Diabetic retinopathy (DR) is a progressive blinding disease that affects vision and quality of life of patients and severely impacts society. This complication, caused by abnormal glucose metabolism, leads to structural, functional, molecular, and biochemical abnormalities in the retina. Oxidative stress (OS) and inflammation also play pivotal roles in the pathogenic process of DR, leading to mitochondrial damage and decrease in the mitochondrial function. DR causes retinal degeneration in glial and neural cells, while the disappearance of pericytes in retinal blood vessels leads to modifications in vascular regulation and stability. Clinical changes include dilatation and blood flow alterations in response to the reduce in retinal perfusion in retinal blood vessels, leading to vascular leakage, neovascularization and neurodegeneration. Thus, DR is a highly complex disease with various biological factors that contribute to its pathogenesis. The interplay between biochemical pathways and non-coding RNAs (ncRNAs) is essential for understanding the development and progression of DR. Abnormal expression of ncRNAs has been confirmed to promote the development of DR, suggesting that ncRNAs such as miRNAs, lnc-RNAs and circ-RNAs have potential as diagnostic biomarkers and theranostic targets in DR. This review provides an overview of interactions between abnormal biochemical pathways and dysregulated expression of ncRNAs under the influence of hyperglycemic environment in DR.

Background: The presence of single nucleotide polymorphisms in the gene encoding key en-zyme in the folate pathway methyltetrahydrofolate reductase (MTHFR), causes methylation disorders associated with CAD development. Methods: Study group: 42 patients with CAD con-firmed by coronary angiography. Controls: 16 patients without CAD symptoms or significant coronary artery stenosis, based on invasive coronary angiography or multislice computed to-mography with coronary artery calcification scoring. Real-time PCR genotyping was assessed using TaqMan™ probes. Folic acid and 5-MTHF concentrations in blood serum were determined by LC-MS. Results: c.[1286A>C];[1286A>C] MTHFR polymorphism occurred significantly more often in (CAD+) patients compared to (CAD-) cohort and to the European population. The con-centration of 5-MTHF and folic acid in the subgroups of patients with methylation disorders di-vided by genotypes and (CAD+) was lower compared to (CAD-). Conclusions: The homozygous c.1286 A>C MTHFR variant can be considered as CAD genetic marker. In the subjects with the c.1286 A>C heterozygous and homozygous genotypes, lower concentrations of methyltetrahy-drofolate (5-MTHF) were observed. 5-MTHF can be considered as a biomarker of CAD. Identifi-cation of people at high risk of CAD using genetic tests can contribute to personalized therapy using active (methylated) form of folic acid (5-MTHF) in CAD patients with MTHFR polymor-phisms.

Rheumatoid arthritis (RA) is a chronic inflammatory disease. Despite new methods of diagnostics and treatment as well as extensive biological and immunosuppressive treatment, the etiology of RA is not fully understood. Moreover, the problem of diagnosis and treatment of RA patients is still current and affects a large group of patients. It is suggested that these ER-related features may impair adaptation to chronic stress, inferring the risk of rheumatoid arthritis. The main goal in this study was evaluation of changes in mRNA translation to determine chronic ER stress conditions in rheumatoid arthritis patients. The study group consist of 86 individuals including total 56 rheumatoid arthritis patients and 30 healthy controls. The expression level of mRNA form blood samples of RA patients as well as controls of the PERK-UPR associated genes: p-eIF2, BCL-2, PERK, ATF4, BAX were investigated by Real-Time qPCR. GAPDH expression was used as a standard control. Considering the median, the expression of PERK, BCL-2, p-eIF2, ATF4, BAX was found to be significantly increased in the blood of RA patients compared with the control group. The p-value for the PERK gene was 0.0000000036, the p-value for the BCL-2 gene was 0.000000014, the p-value for the p-eIF2 gene was 0.006948, the p-value for the ATF4 gene was 0.0000056 and the p-value for the BAX gene was 0.00019, respectively. Thus, it can be concluded that targeting of the components of the PERK-dependent UPR signaling pathway via small-molecule PERK inhibitors, may contribute to the development of novel, innovative treatment strategies against rheumatoid arthritis.