PRDX2 protects against oxidative stress induced by H. pylori and promotes resistance to cisplatin in gastric cancer

miR-148-3p inhibits gastric cancer cell malignant phenotypes and chemotherapy resistance by targeting Bcl2

Gastric cancer (GC) is the fourth most common cancer in the world. This work was designed to explore the biological effects of miR-148-3p on GC. Quantitative reverse transcription-polymerase chain reaction (RT-qPCR) was utilized to analyze the mRNA expression of miR-148-3p in GC cell lines. The mimics and inhibitors of miR-148-3p were carefully transfected into GC cells to up-regulate or down-regulate miR-148-3p expression. Observe the effect on miR-148-3p expression change to GC cell proliferation, colony formation, tumorigenesis, chemotherapy sensitivity, transwell migration, and invasion. Use online database tool to predict the miR-148-3p promising targets, and can be verified via RT-qPCR, Western blot, and luciferase report. We found that miR-148-3p expression level in GC cells was markedly down-regulated (P < 0.05), as compared with human normal gastric mucosal cells GES-1. Otherwise, miR-148-3p overexpression could effectively inhibit the cell proliferation, cell cycle progress, colony formation, anti-apoptosis, anti-migration and anti-invasion in gastric cancer cells, whereas miR-148-3p inhibition exhibited the opposite phenomenon (P < 0.05). Further research revealed that Bcl2 set as a direct downstream target of miR-148-3p. Our study firstly confirmed that, miR-148-3p might play a crucial role in tumorigenesis, as well as development of gastric cancer by targeting Bcl2, and could become a promising target for gastric cancer treatment.

Helicobacter pylori infection induces POU5F1 upregulation and SPP1 activation to promote chemoresistance and T cell inactivation in gastric cancer cells

Infection with Helicobacter pylori (H. pylori or Hp) is associated with an increased susceptibility to gastric diseases, notably gastric cancer (GC). This study investigates the impact of Hp infection on chemoresistance and immune activity in GC cells. Hp infection in AGS and MKN-74 cells promoted proliferation, migration and invasion, apoptosis resistance, and tumorigenic activity of cells under cisplatin (DDP) plus gemcitabine (GEM) treatment. Additionally, it dampened activity of the co-cultured CD8+ T cells. Hp infection increased POU class 5 homeobox 1 (POU5F1) level, which further activated secreted phosphoprotein 1 (SPP1) transcription to increase its expression. Silencing of either SPP1 or POU5F1 enhanced the GEM sensitivity in GC cells, and it increased the populations of CD8+ T cells and the secretion of immune-active cytokines both in vitro and in xenograft tumors in immunocompetent mice. However, the effects of POU5F1 silencing were counteracted by SPP1 overexpression. Furthermore, the POU5F1/SPP1 axis activated the PI3K/AKT signaling pathway. This study demonstrates that Hp infection induces POU5F1 upregulation and SPP1 activation, leading to increased DDP/GEM resistance and T cell inactivation in GC cells.

Loss of Lipocalin2 confers cisplatin vulnerability through modulating NF-ĸB mediated ferroptosis via ferroportin

Cisplatin is a widely used anti-cancer drug. Unfortunately, many cancers often develop resistance, which contributes to tumor recurrence and poorly prognosis. Growing knowledge has suggested the therapeutic potential of ferroptosis in cancer. Lipocalin2 (LCN2) is demonstrated to be a critical iron metabolic factor and implies in ferroptosis. Here, we aim to explore its role in chemotherapy resistance. The influence of LCN2 on colorectal cancer (CRC) cell chemoresistance and ferroptosis were evaluated by in vitro and in vivo approaches. The interaction between LCN2, NF-ĸB and ferroportin (FPN) was assessed by western blots, immunohistochemistry and dual luciferase reporter assays. Results showed that LCN2 was highly expressed in tumor regression grade 1 (TRG1) cases than that in TRG3 specimens. Loss of LCN2 contributed to resistance to cisplatin-induced ferroptosis. Mechanistically, loss of LCN2 inhibited cisplatin sensitivity and cisplatin-induced ferroptosis through elevating FPN expression which was regulated by NF-ĸB, subsequently reducing Fe2+ mediated Fenton reaction. Furthermore, FPN expression rate was much lower in TRG1 cases, and negative correlation between LCN2 and FPN expression was observed in clinical specimens. Collectively, low LCN2 expression enhances insensitivity of cisplatin to CRC cells via Fenton reaction mediated ferroptosis. LCN2/NF-ĸB/FPN pathway might be potentially utilized for chemoresistance strategy. LCN2 and FPN expression might be a promising biomarker of chemotherapy effect for CRC patients.

Capsaicin reverses cisplatin resistance in tongue squamous cell carcinoma by inhibiting the Warburg effect and facilitating mitochondrial-dependent apoptosis via the AMPK/AKT/mTOR axis

Cisplatin is commonly used for the chemotherapy of tongue squamous cell carcinoma (TSCC); however, adverse side effects and drug resistance impact its therapeutic efficacy. Capsaicin is an active ingredient in chili peppers that exerts antitumor effects, whether it exerts antitumor effects on cisplatin-resistant cells remains unknown. Therefore, in this study, we investigated the effect of capsaicin on cisplatin resistance in TSCC cells and explored the underlying mechanisms. A cisplatin-resistant TSCC cell line was established by treated with increasing cisplatin concentrations. Combined treatment with cisplatin and capsaicin decreased the glucose consumption and lactate dehydrogenase activity and increased the adenosine triphosphate production both in vitro and in vivo, suggesting the inhibition of the Warburg effect. Moreover, this combined treatment induced cell apoptosis and significantly upregulated the levels of proapoptotic proteins, such as Bax, cleaved caspase-3, -7, and -9, and apoptosis-inducing factor. In contrast, levels of the antiapoptotic protein, Bcl-2, were downregulated. Additionally, LKB1 and AMPK activities were stimulated, whereas those of AKT and mTOR were suppressed. Notably, AMPK knockdown abolished the inhibitory effects of capsaicin and cisplatin on the AKT/mTOR signaling pathway and Warburg effect. Overall, combined treatment with capsaicin and cisplatin reversed cisplatin resistance by inhibiting the Warburg effect and facilitating mitochondrial-dependent apoptosis via the AMPK/AKT/mTOR axis. Our findings suggest combination therapy with capsaicin and cisplatin as a potentially novel strategy and highlight capsaicin as a promising adjuvant drug for TSCC treatment.

PRDX2 regulates stemness contributing to cisplatin resistance and metastasis in bladder cancer

BACKGROUND

Cisplatin (CDDP)-based chemotherapy has emerged as the primary treatment for muscle-invasive bladder cancer and metastatic bladder cancer. Nevertheless, a significant proportion of patients experience rapidly developed chemoresistance, leading to treatment ineffectiveness. Existing evidence suggests that chemoresistance is governed by various factors, including tumor stem cells, epithelial mesenchymal transition, and reactive oxygen species (ROS). However, limited research has been conducted on the role of PRDX2, a crucial ROS scavenger, in the modulation of chemoresistance in bladder cancer.

METHODS

Cisplatin-resistant cell lines were established using the concentration gradient overlay method, and differentially expressed genes in resistant cells were screened through RNA sequencing. The expression of PRDX2 in cells and tissues was assessed using RT-qPCR, Western Blot, and immunohistochemistry. The expression of PRDX2 in bladder cancer and adjacent tissues was evaluated using a bladder cancer tissue microarray. Furthermore, the impact of PRDX2 knockdown on tumor formation and metastasis was investigated in vivo by applying subcutaneous tumor xenografts tail vein metastasis assays.

RESULTS

We demonstrated that PRDX2 is significantly upregulated in bladder tumors and cisplatin-resistant bladder tumor cell lines. Overexpression of PRDX2 can promote tumor proliferation, migration, and invasion both in vitro and in vivo. We have found that knockdown of PRDX2 expression can effectively reverse cell resistance to cisplatin. Mechanistically, our findings suggest that PRDX2 is involved in regulating tumor stemness and epithelial-mesenchymal transition (EMT). Knockdown of PRDX2 affects the PI3K-AKT and mTOR signaling pathways, thereby influencing tumor stemness and EMT, ultimately impacting the chemotherapy resistance of the tumor.

CONCLUSIONS

This study provides a new insight into the regulation of chemotherapy resistance in bladder cancer by PRDX2. Targeting PRDX2 can serve as a potent therapeutic target for chemotherapy resistance.

Autophagy-driven regulation of cisplatin response in human cancers: Exploring molecular and cell death dynamics

Despite the challenges posed by drug resistance and side effects, chemotherapy remains a pivotal strategy in cancer treatment. A key issue in this context is macroautophagy (commonly known as autophagy), a dysregulated cell death mechanism often observed during chemotherapy. Autophagy plays a cytoprotective role by maintaining cellular homeostasis and recycling organelles, and emerging evidence points to its significant role in promoting cancer progression. Cisplatin, a DNA-intercalating agent known for inducing cell death and cell cycle arrest, often encounters resistance in chemotherapy treatments. Recent studies have shown that autophagy can contribute to cisplatin resistance or insensitivity in tumor cells through various mechanisms. This resistance can be mediated by protective autophagy, which suppresses apoptosis. Additionally, autophagy-related changes in tumor cell metastasis, particularly the induction of Epithelial-Mesenchymal Transition (EMT), can also lead to cisplatin resistance. Nevertheless, pharmacological strategies targeting the regulation of autophagy and apoptosis offer promising avenues to enhance cisplatin sensitivity in cancer therapy. Notably, numerous non-coding RNAs have been identified as regulators of autophagy in the context of cisplatin chemotherapy. Thus, therapeutic targeting of autophagy or its associated pathways holds potential for restoring cisplatin sensitivity, highlighting an important direction for future clinical research.

Data independent acquisition reveals in-depth serum proteome changes in uremic pruritus

Introduction: Uremic pruritus (UP) is a prevalent symptom in patients suffering from uremia, yet its underlying etiology and mechanisms remain incompletely elucidated. Given the significant incidence of UP, identifying specific alterations in proteins present in the blood of UP patients could offer insights into the potential biological pathways associated with UP and facilitate the exploration of biomarkers. Methods: In this study, we employed LC-MS/MS-based data-independent acquisition (DIA) mode to analyze serum samples obtained from 54 UP patients categorized as DKD-UP, HN-UP, and GN-UP (n = 18 for each subgroup), along with 18 uremic patients without pruritus (Negative) and 18 CKD patients without pruritus (CKD). Through DIA mode analysis, a total of 7075 peptides and 959 proteins were quantified. Within these, we identified four upregulated and 13 downregulated Differentially Expressed Proteins (DEPs) in DKD-UP versus Negative, five upregulated and 22 downregulated DEPs in HN-UP versus Negative, and three upregulated and 23 downregulated DEPs in GN-UP versus Negative. Furthermore, we conducted an intersection analysis of the DEPs across these three comparison groups to derive a set of common DEPs (COMP). Subsequently, a total of 67 common DEPs were identified in the three UP groups when compared to the CKD group, with 40 DEPs showing upregulation and 27 DEPs displaying downregulation. Results: Following Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Protein-Protein Interaction (PPI) analyses, we observed that the DEPs distinguishing UP from CKD were primarily associated with mitochondrial function (MT-CYB, PRDX2, TOMM22), inflammation (CD59, CSF1), renal injury (WFDC2), and neural function (CAP1, VGF). Discussion: Our findings contribute to a potential molecular comprehension of UP pathogenesis, shedding light on the identification of these DEPs as plausible biomarkers for UP.

PRDX2 deficiency increases MCD-induced nonalcoholic steatohepatitis in female mice

OBJECTIVE

To evaluate the role of PRDX2 in nonalcoholic steatohepatitis (NASH).

METHODS

NASH was induced in wild-type (WT) mice and liver-specific PRDX2 knockout (PRDX2 LKO) mice that were fed a methionine-choline deficient diet (MCD) for 5 weeks. Assessments of PRDX2 LKO's impact on the pathogenesis of NASH include histological analyses, quantitative PCR (q-PCR), western blotting (WB), and RNA sequencing (RNA-Seq).

RESULTS

PRDX2 LKO mice exhibited a significant increase in hepatic lipid accumulation and inflammation compared to WT mice after MCD feeding. PRDX2 KO markedly elevated circulating levels of aspartate aminotransferase (AST) and the pro-inflammatory signaling pathways within the liver. There was a notable increase in the activities of signal transducer and activator of transcription 1 (STAT1) and nuclear factor kappa B (NF-кB). We also found that PRDX2 KO significantly increased the extent of lipid peroxidation in the liver, most likely owing to the impaired peroxidase activity of PRDX2. Of interest, these findings were observed only in MCD-fed female mice, suggesting the sexual dimorphism of PRDX2 KO in MCD-induced NASH.

CONCLUSION

PRDX2 deficiency increases MCD-induced NASH in female mice, suggesting a protective role for PRDX2.

Energy metabolism: a new target for gastric cancer treatment

Gastric cancer is the fifth most common malignancy worldwide having the fourth highest mortality rate. Energy metabolism is key and closely linked to tumour development. Most important in the reprogramming of cancer metabolism is the Warburg effect, which suggests that tumour cells will utilise glycolysis even with normal oxygen levels. Various molecules exert their effects by acting on enzymes in the glycolytic pathway, integral to glycolysis. Second, mitochondrial abnormalities in the reprogramming of energy metabolism, with consequences for glutamine metabolism, the tricarboxylic acid cycle and oxidative phosphorylation, abnormal fatty acid oxidation and plasma lipoprotein metabolism are important components of tumour metabolism. Third, inflammation-induced oxidative stress is a danger signal for cancer. Fourth, patterns of signalling pathways involve all aspects of metabolic transduction, and many clinical drugs exert their anticancer effects through energy metabolic signalling. This review summarises research on energy metabolism genes, enzymes and proteins and transduction pathways associated with gastric cancer, and discusses the mechanisms affecting their effects on postoperative treatment resistance and prognoses of gastric cancer. We believe that an in-depth understanding of energy metabolism reprogramming will aid the diagnosis and subsequent treatment of gastric cancer.

Exosome-derived miR-23a-5p inhibits HCC proliferation and angiogenesis by regulating PRDX2 expression: MiR-23a-5p/PRDX2 axis in HCC progression

microRNAs (miRNAs) are closely related to the progression of hepatocellular carcinoma (HCC). Cancer-derived exosomes play an essential role in the establishment of the HCC microenvironment. However, the possible effects and underlying mechanisms of exosome (exo) microRNA-23a-5p (miR-23a-5p) in the progression of HCC remain unknown. In this study, we aimed to determine the role and specific molecular mechanism of exo miR-23a-5p in regulating HCC progression and to investigate whether exo miR-23a-5p levels can serve as an indicator of the prognosis of transarterial chemoembolization in patients with HCC. Our findings illustrated that miR-23a-5p was downregulated in exosomes separated from the serum of HCC patients and that miR-23a-5p carried by exosomes inhibited HCC cell proliferation and angiogenesis. Mechanistically, miR-23a-5p negatively targeted peroxiredoxin-2 (PRDX2). Functionally, PRDX2 overexpression relieved exosome-induced inhibition of HCC cell proliferation and angiogenesis by promoting vascular endothelial growth factor (VEGF) expression. In conclusion, Exo miR-23a-5p inhibited HCC proliferation and angiogenesis by regulating PRDX2 expression. Our results revealed the role and specific molecular mechanism of exo miR-23a-5p in regulating HCC progression.

Silencing of peroxiredoxin 2 suppresses proliferation and Wnt/β-catenin pathway, and induces senescence in hepatocellular carcinoma

Hepatocellular carcinoma (HCC), a common malignancy worldwide, still lacks effective clinical treatment. The study aimed to investigate the oncogenes that affect the progression of HCC and their possible mechanisms. In our study, we initially confirmed a higher level of PRDX2 in the bile of HCC patients compared to those with choledocholithiasis by 2-DE, LC-MS, and ELISA. Subsequently, we demonstrated the high expression of peroxiredoxin 2 (PRDX2) in HCC based on the TCGA database and clinical sample analysis. Furthermore, PRDX2 overexpression enhanced the viability of HCC cells. And PRDX2 silencing induced senescence of HCC cells. In vivo, knockdown of PRDX2 significantly reduced the weight of xenograft tumors. PRDX2 also was found to activate the Wnt/β-catenin pathway by inducing β-catenin nuclear translocation. Consequently, we proved that silencing PRDX2 could inhibit proliferation and Wnt/β-catenin pathway while promoting senescence in HCC cells.

Reactive Oxygen Species and H. pylori Infection: A Comprehensive Review of Their Roles in Gastric Cancer Development

Gastric cancer (GC) is the fifth most common cancer worldwide and makes up a significant component of the global cancer burden. Helicobacter pylori (H. pylori) is the most influential risk factor for GC, with the International Agency for Research on Cancer classifying it as a Class I carcinogen for GC. H. pylori has been shown to persist in stomach acid for decades, causing damage to the stomach's mucosal lining, altering gastric hormone release patterns, and potentially altering gastric function. Epidemiological studies have shown that eliminating H. pylori reduces metachronous cancer. Evidence shows that various molecular alterations are present in gastric cancer and precancerous lesions associated with an H. pylori infection. However, although H. pylori can cause oxidative stress-induced gastric cancer, with antioxidants potentially being a treatment for GC, the exact mechanism underlying GC etiology is not fully understood. This review provides an overview of recent research exploring the pathophysiology of H. pylori-induced oxidative stress that can cause cancer and the antioxidant supplements that can reduce or even eliminate GC occurrence.

Gut microbes involvement in gastrointestinal cancers through redox regulation

Gastrointestinal (GI) cancers are among the most common and lethal cancers worldwide. GI microbes play an important role in the occurrence and development of GI cancers. The common mechanisms by which GI microbes may lead to the occurrence and development of cancer include the instability of the microbial internal environment, secretion of cancer-related metabolites, and destabilization of the GI mucosal barrier. In recent years, many studies have found that the relationship between GI microbes and the development of cancer is closely associated with the GI redox level. Redox instability associated with GI microbes may induce oxidative stress, DNA damage, cumulative gene mutation, protein dysfunction and abnormal lipid metabolism in GI cells. Redox-related metabolites of GI microbes, such as short-chain fatty acids, hydrogen sulfide and nitric oxide, which are involved in cancer, may also influence GI redox levels. This paper reviews the redox reactions of GI cells regulated by microorganisms and their metabolites, as well as redox reactions in the cancer-related GI microbes themselves. This study provides a new perspective for the prevention and treatment of GI cancers.

Understanding the age-related alterations in the testis-specific proteome

INTRODUCTION

Fertility rates in developing countries have declined over the past decades, and the trend of delayed fatherhood is rising as societies develop. The reasons behind the decline in male fertility with advancing age remain mysterious, making it a compelling and crucial area for further research. However, the limited number of studies dedicated to unraveling this enigma poses a challenge. Thus, our objective is to illuminate some of the upregulated and downregulated mechanisms in the male testis during the aging process.

AREAS COVERED

Herein, we present a critical overview of the studies addressing the alterations of testicular proteome through the aging process, starting from sexually matured young males to end-of-life-expectancy aged males. The comparative studies of the proteomic testicular profile of men with and without spermatogenic impairment are also discussed and key proteins and pathways involved are highlighted.

EXPERT OPINION

The difficulty of making age-comparative studies, especially of advanced-age study subjects, makes this topic of study quite challenging. Another topic worth mentioning is the heterogeneous nature and vast cellular composition of testicular tissue, which makes proteome data interpretation tricky. The cell type sorting and comorbidities testing in the testicular tissue of the studied subjects would help mitigate these problems.

New insights into the roles of peroxiredoxins in cancer

Oxidative stress is one of the hallmarks of cancer. Tumorigenesis and progression are accompanied by elevated reactive oxygen species (ROS) levels and adaptive elevation of antioxidant expression levels. Peroxiredoxins (PRDXs) are among the most important antioxidants and are widely distributed in a variety of cancers. PRDXs are involved in the regulation of a variety of tumor cell phenotypes, such as invasion, migration, epithelial-mesenchymal transition (EMT) and stemness. PRDXs are also associated with tumor cell resistance to cell death, such as apoptosis and ferroptosis. In addition, PRDXs are involved in the transduction of hypoxic signals in the TME and in the regulation of the function of other cellular components of the TME, such as cancer-associated fibroblasts (CAFs), natural killer (NK) cells and macrophages. This implies that PRDXs are promising targets for cancer treatment. Of course, further studies are needed to realize the clinical application of targeting PRDXs. In this review, we highlight the role of PRDXs in cancer, summarizing the basic features of PRDXs, their association with tumorigenesis, their expression and function in cancer, and their relationship with cancer therapeutic resistance.

MSC-NPRA loop drives fatty acid oxidation to promote stemness and chemoresistance of gastric cancer

Cisplatin (CDDP)-based chemotherapy is the preferred treatment strategy for advanced stage gastric cancer (GC) patients. Despite the efficacy of chemotherapy, the development of chemoresistance negatively affects the prognosis of GC and the underlying mechanism remains poorly understood. Accumulated evidence suggests that mesenchymal stem cells (MSCs) play important roles in drug resistance. The chemoresistance and stemness of GC cells were observed by colony formation, CCK-8, sphere formation and flow cytometry assays. Cell lines and animal models were utilized to investigate related functions. Western blot, quantitative real-time PCR (qRT-PCR) and co-immunoprecipitation were used to explore related pathways. The results showed that MSCs improved the stemness and chemoresistance of GC cells and accounted for the poor prognosis of GC. Natriuretic peptide receptor A (NPRA) was upregulated in GC cells cocultured with MSCs and knockdown of NPRA reversed the MSC-induced stemness and chemoresistance. At the same time, MSCs could be recruited to GC by NPRA, which formed a loop. In addition, NPRA facilitated stemness and chemoresistance through fatty acid oxidation (FAO). Mechanistically, NPRA protected Mfn2 against protein degradation and promoted its mitochondrial localization, which consequently improved FAO. Furthermore, inhibition of FAO with etomoxir (ETX) attenuated MSC-induced CDDP resistance in vivo. In conclusion, MSC-induced NPRA promoted stemness and chemoresistance by upregulating Mfn2 and improving FAO. These findings help us understand the role of NPRA in the prognosis and chemotherapy of GC. NPRA may be a promising target to overcome chemoresistance.

New advances into cisplatin resistance in head and neck squamous carcinoma: Mechanisms and therapeutic aspects

Head and neck squamous cell carcinoma (HNSCC) arises from the interplay of multiple factors, such as smoking, alcohol consumption, and viral infections. Cisplatin-based concurrent radiotherapy regimens represent the first-line treatment for advanced HNSCC cases. However, cisplatin resistance significantly contributes to poor prognoses in HNSCC patients, making it crucial to unravel the underlying mechanisms to overcome this resistance. The complexity of cisplatin resistance in HNSCC involves cancer stem cells, autophagy, epithelial-mesenchymal transition, drug efflux, and metabolic reprogramming. Recent advances in nanodrug delivery systems, combined with existing small-molecule inhibitors and innovative genetic technologies, have opened new therapeutic avenues for addressing cisplatin resistance in HNSCC. This review systematically summarizes research progress from the past five years on cisplatin resistance in HNSCC, with a particular focus on the roles of cancer stem cells and autophagy. Additionally, potential future treatment strategies to overcome cisplatin resistance are discussed, including the targeting of cancer stem cells or autophagy through nanoparticle-based drug delivery systems. Furthermore, the review highlights the prospects and challenges associated with nanodelivery platforms in addressing cisplatin resistance in HNSCC.

Ischemia challenged epicardial adipose tissue stem cells-derived extracellular vesicles alter the gene expression of cardiac fibroblasts to cardiomyocyte like phenotype

The present study hypothesizes that the ischemic insults activate epicardial adipose tissue-derived stem cells (EATDS) to secrete extracellular vesicles (EVs) packed with regenerative mediators to alter the gene expression in cardiac fibroblasts (CF). EATDS and CF were isolated from hyperlipidemic microswine and EVs were harvested from control, simulated ischemia (ISC) and ischemia-reperfusion (ISC/R) groups. The in vitro interaction between ISC-EVs and CF resulted in the upregulation of cardiomyocyte-specific transcription factors including GATA4, Nkx2.5, IRX4, and TBX5 in CF and the healing marker αSMA and the downregulation of fibroblast biomarkers such as vimentin, FSP1, and podoplanin and the cardiac biomarkers such as troponin-I and connexin-43. These results suggest a cardiomyocyte-like phenotype as confirmed by immunostaining and Western blot. The LC-MS/MS analysis of ISC-EVs LGALS1, PRDX2, and CCL2 to be the potent protein mediators which are intimately involved in versatile regenerative processes and connected with a diverse array of regenerative genes. Moreover, the LGALS1+, PRDX2+, and CCL2+ EATDS phenotypes were deciphered at single cell resolution revealing corresponding sub-populations with superior healing potential. Overall, the findings unveiled the healing potential of EATDS-derived EVs and sub-populations of regenerative EATDS promising novel translational opportunities in improved cardiac healing following ischemic injury.

High uric acid aggravates apoptosis of lung epithelial cells induced by cigarette smoke extract through downregulating PRDX2 in chronic obstructive pulmonary disease

Cigarette smoke exposure is the major cause of chronic obstructive pulmonary disease (COPD). Cigarette smoke heightens the elevation of reactive oxygen species (ROS) and thus leads to apoptosis. Hyperuricemia has been considered as a risk factor for COPD. However, the underlying mechanism for this aggravating effect remains unclear. The current study sought to examine the role of high uric acid (HUA) in COPD using cigarette smoke extract (CSE) exposed murine lung epithelial (MLE-12) cells. Our data showed that CSE induced the increase of ROS, mitochondrial dynamics disorder, and apoptosis, while HUA treatment aggravated the effects of CSE. Further studies suggested that HUA decreased the expression of antioxidant enzyme-peroxiredoxin-2 (PRDX2). Overexpression of PRDX2 inhibited excessive ROS generation, mitochondrial dynamics disorder, and apoptosis induced by HUA. Knockdown of PRDX2 by small interfering RNA (siRNA) promoted ROS generation, mitochondrial dynamics disorder, and apoptosis in MLE-12 cells treated with HUA. However, antioxidant N-acetylcysteine (NAC) reversed the effects of PRDX2-siRNA on MLE-12 cells. In conclusion, HUA aggravated CSE-induced cellular ROS levels and led to ROS-dependent mitochondrial dynamics disorder and apoptosis in MLE-12 cells through downregulating PRDX2.

Thioredoxin Signaling Pathways in Cancer

Significance: Thioredoxin (Trx) is a powerful antioxidant that reduces protein disulfides to maintain redox stability in cells and is involved in regulating multiple redox-dependent signaling pathways. Recent Advance: The current accumulation of findings suggests that Trx participates in signaling pathways that interact with various proteins to manipulate their dynamic regulation of structure and function. These network pathways are critical for cancer pathogenesis and therapy. Promising clinical advances have been presented by most anticancer agents targeting such signaling pathways. Critical Issues: We herein link the signaling pathways regulated by the Trx system to potential cancer therapeutic opportunities, focusing on the coordination and strengths of the Trx signaling pathways in apoptosis, ferroptosis, immunomodulation, and drug resistance. We also provide a mechanistic network for the exploitation of therapeutic small molecules targeting the Trx signaling pathways. Future Directions: As research data accumulate, future complex networks of Trx-related signaling pathways will gain in detail. In-depth exploration and establishment of these signaling pathways, including Trx upstream and downstream regulatory proteins, will be critical to advancing novel cancer therapeutics. Antioxid. Redox Signal. 38, 403-424.

A comprehensive evaluation of an animal model for Helicobacter pylori-associated stomach cancer: Fact and controversy

Even though Helicobacter pylori infection was the most causative factor of gastric cancer, numerous in vivo studies failed to induce gastric cancer using H. pylori infection only. The utilization of established animal studies in cancer research is crucial as they aim to investigate the coincidental association between suspected oncogenes and pathogenesis as well as generate models for the development and testing of potential treatments. The methods to establish gastric cancer using infected animal models remain limited, diverse in methods, and showed different results. This study investigates the differences in animal models, which highlight different pathological results in gaster by literature research. Electronic databases searched were performed in PubMed, Science Direct, and Cochrane, without a period filter. A total of 135 articles were used in this study after a full-text assessment was conducted. The most frequent animal models used for gastric cancer were Mice, while Mongolian gerbils and Transgenic mice were the most susceptible model for gastric cancer associated with H. pylori infection. Additionally, transgenic mice showed that the susceptibility to gastric cancer progression was due to genetic and epigenetic factors. These studies showed that in Mongolian gerbil models, H. pylori could function as a single agent to trigger stomach cancer. However, most gastric cancer susceptibilities were not solely relying on H. pylori infection, and numerous factors are involved in cancer progression. Further study using Mongolian gerbils and Transgenic mice is crucial to conduct and establish the best models for gastric cancer associated H. pylori.

Circular RNA hsa_circ_0002360 Promotes Proliferation and Invasion and Inhibits Oxidative Stress in Gastric Cancer by Sponging miR-629-3p and Regulating the PDLIM4 Expression

Many studies have found that circRNA hsa_0002360 (circ0002360) plays an important role in cancer onset and progression. However, its role in gastric cancer (GC) remains uncertain. Circ0002360 was found to be upregulated in GC cells using QRT-PCR. Furthermore, miR-629-3p, a target miRNA of circ0002360, was the most suppressed miRNA following circ0002360 overexpression. RNA immunoprecipitation (RIP), dual-luciferase reporter analyses, clone formation, transwell, DCFH-DA, and ELISA assays demonstrated that circ0002360-targeted miR-629-3p promotes cell proliferation and migration while inhibiting oxidative stress. GC-related mRNA microarrays from the GEO and TCGA databases, including GSE103236, GSE79973, GSE33429, GSE22804, GSE84437, and TCGA-STAD datasets, were used to find hub biomarkers between normal and gastric cancer samples. WGCNA and uni-Cox analysis were used to identify 27 survival-related risk genes, which were then used to build a risk model for prognosis prediction. Following that, all patients from the GSE84437 and TCGA-STAD datasets with 27 survival-related genes and enough data on survival status and time were randomly assigned to train (n = 433) and test (n = 375) cohorts. Furthermore, ROC and Kaplan-Meier (KM) analyses were used to validate the risk model for both cohorts. randomForest analysis indicated that PDLIM4 was the target gene of miR-629-3p, whose level was increased by circ0002360 but reversed by miR-629-3p mimics. Finally, this study confirmed that circ0002360 sponged miR-629-3p and then upregulated PDLIM4 expression. As a result, circ0002360 may be a useful marker for predicting GC prognosis and an anti-GC treatment target.

Antisense long non-coding RNAs in gastric cancer

Gastric cancer is a global health problem with high mortality. The incidence of gastric cancer has significant regional differences. Helicobacter pylori (H. pylori) infection and its interaction with epigenetics are closely related to the occurrence of gastric cancer. It is of great significance to explore the early diagnosis and effective therapeutic targets of gastric cancer. Emerging evidence indicates that antisense long non-coding RNAs (lncRNAs) are closely associated with various biological and functional aspects of gastric cancer. However, diverse antisense lncRNAs in gastric cancer have not been compiled and discussed. In this review, we summarize the predisposing factors and compile the interaction between H. pylori and epigenetics in gastric cancer. Moreover, we focus on the underlying molecular mechanism and regulatory role of each antisense lncRNA in gastric cancer. In addition, we provide a new insight into the potential diagnosis and treatment of antisense lncRNAs in gastric cancer.

Ferroptosis and its Role in Gastric Cancer

Gastric cancer (GC) is the fifth most common cancer and the third leading cause of cancer-related deaths worldwide. Currently, surgery is the treatment of choice for GC. However, the associated expenses and post-surgical pain impose a huge burden on these patients. Furthermore, disease recurrence is also very common in GC patients, thus necessitating the discovery and development of other potential treatment options. A growing body of knowledge about ferroptosis in different cancer types provides a new perspective in cancer therapeutics. Ferroptosis is an iron-dependent form of cell death. It is characterized by intracellular lipid peroxide accumulation and redox imbalance. In this review, we summarized the current findings of ferroptosis regulation in GC. We also tackled on the action of different potential drugs and genes in inducing ferroptosis for treating GC and solving drug resistance. Furthermore, we also explored the relationship between ferroptosis and the tumor microenvironment in GC. Finally, we discussed areas for future studies on the role of ferroptosis in GC to accelerate the clinical utility of ferroptosis induction as a treatment strategy for GC.

MicroRNA-1224-5p Aggravates Sepsis-Related Acute Lung Injury in Mice

Oxidative stress and inflammation are implicated in the development of sepsis-related acute lung injury (ALI). MicroRNA-1224-5p (miR-1224-5p) plays critical roles in regulating inflammatory response and reactive oxygen species (ROS) production. The present study is aimed at investigating the role and underlying mechanisms of miR-1224-5p in sepsis-related ALI. Mice were intratracheally injected with lipopolysaccharide (LPS, 5 mg/kg) for 12 h to induce sepsis-related ALI. To manipulate miR-1224-5p level, mice were intravenously injected with the agomir, antagomir, or matched controls for 3 consecutive days. Murine peritoneal macrophages were stimulated with LPS (100 ng/mL) for 6 h to further validate the role of miR-1224-5p in vitro. To inhibit adenosine 5′-monophosphate-activated protein kinase alpha (AMPKα) or peroxisome proliferator activated receptor-gamma (PPAR-γ), compound C or GW9662 was used in vivo and in vitro. We found that miR-1224-5p levels in lungs were elevated by LPS injection, and that the miR-1224-5p antagomir significantly alleviated LPS-induced inflammation, oxidative stress, and ALI in mice. Conversely, the miR-1224-5p agomir aggravated inflammatory response, ROS generation, and pulmonary dysfunction in LPS-treated mice. In addition, the miR-1224-5p antagomir reduced, while the miR-1224-5p agomir aggravated LPS-induced inflammation and oxidative stress in murine peritoneal macrophages. Further findings revealed that miR-1224-5p is directly bound to the 3′-untranslated regions of PPAR-γ and subsequently suppressed PPAR-γ/AMPKα axis, thereby aggravating LPS-induced ALI in vivo and in vitro. We demonstrate for the first time that endogenous miR-1224-5p is a critical pathogenic factor for inflammation and oxidative damage during LPS-induced ALI through inactivating PPAR-γ/AMPKα axis. Targeting miR-1224-5p may help to develop novel approaches to treat sepsis-related ALI.

Long non-coding RNA NUT family member 2A-antisense RNA 1 sponges microRNA-613 to increase the resistance of gastric cancer cells to matrine through regulating oxidative stress and vascular endothelial growth factor A

Matrine has been shown to play a role in the suppression of gastric cancer (GC) tumorigenesis. However, whether long non-coding RNA NUT family member 2A-antisense RNA 1 (NUTM2A-AS1) is involved in matrine-induced inhibition of GC remains unknown. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, cell colony formation, and terminal deoxynucleotidyl transferase dUTP nick-end labeling assays were employed to determine the proliferation, viability, and apoptosis of GC cells, respectively. The Cancer Genome Atlas database suggested an association between NUTM2A-AS1 and GC. The reverse transcription-quantitative polymerase chain reaction was used to quantify relative levels of NUTM2A-AS1, miR-613, and vascular endothelial growth factor A (VEGFA). Reactive oxygen species generation, glutathione content, and superoxide dismutase activity were determined by corresponding reagents or assay kits. NUTM2A-AS1 knockdown led to attenuated cell viability and proliferation, as well as to enhanced apoptosis of N87 and AGS cells treated with matrine. These changes were prevented by an inhibitor of microRNA (miR)-613. Importantly, NUTM2A-AS1 expression was positively associated with tumor progression in patients with GC. NUTM2A-AS1 and miR-613 regulated the generation of reactive oxygen species, the content of glutathione, and the activity of superoxide dismutase. VEGFA served as an important effector for the NUTM2A-AS1/miR-613-regulated resistance of GC cells to matrine. These results reveal a novel mechanism of matrine resistance in GC.

PRDX2 Knockdown Inhibits Extracellular Matrix Synthesis of Chondrocytes by Inhibiting Wnt5a/YAP1/CTGF and Activating IL-6/JAK2/STAT3 Pathways in Deer Antler

Although peroxiredoxin 2 (PRDX2) plays a vital role in relieving oxidative stress, its physiological function in cartilage development remains almost unknown. In this study, we found that the expression of PRDX2 significantly increased in the chondrocytes compared with pre-chondrocytes. PRDX2 knockdown significantly decreased the expression of extracellular matrix (ECM) protein (Col2a and Aggrecan), which led to blocked cartilage formation. Moreover, PRDX2 knockdown also inhibited the expression of connective tissue growth factor (CTGF). CTGF is an important growth factor that regulates synthesis of ECM proteins. We explored the possible regulatory mechanism by which PRDX2 regulated the expression of CTGF. Our results demonstrated that PRDX2 knockdown downregulated the expression of CTGF by inhibiting Wnt5a/Yes-associated protein 1 (YAP1) pathway. In addition, PRDX2 knockdown promoted the expression of interleukin 6 (IL-6), indicating PRDX2 expression had an anti-inflammatory function during antler growth. Mechanistically, PRDX2 knockdown promoted cartilage matrix degradation by activating the IL-6-mediated Janus Kinase 2/Signal Transducer and Activator of Transcription 3 (JAK2/STAT3) signaling pathway. These results reveal that PRDX2 is a potential regulator that promotes cartilage extracellular matrix synthesis.

Dihydroartemisinin enhances the anti-tumor activity of oxaliplatin in colorectal cancer cells by altering PRDX2-reactive oxygen species-mediated multiple signaling pathways

BACKGROUND

Globally, colorectal cancer (CRC) is one of the leading causes of cancer-related deaths. Oxaliplatin based treatments are frequently used as chemotherapeutic methods for CRC, however, associated side effects and drug resistance often limit their clinical application. Dihydroartemisinin (DHA) induces apoptosis in various cancer cells by increasing reactive oxygen species (ROS) production. However, the direct target of DHA and underlying molecular mechanisms in oxaliplatin-mediated anti-tumor activities against CRC are unclear.

METHODS

We used 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT), flow cytometry, and colony formation assays to investigate cell phenotype alterations and ROS generation. We also used quantitative Real-Time PCR (qRT-PCR) and western blotting to measure relative gene and protein expression. Finally, an in vivo mouse xenograft model was used to assess the anti-tumor activity of oxaliplatin and DHA alone, and combinations.

RESULTS

DHA synergistically enhanced the anti-tumor activity of oxaliplatin in colon cancer cells by regulating ROS-mediated ER stress, signal transducer and activator of transcription 3 (STAT3), C-Jun-amino-terminal kinase (JNK), and p38 signaling pathways. Mechanistically, DHA increased ROS levels by inhibiting peroxiredoxin 2 (PRDX2) expression, and PRDX2 knockdown sensitized DHA-mediated cell growth inhibition and ROS production in CRC cells. A mouse xenograft model showed strong anti-tumor effects from combination treatments when compared with single agents.

CONCLUSIONS

We demonstrated an improved therapeutic strategy for CRC patients by combining DHA and oxaliplatin treatments.

TNF-α induces AQP4 overexpression in astrocytes through the NF-κB pathway causing cellular edema and apoptosis

Aquaporin 4 (AQP4) is highly expressed on astrocytes and is critical for controlling brain water transport in neurological diseases. Tumor necrosis factor (TNF)-α is a common cytokine found in disease microenvironment. The aim of this study was to determine whether TNF-α can regulate the expression of AQP4 in astrocytes. Primary astrocyte cultures were treated with different concentrations of TNF-α and the cell viability was assessed through cell counting kit-8 assay and AQP4 expression was detected by qPCR, western blots, and immunofluorescence assays. The activation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathway was detected by western blot. Further, dual-luciferase reporting system and chromatin immunoprecipitation were used to detect the transcriptional regulation of AQP4 by p65. These experiments demonstrated that treatment with TNF-α can lead to astrocyte edema and an increase in AQP4 expression. Following TNF-α treatment, the expression levels of P-IKKα/β-IκBα and P-p65 increased significantly over time. The results of the dual-luciferase reporter system and chromatin immunoprecipitation assays revealed that p65 protein and AQP4 promoter had a robust binding effect after TNF-α treatment, and the NF-κB pathway inhibitor, BAY 11-7082 could inhibit these effects of TNF-α. The expression level of AQP4 was significantly decreased upon p65 interference, while the astrocyte viability was significantly increased compared to that in the TNF-α only group. In conclusion, TNF-α activated NF-κB pathway, which promoted the binding of p65 to the AQP4 gene promoter region, and enhanced AQP4 expression, ultimately reducing astrocyte viability and causing cell edema.

A Pilot Single Cell Analysis of the Zebrafish Embryo Cellular Responses to Uropathogenic Escherichia coli Infection

Background: Uropathogenic Escherichia coli (UPEC) infections are common and when they disseminate can be of high morbidity. Methods: We studied the effects of UPEC infection using single cell RNA sequencing (scRNAseq) in zebrafish. Bulk RNA sequencing has historically been used to evaluate gene expression patterns, but scRNAseq allows gene expression to be evaluated at the single cell level and is optimal for evaluating heterogeneity within cell types and rare cell types. Zebrafish cohorts were injected with either saline or UPEC,and scRNAseq and canonical pathway analyses were performed. Results: Canonical pathway analysis of scRNAseq data provided key information regarding innate immune pathways in the cells determined to be thymus cells, ionocytes, macrophages/monocytes, and pronephros cells. Pathways activated in thymus cells included interleukin 6 (IL-6) signaling and production of reactive oxygen species. Fc receptor-mediated phagocytosis was a leading canonical pathway in the pronephros and macrophages. Genes that were downregulated in UPEC vs saline exposed embryos involved the cellular response to the Gram-negative endotoxin lipopolysaccharide (LPS) and included Forkhead Box O1a (Foxo1a), Tribbles Pseudokinase 3 (Trib3), Arginase 2 (Arg2) and Polo Like Kinase 3 (Plk3). Conclusions: Because 4-day post fertilization zebrafish embryos only have innate immune systems, the scRNAseq provides insights into pathways and genes that cell types utilize in the bacterial response. Based on our analysis, we have identified genes and pathways that might serve as genetic targets for treatment and further investigation in UPEC infections at the single cell level.

Upregulation of Neogenin-1 by a CREB1-BAF47 Complex in Vascular Endothelial Cells is Implicated in Atherogenesis

Atherosclerosis is generally considered a human pathology of chronic inflammation, to which endothelial dysfunction plays an important role. Here we investigated the role of neogenin 1 (Neo-1) in oxidized low-density lipoprotein (oxLDL) induced endothelial dysfunction focusing on its transcriptional regulation. We report that Neo-1 expression was upregulated by oxLDL in both immortalized vascular endothelial cells and primary aortic endothelial cells. Neo-1 knockdown attenuated whereas Neo-1 over-expression enhanced oxLDL-induced leukocyte adhesion to endothelial cells. Neo-1 regulated endothelial-leukocyte interaction by modulating nuclear factor kappa B (NF-κB) activity to alter the expression of adhesion molecules. Neo-1 blockade with a blocking antibody ameliorated atherogenesis in Apoe^−/− mice fed a Western diet. Ingenuity pathway analysis combined with validation assays confirmed that cAMP response element binding protein 1 (CREB1) and Brg1-associated factor 47 (BAF47) mediated oxLDL induced Neo-1 upregulation. CREB1 interacted with BAF47 and recruited BAF47 to the proximal Neo-1 promoter leading to Neo-1 trans-activation. In conclusion, our data delineate a novel transcriptional mechanism underlying Neo-1 activation in vascular endothelial cells that might contribute to endothelial dysfunction and atherosclerosis.

Helicobacter pylori-induced NF-κB: trailblazer for gastric pathophysiology

NF-κB signaling pathways, induced by a variety of triggers, play a key role in regulating the expression of genes involved in the immune response and cellular responses to stress. The human pathogen Helicobacter pylori induces classical and alternative NF-κB signaling pathways via its effector ADP-L-glycero-β-D-manno-heptose (ADP-heptose). We review H. pylori- and NF-κB-dependent alterations in cellular processes and associated maladaptation leading to deleterious gastric pathophysiology that have implications for the diagnosis and treatment of gastric diseases. Therapeutic options for gastric cancer (GC) include clinically relevant small molecule inhibitors of NF-κB and epigenetic therapy approaches. In this context, gastric organoid biobanks originated from patient material, represent a valuable platform for translational applications to predict patient responses to chemotherapy, with a view to personalized medicine.

PREX2 gene's expression in gastric antral epithelial cells of patients with H. pylori infection

BACKGROUND

The Prex2 protein is a member of the Rac family proteins that belongs to small G proteins with a critical role in cell migration, cell proliferation, and apoptosis through its effects on PI3K cell signaling pathway and phosphatase activity of PTEN protein. The effect of PREX2 gene expression has been shown in some cancer cells. A survey of PREX2 gene expression in gastric antral epithelial cells of gastric cancer patients with Helicobacter pylori various genotypes infection can conduct to better understanding H. pylori infection's carcinogenesis.

METHODS

In a case-control study, PREX2 gene expression was evaluated in gastric antral biopsy samples on four groups of patients referred to Sanandaj hospitals, including gastritis with (n=23) and without (n=27) H. pylori infection and gastric cancer with (n=21) and without (n=32) H. pylori infection. Each gastric biopsy sample's total RNA was extracted and cDNA synthesized by using Kits (Takara Company). The PREX2 gene expression was measured using the relative quantitative real-time RT-PCR method and ΔΔCt formula.

RESULTS

The PREX2 gene expression increased in gastric antral biopsy samples of gastritis and gastric cancer patients with H. pylori infection (case groups) than patients without H. pylori infection (control groups) 2.38 and 2.27 times, respectively. The patients with H. pylori vacA s1m1 and sabB genotypes infection showed a significant increase of PREX2 gene expression in gastric cancer antral epithelial cells.

CONCLUSION

H. pylori vacA s1m1 and sabB genotypes have the positive correlations with PREX2 gene expression in gastric antral epithelial cells of gastritis and gastric cancer patients.

HES5-mediated repression of LIGHT transcription may contribute to apoptosis in hepatocytes

Non-alcoholic fatty liver disease (NAFLD) is prototypical form of metabolic syndrome and has become a global pandemic. Hepatocytes undergo apoptosis in the pathogenesis of NAFLD. We report that the lymphokine LIGHT/TNFSF14 was upregulated in the murine NAFLD livers and in hepatocytes treated with free fatty acids (palmitate, PA). LIGHT knockdown or neutralization attenuated PA-induced apoptosis of hepatocytes. Similarly, knockdown or blockade of LTβR, the receptor for LIGHT, ameliorated apoptosis in hepatocytes exposed to PA. Ingenuity pathway analysis (IPA) revealed several Notch-related transcription factors as upstream regulators of LIGHT, of which HES5 expression was downregulated paralleling LIGHT induction in the pathogenesis of NAFLD. HES5 knockdown enhanced whereas HES5 over-expression weakened LIGHT induction in hepatocytes. HES5 was found to directly bind to the LIGHT promoter and repress LIGHT transcription. Mechanistically, HES5 interacted with SIRT1 to deacetylate histone H3/H4 on the LIGHT promoter to repress LIGHT transcription. SIRT1 knockdown or inhibition offset the effect of HES5 over-expression on LIGHT transcription and hepatocyte apoptosis. In conclusion, our data unveil a novel mechanism that might contribute to excessive apoptosis in hepatocyte exposed to free fatty acids.

Dual Regulation of Tank Binding Kinase 1 by BRG1 in Hepatocytes Contributes to Reactive Oxygen Species Production

Excessive accumulation of reactive oxygen species (ROS) is considered a major culprit for the pathogenesis of non-alcoholic fatty liver disease (NAFLD). We have previously shown that deletion of Brahma related gene 1 (BRG1) mitigated NAFLD in mice in part by attenuating ROS production in hepatocyte. Here we report that BRG1 deletion led to simultaneous down-regulation in expression and phosphorylation of tank binding kinase 1 (TBK1) in vivo and in vitro. On the one hand, BRG1 interacted with AP-1 to bind to the TBK1 promoter and directly activated TBK1 transcription in hepatocytes. On the other hand, BRG1 interacted with Sp1 to activate the transcription of c-SRC, a tyrosine kinase essential for TBK1 phosphorylation. Over-expression of c-SRC and TBK1 corrected the deficiency in ROS production in BRG1-null hepatocytes whereas depletion of TBK1 or c-SRC attenuated ROS production. In conclusion, our data suggest that dual regulation of TBK1 activity, at the transcription level and the post-transcriptional level, by BRG1 may constitute an important mechanism underlying excessive ROS production in hepatocytes.

A KDM4-DBC1-SIRT1 Axis Contributes to TGF-b Induced Mesenchymal Transition of Intestinal Epithelial Cells

Intestinal fibrosis is one of the common pathophysiological processes in inflammatory bowel diseases (IBDs). Previously it has been demonstrated that epithelial-mesenchymal transition (EMT) can contribute to the development of intestinal fibrosis. Here we report that conditional ablation of SIRT1, a class III lysine deacetylase, in intestinal epithelial cells exacerbated 2, 4, 6-trinitro-benzene sulfonic acid (TNBS) induced intestinal fibrosis in mice. SIRT1 activity, but not SIRT1 expression, was down-regulated during EMT likely due to up-regulation of its inhibitor deleted in breast cancer 1 (DBC1). TGF-β augmented the recruitment of KDM4A, a histone H3K9 demethylase, to the DBC1 promoter in cultured intestinal epithelial cells (IEC-6) leading to DBC1 trans-activation. KDM4A depletion or inhibition abrogated DBC1 induction by TGF-β and normalized SIRT1 activity. In addition, KDM4A deficiency attenuated TGF-β induced EMT in IEC-6 cells. In conclusion, our data identify a KDM4-DBC1-SIRT1 pathway that regulates EMT to contribute to intestinal fibrosis.

Down-Regulation of CXXC5 De-Represses MYCL1 to Promote Hepatic Stellate Cell Activation

Liver fibrosis is mediated by myofibroblasts, a specialized cell type involved in wound healing and extracellular matrix production. Hepatic stellate cells (HSC) are the major source of myofibroblasts in the fibrotic livers. In the present study we investigated the involvement of CXXC-type zinc-finger protein 5 (CXXC5) in HSC activation and the underlying mechanism. Down-regulation of CXXC5 was observed in activated HSCs compared to quiescent HSCs both in vivo and in vitro. In accordance, over-expression of CXXC5 suppressed HSC activation. RNA-seq analysis revealed that CXXC5 influenced multiple signaling pathways to regulate HSC activation. The proto-oncogene MYCL1 was identified as a novel target for CXXC5. CXXC5 bound to the proximal MYCL1 promoter to repress MYCL1 transcription in quiescent HSCs. Loss of CXXC5 expression during HSC activation led to the removal of CpG methylation and acquisition of acetylated histone H3K9/H3K27 on the MYCL1 promoter resulting in MYCL1 trans-activation. Finally, MYCL1 knockdown attenuated HSC activation whereas MYCL1 over-expression partially relieved the blockade of HSC activation by CXXC5. In conclusion, our data unveil a novel transcriptional mechanism contributing to HSC activation and liver fibrosis.

Choline Kinase Alpha Is a Novel Transcriptional Target of the Brg1 in Hepatocyte: Implication in Liver Regeneration

Liver regeneration is a key compensatory process in response to liver injury serving to contain damages and to rescue liver functions. Hepatocytes, having temporarily exited the cell cycle after embryogenesis, resume proliferation to regenerate the injured liver parenchyma. In the present study we investigated the transcriptional regulation of choline kinase alpha (Chka) in hepatocytes in the context of liver regeneration. We report that Chka expression was significantly up-regulated in the regenerating livers in the partial hepatectomy (PHx) model and the acetaminophen (APAP) injection model. In addition, treatment with hepatocyte growth factor (HGF), a strong pro-proliferative cue, stimulated Chka expression in primary hepatocytes. Chka depletion attenuated HGF-induced proliferation of hepatocytes as evidenced by quantitative PCR and Western blotting measurements of pro-proliferative genes as well as EdU incorporation into replicating DNA. Of interest, deletion of Brahma-related gene 1 (Brg1), a chromatin remodeling protein, attenuated Chka induction in the regenerating livers in mice and in cultured hepatocytes. Further analysis revealed that Brg1 interacted with hypoxia-inducible factor 1 alpha (HIF-1α) to directly bind to the Chka promoter and activate Chka transcription. Finally, examination of human acute liver failure (ALF) specimens identified a positive correlation between Chka expression and Brg1 expression. In conclusion, our data suggest that Brg1-dependent trans-activation of Chka expression may contribute to liver regeneration.

CircDIDO1 inhibits gastric cancer progression by encoding a novel DIDO1-529aa protein and regulating PRDX2 protein stability

Background

Circular RNAs (circRNAs) play important roles in cancer development and progression. The purpose of this study is to identify aberrantly expressed circRNAs in gastric cancer (GC), unravel their roles in GC progression, and provide new targets for GC diagnosis and therapy.

Methods

Bioinformatic analyses were performed to identify the aberrantly expression of hsa_circ_0061137 (termed as circDIDO1) in GC. Gain- and loss-of-function studies were performed to examine the biological roles of circDIDO1 in GC progression. Tagged RNA affinity purification, mass spectrometry, immunofluorescence, co-immunoprecipitation, and Western blot were used to identify circRNA-interacting and circRNA-encoded proteins. RNA sequencing, qRT-PCR, and Western blot were performed to analyze circRNA-regulated downstream target genes and signaling pathways. Mouse tumor models were used to analyze the effects of circDIDO1 on GC growth and metastasis.

Results

CircDIDO1 was transcribed from human DIDO1 (death-inducer obliterator 1) gene and formed by back-splicing of exons 2–6 of the linear transcript. circDIDO1 was down-regulated in GC tissues and its low levels were associated with larger tumor size, distal metastasis, and poor prognosis. CircDIDO1 overexpression inhibited while knockdown promoted GC cell proliferation, migration and invasion. CircDIDO1 overexpression suppressed GC growth and metastasis in mouse tumor models. Mechanistically, circDIDO1 encoded a novel 529aa protein that directly interacted with poly ADP-ribose polymerase 1 (PARP1) and inhibited its activity. CircDIDO1 also specifically bound to peroxiredoxin 2 (PRDX2) and promoted RBX1-mediated ubiquitination and degradation of PRDX2, which led to the inactivation of its downstream signaling pathways.

Conclusions

CircDIDO1 is a new circRNA that has tumor suppressor function in GC and it may serve as a potential prognostic biomarker and therapeutic target for GC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12943-021-01390-y.

Comprehensive Analysis of the Expression Profiles of Hepatic lncRNAs in the Mouse Model of Alcoholic Liver Disease

Background and Aim: The worldwide prevalence of alcoholic liver disease (ALD) due to escalating alcohol consumption has presented an unprecedented pressure on human health. A few studies have determined long non-coding RNAs (lncRNAs) involved in the pathogenesis of liver diseases. However, the roles of lncRNAs in ALD development is still poorly understood.

Methods: An ALD mouse model was established and confirmed. Expression profiles of lncRNAs were obtained by whole transcriptome sequencing. The altered lncRNAs in ALD mice were further verified by qRT-PCR. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were used to enrich the functions of these lncRNAs. In combination with miRNA and mRNA profiles, we constructed concise endogenous RNA (ceRNA) networks. The function of the most up/downregulated lnRNA was further verified and investigated in both ALD model and AML-12 cells.

Results: Totally, five downregulated lncRNAs were obtained and verified in ALD mice. The GO term and KEGG pathway analyses revealed that the identified lncRNAs were associated with alcohol-induced hepatic oxidative damage, cellular inflammation, and lipid metabolism. Combination the differentially modulated miRNAs and mRNAs with ceRNA network analysis, we constructed five ceRNA networks and obtained 30 miRNAs and 25 mRNAs that may participate in ALD. Further, we verified and investigate the function of the most downregulated lnc_1700023H06Rik. Depletion lnc_1700023H06Rik reduced genes encoding for lipid metabolism, especially mRNA Acat2 (ENSMUST00000159697) and Pgrmc2 (ENSMUST00000058578) both in vivo and in vitro. Knocking down lnc_1700023H06Rik induced triglyceride accumulation and lactate dehydrogenase leakage in AML12 cells, consisting with that in alcohol-treated cells.

Conclusion: The five remarkably downregulated lncRNAs in ALD mouse model were identified as novel biomarkers, highlighting the key role of lncRNAs in the development of ALD. The effect of lnc_1700023H06Rik plays a pivotal role in lipid deposition and its pathological pathway in ALD needs further investigation.

Metabolomics of Artichoke Bud Extract in Spontaneously Hypertensive Rats

Hypertension adversely affects the quality of life in humans across modern society. Studies have attributed increased reactive oxygen species production to the pathophysiology of hypertension. So far, a specific drug to control the disease perfectly has not been developed. However, artichoke, an edible vegetable, plays an essential role in treating many diseases due to its potent antioxidant activities. The objective of this study is to evaluate the effect of artichoke bud extract (ABE) on heart tissue metabolomics of hypertensive rats. Spontaneously hypertensive rats and Wistar-Kyoto (WKY) rats were divided into six groups, then exposed to different doses comprising ABE, Enalapril Maleate, or 1% carboxylmethyl cellulose for 4 weeks. Their blood pressures were recorded at 0, 2, 3, and 4 weeks after the start of the test period. Thereafter, all rats were anesthetized, and blood was collected from their cardiac apexes. Then, we measured the levels for 15 kinds of serum biochemical parameters. An established orthogonal partial least square-discriminant analysis model completed the metabolomic analysis. Hypertensive rats in the ABE group exhibited well-controlled blood pressure, relative to those in the model group. Specifically, artichoke significantly lowered serum levels for total protein (TP), albumin (ALB), and uric acid (UA) in the hypertensive rats. This effect involved the action of eight metabolites, including guanine, 1-methylnicotinamide, p-aminobenzoic acid, NAD, NADH, uridine 5'-monophosphate, adenosine monophosphate, and methylmalonic acid. Collectively, these findings suggest that ABE may play a role in affecting oxidative stress and purine, nicotinate, and nicotinamide metabolism.

Identification of novel antioxidant gene signature to predict the prognosis of patients with gastric cancer

Background

Gastric cancer (GC) commonly relates to dismal prognosis and lacks efficient biomarkers. This study aimed to establish an antioxidant-related gene signature and a comprehensive nomogram to explore novel biomarkers and predict GC prognosis.

Methods

Clinical and expression data of GC patients were extracted from The Cancer Genome Atlas database. Univariate and multivariate Cox analyses were utilized to construct a score-based gene signature and survival analyses were conducted between high- and low-risk groups. Furthermore, we established a prognostic nomogram integrating clinical variables and antioxidant-related gene signature. Its predictive ability was validated by Harrell' concordance index and calibration curves and an independent internal cohort verified the consistency of the antioxidant gene signature-based nomogram.

Results

Four antioxidant-related genes (CHAC1, GGT5, GPX8, and PXDN) were significantly associated with overall survival of GC patients but only two genes, CHAC1 (HR = 0.803, P < 0.05) and GPX8 (HR = 1.358, P < 0.05), were confirmed as independent factors. A score-based signature was constructed and could act as an independent prognosis predictor (P < 0.05). Patients with lower scores showed significantly better prognosis (P < 0.05). Comprehensive nomogram combining the antioxidant-related gene signature and clinical parameters (age, gender, grade, and stage) was established and effectively predicted overall survival of GC patients [3-year survival AUC = 0.680, C index = 0.665 (95% CI 0.614–0.716)]. The independent internal validation cohort verified the reliability and good consistency of the model [3-year survival AUC = 0.703, C index = 0.706 (95% CI 0.612–0.800)].

Conclusions

Innovative antioxidant-related gene signature and nomogram performed well in assessing GC prognoses. This study enlightened further investigation of antioxidant system and provided novel tools for GC patient management.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-021-02328-w.

MicroRNA-328-3p facilitates the progression of gastric cancer via KEAP1/NRF2 axis

Gastric cancer is a common lethal malignancy and causes great cancer-related mortality worldwide. MicroRNA (miR)-328-3p is implicated in the progression of various human cancers; however, its role and mechanism in the progression of gastric cancer remain unclear.Human gastric cancer cells were incubated with miR-328-3p mimic, inhibitor or the matched negative control. Cell viability, colony formation, migrative and invasive capacity, cell apoptosis and oxidative stress were measured. To clarify the involvement of nuclear factor-E2-related factor 2 (NRF2) and kelch-like ECH-associated protein 1 (KEAP1), small interfering RNA was used. miR-328-3p was upregulated in human gastric cancer cells and tissues, and its level positively correlated with the progression of gastric cancer. miR-328-3p promoted cell viability, colony formation, migration and invasion, thereby facilitating the progression of gastric cancer. miR-328-3p mimic reduced, while miR-328-3p inhibitor increased apoptosis and oxidative stress of human gastric cancer cells. Mechanistically, miR-328-3p upregulated NRF2 via targeting KEAP1to attenuate excessive free radical production and cell apoptosis. miR-328-3p functions as an oncogenic gene and inhibiting miR-328-3p may help to develop novel therapeutic strategies of human gastric cancer.

PRDX2 promotes the proliferation of colorectal cancer cells by increasing the ubiquitinated degradation of p53

Colorectal cancer is the most common gastrointestinal cancer and causes severe damage to human health. PRDX2 is a member of the peroxiredoxin family reported to have a high level of expression in colorectal cancer. However, the mechanisms by which PRDX2 promotes the proliferation of colorectal cancer are still unclear. Here, the results indicated that PRDX2 expression was upregulated in colorectal cancer and closely correlated with poor prognosis. Functionally, PRDX2 promoted the proliferation of colorectal cancer cells. Mechanistically, PRDX2 could bind RPL4, reducing the interaction between RPL4 and MDM2. These findings demonstrate that the oncogenic property of PRDX2 may be attributed to its regulation of the RPL4-MDM2-p53 pathway, leading to p53 ubiquitinated degradation.

MicroRNAs as the critical regulators of cisplatin resistance in gastric tumor cells

Combined chemotherapeutic treatment is the method of choice for advanced and metastatic gastric tumors. However, resistance to chemotherapeutic agents is one of the main challenges for the efficient gastric cancer (GC) treatment. Cisplatin (CDDP) is used as an important regimen of chemotherapy for GC which induces cytotoxicity by interfering with DNA replication in cancer cells and inducing their apoptosis. Majority of patients experience cisplatin-resistance which is correlated with tumor metastasis and relapse. Moreover, prolonged and high-dose cisplatin administrations cause serious side effects such as nephrotoxicity, ototoxicity, and anemia. Since, there is a high rate of recurrence after CDDP treatment in GC patients; it is required to clarify the molecular mechanisms associated with CDDP resistance to introduce novel therapeutic methods. There are various cell and molecular processes associated with multidrug resistance (MDR) including drug efflux, detoxification, DNA repair ability, apoptosis alteration, signaling pathways, and epithelial-mesenchymal transition (EMT). MicroRNAs are a class of endogenous non-coding RNAs involved in chemo resistance of GC cells through regulation of all of the MDR mechanisms. In present review we have summarized all of the miRNAs associated with cisplatin resistance based on their target genes and molecular mechanisms in gastric tumor cells. This review paves the way of introducing a miRNA-based panel of prognostic markers to improve the efficacy of chemotherapy and clinical outcomes in GC patients. It was observed that miRNAs are mainly involved in cisplatin response of gastric tumor cells via regulation of signaling pathways, autophagy, and apoptosis.

Identification of potential plasma protein biomarkers for bipolar II disorder: a preliminary/exploratory study

The diagnostic peripheral biomarkers are still lacking for the bipolar II disorder (BD-II). We used isobaric tags for relative and absolute quantification technology to identify five upregulated candidate proteins [matrix metallopeptidase 9 (MMP9), phenylalanyl-tRNA synthetase subunit beta (FARSB), peroxiredoxin 2 (PRDX2), carbonic anhydrase 1 (CA-1), and proprotein convertase subtilisin/kexin type 9 (PCSK9)] for the diagnosis of BD-II. We analysed the differences in the plasma levels of these candidate proteins between BD-II patients and controls (BD-II, n = 185; Controls, n = 186) using ELISA. To establish a diagnostic model for the prediction of BD-II, the participants were divided randomly into a training group (BD-II, n = 149; Controls, n = 150) and a testing group (BD-II, n = 36; Controls, n = 36). Significant increases were found in all five protein levels between BD-II and controls in the training group. Logistic regression was analysed to form the composite probability score of the five proteins in the training group. Receiver-operating characteristic curve analysis revealed the diagnostic validity of the probability score [area under curve (AUC) = 0.89, P < 0.001]. The composite probability score of the testing group also showed good diagnostic validity (AUC = 0.86, P < 0.001). We propose that plasma levels of PRDX2, CA-1, FARSB, MMP9, and PCSK9 may be associated with BD-II as potential biomarkers.

A redox probe screens MTHFD1 as a determinant of gemcitabine chemoresistance in cholangiocarcinoma

Cholangiocarcinoma (CCA) is a type of solid tumor derived from the bile duct epithelium that features universal gemcitabine resistance. Here, we utilized a gene-encoded ROS biosensor probe (HyPer3 probe) to sort subpopulations with different redox statuses from CCA cells. The isolated HyPer-low subpopulation CCA cells, which exhibited relatively lower cellular ROS levels, exhibited higher chemoresistance to gemcitabine than HyPer-high subpopulation CCA cells in vitro and in vivo. Mechanistically, increased expression of MTHFD1 was found in HyPer-low cells. Knocking down MTHFD1 in HyPer-low cells enhanced cellular ROS and restored sensitivity to gemcitabine. Furthermore, the MTHFD1 inhibitor antifolate compound methotrexate (MTX) increased cellular ROS, and combining gemcitabine with MTX effectively suppressed cholangiocarcinoma cell growth. In summary, the MTHFD1 level mediated the heterogeneous cellular redox status in CCA, which resulted in chemoresistance to gemcitabine. Our data suggest a novel strategy for CCA chemotherapy.