Tailored multivalent peptide targeting the B-subunit pentamer of cholera toxin inhibits its intestinal toxicity by inducing aberrant transport of the toxin in cells.

Cholera toxin (Ctx) is a major virulence factor produced by Vibrio cholerae that can cause gastrointestinal diseases, including severe watery diarrhea and dehydration, in humans. Ctx binds to target cells through multivalent interactions between its B-subunit pentamer and the receptor ganglioside GM1 present on the cell surface. Here, we identified a series of tetravalent peptides that specifically bind to the receptor-binding region of the B-subunit pentamer using affinity-based screening of multivalent random-peptide libraries. These tetravalent peptides efficiently inhibited not only the cell-elongation phenotype but also the elevated cAMP levels, both of which are induced by Ctx treatment in CHO cells or a human colon carcinoma cell line (Caco-2 cells), respectively. Importantly, one of these peptides, NRR-tet, which was highly efficient in these two activities, markedly inhibited fluid accumulation in the mouse ileum caused by the direct injection of Ctx. In consistent, NRR-tet reduced the extensive Ctx-induced damage of the intestinal villi. After NRR-tet bound to Ctx, the complex was incorporated into the cultured epithelial cells and accumulated in the recycling endosome, affecting the retrograde transport of Ctx from the endosome to the Golgi, which is an essential process for Ctx to exert its toxicity in cells. Thus, NRR-tet may be a novel type of therapeutic agent against cholera, which induces the aberrant transport of Ctx in the intestinal epithelial cells, detoxifying the toxin.

SARS-CoV-2 exploits cellular RAD51 to promote viral propagation: implication of RAD51 inhibitor as a potential drug candidate against COVID-19.

IMPORTANCE: Viruses are constantly evolving to promote propagation in the host. Here, we show that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) utilizes host RAD51 for replication. Silencing of RAD51 impaired SARS-CoV-2 propagation. Viral RNA colocalized with RAD51 in the cytoplasm of SARS-CoV-2-infected cells, suggesting that both viral RNA and RAD51 may form a replication complex. We, therefore, evaluated RAD51 inhibitors as possible therapeutic agents against SARS-CoV-2. Indeed, RAD51 inhibitors exerted antiviral activities against not only Wuhan but also variants of SARS-CoV-2. Molecular docking model shows that RAD51 inhibitors impede SARS-CoV-2 propagation by interfering with dimerization of RAD51. These data suggest that RAD51 may represent a novel host-based drug target for coronavirus disease 2019 treatment.

Fisetin, a potential skin rejuvenation drug that eliminates senescent cells in the dermis.

Accumulation of senescent fibroblasts, chronic inflammation, and collagen remodeling due to aging-related secretory phenotypes have been hypothesized to cause age-related skin aging, which results in wrinkles and loss of skin elasticity, thus compromising appearance attractiveness. However, the rejuvenating effects of removing senescent cells from the human skin and the efficacy of related therapeutic agents remain unclear. Here, we investigated the effects of fisetin, a potential anti-aging component found in various edible fruits and vegetables, on senescent human dermal fibroblasts (HDFs) and aging human skin. Senescence was induced in primary HDFs using long-term passaging and treatment with ionizing radiation, and cell viability was assessed after treatment with fisetin and a control component. A mouse/human chimeric model was established by subcutaneously transplanting whole skin grafts from aged individuals into nude mice, which were treated intraperitoneally with fisetin or control a component for 30 d. Skin samples were obtained and subjected to senescence-associated-beta-galactosidase staining; the extent of aging was evaluated using western blotting, reverse transcription-quantitative PCR, and histological analysis. Fisetin selectively eliminated senescent dermal fibroblasts in both senescence-induced cellular models; this effect is attributable to cell death induction by caspases 3, 8, and 9-mediated endogenous and exogenous apoptosis. Fisetin-treated senescent human skin grafts showed increased collagen density and decreased senescence-associated secretory phenotypes (SASP), including matrix metalloproteinases and interleukins. No apparent adverse events were observed. Thus, fisetin could improve skin aging through selective removal of senescent dermal fibroblasts and SASP inhibition, indicating its potential as an effective novel therapeutic agent for combating skin aging.

Immunoinformatic-based drug design utilizing hesperetin to target CISD2 activation for liver aging in humans.

The CISD protein family, consisting of CISD1, CISD2, and CISD3, encodes proteins that feature CDGSH iron-sulfur domains crucial for cellular functions and share a common 2Fe-2S domain. CISD2, which is pivotal in cells, regulates intracellular calcium levels, maintains the endoplasmic reticulum and mitochondrial function, and is associated with longevity and overall health, with exercise stimulating CISD2 production. However, CISD2 expression decreases with age, impacting age-related processes. According to in silico docking, HST is a CISD2 activator that affects metabolic dysfunction and age-related illnesses by affecting metabolic pathways. This study investigated the ability of CISD2 and HST to reduce age-related ailments, with a particular emphasis on liver aging. CISD2 deficiency has a major effect on the function of cells, as it undermines the integrity of the ER, mitochondria, and calcium homeostasis. It also increases susceptibility to oxidative stress and metabolic dysregulation, which is linked to Wolfram syndrome and exacerbates age-related illnesses and metabolic disorders. By shielding cells from stress, CISD2 extends the life of cells and maintains liver health as people age. Its protective effecfts on the liver during aging are further enhanced by its control of translation factors such as Nrf2 and IL-6. This work paves the way for future investigations and clinical applications by examining the structural and functional properties of CISD2 and the interaction between CISD2 and HST. This highlights the therapeutic potential of these findings in promoting healthy livers in humans and battling age-related illnesses.

Daturataturin A Ameliorates Psoriasis by Regulating PPAR Pathway.

Psoriasis is a kind of severe immune-mediated systemic skin disorder, becoming a worldwide public health concern. Daturataturin A (DTA), a withanolide compound, exerts excellent anti-inflammatory and anti-proliferative properties. The objective of this study is to elucidate the effect of DTA on psoriasis and its potential mechanism. We established psoriasis-like keratinocytes model by stimulating HaCaT cells with M5 cocktail cytokines including Interleukin (IL)-17A, IL-22, oncostatin M, IL-1α, and tumor necrosis factor-α (TNF-α), followed by intervention with DTA. The potential effects and mechanisms of DTA on psoriasis were evaluated in vitro. DTA was found to be able to inhibit hyperproliferation, promote apoptosis, decrease the release of pro-inflammatory cytokines, downregulate keratin expression, and improve lipid metabolism via regulating the peroxisome proliferator-activated receptor (PPAR) signaling pathway by M5 cocktail cytokines stimulation in HaCaT cells. DTA ameliorated lipid metabolism of psoriasis and exerted the potential anti-psoriasis effects by regulating PPAR pathway in vitro, suggesting that DTA may act as a new therapeutic agent for psoriasis.

Isoorientin alleviates ovalbumin-stimulated allergic rhinitis in mice by restoring Th1/Th2 balance.

Allergic rhinitis (AR) is a chronic, non-infectious inflammatory condition of the nasal mucosa mediated by IgE. There is a need for the development of novel medications to treat this ailment. Isoorientin is a naturally occurring flavonoid that possesses antioxidant, anti--inflammatory, and various other advantageous characteristics. However, its potential effects on AR remain unclear. This study evaluates the therapeutic effects of isoorientin on ovalbumin (OVA)-induced allergic rhinitis (AR) in mice and explores the underlying mechanism. Our study revealed that isoorientin administration effectively decreased the frequency of nose rubbing and sneezing in AR mice. The groups treated with isoorientin showed a significant decrease in serum levels of IgE and histamine, with reductions of 40% and 30%, respectively. Isoorientin ameliorated inflammation of the nasal mucosa and restored the Th1/Th2 balance. In addition, isoorientin inhibited the activation of the NF-κB pathway in nasal tissues. In summary, Isoorientin alleviates OVA-stimulated AR in mice by restoring Th1/Th2 balance and blocking the NF-κB pathway. Thus, isoorientin exhibits promise as a natural therapeutic agent for allergic rhinitis.

Thiolutin, a selective NLRP3 inflammasome inhibitor, attenuates cyclophosphamide-induced impairment of sperm and fertility in mice.

OBJECTIVE: The activation of the NLRP3 inflammasome has been implicated in male infertility. Our study aimed to investigate the therapeutic role of Thiolutin (THL), an inhibitor of the NLRP3 inflammasome, on oligoasthenospermia (OA) and to elucidate its mechanisms. MATERIALS AND METHODS: Semen from 50 OA and 20 healthy males were analyzed to assess the sperm quality and levels of inflammatory markers. Their correlation was determined using Pearson's correlation coefficient. The BALB/c mice were intraperitoneal injected by cyclophosphamide at 60 mg/kg/day for five days to induce OA, followed by a two-week treatment with THL or L-carnitine. Reproductive organ size and H&E staining were determined to observe the organ and seminiferous tubule morphology. ELISA and western blotting were utilized to measure sex hormone levels, inflammatory markers, and NLRP3 inflammasome levels. Furthermore, male and female mice were co-housed to observe pregnancy success rates. RESULTS: OA patients exhibited a decrease in sperm density and motility compared to healthy individuals, along with elevated levels of IL-1ß, IL-18 and NLRP3 inflammasome. In vivo, THL ameliorated OA-induced atrophy of reproductive organs, hormonal imbalance, and improved sperm density, motility, spermatogenesis and pregnancy success rates with negligible adverse effects on weight or liver-kidney function. THL also demonstrated to be able to inhibit the activation of NLRP3 inflammasome and associated proteins in OA mice. DISCUSSION: THL can improve sperm quality and hormonal balance in OA mice through the inhibition of NLRP3 inflammasome activation. Thus, THL holds promising potential as a therapeutic agent for OA.

Unveiling the Chemical Constituents and Inhibitory Roles of Extracts from Pinus pinea L. Nut and Nutshell: A Novel Source for Pharmaceutical Antimicrobials.

Antibiotic resistance in infectious diseases has been a serious problem for the last century, and scientists have focused on discovering new natural antimicrobial agents. Pinus pinea has been used as a natural pharmacotherapeutic agent with antimutagenic, anticarcinogenic, and high antioxidant properties. In this study, GC-MS and LC-HR/MS were employed to analyze Pinus pinea L. nut and nutshell extracts. DPPH radical scavenging assay was performed to analyze the antioxidant properties of the extracts, but no activity was determined. GC-MS analysis showed that linoleic, oleic, and palmitic acids were the three most dominant fatty acids in nut and nutshell extracts, with ratios between 6.75% and 47.06% (v/v). LC-HR/MS revealed that the nutshell methanol extract had a higher phenolic content than other extracts, with vanillic acid (1.4071 mg/g). Antimicrobial activity assays showed that the minimum inhibitory concentrations (MIC) of the extracts varied between 5.94 and 190 mg/mL, and the most significant inhibition was seen in the nutshell methanol extract (MICs: between 5.94 and 47.5 mg/mL). Consequently, the antimicrobial activity of the extracts can be attributed to the dense fatty acids they contain, and the nutshell methanol extract showed the most potent inhibition related to the abundance of phenolic compounds in the extract.

Fibroblast growth factor 21 as a potential master regulator in metabolic disorders.

FGF21 is an endocrine hormone that controls key metabolic processes and induces the synthesis of glucose transporters, resulting in increased glucose absorption levels in fat cells. It is expressed in multiple metabolically active organs and tissues. FGF21 is also a powerful regulator of glucose homeostasis as a direct downregulating gene of peroxisome proliferator-activated receptor (PPAR), which plays a role in regulating the activity of glucose and lipids. Attempts were made to understand various aspects related to FGF21, including properties like receptor binding and genomic linkage map, along with the information about the genes that function in the upregulation of FGF21 and how it, directly and indirectly, downregulates the genes that are vital in various metabolic pathways. Furthermore, various gene regulatory analyses on the specific gene concerning unique micro RNAs and long non-coding RNAs that target FGF21 and alter its functioning along with single-nucleotide polymorphisms (SNPs) were observed, that are the common cause of cell dysregulation, leading to different metabolic diseases and pathogenesis of cancer. Unique protein-protein interaction and cross talk between FGF21 and PPARγ shed light on their combined role in metabolic disorder-related regulatory activities. Its potential and unique role as an effective biomarker for various cardiovascular and metabolic disorders have also been highlighted. This study attempts to highlight the pleiotropic role of FGF21 activity following its overexpression and inhibition of cascades that results in the induction of obesity from diet and simultaneously signals adipocytes to absorb glucose and decrease triglyceride and blood sugar levels in diabetic models (after administration), rendering it a promising treatment for several metabolic and cardiovascular disorders.

Plasma miR-1254 as a predictive biomarker of chemosensitivity and a target of nucleic acid therapy in esophageal cancer.

This study investigated novel tumor suppressor microRNAs (miRNAs) that decrease in plasma and predict chemosensitivity to neoadjuvant chemotherapy (NAC) for esophageal squamous cell carcinoma (ESCC) and revealed their usefulness as novel therapeutic agents. We selected four miRNA candidates (miR-323, 345, 409, and 1254) based on the microRNA microarray comparing pre-treatment plasma levels in ESCC patients with high and low histopathological responses to NAC and an NCBI database review. Among these miRNA candidates, miR-1254 was more highly elevated in pre-treatment plasma of ESCC patients with a high histopathological response than in those with a low histopathological response (P = 0.0021, area under the receiver-operating characteristic curve 0.7621). High plasma miR-1254 levels tended to correlate with the absence of venous invasion (P = 0.0710) and were an independent factor predicting a higher response to chemotherapy (P = 0.0022, odds ratio 7.86) and better prognosis (P = 0.0235, hazard ratio 0.23). Overexpressing miR-1254 in ESCC cells significantly enhanced chemosensitivity to cisplatin through the transcriptional regulation of ABCC1 in vitro. Moreover, increased plasma miR-1254 levels by subcutaneous injection significantly improved responses to cisplatin in mice. Plasma miR-1254 might be a useful biomarker for predicting responses to NAC, and the restoration of plasma miR-1254 levels might improve chemosensitivity in ESCC.

Quinolone: a versatile therapeutic compound class.

The discovery of nalidixic acid is one pinnacle in medicinal chemistry, which opened a new area of research that has led to the discovery of several life-saving antimicrobial agents (generally referred to as fluoroquinolones) for over decades. Although fluoroquinolones are frequently encountered in the literature, the utility of quinolone compounds extends far beyond the applications of fluoroquinolones. Quinolone-based compounds have been reported for activity against malaria, tuberculosis, fungal and helminth infections, etc. Hence, the quinolone scaffold is of great interest to several researchers in diverse disciplines. This article highlights the versatility of the quinolone pharmacophore as a therapeutic agent beyond the fluoroquinolone profile.

Nature-Derived Polysaccharide-Based Composite Hydrogels for Promoting Wound Healing.

Numerous innovative advancements in dressing technology for wound healing have emerged. Among the various types of wound dressings available, hydrogel dressings, structured with a three-dimensional network and composed of predominantly hydrophilic components, are widely used for wound care due to their remarkable capacity to absorb abundant wound exudate, maintain a moisture environment, provide soothing and cooling effects, and mimic the extracellular matrix. Composite hydrogel dressings, one of the evolved dressings, address the limitations of traditional hydrogel dressings by incorporating additional components, including particles, fibers, fabrics, or foams, within the hydrogels, effectively promoting wound treatment and healing. The added elements enhance the features or add specific functionalities of the dressings, such as sensitivity to external factors, adhesiveness, mechanical strength, control over the release of therapeutic agents, antioxidant and antimicrobial properties, and tissue regeneration behavior. They can be categorized as natural or synthetic based on the origin of the main components of the hydrogel network. This review focuses on recent research on developing natural polysaccharide-based composite hydrogel wound dressings. It explores their preparation and composition, the reinforcement materials integrated into hydrogels, and therapeutic agents. Furthermore, it discusses their features and the specific types of wounds where applied.

Advancements in the Application of Nanomedicine in Alzheimer's Disease: A Therapeutic Perspective.

Alzheimer's disease (AD) is a progressive neurodegenerative disease that affects most people worldwide. AD is a complex central nervous system disorder. Several drugs have been designed to cure AD, but with low success rates. Because the blood-brain and blood-cerebrospinal fluid barriers are two barriers that protect the central nervous system, their presence has severely restricted the efficacy of many treatments that have been studied for AD diagnosis and/or therapy. The use of nanoparticles for the diagnosis and treatment of AD is the focus of an established and rapidly developing field of nanomedicine. Recent developments in nanomedicine have made it possible to effectively transport drugs to the brain. However, numerous obstacles remain to the successful use of nanomedicines in clinical settings for AD treatment. Furthermore, given the rapid advancement in nanomedicine therapeutics, better outcomes for patients with AD can be anticipated. This article provides an overview of recent developments in nanomedicine using different types of nanoparticles for the management and treatment of AD.

Can Zinc Supplementation Attenuate High Fat Diet-Induced Non-Alcoholic Fatty Liver Disease?

The pathogenesis of non-alcoholic fatty liver disease (NAFLD), the most prevalent chronic liver disease, is associated with zinc deficiency. Previous studies show zinc supplementation improves steatosis and glucose metabolism, but its therapeutic effects in patients with established NAFLD remain unclear. We developed an in vivo model to characterize the effects of zinc supplementation on high-fat diet (HFD) induced NAFLD and hypothesized that the established NAFLD would be attenuated by zinc supplementation. Male C57BL/6J mice were fed a control diet or HFD for 12 weeks. Mice were then further grouped into normal and zinc-supplemented diets for 8 additional weeks. Body composition and glucose tolerance were determined before and after zinc supplementation. At euthanasia, plasma and liver tissue were collected for characterization and downstream analysis. As expected, 12 weeks of HFD resulted in reduced glucose clearance and altered body composition. Eight weeks of subsequent zinc supplementation did not alter glucose handling, plasma transaminases, steatosis, or hepatic gene expression. Results from our model suggest 8-week zinc supplementation cannot reverse established NAFLD. The HFD may have caused NAFLD disease progression beyond rescue by an 8-week period of zinc supplementation. Future studies will address these limitations and provide insights into zinc as a therapeutic agent for established NAFLD.

Effect of Central Venous Nutrition Infusion, Intravenous Fat Emulsion, and Therapeutic Agents on the Particle Size of Fat Emulsion for Simultaneous Administration of Three Drugs.

BACKGROUND: In Japan, therapeutic agents are often administered through the side tube of a central venous line or mixed with a total parenteral nutrition (TPN) infusion. This is expected to result in the mixture of three drugs in the infusion line: the infusion product for TPN, the fat emulsion, and the therapeutic agent. Therefore, we investigated whether various therapeutic agents affect the particle size of the fat emulsion. METHODS: In model of administration A, the TPN infusion formulation was administered through the main tube, and the fat emulsion and therapeutic agents were simultaneously administered through the side tube; 21 therapeutic agents were used. In model of administration B, the TPN infusion formulation mixed with therapeutic agents was administered through the main tube, and the fat emulsion was simultaneously administered through the side tube; 20 therapeutic agents were used. The number of fine particles for each particle size range in the mixed solution was measured over time using a light-shielding automatic fine-particle measuring device. RESULTS: In model A, the number of fine particles in the fat emulsion changed rapidly for five therapeutic agents and slowly for two therapeutic agents. In model B, this change occurred drastically for five therapeutic agents and slowly for one therapeutic agent. CONCLUSIONS: Some therapeutic agents may contribute to fat particle aggregation. Therefore, these therapeutic agents should not be concurrently administered with fat emulsions.

miR-27 and miR-124 target AR coregulators in prostate cancer: Bioinformatics and in vitro analysis.

The inadequate efficacy of the current treatments for metastatic prostate cancer has directed efforts to the discovery of novel therapies. MicroRNAs (miRNAs) have been considered potential therapeutic agents due to their ability to control gene expression and cellular pathways. The accurate identification of genes and pathways which are targeted by a miRNA is the first step in the therapeutic use of these molecules. In this regard, there are multiple experimental and computational methods to predict and confirm the miRNA-mRNA relationships. The targeting the androgen receptor (AR) indirectly as the most important mediator of prostate cancer has been posited to both control the disease and prevent resistance to treatment. This study aimed to identify miRNAs targeting AR coregulators. For this purpose, we examined target genes by combining miRNA-mRNA computational and experimental data from various databases. miR-27a-3p and miR-124 displayed the highest scores and were selected as miRNAs with the potential to target candidate genes. Next, three cell lines of prostate cancer including PC3, LNCAP, and DU145 were transfected with plasmids which were expressed these selected miRNAs. Then, the gene expression and cell cycle analysis were performed. A decrease was observed in cell viability in all three cell lines than the cells transfected with backbone plasmid. Furthermore, the findings indicated that miR-27a-3p and miR-124 led to a significant decrease in the expression of all genes that were studied in PC3 cell line. In addition, miR-124 caused significant the cellular arrest in the G0/G1 stage, while for miR-27a-3p, this arrest occurred was in the G2/M stage. Our results indicated that the function of a unique miRNA could be different in different cell lines with particular cancer phenotype based on the cell line stage. These findings offer the possibility of employing the miR-124 and miR-27a-3p as therapeutic agents for prostate cancer treatment.

Substituted Syndecan-2-Derived Mimetic Peptides Show Improved Antitumor Activity over the Parent Syndecan-2-Derived Peptide.

We previously showed that a synthetic peptide (S2-P) corresponding to a portion of the human syndecan-2 (SDC2) sequence can bind to the pro-domain of matrix metalloproteinase-7 (MMP-7) to inhibit colon cancer activities. Since S2-P had a relatively weak binding affinity for the MMP-7 pro-domain, we herein modified the amino acid sequence of S2-P to improve the anticancer potential. On the basis of the interaction structure of S2-P and MMP-7, four peptides were generated by replacing amino acids near Tyr 51, which is critical for the interaction. The SDC2-mimetic peptides harboring an Ala-to-Asp substitution at the C-terminal side of Tyr 51 (S2-D) or with an Ala-to-Phe substitution at the N-terminal side of Tyr 51 and an Ala-to-Asp substitution at the C-terminal side of Tyr 51 (S2-FE) showed improved interaction affinities for the MMP-7 pro-domain. Compared to S2-P, S2-FE was better able to inhibit the SDC2-MMP-7 interaction, the cell surface localization of MMP-7, the gelatin degradation activity of MMP-7, and the cancer activities (cell migration, invasion, and colony-forming activity) of human HCT116 colon cancer cells in vitro. In vivo, S2-FE inhibited the primary tumor growth and lung metastasis of CT26 mouse colon cancer cells in a xenograft mouse model. Together, these data suggest that S2-FE could be useful therapeutic anticancer peptides for colon cancer.

Therapeutic Effect of Melittin-dKLA Targeting Tumor-Associated Macrophages in Melanoma.

Melanoma is an immunogenic tumor and a serious type of skin cancer. Tumor-associated macrophages (TAMs) express an M2-like phenotype and are involved in all stages of melanomagenesis; it is hence a promising target for cancer immunotherapy. We herein investigated whether melittin-dKLA inhibits the growth of melanoma by inducing apoptosis of M2-like macrophages. For the in vitro study, a conditioned medium of macrophages was prepared from M0, M1, or M2-differentiated THP-1 cells with and without melittin-dKLA. The affinity of melittin for M2 macrophages was studied with FITC (fluorescein isothiocyanate)-conjugated melittin. For the in vivo study, murine melanoma cells were inoculated subcutaneously in the right flank of mice, melittin-dKLA was intraperitoneally injected at 200 nmol/kg every three days, and flow cytometry analysis of TAMs was performed. Since melittin binds preferentially to M2-like macrophages, melittin-dKLA induced more caspase 3 expression and cell death in M2 macrophages compared with M0 and M1 macrophages and melanoma cells. Melittin-dKLA significantly inhibited the proliferation and migration of M2 macrophages, resulting in a decrease in melanoma tumor growth in vivo. The CD206+ M2-like TAMs were reduced, while the CD86+ M1-like TAMs were not affected. Melittin-dKLA is therapeutically effective against melanoma by inducing the apoptosis of M2-like TAMs.

Effect of rapamycin on mitochondria and lysosomes in fibroblasts from patients with mtDNA mutations.

Maintaining mitochondrial function and dynamics is crucial for cellular health. In muscle, defects in mitochondria result in severe myopathies where accumulation of damaged mitochondria causes deterioration and dysfunction. Importantly, understanding the role of mitochondria in disease is a necessity to determine future therapeutics. One of the most common myopathies is mitochondrial encephalopathy lactic acidosis stroke-like episodes (MELAS), which has no current treatment. Recently, patients with MELAS treated with rapamycin exhibited improved clinical outcomes. However, the cellular mechanisms of rapamycin effects in patients with MELAS are currently unknown. In this study, we used cultured skin fibroblasts as a window into the mitochondrial dysfunction evident in MELAS cells, as well as to study the mechanisms of rapamycin action, compared with control, healthy individuals. We observed that mitochondria from patients were fragmented, had a threefold decline in the average speed of motility, a twofold reduced mitochondrial membrane potential, and a 1.5- to 2-fold decline in basal respiration. Despite the reduction in mitochondrial function, mitochondrial import protein Tim23 was elevated in patient cell lines. MELAS fibroblasts exhibited increased MnSOD levels and lysosomal function when compared with healthy controls. Treatment of MELAS fibroblasts with rapamycin for 24 h resulted in increased mitochondrial respiration compared with control cells, a higher lysosome content, and a greater localization of mitochondria to lysosomes. Our studies suggest that rapamycin has the potential to improve cellular health even in the presence of mtDNA defects, primarily via an increase in lysosomal content.

Unraveling the roles of miRNAs in regulating epithelial-to-mesenchymal transition (EMT) in osteosarcoma.

Osteosarcoma is one of the most prevalent primary bone tumors with a high metastatic and recurrence rate with poor prognosis. MiRNAs are short and non-coding RNAs that could regulate various cellular activities and one of them is the epithelial-to-mesenchymal transition (EMT). Osteosarcoma cells that have undergone EMT would lose their cellular polarity and acquire invasive and metastatic characteristics. Our literature search showed that many pre-clinical and clinical studies have reported the roles of miRNAs in modulating the EMT process in osteosarcoma and compared to other cancers like breast cancer, there is a lack of review article which effectively summarizes the various roles of EMT-regulating miRNAs in osteosarcoma. This review, therefore, was aimed to discuss and summarize the EMT-promoting and EMT-suppressing roles of different miRNAs in osteosarcoma. The review would begin with the discussion on the concepts and principles of EMT, followed by the exploration of the diverse roles of EMT-regulating miRNAs in osteosarcoma. Subsequently, the potential use of miRNAs as prognostic biomarkers in osteosarcoma to predict the likelihood of metastases and as therapeutic agents would be discussed.