Current Molecular Medicine - Volume 21, Issue 8, 2021

Epigenetics has an important role in gene regulation and other cellular processes. DNA methylation, as one of the main mechanisms of epigenetics, is a type of post-replication modifications. Aberrant DNA methylation can alter gene expression patterns; so, it plays a considerable role in the pathogenesis of many diseases. DNA methylated alterations in the promoter of specific genes can be used for the diagnosis and proprietary targets acting as a “biomarker”. Early diagnosis and prevention may be possible due to these biomarkers. According to recent studies, DNA methylation abnormalities have an important role in the retinogenesis and pathogenesis of retinal diseases. Retinal diseases are the main cause of blindness and severe vision loss in the world, which will continue to increase. Also, they inflict an enormous burden on society and health care systems. Therefore, it is important to focus on the better recognition and prevention of retinal diseases and finding new targets for the treatment. DNA methylation is lionized as attractive therapeutic targets due to its reversibility. Epigenetic therapy has a high potency in the treatment of retinal diseases. Here, we reviewed the DNA and histone methylation alterations in common retinal diseases, focusing on agerelated macular degeneration (AMD), diabetic retinopathy, retinal detachment (RD), retinitis pigmentosa, retinal aging, and retinoblastoma. Then we surveyed some new approaches to epigenetic therapy in retinal disorders.

Selected transcription factors have critical roles to play in organism survival by regulating the expression of genes that control the adaptations needed to handle stress conditions. The retinoblastoma (Rb) protein coupled with the E2F transcription factor family was demonstrated to have roles in controlling the cell cycle during freezing and associated environmental stresses (anoxia, dehydration). Rb phosphorylation or acetylation at different sites provides a mechanism for repressing cell proliferation that is under the control of E2F transcription factors in animals facing stresses that disrupt cellular energetics or cell volume controls. Other central regulators of the cell cycle including Cyclins, Cyclin-dependent kinases (Cdks), and checkpoint proteins detect DNA damage or any improper replication, blocking further progression of cell cycle and interrupting cell proliferation. This review provides an insight into the molecular regulatory mechanisms of cell cycle control, focusing on Rb-E2F along with Cyclin-Cdk complexes typically involved in development and differentiation that need to be regulated in order to survive extreme cellular stress.

The nuclear erythroid 2-related-factor (Nrf2) transcription factor/hemoxygenase 1 (HO-1) is a key regulator of an important neuroprotection response by driving the interpretation of various cytoprotective gene to encode for anti-inflammatory, antioxidant, and detoxifying proteins. Various studies investigated that the upregulation of Nrf2/HO-1 has become the potential therapeutic approach in amyotrophic lateral sclerosis (ALS). Amyotrophic lateral sclerosis is a motor neuron disease in which there is a progressive loss of upper motor neuron and lower motor neurons of the motor cortex, brain stem, and corticospinal tract. A result of this upregulation of Nrf2/HO-1 indicates that in the brain, anti-oxidant capacity is reinforced. Further, this shows a cytoprotective effect against oxidative stress in amyotrophic lateral sclerosis. A study reported functions associated with the Nrf2/HO-1 in the neuronal cell, oligodendrocytes, microglia, and astrocytes. Although ALS's pathogenesis is not yet clear, but it is compelling. The evidence shows any dysfunction in the brain such as mitochondrial dysfunction, protein aggregation, glial cell activation, excitotoxicity, and apoptosis which gives ALS-like symptoms. In this review, we have mainly focused on detailing the downregulation of Nrf2/HO-1, which may be the prime reason and may further serve as a pathological hallmark for ALS development. As surveyed, there are limited targetbased interventions that only provide symptomatic relief but do not cure the disease completely. Dysregulation of the Nrf2/HO-1 signaling pathway leads to many physiological changes contributing to neurological conditions, including ALS. Based on the above view, we summarized the combined role of Nrf2/HO-1 signaling in ALS and explored potential therapeutic strategies for disease improvement through pathway modulators.

Background: Triazavirin (2-methylsulfanyl-6-nitro[1,2,4]triazolo[5,1-c][1,2,4] triazin-7(4H)-one, TZV) is an antiviral drug synthesized. TZV is being investigated for potential application against the Coronavirus 2019-nCoV. Aims and Objectives: In order to find candidate drugs for 2019-nCoV, we have carried out a computational study to screen for effective available drug Triazavirin (C5H4N6O3S) which may work as inhibitor for the Mpro of 2019-nCoV. Methods: In the present work, first time the molecular structure of title molecule has been investigated using Density Functional Theory (DFT/B3LYP/MidiX) in gas phase. Results: The molecular HOMO-LUMO, excitation energies and oscillator strengths of investigated compound have also been calculated and presented. The interaction of TZV compound with the Coronavirus was performed by molecular docking studies. Conclusion: Therefore, TZV can be used for potential application against the Coronavirus 2019-nCoV.

Background: Hepatoid adenocarcinoma of the stomach (HAS) has been recognized as a rare primary gastric tumor characterized by hepatocellular carcinomalike histology. HAS often causes diagnostic confusion with conventional gastric adenocarcinoma (CGA) due to the difficulty to detect hepatoid differentiation solely based on findings from hematoxylin and eosin (H) staining. β-catenin is highly expressed in hepatocellular carcinoma (HCC), which is involved in the maintenance of tumor initiating cells, drug resistance, tumor progression, and metastasis. Due to the scarcity of confirmed cases of HAS, there are few studies on β-catenin. Objective: 14 patients diagnosed in our hospital were selected. Methods: The clinical characteristics of 14 patients were statistically studied, and pathological specimens were analyzed by immunohistochemistry. Results: We detected statistically significant difference in the expression of β-catenin (P = 0.000), glypican3 (P = 0.019), and hepar-1 (P = 0.007) between HAS cancer tissues and normal tissues. Furthermore, a significant correlation was found between the expression of β-catenin in HAS cancer tissue and normal tissue (Pearson correlation coefficient: 0.686, P = 0.007). Meanwhile, a significant correlation was observed between the expression of β-catenin and survival time (Spearman correlation coefficient= - 0.482, P = 0.003). However, we found the expression of β-catenin did not correlate with the tumor differentiation and size, age, gender, serum AFP levels, microinvasion, and metastasis (P > 0.05). Conclusion: Our findings establish β-catenin as a useful marker that can distinguish HAS from CGA and may improve the early diagnosis to guide the appropriate and timely treatment of HAS patients.

Background: The shock stage of severe burns is a critical determinant of prognosis and the induction of systemic inflammatory response syndrome and multiple organ failure. Extracellular vesicles (EVs) containing abundant miRNAs are known to participate in various biological processes. Due to the lack of research on alternations of miRNAs in severe burns, our study analyzed the miRNA profiles of EVs in severe burns during the shock stage. Methods: EVs were extracted from the serum of rats with severe burns (30% of total body surface area, III°), and the expression of miRNAs in serum EVs was determined by next-generation sequencing. Functional analysis of target genes of miRNAs that were significantly differentially expressed (DE) was performed using GO Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). Results: Thirty-four DE miRNAs were identified at the early stage of severe burn shock and 63 at the late stage of severe burn shock. In addition, miRNA-339-5p, miRNA-1, miRNA-382-5p, miRNA134-5p, miRNA-133a-5p, and miRNA-365a-5p were DE throughout the entire shock stage, based on P < 0.01 and |log2 (foldchange)| ≥ 1 criteria. GO and KEGG analysis revealed that the target genes of DE miRNAs mainly enriched the metabolic process, immune system processes, and signal pathways. Conclusion: To our best knowledge, this is the first study demonstrating the miRNA expression profiles of EVs isolated from serum with severe burns during the shock stage. There are significant differences between downregulation and upregulation. Thus, miRNAs have the potential for novel biomarkers for the complication of severe burns.

Objectives: Vogt-Koyanagi-Harada syndrome is common autoimmune uveitis that can cause blindness. Recent studies have shown that plasma exosomes carry disease-related proteins that may serve as biomarkers. Here, we aimed to find candidate biomarkers of Vogt-Koyanagi-Harada disease using proteomic analysis of plasma exosomes. Methods: Exosomes were isolated from the plasma of normal controls and Vogt- Koyanagi-Harada patients in the following groups: a) initial inflammatory attack (active stage), b) remission after one month of treatment (unstable stage), and c) stationary phase after three months of treatment (stable stage). Groups were analyzed by mass spectrometry using isobaric tags for relative and absolute quantitation. After functional analysis, proteins of interest were verified by ELISA. Results: 463 proteins were identified in the exosomes. Forty-three were upregulated at the active inflammation stage, including inflammation-associated proteins. Thirty-one were downregulated. Gene ontology and pathway analyses revealed differential proteins related to cell adhesion, cell phagocytosis, cytoskeleton movement, leukocyte migration across endothelial cells, and platelet activation. By ELISA, Carbonic anhydrase 2 and Ras-related protein Rap-1b were verified as more plentiful at the active stage compared to the normal control and stationary phase in exosomes, but not, however, in microvesicles or plasma. Conclusion: Plasma exosomes of Vogt-Koyanagi-Harada patients contain many proteins related to the degree of inflammation. The levels of Carbonic anhydrase 2 and Ras-related protein Rap-1b in exosomes can be used as biomarkers for active inflammation in Vogt-Koyanagi-Harada disease. Further investigation could help study the pathogenesis of Vogt-Koyanagi-Harada disease and identify therapeutic targets.

Objective: This study aimed to examine the effects of apigenin (API) on the proliferation, migration, and invasion of human tongue squamous cell carcinoma Tca8113 cells and explore its probable mechanisms. Methods: After treating Tca8113 cells with API, the cell proliferation, migration, and invasive capacities were identified by tetrazolium salt colorimetry (MTT) assay, cell scratch test, and Transwell chamber test. Cellular immunofluorescence staining was used to localize mitogen-activated protein kinase 1 (MAPK1) and extracellular regulated protein kinase (ERK) 1/2 proteins. Western blot was used to detect the variations of the related protein expression levels. Results: 1 Through the MTT assay, API significantly inhibited cell proliferation (P<0.01). 2 In the cell scratch test, the distance of lateral migration after the API treatment was significantly shorter compared to the control group (P<0.01). 3 The invasion rate in the lower chamber of the Transwell chamber was lower in the API group (P<0.01). 4 Cellular immunofluorescence staining presented that the total-MEKK1 was localized in the cytoplasm, p-MEKK1 was localized in the nuclear membrane and cytoplasm, and p-ERK1/2 was localized in the cytoplasm and nucleus. 5 After API was applied to cells, the expressions of p-MEKK1 and p-ERK1/2 proteins significantly reduced (P<0.01). Conclusion: Apigenin (API) significantly inhibits the proliferation, migration, and invasion of Tca8113 cells and its mechanism may be associated with the MAPK signaling pathway.

Background: Inclusion of anticancer drugs into biocompatible nanoparticulate carriers decreases the general toxicity and improves the efficacy of clinical treatments due to the reduction of soluble circulating free drugs. Methods: In addition, removal of emerging drug contaminants from wastewaters is a necessity that should be seriously attended. Boron nitride (BN) is a choice in drug delivery because of its many surprising properties. Here, boron nitride nanoparticles are prepared, characterized by Fourier-transform infrared spectroscopy (FT-IR) and x-ray diffraction (XRD) and used in the delivery of melphalan anti-cancer drug. Results: Then, density functional theory (DFT) calculations are carried out to study the adsorption of this drug on the surface of pure boron nitride fullerene via familiar hybrid functionals B3LYP and B3PW91. In addition, the polarizable continuum model (PCM) calculations show that BN is stable in water. Conclusion: Finally, the in vitro cellular toxicity and viability of BN nanoparticles was examined on ES-2 cancer cells. The inhibitory dose IC50 of the material confirmed acceptable cytotoxicity and nanoparticles affected the average growth of the ES-2 cancer cells.