Adiponectin: A "Friendly adipokine" in Diabetic Retinopathy?

PURPOSE

Adiponectin has also been associated with diabetic retinopathy, a diabetic microvascular complication. However, the mechanism of action of adiponectin in retinopathy is still under investigation. This review summarizes emerging evidence on the association with diabetic retinopathy in type 2 diabetes.

METHODS

We reviwed papers from 2004 to 2022 and included studies related to retinopathy and its association with blood and intraocular adiponectin in type 2 diabetes.

RESULTS

Most of the studies analyzed in this review suggested an association between the diabetic retinopathy progression and intraocular, serum, or plasma adiponectin levels. Increased levels of adiponectin contributed to the development of the disease in diabetic patients. In a minority of studies, it was indicated an inversely proportional relationship between adiponectin concentration and diabetic retinopathy severity.

CONCLUSION

The high levels of adiponectin in diabetic patients may be related to the decrease in renal clearance. Under this situation, if the predominant isoform is globular adiponectin, this may explain the retinopathy progression, considering a pro-inflammatory response induced by this isoform. However, the actions of adiponectin in diabetic retinopathy pathophysiology are still controversial.

Adipokines from adipose tissue and common variable immunodeficiency: Is there any association?

Adiponectin and leptin are adipokines, secreted by white adipose tissue (WAT), which play an important role in energy homeostasis. Some evidence has shown that adipokine-producing adipose cells present in the bone marrow (BM) appear to exert an influence on hematopoiesis and B cell development. Common variable immunodeficiency (CVID) is one of the most common inborn errors of immunity in humans. In CVID, numerical and/or functional defects of B cells and their precursors result in hypogammaglobulinemia, usually Immunoglobulin (Ig) A and IgG. Manifestations of CVID include immunodeficiency, autoimmunity, inflammation and lymphoproliferation, resulting in a wide range of phenotypes. How adipokines interact and influence the pathophysiology of CVID is still unclear. In this review, we seek to summarize the aspects known so far concerning the interface between adipokines, B cells and CVID. More research is needed to fully understand these interactions; this knowledge is a potential avenue for the discovery of useful biomarkers and may provide new therapeutic targets for the treatment of patients with CVID and related diseases.

Photobiomodulation for the management of xerostomia and oral mucositis in patients with cancer: a randomized clinical trial

To evaluate the applicability of photobiomodulation therapy (PBM-T) in the management of xerostomia and OM. Fifty-three patients with head and neck squamous cell carcinoma were randomized into two groups: Sham and PBM-T. The Sham group received artificial saliva and laser simulation, while the PBM-T group received artificial saliva and PBM-T. Xerostomia-related quality of life (QoL), the presence or absence of OM lesions, the decayed-missing-filled teeth (DMFT) index, and periodontal charts were evaluated. The results of the QoL questionnaire, DMFT index, and periodontal chart were analyzed with the Kruskal-Wallis test, followed by the Student-Newman-Keuls test, while OM findings were compared using the Mann-Whitney test. QoL scores significantly increased in the Sham group (p < 0.0001), denoting more severe xerostomia symptoms (p = 0.0074), and decreased in the PBM-T group, indicating no or very mild xerostomia. Higher grades of OM were found in the Sham group than the PBM-T group (p = 0.0001). There was no significant difference in DMFT index or periodontal charts between the groups (p > 0.05). PBM-T improved QoL in patients with head and neck cancer treated with radiotherapy, whether as radiation alone or as an adjunct to chemotherapy and surgery.

In vitro evaluation of EDTA combined with photodynamic therapy to reduce Streptococcus mutans in carious dentin

BACKGROUND

This in vitro study aimed to evaluate the use of EDTA combined with photodynamic therapy to reduce Streptococcus mutans in carious dentin.

METHODS

Sixty third molars were sectioned to obtain flat dentin surfaces. All specimens were waterproofed, except for the coronal dentin, and subjected to cariogenic challenge in brain-heart infusion (BHI) broth supplemented with 0.5% yeast extract, 1% glucose, 1% sucrose, and standard strain of S. mutans (ATCC 25175). The specimens were divided into 6 groups (n = 10 each): (1) control - caries collection; (2) EDTA - 17% EDTA was actively applied with a microbrush for 1 min; (3) aPDT - antimicrobial photodynamic therapy with 0.01% methylene blue photosensitizer (wavelength of 660 nm, energy of 4 J, power of 100 mW, spot size of 0.028 cm², energy density of 142 J/cm² for 40 s); (4) EDTA+aPDT - 17% EDTA actively applied for 1 min plus aPDT; (5) (EDTA+PT) + L - application of EDTA compounded with photosensitizer plus laser irradiation; and (6) PT - photosensitizer alone. Collection of caries was performed after the different cavity disinfection protocols. Aliquots from each dilution were seeded for colony-forming unit (CFU) counts. The results were log₁₀-transformed and analyzed by the Kruskal-Wallis test (Student-Newman-Keuls).

RESULTS

There was a significant reduction in S. mutans after aPDT (p<0.05), EDTA+aPDT (p<0.001), and (EDTA+PT) + L (p<0.001). The percentage of microbial reduction in ascending order was as follows: EDTA: 1.65%; PT: 15.51%; aPDT: 38.28%; EDTA+aPDT: 75.24%; and (EDTA+PT) + L: 97.35%.

CONCLUSION

Application of 17% EDTA prior to photosensitization or compounded with a photosensitizer increased the antimicrobial effect of aPDT on S. mutans in carious dentin.

Effect of cetrimide 2% with and without photodynamic therapy to reduce Streptococcus mutans burden in dentinal carious lesions

To evaluate the use of cetrimide alone and combined with photodynamic therapy to reduce S. mutans burden in carious lesions. Sixty permanent third molars were sectioned and the coronal dentin exposed. A cariogenic challenge was performed using brain-heart infusion (BHI) medium supplemented and S. mutans ATCC 25175. Specimens were incubated in anaerobic jars at 37 °C for 15 days, with BHI renewed every 24 h. After 15 days, specimens were randomly divided into six groups (n = 10): C, control (no treatment); CHX, application of chlorhexidine 2%; CT, application of cetrimide 2%; CT+aPDT, application of cetrimide 2% followed by methylene blue dye and aPDT (antimicrobial photodynamic therapy: wavelength 660 nm, energy 4J, power 100 mW, spot size 0.0028 cm², energy density 142 J/cm² for 40 s); ES+aPDT, application of experimental solution (methylene blue dye with cetrimide) and aPDT; and aPDT alone. Carious tissue from each specimen was collected before and after the applications. Five decimal dilutions were performed, and the resulting solution was seeded in mitis-salivarius-bacitracin agar. Plates were incubated in anaerobic jars at 37 °C for 48 h. Analysis of variance (ANOVA) with post hoc Tukey's test was used to compare total S. mutans counts. Significant reductions in S. mutans were observed after application of CT+aPDT (0.30 (0.97), p < 0.0001) and ES+aPDT (0.52 (1.13), p < 0.0001). Cetrimide 2% with methylene blue dye, applied consecutively or as a mixture, can be used as a photosensitizing agent for aPDT to reduce S. mutans burden in dentinal caries.

Autoimmunity and periodontal disease: Arguing a possible correlation

Currently, there is a growing interest in studying systemic conditions associated with periodontal disease such as autoimmune disorders. Periodontal disease is a destructive inflammatory disease of the dental supporting tissues. The microorganisms associated with periodontal disease constitute diverse species that can colonize the oral cavity and influence the emergence or evolution of autoimmunity, characterized by a breakdown in the mechanisms of tolerance to self-antigens. Here, we reviewed and discussed a possible correlation between periodontal disease and autoimmunity, placing periodontal-pathogenic microorganisms as orchestrators of these pathological conditions.

Deciphering targets of Th17 cells fate: From metabolism to nuclear receptors

Evidence indicates that reprogramming of metabolism is critically important for the differentiation of CD4 + T lymphocytes, and the manipulation of metabolic pathways in these cells may shape their fate and function. Distinct subgroups from T lymphocytes, such as Th17, adopt specific metabolic programmes to support their needs. Some important metabolic reactions, such as glycolysis, oxidative phosphorylation, are considered important for the differentiation of these lymphocytes. Since their discovery nearly a decade ago, Th17 lymphocytes have received significant attention because of their role in the pathology of several immune-mediated inflammatory diseases such as multiple sclerosis. In this review, it will be discussed as the involvement of T cell metabolism and as metabolic reprogramming in activated T cells dictates fate decisions to Th17. The involvement of nuclear receptors such as RORyt e PPARs in the induction of Th17 cells was also discussed. Understanding the metabolic pathways involved in the differentiation of the distinct subgroups of T lymphocytes helps in the design of promising therapeutic proposals.

Novas evidências: a relação entre os hormônios tireoidianos e a resposta imunológica

Os hormônios tireoidianos tiroxina (T4) e triiodotironina (T3), produzidos pela glândula tireoide, são fundamentais para induzir o estímulo do consumo de O2 na maioria das células, auxiliar na regulação do metabolismo de carboidratos e lipídeos, bem como no desenvolvimento neuronal e crescimento ósseo. 

Vitamin E supplementation reduces oxidative stress in beta thalassaemia intermedia

OBJECTIVE

The aim of this investigation was to study the effect of vitamin E treatment in oxidative stress of red and white cells of beta-thalassaemia intermedia patients.

METHODS

Nine patients undergoing occasional transfusions (5 females/4 males), median age 39 years (range 15-74), were recruited for oral daily administration of 400 IU vitamin E for 3 months. Twenty-seven milliliters of peripheral blood was obtained before and after 3 months of treatment, and 3 months after treatment completion. In the case of transfused patients (n = 4), blood was obtained at least 30 days after transfusion. Reactive oxygen species (ROS) was measured by flow cytometry; red blood cell (RBC) reduced glutathione (GSH) was measured by dinitrothiocyanobenzene reduction, serum malondialdehyde was measured in terms of thiobarbituric acid-reactive substances (TBARS), and alpha-haemoglobin-stabilizing protein (AHSP) mRNA expression was measured by real-time polymerase chain reaction of reticulocyte RNA extracts.

RESULTS

beta-Thalassaemia patients presented basal levels of RBC ROS, GSH and serum TBARS statistically different compared with healthy controls. However, after vitamin E administration, patients presented a significant reduction in erythrocyte RBC ROS and serum TBARS levels. In parallel, red cell GSH was significantly increased after treatment. Peripheral mononuclear cells and T lymphocytes also demonstrated a reduction in ROS production. Therefore, after treatment, no significant differences were detected comparing patients and normal controls. Three months after treatment completion, all measurements showed a tendency of returning to basal values. A significant reduction in reticulocyte number was observed after vitamin E treatment. Vitamin E treatment did not modify levels of haemoglobin or AHSP mRNA expression.

CONCLUSION

Although vitamin E is not capable of reducing anaemia in these patients, it could be useful for reducing oxidative damage in other target organs of beta-thalassaemic patients. Finally, this is the first study to analyse the effects of vitamin E on ROS production in red and white blood cells and AHSP mRNA expression.