The Importance of Thioredoxin-1 in Health and Disease

Hypnea musciformis Seaweed Extract Protected Human Mesenchymal Stem Cells From Oxidative Stress Through NRF2 Activation

Previous studies have shown that Hypnea musciformis seaweed extracts (HMEs) possess antioxidant properties, but the molecular mechanisms accounting for this activity are not known. Thus, the present study investigated the molecular mechanisms through which HME exerted its antioxidant activity in human mesenchymal stem cells (WJ-MSCs). After the isolation of HME, its chemical composition was analyzed with gas chromatography mass spectrometry, indicating that it contained amino acids, organic acids, organic amides, sugar alcohols, saturated fatty acids, hydrogenated diterpene alcohols, and other organic compounds. Afterward, HME was shown in vitro to scavenge DPPH·, ABTS·+, ·OH, and O2 ·- radicals, possess reducing activity, and protect from ROO·-induced DNA strand breakage. Finally, the results showed that HME treatment of WJ-MSCs prevented H2O2-induced oxidative stress by decreasing lipid peroxidation, protein oxidation, reactive oxygen species levels, and DNA damage and by increasing glutathione levels. Moreover, our findings showed for the first time that HME's antioxidant activity in WJ-MSCs was mediated through the activation of NRF2, which upregulated the expression of the antioxidant proteins GCLC, GSR, HMOX1, SOD1, TXN, and GPX1. These results provide new insights into H. musciformis' antioxidant properties, which could help substantially its use as a food supplement or for developing biofunctional foods.

Biological Activities and Chemical Contents of Edible Hohenbuehelia petaloides (Bull.) Schulzer

Mushrooms are a good diet with high protein and polyunsaturated fatty acid contents in health, food, and industry from past to present. Mushrooms have attracted a lot of attention in terms of the bioavailability of natural products. Hohenbuehelia petaloides, a member of the Pleuroteceae family, is an edible wood fungus that grows naturally on the trunks of old and decayed trees. In this study, the cytotoxic activities of hexane, methanol, and water extracts of H. petaloides against various cancer cell lines A549, MCF-7, PC-3, and HT-29 were investigated with the 3-(4,5-dimethylthiazol-2-yl)-2,5-dipenyltetrazolium bromide (MTT) assay. In addition, the apoptotic, inflammatory, angiogenic, and antimicrobial effects of the extracts were examined by flow cytometry, real-time quantitative polymerase chain reaction (RT-qPCR), enzyme-linked immunosorbent assay (ELISA), and well diffusion assays, respectively. Moreover, the antioxidant activity and phenolic and lipid components of H. petaloides were determined. The hexane extract showed the highest cytotoxic activity (IC50 = 26.48 ± 0.02 μg/mL) against A549 cells, while water and methanol extracts exhibited the highest cytotoxicity (IC50 = 83.18 ± 0.05 μg/mL and IC50 = 90.95 ± 0.05 μg/mL, respectively) against PC-3 cells. The hexane extract killed A549 cells via apoptosis. The methanol extract, at the IC50 level, was the most effective in decreasing both tumor necrosis factor-α (TNF-α) and vascular endothelial growth factor (VEGF) release. In antioxidant activity tests performed with 5 different methods, the methanol extract had higher antioxidant activity than the others, followed by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical (IC50 = 82.61 ± 0.90 μg/mL) and 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) cation radical removal (IC50 = 55.20 ± 0.65 μg/mL) and CUPRAC-reducing power (IC50 = 76.41 ± 0.73 μg/mL). Among the extracts studied, the hexane extract showed antimicrobial activity against Bacillus cereus, Staphylococcus aureus, Bacillus subtilis, and Micrococcus luteus with different inhibition zones. The major lipid components of H. petaloides analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC/MS) were elaidic acid (38.22%), palmitic acid (30.59%), stearic acid (13.21%), linoleic acid (4.35%), and azelaic acid (4.29%). The phenolic compounds determined by the high-performance liquid chromatography with photodiode-array detection (HPLC-DAD) system were p-hydroxybenzoic acid (7.42 μg/g extract), cinnamic acid (6.83 μg/g extract), gallic acid (5.36 μg/g extract), and protocatechuic acid (1.83 μg/g extract). The results showed that H. petaloides has the potential to be a natural source for the development of novel anticancer and antimicrobial agents as well as a beneficial food supplement for the prevention of cancer.

Oxidative and endoplasmic reticulum stress in diabetes-related hearing loss: Protective effects of thioredoxin

Diabetes mellitus (DM) induces complex physiological changes in the inner ear environment. This study investigates the roles of oxidative stress (OS) and endoplasmic reticulum stress (ERS) in diabetes-related hearing loss (DRHL) and explores the potential of thioredoxin (Trx) in regulating OS, ERS, and apoptosis-related factors to mitigate the progression of hearing impairment. We conducted auditory and serological assessments in 63 patients with type 2 diabetes and 30 healthy controls. Type 2 diabetes models were induced in wild-type and Trx transgenic (Tg) mice, with auditory brainstem response (ABR) used to evaluate hearing changes. Cochlear tissues were isolated to analyse markers of apoptosis, OS, and ERS. Both patients with diabetes and mouse models exhibited hearing loss, alongside increased serum levels of Trx1, TXNIP, and AOPP, indicating oxidative damage. H&E and succinate dehydrogenase (SDH) staining revealed varying degrees of hair cell loss from the base to the apex of the cochlea in diabetic mice, with decreased expression of the hair cell protein prestin gene. Notably, Tg mice showed significant delay in hearing loss progression. In vitro, advanced glycation end-products (AGEs) induced OS and ERS in cochlear-like HEI-OC1 cells, while Trx overexpression enhanced Nrf2 activity, alleviating AGE-induced cellular stress. In conclusion, Trx exhibits protective effects against DRHL, potentially by enhancing Nrf2/HO-1/SOD2 function to reduce OS and ERS.

Metabolic Pathophysiology of Cortical Spreading Depression: A Review

Cortical spreading depression (CSD) is an electrophysiologic pathological state in which a wave of depolarization in the cerebral cortex is followed by the suppression of spontaneous neuronal activity. This transient spread of neuronal depolarization on the surface of the cortex is the hallmark of CSD. Numerous investigations have demonstrated that transmembrane ion transport, astrocytic ion clearing and fatigue, glucose metabolism, the presence of certain genetic markers, point mutations, and the expression of the enzyme responsible for the production of various arachidonic acid derivatives that participate in the inflammatory response, namely, cyclooxygenase (COX), all influence CSD. Here, we explore the associations between CSD occurrence in the cortex and various factors, including how CSD is related to migraines, how the glucose state affects CSD, the effect of TBI and its relationship with CSD and glucose metabolism, how different markers can be measured to determine the severity of CSD, and possible connections to oligemia, orexin, and leptin.

The protective role of quercetin against copper-induced female reproductive toxicity: Insights from transcriptome analysis

Quercetin has been shown to mitigate the cytotoxic effects of heavy metals. While copper is an essential trace element for bodily functions, excessive intake has been linked to impaired female reproductive function. Transcriptome analysis was employed to identify genes that are differentially expressed in response to high copper and were validated through qRT-PCR and western blotting. ATP content and Tunel were used to identify the damage of mitochondrial and cell apoptosis. PPI analysis revealed that MKI67, TOPII, ASPM, CASP3, PLK1, and TTK are central proteins within the network. Additionally, exposure to elevated levels of copper resulted in the dysregulation of 86 genes associated with mitochondria. Conversely, treatment with quercetin (QUE) in combination with high copper led to the normalization of 42 mitochondria-related genes previously affected by high copper levels. Furthermore, CuSO4 decreases ATP content and induces cell apoptosis, which can be reversed by QUE. Results suggest that elevated copper levels could lead to oxidative stress and apoptosis by inducing mitochondrial damage, while QUE has the potential to mitigate these effects, ultimately safeguarding granulosa cells and halting the progression of cell death. This study provides novel insights into the molecular pathways involved in female reproductive toxicity caused by excessive copper exposure.

The serum thioredoxin-1 levels are not associated with bronchopulmonary dysplasia and retinopathy of prematurity

BACKGROUND

We hypothesized that the serum TRX-1 in extremely preterm infants (EPIs) after birth was associated with the development of severe bronchopulmonary dysplasia (BPD) and retinopathy of prematurity (ROP).

METHODS

This single-centered retrospective study enrolled EPIs treated at our institution. Serum TRX-1 concentrations of the residual samples taken on admission, day 10-20 of life, and 36-40 weeks of postmenstrual age (PMA) were measured with an enzyme-linked immunosorbent assay.

RESULTS

The serum TRX-1 levels on admission were not different between the severe BPD (n = 46) and non-severe BPD groups (n = 67): [median (interquartile range) 147 (73.0-231) vs. 164 (80.5-248) ng/mL] (P = 0.57). These had no significant difference between the severe ROP (n = 47) and non-severe ROP groups (n = 66): [164 (71.3-237) vs. 150 (80.9-250) ng/mL] (P = 0.93). The TRX-1 levels at 10-20 days of life and 36-40 weeks of PMA also had no association with the development of severe BPD and ROP.

CONCLUSION

The serum TRX-1 levels after birth are not predictive of severe BPD and ROP.

IMPACT

Serum thioredoxin-1 levels in extremely preterm infants on the day of birth are lower than those in term or near-term infants hospitalized for transient tachypnea of the newborn. In extremely preterm infants, the serum thioredoxin-1 levels on the day of birth, at 10-20 days of life, and at postmenstrual age of 36-40 weeks were not associated with severe bronchopulmonary dysplasia and retinopathy of prematurity. The thioredoxin system is under development in extremely preterm infants; however, the serum thioredoxin-1 level is not predictive for severe bronchopulmonary dysplasia and retinopathy of prematurity.

The Role of Thioredoxin System in Shank3 Mouse Model of Autism

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder characterized by difficulties in social interaction and communication, repetitive behaviors, and restricted interests. Unfortunately, the underlying molecular mechanism behind ASD remains unknown. It has been reported that oxidative and nitrosative stress are strongly linked to ASD. We have recently found that nitric oxide (NO•) and its products play an important role in this disorder. One of the key proteins associated with NO• is thioredoxin (Trx). We hypothesize that the Trx system is altered in the Shank3 KO mouse model of autism, which may lead to a decreased activity of the nuclear factor erythroid 2-related factor 2 (Nrf2), resulting in oxidative stress, and thus, contributing to ASD-related phenotypes. To test this hypothesis, we conducted in vivo behavioral studies and used primary cortical neurons derived from the Shank3 KO mice and human SH-SY5Y cells with SHANK3 mutation. We showed significant changes in the levels and activity of Trx redox proteins in the Shank3 KO mice. A Trx1 inhibitor PX-12 decreased Trx1 and Nrf2 expression in wild-type mice, causing abnormal alterations in the levels of synaptic proteins and neurotransmission markers, and an elevation of nitrosative stress. Trx inhibition resulted in an ASD-like behavioral phenotype, similar to that of Shank3 KO mice. Taken together, our findings confirm the strong link between the Trx system and ASD pathology, including the increased oxidative/nitrosative stress, and synaptic and behavioral deficits. The results of this study may pave the way for identifying novel drug targets for ASD.

Biologic Brachytherapy: Genetically Modified Surgical Flap as a Therapeutic Tool-A Systematic Review of Animal Studies

Surgical flaps are rudimentary tools in reconstructive surgery, especially following extensive solid tumour resections. They cover skin and soft tissue defects but are prone to ischaemia and necrosis. Since their primary aim is reconstruction, they rarely exhibit a therapeutic activity against the treated disease. Attempts have been made to develop a new therapeutic strategy-biologic brachytherapy, which uses genetically engineered surgical flaps as a drug delivery vehicle, allowing the flap tissue to act as a "biologic pump". This systematic review summarizes the preclinical evidence on using genetically modified surgical flaps. A literature search was conducted in PubMed, EMBASE, Scopus and Web of Science. The initial literature search yielded 714 papers, and, eventually, seventy-seven studies were included in qualitative analysis. The results show that genetic enhancement of flaps has been used as a local or systemic therapy for numerous disease models. Frequently, it has been used to increase flap survival and limit ischaemia or promote flap survival in a non-ischemic context, with some studies focusing on optimizing the technique of such gene therapy. The results show that genetically modified flaps can be successfully used in a variety of contexts, but we need more studies to implement this research into specific clinical scenarios.

Exploring the Thioredoxin System as a Therapeutic Target in Cancer: Mechanisms and Implications

Cells constantly face the challenge of managing oxidants. In aerobic organisms, oxygen (O2) is used for energy production, generating reactive oxygen species (ROS) as byproducts of enzymatic reactions. To protect against oxidative damage, cells possess an intricate system of redox scavengers and antioxidant enzymes, collectively forming the antioxidant defense system. This system maintains the redox equilibrium and enables the generation of localized oxidative signals that regulate essential cellular functions. One key component of this defense is the thioredoxin (Trx) system, which includes Trx, thioredoxin reductase (TrxR), and NADPH. The Trx system reverses oxidation of macromolecules and indirectly neutralizes ROS via peroxiredoxin (Prx). This dual function protects cells from damage accumulation and supports physiological cell signaling. However, the Trx system also shields tumors from oxidative damage, aiding their survival. Due to elevated ROS levels from their metabolism, tumors often rely on the Trx system. In addition, the Trx system regulates critical pathways such as proliferation and neoangiogenesis, which tumors exploit to enhance growth and optimize nutrient and oxygen supply. Consequently, the Trx system is a potential target for cancer therapy. The challenge lies in selectively targeting malignant cells without disrupting the redox equilibrium in healthy cells. The aim of this review article is threefold: first, to elucidate the function of the Trx system; second, to discuss the Trx system as a potential target for cancer therapies; and third, to present the possibilities for inhibiting key components of the Trx system, along with an overview of the latest clinical studies on these inhibitors.

Disulfide stress and its role in cardiovascular diseases

Cardiovascular disease (CVD) is one of the leading causes of mortality in humans, and oxidative stress plays a pivotal role in disease progression. This phenomenon typically arises from weakening of the cellular antioxidant system or excessive accumulation of peroxides. This review focuses on a specialized form of oxidative stress-disulfide stress-which is triggered by an imbalance in the glutaredoxin and thioredoxin antioxidant systems within the cell, leading to the accumulation of disulfide bonds. The genesis of disulfide stress is usually induced by extrinsic pathological factors that disrupt the thiol-dependent antioxidant system, manifesting as sustained glutathionylation of proteins, formation of abnormal intermolecular disulfide bonds between cysteine-rich proteins, or irreversible oxidation of thiol groups to sulfenic and sulfonic acids. Disulfide stress not only precipitates the collapse of the antioxidant system and the accumulation of reactive oxygen species, exacerbating oxidative stress, but may also initiate cellular inflammation, autophagy, and apoptosis through a cascade of signaling pathways. Furthermore, this review explores the detrimental effects of disulfide stress on the progression of various CVDs including atherosclerosis, hypertension, myocardial ischemia-reperfusion injury, diabetic cardiomyopathy, cardiac hypertrophy, and heart failure. This review also proposes several potential therapeutic avenues to improve the future treatment of CVDs.

Sensitization of Multidrug Resistant Cancer Cells to Doxorubicin Using Ebselen by Disturbing Cellular Redox Status

Multidrug resistance (MDR) poses a significant problem in cancer treatment, often causing adverse effects during chemotherapy. Ebselen (Ebs), a synthetic organoselenium compound, affects cellular redox status in cancer cells. In the study, we observed that Ebs disrupted cellular redox balance and sensitized drug-resistant cells to doxorubicin (DOX) treatment. The combination of Ebs and DOX led to increased intracellular reactive oxygen species (ROS) levels and lipid peroxidation while decreasing the activity of thioredoxin reductase (TrxR) and cellular antioxidants in drug-resistant cells. Furthermore, this combination treatment demonstrated notable chemosensitizing effects by reducing cell viability and proliferation in MDR cells compared to DOX treatment alone. Additionally, the combination of Ebs and DOX induced DNA fragmentation and exhibited G2/M phase cell cycle arrest. Immunofluorescent analysis revealed that the Ebs and DOX combination upregulated the expression of p53 and p21, which activated the mitochondrial-dependent apoptotic pathway. The combination treatment also enhanced the upregulation of proapoptotic markers such as Bax, Caspase-3, -9, and cytochrome C, while downregulating the expression of the antiapoptotic marker Bcl-2. Therefore, the current discoveries suggest that Ebs could be employed as a drug candidate for reversing MDR in cancer cells by regulating cellular redox homeostasis.

Regulatory Role and Cytoprotective Effects of Exogenous Recombinant SELENOM under Ischemia-like Conditions and Glutamate Excitotoxicity in Cortical Cells In Vitro

Despite the successes in the prevention and treatment of strokes, it is still necessary to search for effective cytoprotectors that can suppress the damaging factors of cerebral ischemia. Among the known neuroprotectors, there are a number of drugs with a protein nature. In the present study, we were able to obtain recombinant SELENOM, a resident of the endoplasmic reticulum that exhibits antioxidant properties in its structure and functions. The resulting SELENOM was tested in two brain injury (in vitro) models: under ischemia-like conditions (oxygen-glucose deprivation/reoxygenation, OGD/R) and glutamate excitotoxicity (GluTox). Using molecular biology methods, fluorescence microscopy, and immunocytochemistry, recombinant SELENOM was shown to dose-dependently suppress ROS production in cortical cells in toxic models, reduce the global increase in cytosolic calcium ([Ca2+]i), and suppress necrosis and late stages of apoptosis. Activation of SELENOM's cytoprotective properties occurs due to its penetration into cortical cells through actin-dependent transport and activation of the Ca2+ signaling system. The use of SELENOM resulted in increased antioxidant protection of cortical cells and suppression of the proinflammatory factors and cytokines expression.

Progress in Research on the Role of the Thioredoxin System in Chemical Nerve Injury

(1) Background: Various factors, such as oxidative stress, mitochondrial dysfunction, tumors, inflammation, trauma, immune disorders, and neuronal toxicity, can cause nerve damage. Chemical nerve injury, which results from exposure to toxic chemicals, has garnered increasing research attention. The thioredoxin (Trx) system, comprising Trx, Trx reductase, nicotinamide adenine dinucleotide phosphate, and Trx-interacting protein (TXNIP; endogenous Trx inhibitor), helps maintain redox homeostasis in the central nervous system. The dysregulation of this system can cause dementia, cognitive impairment, nerve conduction disorders, movement disorders, and other neurological disorders. Thus, maintaining Trx system homeostasis is crucial for preventing or treating nerve damage. (2) Objective: In this review study, we explored factors influencing the homeostasis of the Trx system and the involvement of its homeostatic imbalance in chemical nerve injury. In addition, we investigated the therapeutic potential of the Trx system-targeting active substances against chemical nerve injury. (3) Conclusions: Chemicals such as morphine, metals, and methylglyoxal interfere with the activity of TXNIP, Trx, and Trx reductase, disrupting Trx system homeostasis by affecting the phosphatidylinositol-3-kinase/protein kinase B, extracellular signal-regulated kinase, and apoptotic signaling-regulated kinase 1/p38 mitogen-activated protein kinase pathways, thereby leading to neurological disorders. Active substances such as resveratrol and lysergic acid sulfide mitigate the symptoms of chemical nerve injury by regulating the Ras/Raf1/extracellular signal-regulated kinase pathway and the miR-146a-5p/TXNIP axis. This study may guide the development of Trx-targeting modulators for treating neurological disorders and chemical nerve injuries.

Current Prognostic Biomarkers for Abdominal Aortic Aneurysm: A Comprehensive Scoping Review of the Literature

Abdominal aortic aneurysm (AAA) is a progressive dilatation of the aorta that can lead to aortic rupture. The pathophysiology of the disease is not well characterized but is known to be caused by the general breakdown of the extracellular matrix within the aortic wall. In this comprehensive literature review, all current research on proteins that have been investigated for their potential prognostic capabilities in patients with AAA was included. A total of 45 proteins were found to be potential prognostic biomarkers for AAA, predicting incidence of AAA, AAA rupture, AAA growth, endoleak, and post-surgical mortality. The 45 proteins fell into the following seven general categories based on their primary function: (1) cardiovascular health, (2) hemostasis, (3) transport proteins, (4) inflammation and immunity, (5) kidney function, (6) cellular structure, (7) and hormones and growth factors. This is the most up-to-date literature review on current prognostic markers for AAA and their functions. This review outlines the wide pathophysiological processes that are implicated in AAA disease progression.

In vitro and in silico study on the seeds of Veitchia merrillii on trematode worms

Background and Aim

The potential of plants as anthelmintics is very large, but there is still very little research conducted in the search for effective, safe, easily obtained, and affordable anthelmintic candidates. Palem putri (Veitchia merrillii) is an ornamental plant that is interesting to study because it is included in the areca nut group which is reported to have strong abilities as anthelmintics. The study aims to evaluate the anthelmintic efficacy of Veitchia merrillii against trematode worms such as Paramphistomum spp. and Fasciola hepatica.

Materials and Methods

This research employs both in vitro and computational techniques. An anthelmintic in vitro test was carried out on Paramphistomum spp. worms at concentrations of 10%, 25%, and 40% (gr/v), assessing mortality index as the observable outcome, followed by a histopathological investigation of the deceased worms for tissue and cellular damage evaluation. Seventeen compounds from V. merrillii seeds were studied in silico for their anthelmintic activity against F. hepatica worms using the quantitative structure-activity relationship technique, molecular docking, and Lipinski's rule analysis for orally administered medication.

Results

About 25% and 40% extracts of V. merrillii damaged the tegument organs in the worms. Seventeen compounds in V. merrillii seed extract, on average, yielded a higher anthelmintic index on F. hepatica than praziquantel. Eleven of the 17 compounds exhibit stronger affinity than praziquantel, with routine and gallic acid being the top two ligands (∆Gbinding values: -11.65 kcal/mol and -11.07 kcal/mol, respectively). According to Lipinski's rule analysis, only routine compounds cannot be orally administered.

Conclusion

The seeds of V. merrilli have potential as an anthelmintic agent for Paramphistomum spp. at concentrations of 25%-40% (gr/v).

Identification and validation of biomarkers in membranous nephropathy and pan-cancer analysis

Background

Membranous nephropathy (MN) is an autoimmune disease and represents the most prevalent type of renal pathology in adult patients afflicted with nephrotic syndrome. Despite substantial evidence suggesting a possible link between MN and cancer, the precise underlying mechanisms remain elusive.

Methods

In this study, we acquired and integrated two MN datasets (comprising a single-cell dataset and a bulk RNA-seq dataset) from the Gene Expression Omnibus database for differential expression gene (DEG) analysis, hub genes were obtained by LASSO and random forest algorithms, the diagnostic ability of hub genes was assessed using ROC curves, and the degree of immune cell infiltration was evaluated using the ssGSEA function. Concurrently, we gathered pan-cancer-related genes from the TCGA and GTEx databases, to analyze the expression, mutation status, drug sensitivity and prognosis of hub genes in pan-cancer.

Results

We conducted intersections between the set of 318 senescence-related genes and the 366 DEGs, resulting in the identification of 13 senescence-related DEGs. Afterwards, we meticulously analyzed these genes using the LASSO and random forest algorithms, which ultimately led to the discovery of six hub genes through intersection (PIK3R1, CCND1, TERF2IP, SLC25A4, CAPN2, and TXN). ROC curves suggest that these hub genes have good recognition of MN. After performing correlation analysis, examining immune infiltration, and conducting a comprehensive pan-cancer investigation, we validated these six hub genes through immunohistochemical analysis using human renal biopsy tissues. The pan-cancer analysis notably accentuates the robust association between these hub genes and the prognoses of individuals afflicted by diverse cancer types, further underscoring the importance of mutations within these hub genes across various cancers.

Conclusion

This evidence indicates that these genes could potentially play a pivotal role as a critical link connecting MN and cancer. As a result, they may hold promise as valuable targets for intervention in cases of both MN and cancer.

Structure and Function of Dynein's Non-Catalytic Subunits

Dynein, an ancient microtubule-based motor protein, performs diverse cellular functions in nearly all eukaryotic cells, with the exception of land plants. It has evolved into three subfamilies-cytoplasmic dynein-1, cytoplasmic dynein-2, and axonemal dyneins-each differentiated by their cellular functions. These megadalton complexes consist of multiple subunits, with the heavy chain being the largest subunit that generates motion and force along microtubules by converting the chemical energy of ATP hydrolysis into mechanical work. Beyond this catalytic core, the functionality of dynein is significantly enhanced by numerous non-catalytic subunits. These subunits are integral to the complex, contributing to its stability, regulating its enzymatic activities, targeting it to specific cellular locations, and mediating its interactions with other cofactors. The diversity of non-catalytic subunits expands dynein's cellular roles, enabling it to perform critical tasks despite the conservation of its heavy chains. In this review, we discuss recent findings and insights regarding these non-catalytic subunits.

Deciphering the Role of Selenoprotein M

Selenocysteine (Sec), the 21st amino acid, is structurally similar to cysteine but with a sulfur to selenium replacement. This single change retains many of the chemical properties of cysteine but often with enhanced catalytic and redox activity. Incorporation of Sec into proteins is unique, requiring additional translation factors and multiple steps to insert Sec at stop (UGA) codons. These Sec-containing proteins (selenoproteins) are found in all three domains of life where they often are involved in cellular homeostasis (e.g., reducing reactive oxygen species). The essential role of selenoproteins in humans requires us to maintain appropriate levels of selenium, the precursor for Sec, in our diet. Too much selenium is also problematic due to its toxic effects. Deciphering the role of Sec in selenoproteins is challenging for many reasons, one of which is due to their complicated biosynthesis pathway. However, clever strategies are surfacing to overcome this and facilitate production of selenoproteins. Here, we focus on one of the 25 human selenoproteins, selenoprotein M (SELENOM), which has wide-spread expression throughout our tissues. Its thioredoxin motif suggests oxidoreductase function; however, its mechanism and functional role(s) are still being uncovered. Furthermore, the connection of both high and low expression levels of SELENOM to separate diseases emphasizes the medical application for studying the role of Sec in this protein. In this review, we aim to decipher the role of SELENOM through detailing and connecting current evidence. With multiple proposed functions in diverse tissues, continued research is still necessary to fully unveil the role of SELENOM.

Quercetin Alleviates Toxicity Induced by High Levels of Copper in Porcine Follicular Granulosa Cells by Scavenging Reactive Oxygen Species and Improving Mitochondrial Function

CuSO4 is the most commonly used feed additive in pig production at present, but long-term ingestion of excessive copper would lead to chronic copper toxicity. High copper could reduce the reproductive efficiency of sows and seriously affect the development of the pig industry. Quercetin (QUE), a powerful antioxidant, reduces toxicity of a number of heavy metals. Porcine granulosa cells (pGCs) are crucial to the fate of follicle development. The present study found that high concentrations of CuSO4 induced ROS production, which resulted in decreased mRNA expression of antioxidant-related genes GPX4, CAT, and SOD2 and increased mRNA expression of SOD1, TRX, and HO-1. The protein expression of antioxidant enzymes SOD2 and HO-1 decreased. Moreover, the concentration of MDA increased, the activity of CAT decreased, and the content of GSH decreased. After high copper treatment, the mitochondrial membrane potential (MMP) was decreased and the morphological structure was changed. However, the combined treatment with Quercetin (QUE) reversed these changes, and the level of cellular oxidative stress decreased. Therefore, we conclude that high copper has oxidative toxicity to pGCs, and QUE could remove the ROS induced by high copper, protect mitochondria from oxidative stress damage, and improve the function of pGCs.

Nuclear translocation of thioredoxin-1 promotes colorectal cancer development via modulation of the IL-6/STAT3 signaling axis through interaction with STAT3

Background: Thioredoxin 1 (Trx-1) is a small redox protein predominantly localized in the cytoplasm. Its expression is increased in several cancers, including colorectal cancer (CRC). However, the function of Trx-1 translocation to the nucleus in cancer is not clear. In this study, we investigated the role of Trx-1 nuclear translocation in development of CRC. Methods: Expression of Trx-1 and STAT3 was analyzed by Western blot and immunofluorescence. Endogenous interaction of Trx-1, STAT3, and karyopherin α1 in CRC cells was analyzed by co-immunoprecipitation. Trx-1 and pSTAT3 nuclear staining in human CRC tissues was analyzed by immunohistochemistry. A mouse model of AOM/DSS induced colitis-associated cancer (CAC) was utilized to investigate the antitumor effect of PX-12, a Trx-1 inhibitor. A knockin mouse with the Txn1(KK81-82EE) mutation was generated via CRISPR/Cas9, and CAC was induced in knockin and wild-type mice. Results: Nuclear translocation of Trx-1 was induced by IL-6, and inhibition of this translocation reversed IL-6-induced epithelial-to-mesenchymal transition, invasion and metastasis. Karyopherin α1 was found to specifically mediate IL-6-induced translocation of the Trx-1-pSTAT3 complex into the nucleus. Nuclear Trx-1 expression was closely correlated with lymph node metastasis and distant metastasis in human CRC. In addition, nuclear staining of Trx-1 showed significant positive correlation with nuclear staining of pSTAT3 in human CRC tissues. PX-12, an inhibitor of Trx-1, significantly impaired the activation of STAT3 and suppressed the development of AOM/DSS-induced CAC in mice. Moreover, AOM/DSS-induced nuclear Trx-1 expression was suppressed in Txn1(KK81-82EE) mice, which inhibited STAT3 activation and cancer progression. Conclusions: These results provide new insights into the mechanisms of STAT3 activation triggered by IL-6 and identify nuclear translocation of Trx-1 as a potential therapeutic target for the treatment of CRC and CAC.