Current Protein and Peptide Science - Volume 24, Issue 5, 2023

Ion channels play critical roles in generating and propagating action potentials and in neurotransmitter release at a subset of excitatory and inhibitory synapses. Dysfunction of these channels has been linked to various health conditions, such as neurodegenerative diseases and chronic pain. Neurodegeneration is one of the underlying causes of a range of neurological pathologies, such as Alzheimer’s disease (AD), Parkinson’s disease (PD), cerebral ischemia, brain injury, and retinal ischemia. Pain is a symptom that can serve as an index of the severity and activity of a disease condition, a prognostic indicator, and a criterion of treatment efficacy. Neurological disorders and pain are conditions that undeniably impact a patient's survival, health, and quality of life, with possible financial consequences. Venoms are the best-known natural source of ion channel modulators. Venom peptides are increasingly recognized as potential therapeutic tools due to their high selectivity and potency gained through millions of years of evolutionary selection pressure. Spiders have been evolving complex and diverse repertoires of peptides in their venoms with vast pharmacological activities for more than 300 million years. These include peptides that potently and selectively modulate a range of targets, such as enzymes, receptors, and ion channels. Thus, components of spider venoms hold considerable capacity as drug candidates for alleviating or reducing neurodegeneration and pain. This review aims to summarize what is known about spider toxins acting upon ion channels, providing neuroprotective and analgesic effects.

Alkaptonuria (AKU), a rare genetic disorder, is characterized by the accumulation of homogentisic acid (HGA) in organs, which occurs because the homogentisate 1,2-dioxygenase (HGD) enzyme is not functional due to gene variants. Over time, HGA oxidation and accumulation cause the formation of the ochronotic pigment, a deposit that provokes tissue degeneration and organ malfunction. Here, we report a comprehensive review of the variants so far reported, the structural studies on the molecular consequences of protein stability and interaction, and molecular simulations for pharmacological chaperones as protein rescuers. Moreover, evidence accumulated so far in alkaptonuria research will be re-proposed as the bases for a precision medicine approach in a rare disease.

Protein misfolding and amyloid formations are associated with many neurodegenerative and systemic diseases. The discovery of Alzheimer’s disease and its association with the accumulation of Amyloid-β (Aβ) peptides in the plaques uncovered the pleiotropic nature of peptides/ proteins. As of today, more than 50 proteins/ peptides are reported to form amyloids or amyloid-like protein aggregates under different conditions, establishing that amyloid formation could be a generic property of many proteins. In principle, under certain conditions, all the proteins have this property to form amyloid-like aggregates, which can be toxic or non-toxic. The extensive research in this direction led to an understanding of the ubiquitous nature of amyloids. Mounting evidences suggest that processed foods, particularly protein-rich foods, could be a plethora of amyloids or amyloid-like protein aggregates. Many are reported to be toxic, and their consumption raises health concerns. The assimilation of dietary proteins in the human body largely depends upon their conformational states and the digestive integrity of the gastrointestinal system. Amyloids or amyloid-like protein aggregates are usually protease resistant, and their presence in foods is likely to reduce nutritional value. Several biochemical and biophysical factors, commonly evident in various food processing industries, such as high temperature, the addition of acid, etc., are likely to induce the formation of protease-resistant protein aggregates. Aging significantly alters gastrointestinal health, predisposing aged individuals to be more susceptible to protein aggregation-related diseases. Consumption of foods containing such protein aggregates will lead to a poor supply of essential amino acids and might exaggerate the amyloid-related disease etiology. On the other hand, the gut microbiome plays a crucial role during pathological events leading to the development of Alzheimer’s and Parkinson’s diseases. The activity of gastrointestinal proteases, pH change, gut microbiome, and intestinal epithelium integrity would largely determine the outcome of consuming foods loaded with such protein aggregates. The current review outlines the recent development in this area and a new perspective for designing safe protein-rich diets for healthy nutrition.

Typically, materials used to create optical devices have chemical and physical properties that have been precisely designed for a narrowly defined purpose, allowing for changes in design to account for device variability. There is a growing need for devices built of materials with changeable optical responses, as optical systems are incorporated into platforms with much functionality. Regenerated silk fibroin is described in this article as an enabling gadget with an active optical response as a result of the inherent characteristics of proteins. Silk's capacity for controlled movement, to swell and shrink reversibly, alter conformation and degradation that is customizable, impacts both the shape and the response of the optical structure-representative silk-based gadgets. The diversity of silk material is shown and discussed in this paper, concentrating on architectures that show reconfigurable behavior, an optical waveguide that is physically temporary and provides reversible responses. Finally, innovative research directions for silk-based materials and optical devices are presented in this paper. Since ancient times, silk, a natural biopolymer, has been used as a repair material in medicine. In the past 20 years, it has attracted a lot of interest to be used in several biomedical applications. Various healthcare items with silk as their substrate have been developed thanks to significant advancements in silk biomaterial research. Silk is a fabric created from spider and silkworm cocoons. Hierarchical structures and conventional structural elements are present in them. Different silk types can be produced using certain methods, such as films, fibers, microspheres, sponges, and hydrogels. The structural characteristics of secondary proteins present in silk can also be modified. This paper investigates the use of silk in biomedical and optical applications, and examines the technical trend in electronic fields.

Preterm birth (PTB) (< 37 completed weeks gestation) is a pathological outcome of pregnancy and its associated complications are the leading global cause of death in children younger than 5 years of age. Babies born prematurely have an elevated risk for short- and long-term adverse effects of medical and neurodevelopmental sequelae. Substantial evidence suggests that multiple sets of symptoms are allied with PTB etiology, and the exact mechanism cannot be recognized. Notably, various proteins, especially (i) complement cascade; (ii) immune system; and (iii) clotting cascade, have become attractive research targets that are associated with PTB. Further, a small imbalance of these proteins in maternal or foetal circulation could serve as a marker/precursor in a series of events that lead to PTBs. Thus, the present review lightens the basic description of the circulating proteins, their role in PTB, and current concepts for future development. Further, deepening the research on these proteins will lead to a better understanding of PTB etiology and alleviate scientists' confidence in the early identification of PTB mechanisms and biological markers.

Background: Intrahepatic cholangiocarcinoma (ICC) is a highly aggressive malignancy with a poor prognosis. Aspartate β-hydroxylase (ASPH) is an α-ketoglutarate-dependent dioxygenase involved in the post-translational hydroxylation of target proteins. ASPH has been demonstrated to be upregulated in ICC, yet its role remains to be elucidated. This study aimed to investigate the potential function of ASPH in ICC metastasis. Methods: Survival curves for the overall survival of pan-cancer data from The Cancer Genome Atlas (TCGA) database was depicted using the Kaplan-Meier method and compared using the log-rank test. The expression of ASPH, glycogen synthase kinase (GSK)-3β, phosphorylation GSK-3β (p-GSK-3β), epithelial-mesenchymal transition (EMT) biomarkers, and sonic hedgehog (SHH) signaling elements in ICC cell lines was analyzed by western blot. Wound healing and transwell assays were conducted to examine the effects of ASPH knockdown and overexpression on cell migration and invasion. An immunofluorescence assay was conducted to evaluate the expression of glioma-associated oncogene 2 (GLI2), GSK-3β and ASPH. The effect of ASPH on tumor in vivo was analyzed using a nude mouse xenograft model. Results: Pan-cancer data showed that expressed ASPH was significantly correlated with a poor prognosis in patients. ASPH knockdown inhibited the migration and invasion of human ICC cells lines QBC939 and RBE. ASPH overexpression contributed to an increase in the N-cadherin and Vimentin, resulting in the promotion of the EMT process. The p-GSK-3β levels decreased in the presence of ASPH overexpression. The overexpression of ASPH led to an upregulation of the expression of SHH signaling elements GLI2 and SUFU. The results of in vivo experiments with a lung metastasis model in nude mice with ICC cell line RBE are consistent with these results. Conclusion: ASPH accelerated metastasis of ICC cells by facilitating EMT via a GSK-3β/SHH/GLI2 axis-dependent manner, in which phosphorylation of GSK-3β was downregulated and the SHH signaling pathway was activated.