Abstract. The active vitamin D (1,25(OH)2D) acts through a nuclear receptor to perform several functions in cellular metabolism. 1,25(OH)2D participates directly in calcium homeostasis, regulates the immune system, nervous system, blood pressure, insulin secretion, among others. Vitamin D deficiency could also be associated with several diseases and increased cellular oxidative damage. The present study aimed to investigate whether lipid peroxidation and/or protein oxidation are affected by vitamin D deficiency and whether sunlight exposure/diet, gender, and age might influence this relationship. Vitamin D concentrations were obtained from the Heart Hospital database and a questionnaire was applied among the 212 participants. We used the inactive vitamin D (25(OH)2) in the analyses since 1,25(OH)2D has a short half-life and a low blood concentration. Lipid peroxidation and protein oxidation analyses were performed using spectrophotometry. Multivariate analyses suggested the participation of vitamin D deficiency (<30 ng/mL) and sunlight/diet in oxidative stress (p <0.05; R2 MDA: 0.562; R2 CG: 0.429). Multiple linear regression test show that the age and gender of patients are not interfering in the analyses (p>0.05). Therefore, we suggest that the relationship between vitamin D deficiency and oxidative stress can be independent of age and gender.

Background: Vitamin D (VD) deficiency affects individuals of different ages in many countries. VD deficiency may be related to several diseases, including cancer. Objective: This study aimed to review the relationship between VD deficiency and cancer. Methods: We describe the proteins involved in cancer pathogenesis and how those proteins can be influenced by VD deficiency. We also investigated a relationship between cancer death rate and solar radiation. Results: We found an increased bladder cancer, breast cancer, colon-rectum cancer, lung cancer, oesophagus cancer, oral cancer, ovary cancer, pancreas cancer, skin cancer and stomach cancer death rate in countries with low sunlight. It was also observed that amyloid precursor protein, ryanodine receptor, mammalian target of rapamycin complex 1, and receptor for advanced glycation end products are associated with a worse prognosis in cancer. While the Klotho protein and VD receptor are associated with a better prognosis in the disease. Nfr2 is associated with both worse and better prognosis in cancer. Conclusion: The literature suggests that VD deficiency might be involved in cancer progression. According to sunlight data, we can conclude that countries with low average sunlight have high cancers death rate. New studies involving transcriptional and genomic data in combination with VD measurement in long-term experiments are required to establish new relationships between VD and cancer.

Objective: This review aims to study the receptor's family and functions most related to COVID-19 infection, also suggesting the tissue and cell location that the majority of COVID-19 receptors are mainly expressed. Methods: This systematic review (PROSPERO: CRD42020210643) is according to PRISMA guidelines. PubMed, Cochrane, SciELO, Lilacs, Web of Science, and DOAJ databases were used. Clinical trials and research articles studying receptors related to COVID-19 were included in this review. R programming language was used to elaborate charts and receptors network and SPSS(26v) software was used to perform statistical analyses. Results: The majority of studies regarding the involvement of receptors in COVID-19 included plasma receptors and G protein-coupled receptor families (p<0.05). These receptors are highly expressed in the brain (24%) and 80% of them can interact with each other in a protein network, exerting some regulatory effects in various tissues. The main influential receptor on the network of receptors involved in COVID-19 was the EGFR and the majority of receptors were associated with pathological processes in the disease (p<0.05), including the amplification of inflammatory responses in COVID-19, which may be related to neurological disorders in some cases. Humans from the United States, Spain, and Brazil were the most used model in studies adressing receptors involved in COVID-19 (p<0.05). Conclusions: Plasma receptors and G protein-coupled receptors, especially the EGFR, and involved with pathological effects on the COVID-19 inflammatory process in the brain have shown significant importance in this review.

The nociceptin/orphanin FQ receptor (NOP receptor) has wide expression in the nervous system and is involved in neurotransmitter release. However, the role of the NOPR in depression is not widely recognized. This study aims to evaluate behavioral and biochemical effects of the NOPR agonist Ro 65-6570 in mice submitted to social defeat protocol. The open-field test, social interaction test, and tail suspension test were applied to evaluate depressive behavior in male Swiss mice. Blood and brain tissue samples were obtained to evaluate the oxidative stress. The NOP agonist, Ro 65-6570 (1 mg/kg), or the social defeat stress reduced exploration rate in the open-field test. The social defeat stress and/or the NOP agonist also increased immobility time in the tail suspension test and the grooming time, as well as reduced the social interaction on the last day of social defeat protocol. Seven days after the end of the protocol, only the drug alone was able to affect the animals' interaction. Additionally, the NOP agonist increased the concentration of carbonyl groups (CGs) in hippocampus and malondialdehyde in serum. The stress of social defeat and the NOP agonist, together, increased malondialdehyde in animals' serum and prefrontal cortex, as well as increased the CGs concentration in the prefrontal cortex. These findings indicate a chronic depressive effect induced by the NOPR activation, sometimes regardless of the social defeat stress. We suggest that the NOPR signaling can activate pathways involved in cellular oxidative stress, contributing to the depression pathology.

Background: Over the past few years, experimental research has been carried out to analyze the role of specific receptors in depression to better understanding the mechanisms and pathophysiological aspects of the disease. Objective: In this paper, we aim to investigate the receptors family most involved in depression, as well as the tissue that most depression related-receptors are expressed. The article also aims to identify the main receptors functions predominantly associated with the pathology. Methods: This review used a systematic methodology (Prospero; ID 168584) and followed the PRISMA guidelines. Studies were searched in PubMed/MEDLINE, Scientific Electronic Library Online, Web of Science, and Directory of Open Access Journals databases. Quantitative studies with conclusive results regarding receptors involved in depression were selected. The charts and network were made using R programming language and statistical analyses were made using SPSS v25 software. Results: It can be seen that G protein-coupled receptors family was the most studied (p<0.05). These receptors are expressed in the cerebral cortex, basal ganglia, and can interact with each other. A great number of studies evaluated receptors related to beneficial effects in the disease (p<0.05). The inflammation response and cell survival/proliferation were the main functions related to these receptors (p<0.01) and behavioral tests in mice were the main methodologies applied in these studies (p<0.05). Finally, the most influential protein on the network of receptors involved in depression was the Bradykinin receptor B1. Conclusions: G protein-coupled receptors located in cell membranes, involved especially with protective effects on depression and expressed mainly in the cerebral cortex and basal ganglia have shown significant importance in this review. In addition, inflammation response or cell survival/proliferation was the main functions performed by the receptors related to depression in this work.