Correlation between Oxidative Stress and Transforming Growth Factor-Beta in Cancers

Trimethylamine N-oxide: a meta-organismal axis linking the gut and fibrosis

BACKGROUND

Tissue fibrosis is a common pathway to failure in many organ systems and is the cellular and molecular driver of myriad chronic diseases that are incompletely understood and lack effective treatment. Recent studies suggest that gut microbe-dependent metabolites might be involved in the initiation and progression of fibrosis in multiple organ systems.

MAIN BODY OF THE MANUSCRIPT

In a meta-organismal pathway that begins in the gut, gut microbiota convert dietary precursors such as choline, phosphatidylcholine, and L-carnitine into trimethylamine (TMA), which is absorbed and subsequently converted to trimethylamine N-oxide (TMAO) via the host enzyme flavin-containing monooxygenase 3 (FMO3) in the liver. Chronic exposure to elevated TMAO appears to be associated with vascular injury and enhanced fibrosis propensity in diverse conditions, including chronic kidney disease, heart failure, metabolic dysfunction-associated steatotic liver disease, and systemic sclerosis.

CONCLUSION

Despite the high prevalence of fibrosis, little is known to date about the role of gut dysbiosis and of microbe-dependent metabolites in its pathogenesis. This review summarizes recent important advances in the understanding of the complex metabolism and functional role of TMAO in pathologic fibrosis and highlights unanswered questions.

Therapeutic targeting of TGF-β in lung cancer

Transforming growth factor-β (TGF-β) plays a complex role in lung cancer pathophysiology, initially acting as a tumor suppressor by inhibiting early-stage tumor growth. However, its role evolves in the advanced stages of the disease, where it contributes to tumor progression not by directly promoting cell proliferation but by enhancing epithelial-mesenchymal transition (EMT) and creating a conducive tumor microenvironment. While EMT is typically associated with enhanced migratory and invasive capabilities rather than proliferation per se, TGF-β's influence on this process facilitates the complex dynamics of tumor metastasis. Additionally, TGF-β impacts the tumor microenvironment by interacting with immune cells, a process influenced by genetic and epigenetic changes within tumor cells. This interaction highlights its role in immune evasion and chemoresistance, further complicating lung cancer therapy. This review provides a critical overview of recent findings on TGF-β's involvement in lung cancer, its contribution to chemoresistance, and its modulation of the immune response. Despite the considerable challenges encountered in clinical trials and the development of new treatments targeting the TGF-β pathway, this review highlights the necessity for continued, in-depth investigation into the roles of TGF-β. A deeper comprehension of these roles may lead to novel, targeted therapies for lung cancer. Despite the intricate behavior of TGF-β signaling in tumors and previous challenges, further research could yield innovative treatment strategies.

Polystyrene nanoplastics exposure causes erectile dysfunction in rats

Polystyrene nanoplastics (PS-NPs), emerging and increasingly pervasive environmental contaminants, have the potential to cause persistent harm to organisms. Although previous reports have documented local accumulation and adverse effects in a variety of major organs after PS-NPs exposure, the impact of PS-NPs exposure on erectile function remains unexplored. Herein, we established a rat model of oral exposure to 100 nm PS-NPs for 28 days. To determine the best dose range of PS-NPs, we designed both low-dose and high-dose PS-NPs groups, which correspond to the minimum and maximum human intake doses, respectively. The findings indicated that PS-NPs could accumulate within the corpus cavernosum and high dose but not low dose of PS-NPs triggered erectile dysfunction. Moreover, the toxicological effects of PS-NPs on erectile function include fibrosis in the corpus cavernous, endothelial dysfunction, reduction in testosterone levels, elevated oxidative stress and apoptosis. Overall, this study revealed that PS-NPs exposure can cause erectile dysfunction via multiple ways, which provided new insights into the toxicity of PS-NPs.

The Role of Nrf2 in the Regulation of Mitochondrial Function and Ferroptosis in Pancreatic Cancer

The transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) represents the master regulator of the cellular antioxidant response and plays a critical role in tumorigenesis. This includes a preventive effect of Nrf2 on cell death through ferroptosis, which represents an essential mechanism of therapy resistance in malignant tumors, such as pancreatic ductal adenocarcinoma (PDAC) as one of the most aggressive and still incurable tumors. Addressing this issue, we provide an overview on Nrf2 mediated antioxidant response with particular emphasis on its effect on mitochondria as the organelle responsible for the execution of ferroptosis. We further outline how deregulated Nrf2 adds to the progression and therapy resistance of PDAC, especially with respect to the role of ferroptosis in anti-cancer drug mediated cell killing and how this is impaired by Nrf2 as an essential mechanism of drug resistance. Our review further discusses recent approaches for Nrf2 inhibition by natural and synthetic compounds to overcome drug resistance based on enhanced ferroptosis. Finally, we provide an outlook on therapeutic strategies based on Nrf2 inhibition combined with ferroptosis inducing drugs.

Prolonged exposure to mercuric chloride induces oxidative stress-mediated nephrotoxicity in freshwater food fish Channa punctatus

Mercury (Hg) is regarded as a serious hazard to aquatic life and is particularly prevalent in aquatic ecosystems. However, there is little evidence available regarding the toxicity of mercury chloride (HgCl2) in vital organs of fish. This study was conducted to assess the effects of HgCl2 (0.039 mg/L and 0.078 mg/L) on oxidative stress-mediated genotoxicity, poikilocytosis, apoptosis, and renal fibrosis after 15, 30, and 45 days of the exposure period. According to the findings, HgCl2 intoxication in fish resulted in a significantly (P < 0.05) elevated lipid peroxidation (LPO), protein carbonyls (PC), lactate dehydrogenase (LDH) activity levels in kidney tissues and significantly (P < 0.05) increased reactive oxygen species (ROS), poikilocytosis, DNA tail length, and the frequency of apoptotic cells (AC%) in blood cells. Kidney's ultra-structure and histopathology revealed its fibrosis, which was evident by mRNA expression of targeted genes KIM1, NOX4, TGFβ, and NFϏβ. Different indicators of oxidative stress, apoptosis, and genotoxicity were altered in a dose and time-dependent manner, according to a two-way ANOVA analysis. There was a considerable positive link between oxidative stress and kidney fibrosis in the fish Channa punctatus, and it is evident from regression correlation and PCA data analysis. The kidney's ultra-structure evaluation and histopathology both revealed a noticeable fibrosis state. Additionally, a significant (P < 0.05) downregulation in PPARδ reveals that fish body was unable to combat diseases such as kidney fibrosis induced by HgCl2. This study shed fresh light on the mechanisms underlying nephrotoxicity caused by HgCl2 exposure.

Thrombospondins in the tumor microenvironment

Many cancers begin with the formation of a small nest of transformed cells that can remain dormant for years. Thrombospondin-1 (TSP-1) initially promotes dormancy by suppressing angiogenesis, a key early step in tumor progression. Over time, increases in drivers of angiogenesis predominate, and vascular cells, immune cells, and fibroblasts are recruited to the tumor mass forming a complex tissue, designated the tumor microenvironment. Numerous factors, including growth factors, chemokine/cytokine, and extracellular matrix, participate in the desmoplastic response that in many ways mimics wound healing. Vascular and lymphatic endothelial cells, and cancer-associated pericytes, fibroblasts, macrophages and immune cells are recruited to the tumor microenvironment, where multiple members of the TSP gene family promote their proliferation, migration and invasion. The TSPs also affect the immune signature of tumor tissue and the phenotype of tumor-associated macrophages. Consistent with these observations, expression of some TSPs has been established to correlate with poor outcomes in specific types of cancer.

Role of lung ornithine aminotransferase in idiopathic pulmonary fibrosis: regulation of mitochondrial ROS generation and TGF-β1 activity

Idiopathic pulmonary fibrosis (IPF) is characterized by aberrant lung remodeling and the excessive accumulation of extracellular matrix (ECM) proteins. In a previous study, we found that the levels of ornithine aminotransferase (OAT), a principal enzyme in the proline metabolism pathway, were increased in the lungs of patients with IPF. However, the precise role played by OAT in the pathogenesis of IPF is not yet clear. The mechanism by which OAT affects fibrogenesis was assessed in vitro using OAT-overexpressing and OAT-knockdown lung fibroblasts. The therapeutic effects of OAT inhibition were assessed in the lungs of bleomycin-treated mice. OAT expression was increased in fibrotic areas, principally in interstitial fibroblasts, of lungs affected by IPF. OAT levels in the bronchoalveolar lavage fluid of IPF patients were inversely correlated with lung function. The survival rate was significantly lower in the group with an OAT level >75.659 ng/mL than in the group with an OAT level ≤75.659 ng/mL (HR, 29.53; p = 0.0008). OAT overexpression and knockdown increased and decreased ECM component production by lung fibroblasts, respectively. OAT knockdown also inhibited transforming growth factor-β1 (TGF)-β1 activity and TGF-β1 pathway signaling. OAT overexpression increased the generation of mitochondrial reactive oxygen species (ROS) by activating proline dehydrogenase. The OAT inhibitor L-canaline significantly attenuated bleomycin-induced lung injury and fibrosis. In conclusion, increased OAT levels in lungs affected by IPF contribute to the progression of fibrosis by promoting excessive mitochondrial ROS production, which in turn activates TGF-β1 signaling. OAT may be a useful target for treating patients with fibrotic lung diseases, including IPF.

Kinetics of neutrophil extracellular traps and cytokines in oral mucositis and Candida infection

OBJECTIVE

This study investigated the concentrations of neutrophil extracellular traps (NET) and salivary cytokines (IL-1β, IL-6, IL-8/CXCL8, TNF, and TGF-β1) in patients undergoing chemotherapy and their associations with oral mucositis (OM) and Candida infection.

MATERIALS AND METHODS

This prospective longitudinal study performed at a Brazilian service included 60 adults diagnosed with hematolymphoid diseases. Saliva samples were collected on days D0, D3, D10, and D15. Cytokines were analyzed by ELISA and NET formation by identification of the myeloperoxidase-DNA complex. Oral Candida spp. was cultured.

RESULTS

OM occurred in 43.3% of patients and oral candidiasis in 20%. However, 66% of individuals had positive cultures for C. albicans. Higher concentrations of IL-6, IL-8/CXCL8, and TNF and lower concentrations of TGF-β1 were observed in patients with OM. C. albicans infection contributed to the increase in IL-8/CXCL8, TGF-β1, and TNF. Individuals with OM or with oral candidiasis had significant reductions in NET formation. In contrast, individuals with C. albicans and with concomitant C. albicans and OM exhibited higher NET formation.

CONCLUSION

The kinetics of cytokine levels and NET formation in chemotherapy-induced OM appears to be altered by Candida infection, even in the absence of clinical signs of oral candidiasis.

Chimeric TβRII-SE/Fc overexpression by a lentiviral vector exerts strong antitumoral activity on colorectal cancer-derived cell lines in vitro and on xenografts

The TGF signaling pathway is a key regulator of cancer progression. In this work, we report for the first time the antitumor activity of TβRII-SE/Fc, a novel peptibody whose targeting domain is comprised of the soluble endogenous isoform of the human TGF-β type II receptor (TβRII-SE). Overexpression of TβRIISE/Fc reduces in vitro cell proliferation and migration while inducing cell cycle arrest and apoptosis in human colorectal cancer-derived cell lines. Moreover, TβRII-SE/Fc overexpression reduces tumorigenicity in BALB/c nude athymic mice. Our results revealed that TRII-SE/Fc-expressing tumors were significantly reduced in size or were even incapable of developing. We also demonstrated that the novel peptibody has the ability to inhibit the canonical TGF-β and BMP signaling pathways while identifying SMAD-dependent and independent proteins involved in tumor progression that are modulated by TβRII-SE/Fc. These findings provide insights into the underlying mechanism responsible for the antitumor activity of TβRII-SE/Fc. Although more studies are required to demonstrate the effectiveness and safety of the novel peptibody as a new therapeutic for the treatment of cancer, our initial in vitro and in vivo results in human colorectal tumor-derived cell lines are highly encouraging. Our results may serve as the foundation for further research and development of a novel biopharmaceutical for oncology.

Role of osteopontin in oral epithelial dysplasia, oral submucous fibrosis and oral squamous cell carcinoma

Background

Inflammatory cells and cytokines in the chronically injured mucosa promote fibrosis in the oral submucous fibrosis (OSF) fibrotic milieu. Osteopontin (OPN) is a wound-healing mediator that upregulates the inflammatory response and is involved in the malignancy and fibrosis of multiple organ systems.

Objectives

We investigated the expression of OPN in oral potentially malignant disorders (OPMDs) and oral squamous cell carcinomas (OSCCs) to determine its role in the malignant transformation and fibrosis of oral tissues. The expression of OPN in OPMDs and OSCCs was compared and correlated, and the role of OPN as a fibrotic mediator in OSF was explained.

Study Design

A total of 30 cases of normal mucosa and OPMDs (mild dysplasia, severe dysplasia, OSF and OSCCs) were studied by purposive sampling. In these groups, OPN immunoreactivity was examined and correlated with clinical findings.

Results

In mild dysplasia, OPN expression was restricted to the basal cell layer with moderate staining intensity. In severe dysplasia, it was extremely intense and extended throughout the epithelium. In the OSF, OPN expression was moderate in the perinuclear areas of the basal cell layer. The expression of OPN was very strong in OSCC. A flow diagram explaining the profibrotic role of OPN in OSF has been provided.

Conclusion

A positive role of OPN in both pathogenesis and malignant transformation of OPMDs and OSCC has been demonstrated.

TGF-β1 mediates tumor immunosuppression aggravating at the late stage post-high-light-dose photodynamic therapy

Photodynamic therapy (PDT) is an emerging clinical treatment that is expected to become an important adjuvant strategy for the immunotherapeutic cancer treatment. Recently, numerous works have reported combination strategies. However, clinical data showed that the anti-tumor immune response of PDT was not lasting though existing. The immune activation effect will eventually turn to immunosuppressive effect and get aggravated at the late stage post-PDT. So far, the mechanism is still unclear, which limits the design of specific correction strategies and further development of PDT. Several lines of evidence suggest a role for TGF-β1 in the immunosuppression associated with PDT. Herein, this study systematically illustrated the dynamic changes of immune states post-PDT within the tumor microenvironment. The results clearly demonstrated that high-light-dose PDT, as a therapeutic dose, induced early immune activation followed by late immunosuppression, which was mediated by the activated TGF-β1 upregulation. Then, the mechanism of PDT-induced TGF-β1 accumulation and immunosuppression was elucidated, including the ROS/TGF-β1/MMP-9 positive feedback loop and CD44-mediated local amplification, which was further confirmed by spatial transcriptomics, as well as by the extensive immune inhibitory effect of local high concentration of TGF-β1. Finally, a TGF-β blockade treatment strategy was presented as a promising combinational strategy to reverse high-light-dose PDT-associated immunosuppression. The results of this study provide new insights for the biology mechanism and smart improvement approaches to enhance tumor photodynamic immunotherapy.

Iron-overload-induced ferroptosis in mouse cerebral toxoplasmosis promotes brain injury and could be inhibited by Deferiprone

Iron is a trace metal element that is essential for the survival of cells and parasites. The role of iron in cerebral toxoplasmosis (CT) is still unclear. Deferiprone (DFP) is the orally active iron chelator that binds iron in a molar ratio of 3:1 (ligand:iron) and promotes urinary iron excretion to remove excess iron from the body. The aims of this experiment were to observe the alterations in iron in brains with Toxoplasma gondii (T. gondii) acute infections and to investigate the mechanism of ferroptosis in CT using DFP. We established a cerebral toxoplasmosis model in vivo using TgCtwh3, the dominant strains of which are prevalent in China, and treated the mice with DFP at a dose of 75 mg/kg/d. Meanwhile, we treated the HT-22 cells with 100 μM DFP for half an hour and then infected cells with TgCtwh3 in vitro. A qRT-PCR assay of TgSAG1 levels showed a response to the T. gondii burden. We used inductively coupled plasma mass spectrometry, an iron ion assay kit, Western blot analysis, glutathione and glutathione disulfide assay kits, a malonaldehyde assay kit, and immunofluorescence to detect the ferroptosis-related indexes in the mouse hippocampus and HT-22 cells. The inflammatory factors interferon-γ, tumor necrosis factor-α, transforming growth factor-β, and arginase 1 in the hippocampus and cells were detected using the Western blot assay. Hematoxylin and eosin staining, electron microscopy, and the Morris water maze experiment were used to evaluate the brain injuries of the mice. The results showed that TgCtwh3 infection is followed by the activation of ferroptosis-related signaling pathways and hippocampal pathological damage in mice. The use of DFP led to ferroptosis resistance and attenuated pathological changes, inflammatory reactions and T. gondii burden of the mice, prolonging their survival time. The HT-22 cells with TgCtwh3 activated the ferroptosis pathway and was inhibit by DFP in vitro. In TgCtwh3-infected cells, inflammatory response and mitochondrial damage were severe, but these effects could be reduced by DFP. Our study elucidates the mechanism by which T. gondii interferes with the host's iron metabolism and activates ferroptosis, complementing the pathogenic mechanism of CT and further demonstrating the potential value of DFP for the treatment of CT.

Melatonin and TGF-β-Mediated Release of Extracellular Vesicles

The immune system, unlike other systems, must be flexible and able to "adapt" to fully cope with lurking dangers. The transition from intracorporeal balance to homeostasis disruption is associated with activation of inflammatory signaling pathways, which causes modulation of the immunology response. Chemotactic cytokines, signaling molecules, and extracellular vesicles act as critical mediators of inflammation and participate in intercellular communication, conditioning the immune system's proper response. Among the well-known cytokines allowing for the development and proper functioning of the immune system by mediating cell survival and cell-death-inducing signaling, the tumor necrosis factor α (TNF-α) and transforming growth factor β (TGF-β) are noteworthy. The high bloodstream concentration of those pleiotropic cytokines can be characterized by anti- and pro-inflammatory activity, considering the powerful anti-inflammatory and anti-oxidative stress capabilities of TGF-β known from the literature. Together with the chemokines, the immune system response is also influenced by biologically active chemicals, such as melatonin. The enhanced cellular communication shows the relationship between the TGF-β signaling pathway and the extracellular vesicles (EVs) secreted under the influence of melatonin. This review outlines the findings on melatonin activity on TGF-β-dependent inflammatory response regulation in cell-to-cell communication leading to secretion of the different EV populations.

Black Tea Extract, via Modulation of TGF-β Pathway, Prevents Inorganic Arsenic-induced Development of Squamous Cell Carcinoma of the Skin in Swiss Albino Mice

Chronic exposure to inorganic arsenic (iAs) elevates reactive oxygen species (ROS) generation and up-regulates TGF-β signalling. This promotes induction of epithelial to mesenchymal transition (EMT) and causes the development of squamous cell carcinoma (SCC) of skin. Black tea is a popular beverage worldwide and an effective antioxidant. Chemopreventive potential of black tea extract (BTE) against iAs induced carcinogenicity has been explored here. The study aims to investigate the role of BTE in prevention of iAs-induced SCC of skin in Swiss albino mice via the modulation of TGF-β signalling and EMT. Mice were divided into (1) control, (2) iAs, (3) iAs+BTE, and (4) BTE groups and were administered iAs and BTE alone, or in combination for 330 days. Histological studies were performed to assess development of SCC. ROS generation was estimated by flowcytometry. Expression of TGF-β and downstream proteins belonging to suppressor of mothers against decapentaplegic (Smad), phosphoinositide-3-kinase (PI3K)-protein kinase B (AKT) and mitogen-activated protein kinase (MAPK) pathways was assessed by immunoblotting. Expression of EMT markers was evaluated by immunoblotting, immunohistochemistry and semi-quantitative reverse transcriptase-PCR. After 330 days of iAs treatment, development of invasive SCC of skin probably due to excess ROS generation, elevation of TGF-β, downregulation of the Smad pathway, upregulation of PI3K-AKT and MAPK signalling molecules and induction of EMT was observed. All these modulations were found to be reversed by BTE, which inhibits iAs induced SCC of skin by quenching excess ROS, promoting Smad mediated TGF-β signalling, downregulating signalling intermediates of PI3K-AKT and MAPK pathways and inhibiting EMT.

TGF-β-3 Induces Different Effects from TGF-β-1 and -2 on Cellular Metabolism and the Spatial Properties of the Human Trabecular Meshwork Cells

To compare the effects among three TGF-β isoforms (TGF-β-1, TGF-β-2, and TGF-β-3) on the human trabecular meshwork (HTM), two-dimensional (2D) and three-dimensional (3D) cultures of commercially available certified immortalized HTM cells were used, and the following analyses were conducted: (1) trans-endothelial electrical resistance (TEER) and FITC dextran permeability measurements (2D); (2) a real-time cellular metabolic analysis (2D); (3) analysis of the physical property of the 3D HTM spheroids; and (4) an assessment of the gene expression levels of extracellular matrix (ECM) components (2D and 3D). All three TGF-β isoforms induced a significant increase in TEER values and a relative decrease in FITC dextran permeability in the 2D-cultured HTM cells, but these effects were the most potent in the case of TGF-β-3. The findings indicated that solutions containing 10 ng/mL of TGF-β-1, 5 ng/mL of TGF-β-2, and 1 ng/mL of TGF-β-3 had nearly comparable effects on TEER measurements. However, a real-time cellular metabolic analysis of the 2D-cultured HTM cells under these concentrations revealed that TGF-3-β induced quite different effects on the metabolic phenotype, with a decreased ATP-linked respiration, increased proton leakage, and decreased glycolytic capacity compared with TGF-β-1 and TGF-β-2. In addition, the concentrations of the three TGF-β isoforms also caused diverse effects on the physical properties of 3D HTM spheroids and the mRNA expression of ECMs and their modulators, in many of which, the effects of TGF-β-3 were markedly different from TGF-β-1 and TGF-β-2. The findings presented herein suggest that these diverse efficacies among the TGF-β isoforms, especially the unique action of TGF-β-3 toward HTM, may induce different effects within the pathogenesis of glaucoma.

Losartan enhances the suppressive effect of pirfenidone on the bleomycin-induced epithelial-mesenchymal transition and oxidative stress in A549 cell line

Objectives

Idiopathic pulmonary fibrosis (IPF) is a fatal lung disease. Despite the promising anti-fibrotic effect, the toleration of pirfenidone (PFD) by the patients in full dose is low. Combination therapy is a method for enhancing the therapeutic efficiency of PFD and decreasing its dose. Therefore, the present study evaluated the effect of a combination of losartan (LOS) and PFD on oxidative stress parameters and the epithelial-mesenchymal transition (EMT) process induced by bleomycin (BLM) in human lung adenocarcinoma A549 cells.

Materials and Methods

The non-toxic concentrations of BLM, LOS, and PFD were assessed by the MTT assay. Malondialdehyde (MDA) and anti-oxidant enzyme activity including catalase (CAT) and superoxide dismutase (SOD) were assessed after co-treatment. Migration and western blot assays were used to evaluate EMT in BLM-exposed A549 after single or combined treatments.

Results

The combination treatment exhibited a remarkable decrease in cellular migration compared with both single and BLM-exposed groups. Furthermore, the combination treatment significantly improved cellular anti-oxidant markers compared with the BLM-treated group. Moreover, combined therapy markedly increased epithelial markers while decreasing mesenchymal markers.

Conclusion

This in vitro study revealed that the combination of PFD with LOS might be more protective in pulmonary fibrosis (PF) than single therapy because of its greater efficacy in regulating the EMT process and oxidative stress. The current results might offer a promising therapeutic strategy for the future clinical therapy of lung fibrosis.

Diagnosis by Volatile Organic Compounds in Exhaled Breath in Exhaled Breath from Patients with Gastric and Colorectal Cancers

One in three cancer deaths worldwide are caused by gastric and colorectal cancer malignancies. Although the incidence and fatality rates differ significantly from country to country, the rates of these cancers in East Asian nations such as South Korea and Japan have been increasing each year. Above all, the biggest danger of this disease is how challenging it is to recognize in its early stages. Moreover, most patients with these cancers do not present with any disease symptoms before receiving a definitive diagnosis. Currently, volatile organic compounds (VOCs) are being used for the early prediction of several other diseases, and research has been carried out on these applications. Exhaled VOCs from patients possess remarkable potential as novel biomarkers, and their analysis could be transformative in the prevention and early diagnosis of colon and stomach cancers. VOCs have been spotlighted in recent studies due to their ease of use. Diagnosis on the basis of patient VOC analysis takes less time than methods using gas chromatography, and results in the literature demonstrate that it is possible to determine whether a patient has certain diseases by using organic compounds in their breath as indicators. This study describes how VOCs can be used to precisely detect cancers; as more data are accumulated, the accuracy of this method will increase, and it can be applied in more fields.

Novel ROCK Inhibitors, Sovesudil and PHP-0961, Enhance Proliferation, Adhesion and Migration of Corneal Endothelial Cells

The loss or dysfunction of human corneal endothelial cells (hCEnCs) is a leading cause of blindness due to corneal failure. Corneal transplantation with a healthy donor cornea has been the only available treatment for corneal endothelial disease. However, the need for way to regenerate the CEnCs has been increased due to the global shortage of donor corneas. The aim of the study is to investigate whether novel Rho-kinase (ROCK) inhibitors can induce the cultivation and regeneration of hCEnCs. Cultured hCEnCs were treated with Y-27632, sovesudil, or PHP-0961 for 24 h. Cellular responses, including cell viability, cytotoxicity, proliferation, and Ki67 expression with ROCK inhibitors were evaluated. We also evaluated wound healing and cell adhesion assays. Porcine corneas were used ex vivo to evaluate the effects of Y-27632, sovesudil, and PHP-0961 on wound healing and regeneration. We performed live/dead cell assays and immunofluorescence staining for SRY (sex determining region Y)-box 2 (SOX2), β-catenin, and ZO-1 on porcine corneas after ROCK inhibitor treatments. Cell viability, cell proliferation rate, and the number of Ki67-positive cells were higher in Y-27632, sovesudil and PHP-0961 treated cells compared to the control. There was no difference in LDH cytotoxicity test between any groups. Cells treated with Y-27632, sovesudil and PHP-0961 showed faster migration, wound healing, and cell adhesion. In the porcine ex vivo experiments, wound healing, the number of live cells, and SOX2-positive cells were higher in Y-27632, sovesudil and PHP-0961 treated corneas. In all experiments, sovesudil and PHP-0961, the novel ROCK inhibitors, were equal or superior to the results of the ROCK inhibitor positive control, Y-27632. In conclusion, sovesudil and PHP-0961, novel ROCK inhibitors have the capacity to regenerate hCEnCs by enhancing cell proliferation and adhesion between cells.

Combination of Metformin and Sorafenib Induces Ferroptosis of Hepatocellular Carcinoma Through p62-Keap1-Nrf2 Pathway

Hepatocellular carcinoma (HCC) is one of the most lethal cancers in the world. Sorafenib is the first small-molecule multi-kinase inhibitors approved by FDA for treatment of advanced HCC. Metformin has been demonstrated to have benefit for preventing cancer progression. In human recurrent HCCs, NF-E2-related factor 2 (Nrf2) was overexpressed and associated with poor survival. Nrf2 related signaling pathway plays central role to mediate cellular resistance to sorafenib through protecting HCC cells from ferroptosis. The effect of Combination treatment for HCC cells and the intrinsic mechanism have not been reported. In this study, metformin augmented the anti-tumor effect of sorafenib for HCC through ferroptosis induction by inhibiting Nrf2 related pathway. Based on the results of Nrf2 knockdown and p62 knockdown study, the combination of sorafenib and metformin suppressed proliferation of HCC cells through p62-Keap1-Nrf2/HO1 signaling way. Size of xenografts treated with the combination of sorafenib and metformin was smaller than other groups in vivo. Moreover, the combination treatment greatly induced ferroptosis in HCC cells through inhibiting Nrf2 expression. Based on our findings, the combination treatment suppressed proliferation of HCC cells through ferroptosis induction, by p62-Keap1-Nrf2/HO1 signaling way.

Cellular and Molecular Mechanisms in Oxidative Stress-Related Diseases

The redox equilibrium is important in preserving the correct functionality of vital cellular functions [...]

Effect of ALA-PDT on inhibition of oral precancerous cell growth and its related mechanisms

BACKROUND

Early treatment of oral precancerous lesions is considered as a key strategy for in oral carcinogenesis prevention. Increasing evidence has suggested that the transforming growth factor beta (TGF-β) signaling pathway is tightly involved in the process of oral-carcinogenesis. In this study, we investigated the inhibition effect and potential mechanism of 5-aminolaevulinic acid photodynamic therapy (ALA-PDT) in human oral precancerous cells via TGF-β pathway.

MATERIALS AND METHODS

Here, the dysplastic oral keratinocyte (DOK) cells were incubated with ALA concentration of 1 mM/mL for 4 h and then irradiated with a Helium-Neon (He-Ne) ion laser at 633 nm (200 mW/cm²). The control cells were cultured in Dulbecco's modified Eagle's medium (DMEM) medium. We analyzed the differentially expressed genes and correlated pathways in oral precancerous cells following ALA-PDT using Affymetrix microarrays. TGF-β pathway was analyzed by quantitative real-time polymerase chain reaction (RT-qPCR) and western blotting. Bioinformatics analysis was performed to evaluate the expression of TGF-β1 in human oral cancer samples and adjacent normal samples. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT), flow cytometry, 2'-7'-dichlorodihydrofluorescein diacetate (DCFH-DA), and wound healing assay were used to assess the effects of ALA-PDT plus TGF-β receptor inhibitor (LY2109761) in DOK cells.

RESULTS

The TGF-β signaling could exert in suppressive effects on DOK cells after ALA-PDT. The cell proliferation and migration rate of DOK cells was significantly reduced and apoptosis and ROS generation induced more effectively by ALA-PDT combined with LY2109761. Furthermore, cell cycle analysis revealed that the combined treatment resulted in G0/G1 phase arrest.

CONCLUSIONS

ALA-PDT suppresses the growth of oral precancerous cells by regulating the TGF-β signaling pathway, and its suppressive effect was enhanced using LY2109761. These results indicate that it could be a promising alternative treatment against oral precancerous lesions.