 7, thoracic computed tomography (CT) findings and oral anti-diabetic drugs used were extracted from medical records. In all patients, 75-days mortality was recorded. Data were assessed independently.

RESULTS

There was pneumonia in 386 (89.4%) of 432 patients with diabetes. The risk for pneumonia was markedly higher in patients on DPP-4 inhibitors; however, there was no significant among other oral anti-diabetic groups and subgroups. In addition, elevated CRP was linked to the increased risk for pneumonia. Only patients in the pneumonia group had SGLT-2 inhibitor use. During follow-up, 91 patients died. In Cox regression analysis, low Glasgow Coma Scale score, and increased lactate dehydrogenase levels were identified as significant independent risk factors for mortality.

CONCLUSION

The study indicated that DPP-4 inhibitor used and elevated CRP level were associated with pneumonia development. Only patients in the pneumonia group had SGLT-2 inhibitor use. No oral anti-diabetics was found to be associated with COVID-19 related death.

LTB4-Driven Inflammation and Increased Expression of ALOX5/ACE2 During Severe COVID-19 in Individuals With Diabetes

Diabetes is a known risk factor for severe coronavirus disease 2019 (COVID-19), the disease caused by the new coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, there is a lack of knowledge about the mechanisms involved in the evolution of COVID-19 in individuals with diabetes. We aimed to evaluate whether the chronic low-grade inflammation of diabetes could play a role in the development of severe COVID-19. We collected clinical data and blood samples of patients with and without diabetes hospitalized for COVID-19. Plasma samples were used to measure inflammatory mediators and peripheral blood mononuclear cells, for gene expression analysis of the SARS-CoV-2 main receptor system (ACE2/TMPRSS2), and for the main molecule of the leukotriene B₄ (LTB₄) pathway (ALOX5). We found that diabetes activates the LTB₄ pathway and that during COVID-19 it increases ACE2/TMPRSS2 as well as ALOX5 expression. Diabetes was also associated with COVID-19-related disorders, such as reduced oxygen saturation as measured by pulse oximetry/fraction of inspired oxygen (FiO₂) and arterial partial pressure of oxygen/FiO₂ levels, and increased disease duration. In addition, the expressions of ACE2 and ALOX5 are positively correlated, with increased expression in patients with diabetes and COVID-19 requiring intensive care assistance. We confirmed these molecular results at the protein level, where plasma LTB₄ is significantly increased in individuals with diabetes. In addition, IL-6 serum levels are increased only in individuals with diabetes requiring intensive care assistance. Together, these results indicate that LTB₄ and IL-6 systemic levels, as well as ACE2/ALOX5 blood expression, could be early markers of severe COVID-19 in individuals with diabetes.

Impairment of effector molecules response in diabetes induces susceptibility to Leishmania amazonensis infection

Type 2 Diabetes is a chronic disease resulting from insulin dysfunction that triggers a low-grade inflammatory state and immune impairment. Leishmaniasis is an infectious disease characterized by chronic inflammation resulted from the parasite's immunomodulation ability. Thus, due to the delicate immune balance required in the combat and resistance to Leishmania infection and the chronic deregulation of the inflammatory response observed in type 2 diabetes, we evaluated the response of PBMC from diabetic patients to in vitro Leishmania amazonensis infection. For that, peripheral blood was collected from 25 diabetic patients and 25 healthy controls matched for age for cells extraction and subsequent experimental infection for 2 or 24 h and analyzed for phagocytic and leishmanicidal capacity by optical microscopy, oxidative stress by GSSG generation, labeling of intracellular mediators by enzyme-Linked immunosorbent assay, and cytokines measurement with cytometric beads array technique. We found that the diabetic group had a higher percentage of infected cells and a greater number of amastigotes per cell. Also, even inducing NF-kB phosphorylation and increasing TNF production after infection, cells from diabetic patients were unable to downregulate NRF2 and generate oxidative stress, which may be associated with the exacerbated levels of IL-6 observed. PBMC of diabetic individuals are more susceptible to infection by L. amazonensis and fail to control the infection over time due to the inability to generate effector microbicidal molecules.