Protein and Peptide Letters - Volume 30, Issue 12, 2023

In recent years, plant-derived bioactive compounds have been developed as antiviral agents. Plants synthesize a variety of compounds, especially peptides, which possess antimicrobial activity. Current studies have shown that some antimicrobial peptides have antiviral activity against a wide range of human DNA and RNA viruses and play an effective role in the treatment of human viral diseases. These peptides act through different mechanisms. They can integrate into the envelope of the target virus or cell membrane of the host, resulting in an unstable membrane. For instance, some peptides prevent the attachment of viral spike proteins to host cells. On the other hand, some peptides may alter the cellular pathways, including DNA replication or protein synthesis, leading to the suppression of viral infection. However, the antiviral activity of peptides can be affected by their chemical and structural properties. In several studies, the properties of antimicrobial (antiviral) peptides were altered by minor modifications, but these changes require tools to predict. Recently, computational approaches have been introduced to analyze the effects of structural modifications on the physicochemical properties, mechanism of action, stability, and activity of peptides. In this mini-review, we will describe the design and function of antiviral peptides derived from plants.

Hypocretin (orexin, Hcrt) neurons located in the lateral hypothalamus (LH) project widely into the brain and are thus responsible for the physiological action of the hypocretin complex. Hypocretin is involved in both arousal and addiction, and brainstem areas such as the locus coeruleus (LC), paragigantocellularis (PGi), and dorsal raphe (DR) contribute to these functions. In the present review, we focus on the effect of Hcrt on drug abuse and arousal in the brainstem.

Objectives: We aim to investigate the regulatory mechanisms of miR-455-5p/SOCS3 pathway that underlie the proliferation, migration, and invasion of triple-negative breast cancer (TNBC) cells.Methods: Reverse transcription-quantitative PCR (RT-qPCR) was used to detect miR-455-5p expression in breast cancer tissues and cell lines. CCK8 and Transwell assays were conducted to assess the effects of miR-455-5p on breast cancer line proliferation, migration, and invasion. SOCS3 expression level in breast cancer tissues and cell lines was determined by qPCR and western blotting. The targeting relationship between miR-455-5p and SOCS3 was determined by dual luciferase reporter gene assay in different breast cancer cell lines. Finally, the upstream and downstream regulatory association between miR-455-5p and SOCS3 was confirmed in breast cancer cells by CCK8, western blot, and Transwell assays.Results: MiR-455-5p expression was up-regulated in breast cancer tissues; miR-455-5p regulates TNBC proliferation, migration, and invasion of TNBC. SOCS3 was the direct target of miR-455-5p and was down-regulated in breast cancer. Interference with SOCS3 reversed the inhibitory effect of the miR-455-5p inhibitor on breast cancer cells' malignant potential.Conclusion: MiR-455-5p promotes breast cancer progression by targeting the SOCS3 pathway and may be a potential therapeutic target for breast cancer.

Background: Fibromyalgia is a soft tissue rheumatism characterized by chronic and widespread musculoskeletal pain at specific points in the body.Objectives: In this study, we aimed to investigate the relationship between Early Growth Response (EGR1, EGR2, and EGR3) protein levels in patients with Fibromyalgia Syndrome (FMS) and healthy controls.Methods: In our studies, 76 FMS patient group and 78 healthy control group who were newly diagnosed with primary FMS according to the 2010 American College of Rheumatology criteria for fibromyalgia in Sivas Cumhuriyet University Hospital, Physical Therapy, and Rehabilitation were used. Venous blood samples were taken from both groups for the measurement of EGR1, EGR2, and EGR3 protein plasma levels, and protein levels were determined using ELISA methods. Statistical parametric test assumptions were compared using the Independent Student's t-test. In addition, specificity, sensitivity, and AUC values were calculated with the ROC curve.Results: The relationship between plasma EGR1 protein levels of FMS patients and control groups was statistically significant (p=0.001).Conclusion: EGR1 protein levels were found to be lower in the patient group diagnosed with FMS compared to the control group. It has been suggested that EGR1 protein levels can be important in the diagnosis of FMS disease.

Background: Islet β-cell dedifferentiation may be the main cause of reduced insulin secretion. Angiotensin-(1-7) [Ang-(1-7)] can attenuate high glucose-induced apoptosis and dedifferentiation of pancreatic β-cell, but the specific signal transduction pathway and mechanism are not yet clear.Objectives: This study aimed to investigate the effects of Ang-(1-7) on high glucose-induced islet β-cell dedifferentiation by activating the phosphatidylinositol-3-kinase/Protein kinase B/ Forkhead box transcription factor O1 (PI3K/Akt/FoxO1) signaling pathway. Methods: The mouse islet β-cell line MIN6 cells were passaged and cultured and randomly divided into five groups: control (Con) group, high glucose (HG) group, HG with Ang-(1-7) group, HG with Ang-(1-7) and specific MasR antagonist A-779 group, and HG with Ang-(1-7) and PI3K inhibitor LY294002 group. After 48 hours, glucose-stimulated insulin secretion (GSIS) was detected by Enzyme-Linked Immunosorbent Assay (ELISA). The mRNA and protein expression levels of β-cell-specific factors (Pancreatic duodenal homeobox-1 (Pdx1), v-maf musculoaponeurotic fibrosarcoma oncogene homolog A(MafA)) and endocrine progenitor cell-specific factors (Octamer binding transcription factor 4(Oct4), Nanog) were measured by Real Time-PCR and Western blot. The factors of protein expression levels of PI3K/Akt/FoxO1 signaling pathway (Akt, p-Akt, Fox- O1, p-FoxO1) were determined by Western blot.Results: We observed for the first time that high glucotoxicity can induce dedifferentiation of pancreatic islet β-cell, causing a decrease in insulin secretion levels and expression of Pdx1, MafA, p-- FoxO1, and p-Akt and an increase in expression of Oct4 and Nanog. After Ang-(1-7) intervention, insulin secretion levels and expression of Pdx1, MafA, p-FoxO1 and p-Akt were increased, and the levels of Oct4 and Nanog were reduced. However, A-779 and LY294002 could reverse this effect. During these processes, the total Akt and total FoxO1 expression did not change significantly.Conclusion: Ang-(1-7) may prevent high glucose-induced pathological dedifferentiation of pancreatic β-cell by activating the PI3K/Akt/FoxO1 signaling pathway.

Background: Revealing the process and mechanism of colorectal cancer will facilitate the discovery of new biomarkers and contribute to the development of targeted drugs.Objectives: This study aimed to explore the potentially functional circRNA-miRNA-mRNA network in colorectal cancer (CRC), and further explore its mechanism.Methods: Bioinformatics analysis was used to identify the differentially expressed circRNAs and mRNAs. Gene set enrichment analysis and KEGG pathways analysis were used to screen out the differentially expressed genes and observe crucial pathways that might have a strong association with CRC. Then, a network targeting circRNA, miRNA, and mRNA has been built by using the Cytoscape software. In addition, the expression of circRNA_0001573, miR-382-5p, and FZD3 was detected by qRT-PCR in CRC tissues and cells (SW480, HCT116, and HT29).Results: Abnormal expressions of circRNAs and mRNAs were obtained by bioinformatics analysis and visualized by Volcano plot and Heatmap. A series of highly correlated pathways were enriched by KEGG analysis. The interaction network of circRNA_0001573/miR-382-5p/FZD3 axis was predicted. The expressions of circRNA_0001573 and FZD3 were highly upregulated and the miR- 382-5p expression level was decreased in CRC tissues and cell lines (SW480, HCT116, and HT29).Conclusion: Our study suggests that circRNA_0001573 and circRNA_0001573/miR-382-5p/FZD3 regulatory networks might provide a potential diagnosis for colorectal cancer.

Background: Oxidative stress is a pathophysiological state that arises due to an imbalance created between ROS generation and the antioxidant potential of the host cell. Transfusion- dependent beta-thalassemia major patients are at high risk of cellular and molecular damages induced by ROS mainly due to iron overload caused by repetitive blood transfusion.Objectives: To analyze oxidative stress status levels in β-thalassemia patients. To analyze the expression profile of enzymatic (NOS2, OGG1, HuR, SOD2) and non-enzymatic (VDR) redox regulators in β-thalassemia patients. To assess polymorphism in VDR (rs2228570) and NOS2 (rs944725) in β-thalassemia patients. To analyze serum vitamin D levels of β-TM patients compared to healthy individuals.Methods: The present case-control study aimed to identify Vitamin D levels in the serum of β-thalassemia patients and compared it with healthy subjects. The study further analyzed VDR FOKI (rs2228570) polymorphism through ARMS-PCR. Expression profiling of VDR, anti-oxidant enzyme (SOD2 and GPx), and their respective regulator (HuR and NrF2) transcripts was done by the 2^–ΔΔCt method.Results: The study reports that there is no a significant difference between the Vitamin D levels among healthy and patients. VDR polymorphism analysis (rs2228570) demonstrates that although the C allele is prevalent in the study cohort, the frequency of the T allele is comparatively higher in β-thalassemia patients as compared to healthy subjects. Furthermore, patients express lower levels of anti-oxidant enzymes despite having increased oxidative stress.Conclusion: The study reports that β-thalassemia patients are at higher risk of cellular and molecular damages induced by oxidative stress and their associated pathologies inefficient enzymatic and non-enzymatic anti-oxidant defense systems.

Background: Clinically, Fuzhengkangai formulation (FZKA) has been proven to have significant therapeutic effects on non-small lung cancer (NSCLC), although the mechanism is unknown. We aimed to explore the potential mechanism of FZKA in the treatment of NSCLC in this study.Methods: We obtained the active components and targets of FZKA by TCMSP. The target genes of NSCLC were searched from OMIM, GEO (GSE18842), and GeneCards database. Cytoscape (3.7.2) software was used to construct a "drug-compound-cross-target interaction" interaction network, and the STING database was used to analyze previous cross-target interactions. Meanwhile, the results were visualized and processed by performing GO enrichment analysis and KEGG signaling pathway enrichment analysis at the target site. The core targets were docked with active components through AutoDockTools-1.5.6 software. Finally, we used cellular experiments to validate the bioinformatics predictions.Results: There were 40 active and 465 potential genes from the TCMSP database. Key active chemicals, namely Quercetin, Kaempferol, Luteolin, and Tanshinone IIA, and 176 targets were deemed as targets of FZKA against NSCLC by PPI network analysis. GO and KEGG enrichment analyses suggest that FZKA acts primarily through the PI3K-AKT and MAPK signaling pathways in the treatment of NSCLC. Moreover, cellular assays showed that Quercetin, Kaempferol, Luteolin, and Tanshinone IIA not only reduced the viability of A549 cells and promoted apoptosis but also significantly decreased the p-AKT/AKT and p-ERK1/2/ERK1/2 ratios.Conclusion: Our data suggested that FZKA can be involved in the treatment of NSCLC through multiple components, targets and pathways.

Objectives: The present study investigated the anti-depressive-like (anti-immobility) effect of a lectin from Moringa oleifera seeds (WSMoL) in mice.Methods: To evaluate an acute effect, the animals were treated with WSMoL (1, 2, and 4 mg/kg, i.p.) 30 min before the tail suspension test (TST). To investigate the involvement of monoaminergic and nitrergic signaling, the mice were pre-treated with selective antagonists. The role of the WSMoL carbohydrate-recognizing domain (CRD) was verified using previous blockage with casein (0.5 mg/mL). The subacute anti-immobility effect was also evaluated by administering WSMoL (1, 2, and 4 mg/kg, i.p.) once a day for 7 d. Finally, an open field test (OFT) was performed to identify possible interferences of WSMoL on animal locomotory behavior.Results: WSMoL reduced the immobility time of mice in the TST at all doses, and combined treatment with fluoxetine (5 mg/kg, i.p.) and WSMoL (1 mg/kg) was also effective. The CRD appeared to be involved in the anti-immobility effect since the solution of WSMoL (4 mg/kg) pre-incubated with casein showed no activity. The lectin effect was prevented by the pre-treatment of mice with ketanserin, yohimbine, and SCH 23390, thereby demonstrating the involvement of monoaminergic pathways. In contrast, pre-treatment with L-NAME, aminoguanidine, and L-arginine did not interfere with lectin action. WSMoL exhibited a subacute effect in the TST, thereby reducing immobility time and increasing agitation time even on the seventh day. OFT data revealed that the anti-immobility effect was not caused by interference with locomotor behavior.Conclusion: WSMoL elicits an anti-depressant-like effect that is dependent on monoaminergic signaling.

Background: STAM-binding protein-like 1 (STAMBPL1) functions as a deubiquitinase to cleave Lys63 ubiquitin linkage, and is associated with cancer dissemination and progression. The role of STAMBPL1 in colorectal cancer (CRC) remains unclear.Methods: STAMBPL1 expression was determined by western blot and qRT-PCR. Cell proliferation was detected by colony formation and MTT assays, and apoptosis was assessed by flow cytometry. The metastasis was evaluated by transwell and wound healing assays. An animal xenograft experiment was used to investigate the effect of STAMBPL1 on tumor growth.Results: The expression of STAMBPL1 was elevated in CRC cells. Knockdown of STAMBPL1 reduced cell viability of CRC and suppressed the proliferation, invasion, and migration. Apoptosis of CRC was induced by silence of STAMBPL1. Tumor growth of CRC was also suppressed by the silence of STAMBPL1. Knockdown of STAMBPL1 increased IΚB and decreased phosphorylation of IΚB to reduce p65 phosphorylation.Conclusion: Knockdown of STAMBPL1 inhibited cell growth and metastasis of CRC through inactivation of the NF-ΚB pathway.