Protein and Peptide Letters - Volume 30, Issue 8, 2023

Orexin (OX, hypocretin: HCRT) as a neuropeptide is produced in a distinct population of neurons in the posterior lateral hypothalamus (LH). OX neurons implicate in reward function. OX makes a main input from the hypothalamus to the ventral tegmental area (VTA) of the midbrain. OX, through OX receptors (OXR1, OXR2) activates VTA dopamine (DA) neurons. VTA neurons are involved in reward processing and motivation. In this review, we will discuss the OX effect on addiction through VTA activation and related areas of the brain.

Bioactive peptides obtained from natural resources are useful due to their ability to prevent the risk of dreadful conditions such as hypertension, cancers, obesity and cardiovascular diseases. Proteins from food, plants, animals and dairy products are chemically or enzymatically hydrolyzed or fermented in the presence of microbes to produce bioactive peptides. Bioactive peptides are antioxidant, antihypertensive, anti-inflammatory, antiproliferative, antibacterial, anticancer, antimicrobial and some of them also show multiple bioactivities. Also, bioactive peptides offer much potential as nutraceuticals or functional food components. This paper reviews recent progress (2020-2022) on bioactive peptides derived from food, animals, plants, and dairy products. Emphasis is given to their production, purification, and potential use for health promotions and medicinal applications.

Many degenerative disorders have started to develop as a result of the deposition of insoluble protein fibrillar clumps known as amyloid. This deposition mostly limits normal cellular function and signaling. This build-up of amyloid in vivo results in a variety of illnesses in the body, including type 2 diabetes, several neurodegenerative diseases (such as Alzheimer's disease and spongiform encephalopathy), and Alzheimer's disease. Growing interest has been demonstrated in nanoparticles as a potential treatments for amyloidosis throughout the past few decades. Inorganic nanoparticles are one of them and have also been in substantial research as a potential anti-amyloid drug. Inorganic nanoparticles have emerged as a good study candidates because of their nano size, distinctive physical characteristics, and capacity to traverse the blood-brain barrier. In the current review, we have focused on the effects of different types of inorganic nanoparticles on amyloidogenesis and attempted to understand their underlying mechanism of action.

Ovarian cancer is a highly prevalent malignancy among women and affects a significant population worldwide. Different forms of hormonal treatments or chemotherapies are used to treat ovarian cancer, but the possible side effects, including menopausal symptoms, can be severe, forcing some patients to prematurely stop the treatment. The emerging genome editing technology, known as clustered regularly interspaced short palindromic repeats (CRISPR)-caspase 9 (Cas9), has the potential to treat ovarian cancer via gene editing strategies. Studies have reported CRISPR knockouts of several oncogenes that are involved in the pathogenesis of ovarian cancer, such as BMI1, CXCR2, MTF1, miR-21, and BIRC5, and demonstrate the potential of the CRISPR-Cas9 genome editing technique to effectively treat ovarian cancer. However, there are limitations that restrict the biomedical applications of CRISPR-Cas9 and limit the implementation of Gene therapy for ovarian cancer. These include offtarget DNA cleavage and the effects of CRISPR-Cas9 in non-target, normal cells. This article aims to review the current state of ovarian cancer research, highlight the significance of CRISPR-Cas9 in ovarian cancer treatment, and establish the groundwork for potential clinical research.

Background: UBE2Q1-dependent ubiquitination of key proteins including β 1,4- galactosyltransferase (GalT1), and P53 might play a pivotal role in cancer development. Objective: The present study aimed to evaluate the molecular analysis of possible interactions between UBE2Q1 with B4GALT1 and P53 proteins. Methods: We established SW1116 colorectal cancer cell line stably transfected with UBE2Q1. To verify the overexpression of UBE2Q1, we performed western blot and fluorescent microscopy analysis. Using the immunoprecipitation (IP) product of the over-expressed protein on the silver staining gel, we observed the potential interacting partners of UBE2Q1. The Molecular Operating Environment (MOE) software was also used to perform the molecular docking of the UBC domain of UBE2Q1 (2QGX) with B4GALT1 (2AGD), and P53 (tetramerization (1AIE) and DNA binding domains (1GZH)) proteins. Results: Western blot and IP analysis detected a UBE2Q1-GFP band in transfected cells, while no band was detected for mock-transfected cells. Moreover, the overexpression of UBE2Q1 tagged with GFP was observed under fluorescent microscopy as well with about 60-70% shining. Silver staining of IP gel revealed several bands in colorectal cancer (CRC) with UBE2Q1 overexpression. Protein- Protein interaction (PPI) analysis also depicted a high affinity of the UBC domain of UBE2Q1 to the B4GALT1 and P53 (tetramerization and DNA binding domains). Molecular docking also revealed hot-spot regions for all poses. Conclusion: Our data suggest that UBE2Q1 as an E2 enzyme of ubiquitination system can interact with B4GALT1 and P53, and may contribute to the accumulation of misfolded important proteins and colorectal tumor development.

Introduction: The first vertebrates were jawless fish, or Agnatha, whose evolution diverged into jawed fish, or Gnathostomes, around 550 million years ago. Methods: In this study, we investigated β PFT proteins' evolutionary divergence of lamprey immune protein from Agnatha, reportedly possessing anti-cancer activity, into Dln1 protein from Gnathostomes. Both proteins showed structural and functional divergence, and shared evolutionary origin. Primary, secondary and tertiary sequences were compared to discover functional domains and conserved motifs in order to study the evolution of these two proteins. The structural and functional information relevant to evolutionary divergence was revealed using hydrophobic cluster analysis. Results: The findings demonstrate that two membrane proteins with only a small degree of sequence identity can have remarkably similar hydropathy profiles, pointing towards conserved and similar global structures. When facing the lipid bilayer or lining the pore lumen, the two proteins' aerolysin domains' corresponding residues displayed a similar and largely conserved pattern. Aerolysin-like proteins from different species can be identified using a fingerprint created by PIPSA analysis of the pore-forming protein. Conclusion: We were able to fully understand the mechanism of action during pore formation through structural studies of these proteins.

Background: Antimicrobial resistance is an emerging global health challenge that has led researchers to study alternatives to conventional antibiotics. A promising alternative is antimicrobial peptides (AMPs), produced as the first line of defense by almost all living organisms. To improve its biological activity, the conjugation of AMPs is a promising approach. Objective: In this study, we evaluated the N-terminal conjugation of p-Bt (a peptide derived from Bothrops Jararacuçu`s venom) with ferrocene (Fc) and gallic acid (GA). Acetylated and linear versions of p-Bt were also synthesized to evaluate the importance of N-terminal charge and dimeric structure. Methods: The compounds were obtained using solid-phase peptide synthesis. Circular dichroism, vesicle permeabilization, antimicrobial activity, and cytotoxicity studies were conducted. Results: No increase in antibacterial activity against Escherichia coli was observed by adding either Fc or GA to p-Bt. However, Fc-p-Bt and GA-p-Bt exhibited improved activity against Staphylococcus aureus. No cytotoxicity upon fibroblast was observed for GA-p-Bt. On the other hand, conjugation with Fc increased cytotoxicity. This toxicity may be related to the membrane permeabilization capacity of this bioconjugate, which showed the highest carboxyfluorescein leakage in vesicle permeabilization experiments. Conclusion: Considering these observations, our findings highlight the importance of adding bioactive organic compounds in the N-terminal position as a tool to modulate the activity of AMPs.

Background: Studies have found that microRNAs (miRNAs) participate in the pathogenesis of myocardial ischemia-reperfusion injury (MIRI). miR-330-5p alleviated cerebral IR injury and regulated myocardial damage. However, the mechanism of the effect of miR-330-5p on MIRI needs to be further studied. Objective: The study aimed to explore the role and mechanism of miR-330-5p in MIRI. Methods: The oxygen-glucose deprivation reperfusion (OGD/R) model was constructed in cardiomyocytes to simulate MIRI in vitro. QRT-PCR was used for the detection of gene expression. ELISA was used for evaluation of the levels of aldehyde dehydrogenase 2 family member (ALDH2), 4-hydroxynonenal (4-HNE), and malondialdehyde (MDA). Flow cytometry was used to evaluate apoptosis. Western blot was employed for protein determination. Bioinformatic analysis was performed for predicting the targets of miR-330-5p. Results: miR-330-5p was found to be down-regulated in MIRI-induced cardiomyocytes (Model group). miR-330-5p mimic enhanced ALDH2 activity, inhibited apoptosis, and suppressed 4-HNE and MDA of MIRI-induced cardiomyocytes. miR-330-5p inhibited ERK expression while increasing the p38 expression. Bioinformatic analysis showed hydroxysteroid 11-beta dehydrogenase 1 (HSD11B1) to be a target of miR-330-5p. HSD11B1 expression was inhibited by miR-330-5p mimic while increased by miR-330-5p inhibitor in MIRI-induced cardiomyocytes. HSD11B1 overexpression reversed the effect of miR-330-5p on ALDH2, 4-HNE, MDA, apoptosis, and ERK/p38 signaling pathway. Furthermore, lncRNA small nucleolar RNA host gene 3 (SNHG3) was the upstream lncRNA of miR-330-5p. SNHG3 decreased miR-330-5p expression and increased HSD11B1 expression. Conclusion: SNHG3/miR-330-5p alleviated MIRI in vitro by targeting HSD11B1 to regulate the ERK/p38 signaling pathway.