CXCL10 chemokine regulates heterogeneity of the CD8+ T cell response and viral set point during chronic infection

CD8+ T cells responding to chronic infection adapt an altered differentiation program that provides some restraint on pathogen replication yet limits immunopathology. This adaptation is imprinted in stem-like cells and propagated to their progeny. Understanding the molecular control of CD8+ T cell differentiation in chronic infection has important therapeutic implications. Here, we find that the chemokine receptor CXCR3 is highly expressed on viral-specific stem-like CD8+ T cells and that one of its ligands, CXCL10, regulates the persistence and heterogeneity of responding CD8+ T cells in spleens of mice chronically infected with lymphocytic choriomeningitis virus. CXCL10 is produced by inflammatory monocytes and fibroblasts of the splenic red pulp, where it grants stem-like cells access to signals promoting differentiation and limits their exposure to pro-survival niches in the white pulp. Consequently, functional CD8+ T cell responses are greater in Cxcl10-/- mice and are associated with a lower viral set point.

Scalable Dual-Fluorescence Assay for Functional Interpretation of HNF-4α Missense Variants

AIM

The study aimed to develop a scalable dual-fluorescence assay in cells to enable the functional interpretation of HNF-4α missense variants identified in exome sequencing, which can be used to guide clinical diagnosis.

METHODS

Using mOrange2 and GFP fluorescence proteins to track the expression of HNF-4α (HNF-4α-mOrange2) and reporter activity under the control of the HNF-1α promoter (pHNF1A-GFP), respectively, we designed a dual-fluorescence assay to evaluate the expression level, cellular localization, and transcriptional function of HNF-4α simultaneously in live cells. To assess the scalable characteristic of the assay, a small library containing five previously reported mutations and wild-type HNF-4α was constructed. Cells infected with this library were sorted into different populations through fluorescence-activated cell sorting (FACS) according to the transcription activity and expression abundance. Cloning and Sanger sequencing were used to detect the mutations of the different groups. High content screening (HCS) assay was used for the validation of individual mutants in the function and expression point of view.

RESULTS

HNF-4α-mOrange2 exhibited nuclear localization and transactivation capability on the HNF-1α promoter as physical HNF-4α does. The expression of HNF-4α-mOrange2 shows a 6-fold induction of GFP expression compared to the control without HNF-4α-mOrange2, which was significantly abolished by the known loss-of-function mutant M373R. The different performances of wild-type and mutant M373R made them distinguishable in the FACS system, empowering the scalable capability of this assay for classifying large numbers of variants combining functional stratification and sequencing. Further application of the assay in the small library showed that three cell populations were seen grouped as Normal (same transactivation as wild type), Reduced^exp_nor (reduced transactivation with normal or higher expression), and Reduced^exp_low (reduced transactivation with lower expression). Subsequently, Sanger sequencing showed that wild-type HNF-4α was in the Normal group, two mutations (M373R and G79C) were enriched in the Reduced^exp_nor group, and three mutations (C115S, L272P, and F83C) belonged to the Reduced^exp_low group. These results were validated by further imaging data using HCS assay for individual mutation.

CONCLUSIONS

Our study proposes a scalable and informative approach for the characterization of the variants in HNF-4α genes in a quantitative and high-throughput manner.

HNF1A：From Monogenic Diabetes to Type 2 Diabetes and Gestational Diabetes Mellitus

Diabetes, a disease characterized by hyperglycemia, has a serious impact on the lives and families of patients as well as on society. Diabetes is a group of highly heterogeneous metabolic diseases that can be classified as type 1 diabetes (T1D), type 2 diabetes (T2D), gestational diabetes mellitus (GDM), or other according to the etiology. The clinical manifestations are more or less similar among the different types of diabetes, and each type is highly heterogeneous due to different pathogenic factors. Therefore, distinguishing between various types of diabetes and defining their subtypes are major challenges hindering the precise treatment of the disease. T2D is the main type of diabetes in humans as well as the most heterogeneous. Fortunately, some studies have shown that variants of certain genes involved in monogenic diabetes also increase the risk of T2D. We hope this finding will enable breakthroughs regarding the pathogenesis of T2D and facilitate personalized treatment of the disease by exploring the function of the signal genes involved. Hepatocyte nuclear factor 1 homeobox A (HNF1α) is widely expressed in pancreatic β cells, the liver, the intestines, and other organs. HNF1α is highly polymorphic, but lacks a mutation hot spot. Mutations can be found at any site of the gene. Some single nucleotide polymorphisms (SNPs) cause maturity-onset diabetes of the young type 3 (MODY3) while some others do not cause MODY3 but increase the susceptibility to T2D or GDM. The phenotypes of MODY3 caused by different SNPs also differ. MODY3 is among the most common types of MODY, which is a form of monogenic diabetes mellitus caused by a single gene mutation. Both T2D and GDM are multifactorial diseases caused by both genetic and environmental factors. Different types of diabetes mellitus have different clinical phenotypes and treatments. This review focuses on HNF1α gene polymorphisms, HNF1A-MODY3, HNF1A-associated T2D and GDM, and the related pathogenesis and treatment methods. We hope this review will provide a valuable reference for the precise and individualized treatment of diabetes caused by abnormal HNF1α by summarizing the clinical heterogeneity of blood glucose abnormalities caused by HNF1α mutation.

PIWI-interacting RNA-23210 protects against acetaminophen-induced liver injury by targeting HNF1A and HNF4A

Acetaminophen (APAP) overdose is one of the leading causes of acute liver failure in the US and other developed countries, the molecular mechanisms of APAP-induced hepatotoxicity remain speculative. PIWI-interacting RNAs (piRNAs), a novel class of small non-coding RNAs, have been identified as epigenetic regulators of transposon silencing, mRNA deadenylation, and elimination. However, the functional role of piRNAs in APAP-induced liver injury remains unclear. In the current study, the piRNA profiles were constructed in HepaRG cells after APAP exposure, and the roles of piR-23210 in regulating nuclear receptors (NRs) expression, metabolizing enzymes expression, and consequently APAP-induced liver injury were systematically investigated. As a result, 57 upregulated piRNAs were identified after APAP exposure, indicating the stress-response characteristic of piRNA molecules. Subsequent in vitro and in vivo experiments proved that piR-23210 is a novel self-protective molecule that targets HNF1A and HNF4A transcripts by interacting with RNA binding protein Nucleolin (NCL), suppresses downstream CYPs (CYP2E1, CYP3A4, and CYP1A2) expression, and protects against APAP-induced liver injury. In conclusion, our findings provided new mechanistic clues revealing potential protective role of a piRNA against the hepatoxicity of APAP.

The Energy Sensor AMPKα1 Is Critical in Rapamycin-Inhibition of mTORC1-S6K-Induced T-cell Memory

Energy sensors mTORC1 and AMPKα1 regulate T-cell metabolism and differentiation, while rapamycin (Rapa)-inhibition of mTORC1 (RIM) promotes T-cell memory. However, the underlying pathway and the role of AMPKα1 in Rapa-induced T-cell memory remain elusive. Using genetic and pharmaceutical tools, we demonstrate that Rapa promotes T-cell memory in mice in vivo post Listeria monocytogenesis rLmOVA infection and in vitro transition of effector T (TE) to memory T (TM) cells. IL-2- and IL-2+Rapa-stimulated T [IL-2/T and IL-2(Rapa+)/T] cells, when transferred into mice, differentiate into short-term IL-7R-CD62L-KLRG1+ TE and long-lived IL-7R+CD62L+KLRG1- TM cells, respectively. To assess the underlying pathways, we performed Western blotting, confocal microscopy and Seahorse-assay analyses using IL-2/T and IL-2(Rapa+)/T-cells. We determined that IL-2(Rapa+)/T-cells activate transcription FOXO1, TCF1 and Eomes and metabolic pAMPKα1(T172), pULK1(S555) and ATG7 molecules and promote mitochondrial biogenesis and fatty-acid oxidation (FAO). We found that rapamycin-treated AMPKα-deficient AMPKα1-KO IL-2(Rapa+)/TM cells up-regulate transcription factor HIF-1α and induce a metabolic switch from FAO to glycolysis. Interestingly, despite the rapamycin treatment, AMPKα-deficient TM cells lost their cell survival capacity. Taken together, our data indicate that rapamycin promotes T-cell memory via transcriptional FOXO1-TCF1-Eomes programs and AMPKα1-ULK1-ATG7 metabolic axis, and that AMPKα1 plays a critical role in RIM-induced T-cell memory.

Costimulation molecules differentially regulate the ERK-Zfp831 axis to shape T follicular helper cell differentiation

T follicular helper (Tfh) cells play essential roles in regulating humoral immunity, especially germinal center reactions. However, how CD4⁺ T cells integrate the antigenic and costimulatory signals in Tfh cell development is still poorly understood. Here, we found that phorbol 12-myristate 13-acetate (PMA) + ionomycin (P+I) stimulation, together with interleukin-6 (IL-6), potently induce Tfh cell-like transcriptomic programs in vitro. The ERK kinase pathway was attenuated under P+I stimulation; ERK2 inhibition enhanced Tfh cell development in vitro and in vivo. We observed that inducible T cell costimulator (ICOS), but not CD28, lacked the ability to activate ERK, which was important in sustaining Tfh cell development. The transcription factor Zfp831, whose expression was repressed by ERK, promoted Tfh cell differentiation by directly upregulating the expression of the transcription factors Bcl6 and Tcf7. We have hence identified an ERK-Zfp831 axis, regulated by costimulation signaling, in critical regulation of Tfh cell development.

Exercise or Dietotherapy Is Not Better than Returning to a Regular Diet to Rebuild Lipid Homeostasis of Rats

Our aim was to explore the effects of dietary and behavior interventions on lipometabolism caused by an unhealthy high-fat diet and the best method to rebuild lipid homeostasis of this lifestyle. Apart from normal diet rats, 34 rats were fed with high-fat emulsion for 4 weeks and then intervened for another 4 weeks. Eight of them were classified into high-fat control group, and 9 were sorted into high-fat diet with rice vinegar group. Meanwhile, 10 were put into high-fat diet in swimming group, and 7 were just for refeeding normal diet group. Then, the data of body weight was recorded and analyzed. Indexes of serum samples were tested by kits. AMPKα, HNF1α, and CTRP6 in pancreas, liver, cardiac, and epididymis adipose tissues were detected by western blot. According to our experiments, swimming and refeeding groups reflected a better regulation on lipid homeostasis mainly by upregulating the expression of pancreas AMPKα. To be more specific, the refeeding rats showed lower T-CHO (P < 0.001) and LDL-C (P < 0.05), but higher weight gain (P < 0.001), insulin level (P < 0.01), and pancreas AMPKα (P < 0.01) than high-fat control rats. Compared with rats intervened by swimming or rice vinegar, they showed higher weight gain (P < 0.001), insulin level (P < 0.01), and HNF1α, but lower of CTRP6. In summary, refeeding diet functioned better in regulating the lipometabolic level after high-fat diet. Whatever approach mentioned above we adopted to intervene, the best policy to keep the balance of lipid homeostasis is to maintain a healthy diet.

Antigen dominance hierarchies shape TCF1+ progenitor CD8 T cell phenotypes in tumors

CD8 T cell responses against different tumor neoantigens occur simultaneously, yet little is known about the interplay between responses and its impact on T cell function and tumor control. In mouse lung adenocarcinoma, we found that immunodominance is established in tumors, wherein CD8 T cell expansion is predominantly driven by the antigen that most stably binds MHC. T cells responding to subdominant antigens were enriched for a TCF1+ progenitor phenotype correlated with response to immune checkpoint blockade (ICB) therapy. However, the subdominant T cell response did not preferentially benefit from ICB due to a dysfunctional subset of TCF1+ cells marked by CCR6 and Tc17 differentiation. Analysis of human samples and sequencing datasets revealed that CCR6+ TCF1+ cells exist across human cancers and are not correlated with ICB response. Vaccination eliminated CCR6+ TCF1+ cells and dramatically improved the subdominant response, highlighting a strategy to optimally engage concurrent neoantigen responses against tumors.

TCF/LEF regulation of the topologically associated domain ADI promotes mESCs to exit the pluripotent ground state

Mouse embryonic stem cells (mESCs) can be maintained in vitro in defined N2B27 medium supplemented with two chemical inhibitors for GSK3 and MEK (2i) and the cytokine leukemia inhibitory factor (LIF), which act synergistically to promote self-renewal and pluripotency. Here, we find that genetic deletion of the four genes encoding the TCF/LEF transcription factors confers mESCs with the ability to self-renew in N2B27 medium alone. TCF/LEF quadruple knockout (qKO) mESCs display dysregulation of several genes, including Aire, Dnmt3l, and IcosL, located adjacent to each other within a topologically associated domain (TAD). Aire, Dnmt3l, and IcosL appear to be regulated by TCF/LEF in a β-catenin independent manner. Moreover, downregulation of Aire and Dnmt3l in wild-type mESCs mimics the loss of TCF/LEF and increases mESC survival in the absence of 2iL. Hence, this study identifies TCF/LEF effectors that mediate exit from the pluripotent state.

Transient rest restores functionality in exhausted CAR-T cells through epigenetic remodeling

T cell exhaustion limits immune responses against cancer and is a major cause of resistance to chimeric antigen receptor (CAR)-T cell therapeutics. Using murine xenograft models and an in vitro model wherein tonic CAR signaling induces hallmark features of exhaustion, we tested the effect of transient cessation of receptor signaling, or rest, on the development and maintenance of exhaustion. Induction of rest through enforced down-regulation of the CAR protein using a drug-regulatable system or treatment with the multikinase inhibitor dasatinib resulted in the acquisition of a memory-like phenotype, global transcriptional and epigenetic reprogramming, and restored antitumor functionality in exhausted CAR-T cells. This work demonstrates that rest can enhance CAR-T cell efficacy by preventing or reversing exhaustion, and it challenges the notion that exhaustion is an epigenetically fixed state.

Wnt-β-catenin activation epigenetically reprograms Treg cells in inflammatory bowel disease and dysplastic progression

The diversity of regulatory T (Treg) cells in health and in disease remains unclear. Individuals with colorectal cancer harbor a subpopulation of RORγt+ Treg cells with elevated expression of β-catenin and pro-inflammatory properties. Here we show progressive expansion of RORγt+ Treg cells in individuals with inflammatory bowel disease during inflammation and early dysplasia. Activating Wnt-β-catenin signaling in human and murine Treg cells was sufficient to recapitulate the disease-associated increase in the frequency of RORγt+ Treg cells coexpressing multiple pro-inflammatory cytokines. Binding of the β-catenin interacting partner, TCF-1, to DNA overlapped with Foxp3 binding at enhancer sites of pro-inflammatory pathway genes. Sustained Wnt-β-catenin activation induced newly accessible chromatin sites in these genes and upregulated their expression. These findings indicate that TCF-1 and Foxp3 together limit the expression of pro-inflammatory genes in Treg cells. Activation of β-catenin signaling interferes with this function and promotes the disease-associated RORγt+ Treg phenotype.

Upregulation of Vitamin C Transporter Functional Expression in 5xFAD Mouse Intestine

The process of obtaining ascorbic acid (AA) via intestinal absorption and blood circulation is carrier-mediated utilizing the AA transporters SVCT1 and SVCT2, which are expressed in the intestine and brain (SVCT2 in abundance). AA concentration is decreased in Alzheimer’s disease (AD), but information regarding the status of intestinal AA uptake in the AD is still lacking. We aimed here to understand how AA homeostasis is modulated in a transgenic mouse model (5xFAD) of AD. AA levels in serum from 5xFAD mice were markedly lower than controls. Expression of oxidative stress response genes (glutathione peroxidase 1 (GPX1) and superoxide dismutase 1 (SOD1)) were significantly increased in AD mice jejunum, and this increase was mitigated by AA supplementation. Uptake of AA in the jejunum was upregulated. This increased AA transport was caused by a marked increase in SVCT1 and SVCT2 protein, mRNA, and heterogeneous nuclear RNA (hnRNA) expression. A significant increase in the expression of HNF1α and specific protein 1 (Sp1), which drive SLC23A1 and SLC23A2 promoter activity, respectively, was observed. Expression of hSVCT interacting proteins GRHPR and CLSTN3 were also increased. SVCT2 protein and mRNA expression in the hippocampus of 5xFAD mice was not altered. Together, these investigations reveal adaptive up-regulation of intestinal AA uptake in the 5xFAD mouse model.

Investigation for GSK3β expression in diabetic osteoporosis and negative osteogenic effects of GSK3β on bone marrow mesenchymal stem cells under a high glucose microenvironment

Osteoporosis is a common skeletal complication of diabetes mellitus (DM). The mechanisms underlying the pathophysiology of diabetic osteoporosis are complex. Glycogen synthase kinase-3β (GSK-3β) is a widely expressed serine/threonine kinase and associated with both DM and bone metabolism, which arouse our concern. In this study, we established the diabetic mouse model by high-fat diet combined with streptozotocin injection. Decreased bone mass and reduced osteogenesis were observed in femurs of the mice. Besides, we identified that there is an activated expression of GSK3β in the bone marrow mesenchymal stem cells (BMSCs) of diabetic mice. To explore the link between GSK3β and diabetic osteoporosis, we exposed BMSCs to a high glucose microenvironment in vitro and discovered that the glucose-induced GSK3β activation has negative osteogenic effects on BMSCs by suppressing β-catenin/Tcf7/Ccn4 signaling axis. Inhibition of GSK3β by specific concentrations of LiCl could reverse the impaired osteogenesis of BMSCs and increase expression of β-catenin, Tcf7 and Ccn4. Our research indicated that abnormal activation of GSK3β plays a role in diabetic osteoporosis and might be a potential target to treat diabetic osteoporosis.

Molecular Dynamics Simulations Predict That rSNP Located in the HNF‑1α Gene Promotor Region Linked with MODY3 and Hepatocellular Carcinoma Promotes Stronger Binding of the HNF‑4α Transcription Factor

Our study aims to investigate the impact of the Maturity-onset diabetes of the young 3 disease-linked rSNP rs35126805 located in the HNF-1α gene promotor on the binding of the transcription factor HNF-4α and consequently on the regulation of HNF-1α gene expression. Our focus is to calculate the change in the binding affinity of the transcription factor HNF-4α to the DNA, caused by the regulatory single nucleotide polymorphism (rSNP) through molecular dynamics simulations and thermodynamic analysis of acquired results. Both root-mean-square difference (RMSD) and the relative binding free energy ΔΔG_bind reveal that the HNF-4α binds slightly more strongly to the DNA containing the mutation (rSNP) making the complex more stable/rigid, and thereby influencing the expression of the HNF-1α gene. The resulting disruption of the HNF-4α/HNF-1α pathway is also linked to hepatocellular carcinoma metastasis and enhanced apoptosis in pancreatic cancer cells. To the best of our knowledge, this represents the first study where thermodynamic analysis of the results obtained from molecular dynamics simulations is performed to uncover the influence of rSNP on the protein binding to DNA. Therefore, our approach can be generally applied for studying the impact of regulatory single nucleotide polymorphisms on the binding of transcription factors to the DNA.

Cyclophosphamide and Vinorelbine Activate Stem-Like CD8+ T Cells and Improve Anti-PD-1 Efficacy in Triple-Negative Breast Cancer

Checkpoint inhibitors (CI) instigate anticancer immunity in many neoplastic diseases, albeit only in a fraction of patients. The clinical success of cyclophosphamide (C)-based haploidentical stem-cell transplants indicates that this drug may re-orchestrate the immune system. Using models of triple-negative breast cancer (TNBC) with different intratumoral immune contexture, we demonstrate that a combinatorial therapy of intermittent C, CI, and vinorelbine activates antigen-presenting cells (APC), and abrogates local and metastatic tumor growth by a T-cell-related effect. Single-cell transcriptome analysis of >50,000 intratumoral immune cells after therapy treatment showed a gene signature suggestive of a change resulting from exposure to a mitogen, ligand, or antigen for which it is specific, as well as APC-to-T-cell adhesion. This transcriptional program also increased intratumoral Tcf1⁺ stem-like CD8⁺ T cells and altered the balance between terminally and progenitor-exhausted T cells favoring the latter. Overall, our data support the clinical investigation of this therapy in TNBC. SIGNIFICANCE: A combinatorial therapy in mouse models of breast cancer increases checkpoint inhibition by activating antigen-presenting cells, enhancing intratumoral Tcf1⁺ stem-like CD8⁺ T cells, and increasing progenitor exhausted CD8⁺ T cells.

Inhibition of Proprotein Convertase Subtilisin/Kexin Type 9 Ameliorates Liver Fibrosis via Mitigation of Intestinal Endotoxemia

Lipopolysaccharide (LPS) is demonstrated to cause "two-hit" injury to liver. Proprotein convertase subtilisin/kexin type 9 (PCSK9) plays an important role in LPS clearance. Hepatocyte nuclear factor-1 alpha (HNF-1α) and sterol regulatory element-binding protein 2 (SREBP2) were reported to be responsible for PCSK9 gene transcription and regulation. We aim to clarify the expression status of PCSK9 during the process of liver fibrosis and to verify the effect on liver fibrosis via PCSK9 inhibition. In this study, we found that PCSK9 increased significantly in human and BDL mouse injured liver tissues, so did HNF-1α and SREBP2. No significant difference of plasma PCSK9 was observed. Inhibited PCSK9 using CRISPR-PCSK9 adeno-associated virus in BDL mice ameliorated liver inflammation and fibrosis, with LPS decrease in serum, without any change in intestinal wall integrity. PCSK9 expression of L02 hepatocytes can be induced by LPS; however, they lose the ability at high content of LPS. L02 cells increased LPS uptake after PCSK9 knockout. Taken together, these results suggest that, with PCSK9 increasing during liver fibrosis advancement, its inhibition can ameliorate liver injury by enhancing LPS uptake in hepatocytes; however, the enhancement is limited for destruction to hepatocytes by high LPS.

HNF1A recruits KDM6A to activate differentiated acinar cell programs that suppress pancreatic cancer

Defects in transcriptional regulators of pancreatic exocrine differentiation have been implicated in pancreatic tumorigenesis, but the molecular mechanisms are poorly understood. The locus encoding the transcription factor HNF1A harbors susceptibility variants for pancreatic ductal adenocarcinoma (PDAC), while KDM6A, encoding Lysine-specific demethylase 6A, carries somatic mutations in PDAC. Here, we show that pancreas-specific Hnf1a null mutant transcriptomes phenocopy those of Kdm6a mutations, and both defects synergize with KrasG12D to cause PDAC with sarcomatoid features. We combine genetic, epigenomic, and biochemical studies to show that HNF1A recruits KDM6A to genomic binding sites in pancreatic acinar cells. This remodels the acinar enhancer landscape, activates differentiated acinar cell programs, and indirectly suppresses oncogenic and epithelial-mesenchymal transition genes. We also identify a subset of non-classical PDAC samples that exhibit the HNF1A/KDM6A-deficient molecular phenotype. These findings provide direct genetic evidence that HNF1A deficiency promotes PDAC. They also connect the tumor-suppressive role of KDM6A deficiency with a cell-specific molecular mechanism that underlies PDAC subtype definition.

HNF-1a promotes pancreatic cancer growth and apoptosis resistance via its target gene PKLR

Pancreatic ductal adenocarcinoma is one of the deadliest malignant tumors, and many genes play important roles in its development. The hepatocyte nuclear factor-1a (HNF-1a) gene encodes HNF-1a, which is a transcriptional activator. HNF-1a regulates the tissue-specific expression of multiple genes, especially in pancreatic islet cells and in the liver. However, the role of the HNF-1a gene in the development of pancreatic cancer is still unclear. Here, we used immunohistochemical staining and real-time PCR to analyze HNF-1a expression in pancreatic cancer tissue. Stable cell lines with HNF-1a knockdown or overexpression were established to analyze the role of HNF-1a in pancreatic cancer cell proliferation and apoptosis by colony formation assay and flow cytometry. We also analyzed the L-type pyruvate kinase (PKLR) promoter sequence to identify the regulatory effect of HNF-1a on PKLR transcription and confirmed the HNF-1a binding site in the PKLR promoter via a chromatin immunoprecipitation assay. HNF-1a was found to be overexpressed in pancreatic cancer and promoted proliferation while inhibiting apoptosis in pancreatic cancer cells. PKLR was identified as the downstream target gene of HNF-1a and binding of HNF-1a at two sites in PKLR (-1931/-1926 and -966/-961) regulated PKLR transcription. In conclusion, HNF-1a is overexpressed in pancreatic cancer, and the transcription factor HNF-1a can promote pancreatic cancer growth and apoptosis resistance via its target gene PKLR.

Liver adenomatosis in patients with hepatocyte nuclear factor-1 alpha maturity onset diabetes of the young (HNF1A-MODY): Clinical, radiological and pathological characteristics in a French series

BACKGROUND

Liver adenomatosis (LA) is a rare disease resulting from biallelic inactivation of the hepatocyte nuclear factor-1 alpha (HNF1A) gene, which induces the proliferation of adenoma cells in liver parenchyma. Liver adenomatosis has only been documented in case reports from patients carrying a HNF1A germline mutation. We have evaluated the frequency of LA among a large cohort of patients with HNF1A-maturity onset diabetes of the young (MODY), previously termed "MODY3," and herein describe its clinical, radiological, and pathological characteristics.

METHODS

In all, 137 HNF1A-MODY subjects from 74 families were screened by liver ultrasonography in 13 centers, and 15 additional cases of LA were later included in the series. Liver adenomatosis was confirmed by liver computed tomography, magnetic resonance imaging (MRI), and/or histopathology.

RESULTS

Among 137 carriers of an HNF1A mutation, 9 patients (6.5%) from seven families were diagnosed with LA. Diabetes mellitus was present in 87.5% of patients with LA. In 25% of patients, LA was diagnosed due to intra-abdominal or intratumoral bleeding. Liver biochemistry was near normal in all patients. Liver imaging showed adenomas of various sizes and numbers. On MRI, most nodules had the radiological characteristics of steatotic adenomas. Histopathological confirmation of LA was available in 13 cases, and these adenomas were mostly steatotic. Surgery was initially performed in 37.5% of patients, and liver disease progression was observed in 30%. No disease progression was observed in 14 pregnancies.

CONCLUSIONS

The frequency of LA in a cohort of screened HNF1A-MODY patients and the high incidence of LA progression and/or hemorrhage warrants systematic screening for liver adenomatosis in HNF1A-MODY families.

Tissue-specific transcription reprogramming promotes liver metastasis of colorectal cancer

Metastasis, the development of secondary malignant growths at a distance from a primary tumor, is the cause of death for 90% of cancer patients, but little is known about how metastatic cancer cells adapt to and colonize new tissue environments. Here, using clinical samples, patient-derived xenograft (PDX) samples, PDX cells, and primary/metastatic cell lines, we discovered that liver metastatic colorectal cancer (CRC) cells lose their colon-specific gene transcription program yet gain a liver-specific gene transcription program. We showed that this transcription reprogramming is driven by a reshaped epigenetic landscape of both typical enhancers and super-enhancers. Further, we identified that the liver-specific transcription factors FOXA2 and HNF1A can bind to the gained enhancers and activate the liver-specific gene transcription, thereby driving CRC liver metastasis. Importantly, similar transcription reprogramming can be observed in multiple cancer types. Our data suggest that reprogrammed tissue-specific transcription promotes metastasis and should be targeted therapeutically.

Proliferating Transitory T Cells with an Effector-like Transcriptional Signature Emerge from PD-1+ Stem-like CD8+ T Cells during Chronic Infection

T cell dysfunction is a characteristic feature of chronic viral infection and cancer. Recent studies in chronic lymphocytic choriomeningitis virus (LCMV) infection have defined a PD-1+ Tcf-1+ CD8+ T cell subset capable of self-renewal and differentiation into more terminally differentiated cells that downregulate Tcf-1 and express additional inhibitory molecules such as Tim3. Here, we demonstrated that expression of the glycoprotein CD101 divides this terminally differentiated population into two subsets. Stem-like Tcf-1+ CD8+ T cells initially differentiated into a transitory population of CD101-Tim3+ cells that later converted into CD101+ Tim3+ cells. Recently generated CD101-Tim3+ cells proliferated in vivo, contributed to viral control, and were marked by an effector-like transcriptional signature including expression of the chemokine receptor CX3CR1, pro-inflammatory cytokines, and granzyme B. PD-1 pathway blockade increased the numbers of CD101-Tim3+ CD8+ T cells, suggesting that these newly generated transitional cells play a critical role in PD-1-based immunotherapy.

Cytotoxic potentials of S. cumini methanolic seed kernel extract in human hepatoma HepG2 cells

Syzygium cumini (Myrtaceae) is commonly called as Jamun or Jambolan. It has antidiabetic, anti-inflammatory, antipyretic, and antioxidant activities. Hepatocellular carcinoma is the most frequent and deadliest cancers worldwide. We investigated the cytotoxic potentials of S. cumini methanolic seed kernel extract against human hepatoma HepG2 cells. HepG2 cells were treated with 10, 20, and 40 μg/mL of seed kernel extract for 24 hours and cytotoxic analysis was performed by MTT assay. S. cumini induced apoptosis related morphological changes in HepG2 cells were analyzed by annexin V and propidium iodide double staining. Nuclear fragmentation and chromatin condensation were analyzed by Hoechst nuclear staining. Mitochondrial membrane potential (MMP) was investigated by 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolyl-carbocyanine iodide (JC-1) staining. Protein expressions of hepatocyte nuclear factor-1α (HFN-1α) was performed using western blotting. S. cumini treatments caused a significant and a concentration-dependent increase in the cytotoxicity of HepG2 cells. S. cumini treatments increased the percentage of cells in an early and late apoptosis stage. This treatment also caused chromatin condensation and nuclear fragmentation. Further, S. cumini treatments decreased MMP and also caused a significant downregulation of HFN-1α protein expression. The present study demonstrated that S. cumini seed extract induced apoptosis in HepG2 cells through decrease in MMP and downregulation of HFN-1α.

The effect and molecular mechanism of statins on the expression of human anti-coagulation genes

Statins are potent lipid-lowering drugs. Large prospective clinical trials have shown the anti-thrombotic effect of statins, e.g., preventing deep vein thrombosis. However, the mechanism underlying the beneficial effect of statins in reducing thrombus formation remains to be established. We, thus, conduct this study to investigate the potential molecular mechanisms. The cultured human hepatoma cells (HepG2) were used as the in vitro model. The human protein C gene promoter was cloned into the luciferase reporter to study the transcriptional regulation of human protein C gene. Wistar rats fed with simvastatin (5 mg/kg day) were used as the in vivo model. We found that simvastatin increased the expression of protein C in hepatocytes (361 ± 64% and 313 ± 59% after 2 h and 6 h of stimulation, respectively, both p < 0.01). In the animal study, the serum protein C levels were increased in the simvastatin-treated group (7 ± 2.2 unit/ml vs 23.4 ± 19.3 unit/ml and 23.4 ± 18.2 unit/ml and 1 and 2 weeks of treatment, respectively, both p < 0.05). Regarding the possible molecular mechanism, we found that the level of hepatocyte nuclear factor 1α (HNF1α) was also increased in both the in vivo and in vitro models. We found that the protein C promoter activity was increased by simvastatin, and this effect was inhibited by HNF1α knockdown and constitutively active Rac1. Therefore, stains may modulate protein C expression through small GTPase Rac 1 and HNF1α.

Functional characterization of p.Pro409His variant in HNF1A, a hypomorphic mutation involved in pancreatic β-cell dysfunction

AIMS

HNF1A is a gene coding for the transcription factor HNF1-α, mutated in some forms of MODY and type 2 diabetes mellitus characterized by a strong genetic component. The penetrance of HNF1A variants differs considerably; thus, to assess the genetic risk of diabetes in carrier subjects of a HNF1A mutant allele, a functional characterization of mutant forms is of paramount importance.

METHODS

The HNF1A gene was sequenced in two patients with partly discordant diabetic phenotype, carrying the p.Pro409His variant. To evaluate the pathogenicity of the variant, we measured the transactivation power of the corresponding P408H HNF1-α mutant mouse form on HNF1-α target promoters.

RESULTS

We found a lower but detectable activity of transactivation of the mutant form compared with the wild-type form and we excluded mechanisms of protein degradation or nuclear mislocalization.

CONCLUSIONS

The HNF1A mutation p.Pro409His can be considered a mild variant that confers a moderate risk of type 2 diabetes mellitus in heterozygous carriers.

Modeling Monogenic Diabetes using Human ESCs Reveals Developmental and Metabolic Deficiencies Caused by Mutations in HNF1A

Human monogenic diabetes, caused by mutations in genes involved in beta cell development and function, has been a challenge to study because multiple mouse models have not fully recapitulated the human disease. Here, we use genome edited human embryonic stem cells to understand the most common form of monogenic diabetes, MODY3, caused by mutations in the transcription factor HNF1A. We found that HNF1A is necessary to repress an alpha cell gene expression signature, maintain endocrine cell function, and regulate cellular metabolism. In addition, we identified the human-specific long non-coding RNA, LINKA, as an HNF1A target necessary for normal mitochondrial respiration. These findings provide a possible explanation for the species difference in disease phenotypes observed with HNF1A mutations and offer mechanistic insights into how the HNF1A gene may also influence type 2 diabetes.