Collagen in hepatocellular carcinoma: A novel biomarker and therapeutic target.

HCC is globally recognized as a major health threat. Despite significant progress in the development of treatment strategies for liver cancer, recurrence, metastasis, and drug resistance remain key factors leading to a poor prognosis for the majority of liver cancer patients. Thus, there is an urgent need to develop effective biomarkers and therapeutic targets for HCC. Collagen, the most abundant and diverse protein in the tumor microenvironment, is highly expressed in various solid tumors and plays a crucial role in the initiation and progression of tumors. Recent studies have shown that abnormal expression of collagen in the tumor microenvironment is closely related to the occurrence, development, invasion, metastasis, drug resistance, and treatment of liver cancer, making it a potential therapeutic target and a possible diagnostic and prognostic biomarker for HCC. This article provides a comprehensive review of the structure, classification, and origin of collagen, as well as its role in the progression and treatment of HCC and its potential clinical value, offering new insights into the diagnosis, treatment, and prognosis assessment of liver cancer.

Single-cell analysis reveals hypoxia-induced immunosuppressive microenvironment in intrahepatic cholangiocarcinoma.

The role of hypoxia in the tumor microenvironment of intrahepatic cholangiocarcinoma (iCCA) remains unclear. Here, we generated a comprehensive atlas of the entire tumor microenvironment and delineated the multifaceted cell-cell interactions to decipher hypoxia-induced pro-tumor immune suppression. We discovered hypoxia is significantly associated with iCCA progression via the activation of HIF1A expression. Moreover, hypoxia-dependent PPARγ-mediated fatty acid oxidation in APOE+ TAMs promoted M2 macrophage polarization by activating the HIF1A-PPARG-CD36 axis. These polarized APOE+ TAMs recruited Treg cell infiltration via the CCL3-CCR5 pair to form an immunosuppressive microenvironment. APOE+ TAMs tended to co-localize spatially with Treg cells in the malignant tissue based on spatial transcriptome data and immunofluorescence analysis results. We identified tumor-reactive CXCL13+ CD8-PreTex with specific high expression of ENTPD1 and ITGAE, which acted as precursors of CD8-Tex and had higher cytotoxicity, lower exhaustion, and more vigorous proliferation. Consequently, CXCL13+ CD8-PreTex functioned as a positive regulator of antitumor immunity by expressing the pro-inflammatory cytokines IFNG and TNF, associated with a better survival outcome. Our study reveals the mechanisms involved in hypoxia-induced immunosuppression and suggests that targeting precursor-exhausted CXCL13+CD8+ T cells might provide a pratical immunotherapeutic approach.

Spatial multimodal analysis revealed tertiary lymphoid structures as a risk stratification indicator in combined hepatocellular-cholangiocarcinoma.

The microenvironment created by tertiary lymphoid structures (TLSs) can support and regulate immune responses, affecting the prognosis and immune treatment of patients. Nevertheless, the actual importance of TLSs for predicting the prognosis of combined hepatocellular-cholangiocarcinoma (cHCC-CCA) patients remains unclear. Herein, using spatial transcriptomic analysis, we revealed that a gene signature of TLSs specific to cHCC-CCA was associated with high-intensity immune infiltration. Then, a novel scoring system was developed to evaluate the distribution and frequency of TLSs in intra-tumoral and extra-tumoral regions (iTLS and eTLS scores) in 146 cHCC-CCA patients. iTLS score was positively associated with promising prognosis, likely due to the decreased frequency of suppressive immune cell like Tregs, and the ratio of CD163+ macrophages to macrophages in intra-tumoral TLSs via imaging mass cytometry, while improved prognosis is not necessarily indicated by a higher eTLS score. Overall, this study highlights the potential of TLSs as a prognostic factor and an indicator of immune therapy in cHCC-CCA.

Perioperative and long-term survival outcomes of laparoscopic versus open hepatectomy for BCLC stage A large hepatocellular carcinoma patients in difficult segments: A two-centre, propensity score matching analysis.

Background: The differences in short- and long-term outcome between laparoscopic liver resection (LLR) and open liver resection (OLR) for BCLC stage A large hepatocellular carcinoma (HCC) in difficult segments (I, IVa, VII, VIII) remain unclear. This PSM two-centre study aimed to compare perioperative and long-term survival outcomes of LLR with OLR for this HCC. Methods: HCC patients with BCLC stage A who underwent OLR or LLR in two medical centres were enrolled in the study. PSM analysis was performed to match patients between the LLR cohort and OLR cohort. Survival was analysed based on the Kaplan-Meier method. Independent risk factors were identified by Cox regression. Results: After PSM, 35 patients remained in the LLR cohort, and 84 remained in the OLR cohort. Patients in the LLR cohort had more intraoperative blood loss (p=0.036) and shorter hospital stays after surgery (p<0.001). The LLR cohort and OLR cohort had no difference in intraoperative blood transfusion, surgical margin or postoperative short-term outcomes. The OS and RFS were not significantly different between the two cohorts. The OS and RFS of these two cohorts were not different in the subgroup analysis. Surgical margin was identified as an independent risk factor for tumour recurrence. Conclusion: For BCLC stage A large HCC patients with lesions in difficult segments, LLR was feasible and had shorter hospital stay than OLR. In addition, a surgical margin ≥1 cm could significantly decrease the recurrence probability for large HCC located in different segments without compromising short-term outcomes.

CoQ10 alleviates hepatic ischemia reperfusion injury via inhibiting NLRP3 activity and promoting Tregs infiltration.

Hepatic ischemia-reperfusion injury (IRI) has been concerned as a main complication of liver surgery and transplantation. Previous studies show that reactive oxygen species (ROS) associated inflammation response and contribute to the liver damage during IRI. Coenzyme Q10 (CoQ10) has shown many beneficial effects on abrogating ROS production and ameliorating liver injury. This study found lower CoQ10 level in the process of liver IRI in a mouse model of hepatic IRI. Meanwhile, our results showed that CoQ10 administration significantly attenuate hepatic IRI proved by HE staining, serum ALT/AST. The NOD-like receptor protein 3 (NLRP3) inflammasome is activated by ROS which triggers the activation of inflammatory caspases. In this study, NLRP3 was significantly suppressed by CoQ10 while Foxp3 exhibited increased expression in liver. Furthermore, Kupffer cells (KCs) pretreated with CoQ10 under the condition of hypoxia and reoxygenation contributed to improved CD4+CD25+Foxp3+ regulatory T cells (Tregs) ratio in co-culture system. Furthermore, NLRP3 inflammasome activator treatment in vivo resulted in higher expression of caspase-1 and NLRP3 and reduction of Tregs in liver, which reversed the protection of CoQ10 in the liver injury. Taken together, our study discovered that CoQ10 can suppress NLRP3 activity in KCs and improves Foxp3+ Tregs differentiation depending on M2 macrophage polarization of KCs to ameliorate hepatic IRI.

Development of preoperative prognostic models including radiological features for survival of singular nodular HCC patients.

BACKGROUND: Early singular nodular hepatocellular carcinoma (HCC) is an ideal surgical indication in clinical practice. However, almost half of the patients have tumor recurrence, and there is no reliable prognostic prediction tool. Besides, it is unclear whether preoperative neoadjuvant therapy is necessary for patients with early singular nodular HCC and which patient needs it. It is critical to identify the patients with high risk of recurrence and to treat these patients preoperatively with neoadjuvant therapy and thus, to improve the outcomes of these patients. The present study aimed to develop two prognostic models to preoperatively predict the recurrence-free survival (RFS) and overall survival (OS) in patients with singular nodular HCC by integrating the clinical data and radiological features. METHODS: We retrospective recruited 211 patients with singular nodular HCC from December 2009 to January 2019 at Eastern Hepatobiliary Surgery Hospital (EHBH). They all met the surgical indications and underwent radical resection. We randomly divided the patients into the training cohort (n =132) and the validation cohort (n = 79). We established and validated multivariate Cox proportional hazard models by the preoperative clinicopathologic factors and radiological features for association with RFS and OS. By analyzing the receiver operating characteristic (ROC) curve, the discrimination accuracy of the models was compared with that of the traditional predictive models. RESULTS: Our RFS model was based on HBV-DNA score, cirrhosis, tumor diameter and tumor capsule in imaging. RFS nomogram had fine calibration and discrimination capabilities, with a C-index of 0.74 (95% CI: 0.68-0.80). The OS nomogram, based on cirrhosis, tumor diameter and tumor capsule in imaging, had fine calibration and discrimination capabilities, with a C-index of 0.81 (95% CI: 0.74-0.87). The area under the receiver operating characteristic curve (AUC) of our model was larger than that of traditional liver cancer staging system, Korea model and Nomograms in Hepatectomy Patients with Hepatitis B Virus-Related Hepatocellular Carcinoma, indicating better discrimination capability. According to the models, we fitted the linear prediction equations. These results were validated in the validation cohort. CONCLUSIONS: Compared with previous radiography model, the new-developed predictive model was concise and applicable to predict the postoperative survival of patients with singular nodular HCC. Our models may preoperatively identify patients with high risk of recurrence. These patients may benefit from neoadjuvant therapy which may improve the patients' outcomes.

Serum thrombospondin-1 serves as a novel biomarker and agonist of gemcitabine-based chemotherapy in intrahepatic cholangiocarcinoma.

BACKGROUND: At present, the first-line treatment for advanced intrahepatic cholangiocarcinoma (ICC) is gemcitabine combined with cisplatin, but a considerable portion of ICC patients exhibit resistance to gemcitabine. Therefore, finding sensitisers for gemcitabine chemotherapy in ICC patients and predicting molecular markers for chemotherapy efficacy have become urgent needs. METHODS: In this study, PDX models were established to conduct gemcitabine susceptibility tests. The selected PDX tissues of the chemotherapy-sensitive group and drug-resistant group were subjected to transcriptome sequencing and protein chip technology to identify the key genes. Sixty-one ICC patients treated with gemcitabine chemotherapy were recruited for clinical follow-up validation. RESULTS: We found that thrombospondin-1 (TSP1) can predict gemcitabine chemosensitivity in ICC patients. The expression level of TSP1 could reflect the sensitivity of ICC patients to gemcitabine chemotherapy. Functional experiments further confirmed that TSP1 can increase the efficacy of gemcitabine chemotherapy for ICC. A mechanism study showed that TSP1 may affect the intake of oleic acid by binding to the CD36 receptor. CONCLUSIONS: In summary, we found a key molecule-TSP1-that can predict and improve the sensitivity of ICC patients to gemcitabine chemotherapy, which is of great significance for the treatment of advanced cholangiocarcinoma.

DANCR deletion retards the initiation and progression of hepatocellular carcinoma based on gene knockout and patient-derived xenograft in situ hepatoma mice model.

Our previous study has demonstrated that the expression level of long noncoding RNA (lncRNA)-differentiation antagonizing non-protein coding RNA (DANCR) increases in hepatocellular carcinoma (HCC), contributing to the initiation and aggravation of such kind of malignant tumor, which is recognized as a promising therapeutic target for patients with HCC. To further investigate the effect of DANCR on HCC in preclinical models, we generated a Dancr knockout (KO) mice model by Cas9/gRNA technology and a patient-derived xenograft (PDX) in situ hepatoma mice model using immunodeficient mice and utilized adeno-associated virus 8 (AAV8) delivery DANCR-shRNA system to silence the expression of DANCR in xenograft tumor. Here, we reported that Dancr expression mainly occurred in hepatocytes and its depletion significantly alleviated hepatic fibrosis in mice and showed a prospective result with smaller tumor size and fewer number of tumors in HCC preclinical mice model. Additionally, we found that the expression of Dancr in mice cirrhotic liver was positively correlated with the content of Dancr in serum. Overall, DANCR KO can inhibit the occurrence and development of HCC and is a target worthy of further study in patients with HCC.

FTO promotes liver inflammation by suppressing m6A mRNA methylation of IL-17RA.

Background: Previous studies have demonstrated that inflammation-related interleukin-17 (IL-17) signaling plays a pivotal role in the pathogenesis of non-alcoholic steatohepatitis (NASH)- and alcoholic liver disease (ALD)-induced hepatocellular carcinoma (HCC). However, rare efforts have been intended at implementing the analysis of N6-methyladenosine (m6A) mRNA methylation to elucidate the underpinning function of the IL-17 receptor A (IL-17RA) during the inflammation-carcinogenesis transformation of HCC. Methods: We performed methylated RNA immunoprecipitation sequencing (MeRIP-seq) using normal, HCC tumor and paired tumor adjacent tissues from patients to investigate the dynamic changes of m6A mRNA methylation in the process of HCC. Additionally, murine non-alcoholic fatty liver disease (NAFLD) model and murine chronic liver injury model were utilized to investigate the role of IL-17RA regulated by m6A mRNA modulator fat mass and obesity-associated (FTO) in chronic hepatic inflammation. Results: MeRIP-seq revealed the reduction of m6A mRNA methylation of IL-17RA in tumor adjacent tissues with chronic inflammation, suggesting the potential role of IL-17RA in the inflammation-carcinogenesis transformation of HCC. Besides, we demonstrated that FTO, rather than methyltransferase-like 3 (METTL3), methyltransferase-like 14 (METTL14), and alkB homolog 5 (ALKBH5) functions as a main modulator for the decrease of m6A mRNA methylation of IL-17RA via knockdown and overexpression of FTO in vitro and in vivo. Conclusions: Overall, we elaborated the underlying mechanisms of the increase of IL-17RA resulting in chronic inflammation via the demethylation of FTO in tumor adjacent tissues and demonstrated that targeting the specific m6A modulator FTO may provide an effective treatment for hepatitis patients to prevent the development of HCC.

DNA hypermethylation modification promotes the development of hepatocellular carcinoma by depressing the tumor suppressor gene ZNF334.

DNA methylation plays a pivotal role in the development and progression of tumors. However, studies focused on the dynamic changes of DNA methylation in the development of hepatocellular carcinoma (HCC) are rare. To systematically illustrate the dynamic DNA methylation alternation from premalignant to early-stage liver cancer with the same genetic background, this study enrolled 5 HBV-related patients preceded with liver cirrhosis, pathologically identified as early-stage HCC with dysplastic nodules. Liver fibrosis tissues, dysplastic nodules and early HCC tissues from these patients were used to measure DNA methylation. Here, we report significant differences in the DNA methylation spectrum among the three types of tissues. In the early stage of HCC, DNA hypermethylation of tumor suppressor genes is predominant. Additionally, DNA hypermethylation in the early stage of HCC changes the binding ability of transcription factor TP53 to the promoter of tumor suppressor gene ZNF334, and inhibits the expression of ZNF334 at the transcription level. Furthermore, through a series of in vivo and in vitro experiments, we have clarified the exacerbation effect of tumor suppressor gene ZNF334 deletion in the occurrence of HCC. Combined with clinical data, we found that the overall survival and relapse-free survival of patients with high ZNF334 expression are significantly longer. Thus, we partly elucidated a sequential alternation of DNA methylation modification during the occurrence of HCC, and clarified the biological function and regulatory mechanism of the tumor suppressor gene ZNF334, which is regulated by related DNA methylation sites. Our study provides a new target and clinical evidence for the early diagnosis and sheds light on the precise treatment of liver cancer.

IL-10 derived from Hepatocarcinoma cells improves human induced regulatory T cells function via JAK1/STAT5 pathway in tumor microenvironment.

Forkhead box P3 (Foxp3) expressing CD4+CD25+ regulatory T cells (Tregs), an essential subset of immune T cells for maintaining immune homeostasis is implicated as a negative regulator in an anti-tumor immune response. Current researches suggest that reducing tumor-infiltrating Tregs contribute to enhanced anti-cancer effect. However, the mechanism of infiltration of a large number of Tregs into tumor tissues is still unclear. In this study, human induced Tregs (iTregs) were co-cultured with human hepatocytes and various types of cancer cells (HepG2, NSCLC, and AsPC-1) supernatants. Foxp3, multiple cytokines, levels of apoptosis and suppressive ability of iTregs were detected by FACS. Western blot was employed to test of proteins. Impact of HepG2 supernatants on T cell subpopulations differentiation, cytokines in supernatants were examed by FACS and ELISA respectively. Anti-IL-10R antibody and JAK1 inhibitor were used to reconfirm the role of tumor-derived IL-10 play in the regulation on iTregs. Hepatocarcinoma cells (HCC) supernatants treatment increases Foxp3 stability and reduces apoptosis level in human iTregs without influencing its differentiation trend. Furthermore, IL-10 was found to be extremely higher in HCC supernatants than other groups, IL-10R blockade neutralize the effect of HCC supernatants on iTregs in vitro obviously. HCC supernatants also reversed IL-1ß/6 triggered decline on Foxp3 which may be related to higher expression of JAK1 and elevated phosphorylation level of STAT5 induced by IL-10. Our results suggest that improved stability and abnormal accumulation of Tregs in tumor microenvironment is IL-10/JAK1/STAT5 signal pathway-dependent and provide a novel approach for improving the efficiency of anti-tumor immunotherapy.

Cancer-associated fibroblasts enhance the chemoresistance of CD73+ hepatocellular carcinoma cancer cells via HGF-Met-ERK1/2 pathway.

BACKGROUND: Cancer-associated fibroblasts (CAFs) are a major component of hepatocellular carcinoma (HCC) stroma that are critically involved in HCC cancer chemoresistance, but the mechanism has not been elucidated. Previous studies have reported CD73 exerted an immunosuppressive function in cancer. Here, we explored the mechanism by which CAFs regulates CD73+ HCC cells and clarified whether CAFs promote chemoresistance of CD73+ cells. METHODS: We used the co-culture method to study the relationship between CAFs and HCC cells. Immunohistochemistry was applied to evaluate the correlation between α-smooth-muscle actin (α-SMA) and CD73. CD73 mRNA and protein were determined by real-time polymerase chain reaction (RT-PCR) and western blotting, and hepatocyte growth factor (HGF) was assayed by enzyme-linked immunosorbent assay (ELISA). Western blotting was used to explore the regulated pathway of CD73+ HCC. We then knocked down CD73 in cells, and then assessed the effect of CD73 on the apoptosis by flow cytometry. Finally, a sphere formation assay was applied to investigate the stemness of cancer cells, and xenograft tumors in nude mice were built to investigate the tumorigenicity. RESULTS: We found that the proportion of CAFs was positively correlated with CD73 expression in HCC cells. Mechanistically, c-Met and the MEK-ERK1/2 pathway were activated by HGF from CAFs which upregulated CD73 expression in HCC cells. Also, we found that CD73 promote sorafenib and cisplatin resistance in HCC, and CD73+ HCC cells indicated the higher capability of tumorigenicity compared to CD73- HCC cells in vivo. Furthermore, HGF further enhanced the chemoresistant characteristics of CD73+ tumor cells. CONCLUSIONS: Our findings collectively suggest that CD73 is a vital HCC-chemoresistance force controlled by cross-talking between CAFs and HCC cells, thereby establishing CD73 as a potential new therapeutic target for HCC.

Traf6 inhibitor boosts antitumor immunity by impeding regulatory T cell migration in Hepa1-6 tumor model.

Tumors escape immune attacks via various mechanisms, among which activation of regulatory pathways in effector immune cells and recruitment of immunosuppressive cells are usually employed. Traf6 is a member of the family of tumor necrosis factor receptor-associated factors and involved in many signaling pathways. While it plays important roles in both tumor biology and immune system, the potential therapeutic role of Traf6 in tumor immunotherapy hasn't ever been assessed. Here, we confirmed the anti-tumor effect of Traf6 inhibitor in Hepa1-6 tumor model. Flow cytometry-based analysis revealed that T cell-mediated antitumor immunity was provoked and the infiltration of Treg cells was restrained when treated with Traf6 inhibitor. Via an in vivo migration assay, we found that Traf6 inhibitor decreased the population of intratumor Tregs by impeding the migration of Tregs towards tumor. Finally, we demonstrated that combination of Traf6 inhibitor and PD-1 blockade could receive a better antitumor efficiency. These results implicated that Traf6 inhibitor could serve as a supplement for immune checkpoint therapy.

Human amniotic mesenchymal stromal cells alleviate acute liver injury by inhibiting the pro-inflammatory response of liver resident macrophage through autophagy.

BACKGROUND: The activation and polarization of macrophages are crucial during the pathogenesis of liver injury induced by the toxin. Human amniotic mesenchymal stromal cells (hAMSCs) are newly identified mesenchymal stem cells and have been shown to have an immunoregulatory ability for multiple autoimmune diseases. METHODS: Mice were intraperitoneally injected with Acetaminophen (APAP) to establish a liver injury model. hAMSCs were injected through the tail vein, and the liver function was observed through a liver function and pathology analysis. To test the regulative ability of hAMSCs in vitro, the supernatant of hAMSCs were collected and co-cultured with Kupffer cells (KCs). Liposome was used to abolish the function of KCs in vivo. RESULTS: Infusion of hAMSCs reduced the level of liver function injury and inflammation expression in APAP-induced liver injury. hAMSCs markedly promoted M2 polarization of KCs instead of M1 polarization in vitro. Furthermore, the mechanism study also proved that hAMSCs reduced autophagy, as revealed by down-regulated LC3B-II levels. The elimination of KCs in vivo abolished the protective ability of hAMSCs in liver injury, which resulted in a significant increase of liver pathogenesis along with an increase in alanine aminotransaminase (ALT) and aspartate aminotransaminase (AST) levels. CONCLUSIONS: Our results proved that hAMSCs suppressed M1 polarization and promoted M2 polarization of KCs through regulating autophagy in the model of APAP-treated livers. Thus, the injury of the liver was attenuated. This study provides us a new therapeutic strategy for the disease of acute liver injury.

Hyperglycemia exacerbates acetaminophen-induced acute liver injury by promoting liver-resident macrophage proinflammatory response via AMPK/PI3K/AKT-mediated oxidative stress.

Although diabetes mellitus/hyperglycemia is a risk factor for acute liver injury, the underlying mechanism remains largely unknown. Liver-resident macrophages (Kupffer cells, KCs) and oxidative stress play critical roles in the pathogenesis of toxin-induced liver injury. Here, we evaluated the role of oxidative stress in regulating KC polarization against acetaminophen (APAP)-mediated acute liver injury in a streptozotocin-induced hyperglycemic murine model. Compared to the controls, hyperglycemic mice exhibited a significant increase in liver injury and intrahepatic inflammation. KCs obtained from hyperglycemic mice secreted higher levels of the proinflammatory factors, such as TNF-α and IL-6, lower levels of the anti-inflammatory factor IL-10. Furthermore, enhanced oxidative stress was revealed by increased levels of reactive oxygen species (ROS) in KCs from hyperglycemic mice post APAP treatment. In addition, ROS inhibitor NAC resulted in a significant decrease of ROS production in hyperglycemic KCs from mice posttreated with APAP. We also analyzed the role of hyperglycemia in macrophage M1/M2 polarization. Interestingly, we found that hyperglycemia promoted M1 polarization, but inhibited M2 polarization of KCs obtained from APAP-exposed livers, as evidenced by increased MCP-1 and inducible NO synthase (iNOS) gene induction but decreased Arg-1 and CD206 gene induction accompanied by increased STAT1 activation and decreased STAT6 activation. NAC restored Arg-1, CD206 gene induction, and STAT6 activation. To explore the mechanism how hyperglycemia regulates KCs polarization against APAP-induced acute liver injury, we examined the AMPK/PI3K/AKT signaling pathway and found decreased AMPK activation and increased AKT activation in liver and KCs from hyperglycemic mice post APAP treatment. AMPK activation by its agonist AICAR or PI3K inhibition by its antagonist LY294002 inhibited ROS production in KCs from hyperglycemic mice post APAP treatment and significantly attenuated APAP-induced liver injury in the hyperglycemic mice, compared to the control mice. Our results demonstrated that hyperglycemia exacerbated APAP-induced acute liver injury by promoting liver-resident macrophage proinflammatory response via AMPK/PI3K/AKT-mediated oxidative stress.

Blockade of miR-142-3p promotes anti-apoptotic and suppressive function by inducing KDM6A-mediated H3K27me3 demethylation in induced regulatory T cells.

In vitro induced human regulatory T cells (iTregs) have in vivo therapeutic utility. MicroRNAs (miRNAs) are a family of approximately 22-nucleotide non-coding RNAs that are processed from longer precursors by the RNases Drosha and Dicer. miRNAs regulate post-transcriptional protein expression through messenger RNA destabilization or translational silencing; miR-142-3p regulates natural Treg function through autophagy. We hypothesized that this miRNA may also have an iTreg regulation function. Antagomir-mediated knockdown of miR-142-3p improved Foxp3 (forkhead box P3) expression, regulatory function, cytokine expression, and apoptosis of iTregs in vitro, with or without inflammatory cytokine stimulation. miR-142-3p knockdown increased autophagy-related protein 16-1-mediated autophagy. Target prediction and luciferase assay results indicated that miR-142-3p binds directly to lysine demethylase 6A (KDM6A), which resulted in demethylation of H3K27me3 and in turn upregulated expression of the anti-apoptotic protein Bcl-2. Based on these results, we propose a novel strategy that uses knockdown of miR-142-3p to enhance anti-apoptotic ability and function of iTregs by increasing KDM6A and Bcl-2 expression. This approach might be used as a treatment to control established chronic immune-mediated autoimmune and inflammatory diseases.

Human gingiva-derived mesenchymal stem cells alleviate inflammatory bowel disease via IL-10 signalling-dependent modulation of immune cells.

Current evidence indicates that inflammatory bowel disease (IBD) is caused primarily by impaired mucosal immunity, resulting in an imbalance between epithelial barrier function and tissue inflammation. Human gingiva-derived mesenchymal stem cells (GMSCs) exhibit immunomodulatory and anti-inflammatory effects in a variety of immunity- and inflammation-associated diseases. However, the role of GMSCs in treating IBD has not been elucidated. Our study, therefore, examined the therapeutic effect and mechanism of GMSCs in a murine colitis model of IBD. Our results indicate that the infusion of GMSCs significantly prolonged survival and relieved symptoms. Phenotype analyses showed that the frequencies of NK1.1+ and CD11b+ cells, as well as CD4 T cells in the spleen, were suppressed in GMSC-treated mice compared with the PBS- or fibroblast-treated control groups. Additionally, GMSC treatment markedly increased the numbers of interleukin (IL)-10+ regulatory T cells, reduced the secretion of pro-inflammatory cytokines, and increased production of anti-inflammatory cytokines. A mechanistic study revealed that anti-IL-10R antibody abolished the protective effect of GMSCs compared with mice treated with anti-IgG antibody. Thus, our results indicate that GMSCs play a critical role in alleviating colitis by modulating inflammatory immune cells via IL-10 signalling.

Vitamin D alleviates acute graft-versus-host disease through promoting the generation of Foxp3+ T cells.

BACKGROUND: Acute graft-versus-host disease (aGVHD) is a medical complication which may result in significant morbidity and mortality after transplantation. The aim of this study investigated the therapeutic effect and underlying mechanism of 1,25-dihydroxyvitamin D3 (1α,25(OH)2D3) in the treatment of aGVHD. METHOD: An aGVHD model was built by transferring splenocytes of B6 mice into B6D2F1 mice. 1α,25(OH)2D3 was added to evaluate the protective function to aGVHD; the phenotype and cytokine expression profile of spleen cells from the aGVHD model were determined using flow cytometry 2 weeks after the model is established. RESULT: Administration of 1α,25(OH)2D3 significantly slowed aGVHD progression and improved survival of B6D2F1 recipients of grafted B6 splenocytes. 1α,25(OH)2D3 treatment also resulted in an increased number of CD4+Foxp3+ regulatory T cells (Tregs) but decreased the number of CD4+IL-4+ cells. In vitro analysis demonstrated that 1α,25(OH)2D3 directly increased forkhead box P3 (Foxp3) and IL-10 expression and enhanced the function of induced Tregs (iTregs). CONCLUSIONS: This analysis indicated that the effect of 1α,25(OH)2D3 is mediated in part by improving the number of Tregs. 1α,25(OH)2D3 administration thus represents a viable approach for treating aGVHD.

Acidic Microenvironment Regulates the Severity of Hepatic Ischemia/Reperfusion Injury by Modulating the Generation and Function of Tregs via the PI3K-mTOR Pathway.

Hepatic ischemia/reperfusion injury (HIRI) is a major cause of liver dysfunction and even liver failure after liver transplantation and hepatectomy. One of the critical mechanisms that lead to HIRI is an acidic microenvironment, which develops due to the accumulation of high acid-like substances such as lactic acid and ketone bodies. Previous studies have shown that the adoptive transfer of induced regulatory T cells (iTregs) attenuates HIRI; however, little is known about the function of Tregs in the acidic microenvironment of a HIRI model. In the present study, we examined the effect of acidic microenvironment on Tregs in vitro and in vivo. Here, we report that microenvironment acidification and dysfunction of the liver is induced during HIRI in humans and mice and that an acidic microenvironment can inhibit the generation and function of CD4+CD25+Foxp3+ iTregs via the PI3K/Akt/mTOR signaling pathway. By contrast, the reversal of the acidic microenvironment restored Foxp3 expression and iTreg function. In addition, the results of cell culture in vitro indicated that the proton pump inhibitor omeprazole improves decreased iTreg differentiation caused by the acidic microenvironment, suggesting the potential clinical use of proton pump inhibitors as immunoregulatory therapy in the treatment of HIRI. Furthermore, our findings demonstrate that buffering the acidic microenvironment to attenuate HIRI in mice has an inseparable relationship with Tregs. Thus, an acidic microenvironment is a key regulator in HIRI, involved in modulating the generation and function of Tregs.

Age-dependent loss of induced regulatory T cell function exacerbates liver ischemia-reperfusion injury.

Previous studies demonstrate that the number of induced regulatory T cells (iTregs) increases in aged mice. However, these studies do not characterize iTregs across different ages or how these immune modulators contribute to the dysregulation of immunity in murine disease models. Therefore, this study aimed to examine the relationship between age and iTreg function using a mouse model of hepatic ischemia-reperfusion injury (IRI). In this model, aged-mice suffered more serious injury than Young-mice, with higher serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and higher histological scores from liver biopsies. iTregs isolated from Young-mice exhibited stronger immunosuppressive ability in vitro and had a greater response during IRI in vivo. In addition, aged-mice that were pretreated with iTregs generated in Young-mice (Y-iTregs) had alleviated injury compared with mice pretreated with iTregs from aged-mice (A-iTregs) or no treatment group. Adoptive transfer of iTregs ameliorated liver IRI and promoted liver recovery with decreased levels of interferon-γ (IFN-γ) and interleukin-17 (IL-17). These results demonstrate that the exacerbated IRI observed in aged-mice is a result of decreased iTreg function. Therefore, improving iTreg function is important for disease treatment in elder patients.