Probes for INS

Cellular senescence and the senescence-associated secretory phenotype (SASP) are implicated in aging and age-related disease, and SASP-related inflammation is thought to contribute to tissue dysfunction in aging and diseased animals. However, whether and how SASP factors influence the regenerative capacity of tissues remains unclear. Here, using intestinal organoids as a model of tissue regeneration, we show that SASP factors released by senescent fibroblasts deregulate stem cell activity and differentiation and ultimately impair crypt formation. We identify the secreted N-terminal domain of Ptk7 as a key component of the SASP that activates non-canonical Wnt / Ca2+ signaling through FZD7 in intestinal stem cells (ISCs). Changes in cytosolic [Ca2+] elicited by Ptk7 promote nuclear translocation of YAP and induce expression of YAP/TEAD target genes, impairing symmetry breaking and stem cell differentiation. Our study discovers secreted Ptk7 as a factor released by senescent cells and provides insight into the mechanism by which cellular senescence contributes to tissue dysfunction in aging and disease.

Background: Hepatocellular Carcinoma (HCC) is a major form of liver cancer and a leading cause of cancer-related death worldwide. New insights into HCC pathobiology and mechanism of drug actions are urgently needed to improve patient outcomes. HCC undergoes metabolic reprogramming of glucose metabolism from respiration to aerobic glycolysis, a phenomenon known as the 'Warburg Effect' that supports rapid cancer cell growth, survival, and invasion. mTOR is known to promote Warburg Effect, but the underlying mechanism(s) remains poorly defined. The aim of this study is to understand the mechanism(s) and significance of mTOR regulation of aerobic glycolysis in HCC. Methods: We profiled mTORC1-dependent long non-coding RNAs (lncRNAs) by RNA-seq of HCC cells treated with rapamycin. Chromatin immunoprecipitation (ChIP) and luciferase reporter assays were used to explore the transcriptional regulation of NEAT1 by mTORC1. [U-13C]-glucose labeling and metabolomic analysis, extracellular acidification Rate (ECAR) by Seahorse XF Analyzer, and glucose uptake assay were used to investigate the role of mTOR-NEAT1-NONO signaling in the regulation of aerobic glycolysis. RNA immunoprecipitation (RIP) and NONO-binding motif scanning were performed to identify the regulatory mechanism of pre-mRNA splicing by mTOR-NEAT1. Myristoylated AKT1 (mAKT1)/NRASV12-driven HCC model developed by hydrodynamic transfection (HDT) was employed to explore the significance of mTOR-NEAT1 signaling in HCC tumorigenesis and mTOR-targeted therapy. Results: mTOR regulates lncRNA transcriptome in HCC and that NEAT1 is a major mTOR transcriptional target. Interestingly, although both NEAT1_1 and NEAT1_2 are down-regulated in HCC, only NEAT1_2 is significantly correlated with poor overall survival of HCC patients. NEAT1_2 is the organizer of nuclear paraspeckles that sequester the RNA-binding proteins NONO and SFPQ. We show that upon oncogenic activation, mTORC1 suppresses NEAT1_2 expression and paraspeckle biogenesis, liberating NONO/SFPQ, which in turn, binds to U5 within the spliceosome, stimulating mRNA splicing and expression of key glycolytic enzymes. This series of actions lead to enhanced glucose transport, aerobic glycolytic flux, lactate production, and HCC growth both in vitro and in vivo. Furthermore, the paraspeckle-mediated mechanism is important for the anticancer action of US FDA-approved drugs rapamycin/temsirolimus. Conclusions: These findings reveal a molecular mechanism by which mTOR promotes the 'Warburg Effect', which is important for the metabolism and development of HCC, and anticancer response of mTOR-targeted therapy.

Fragile X syndrome is a neurodevelopmental disorder caused by the absence of the mRNA-binding protein fragile X messenger ribonucleoprotein (FMRP). Because FMRP is a highly pleiotropic protein controlling the expression of hundreds of genes, viral vector-mediated gene replacement therapy is viewed as a potential viable treatment to correct the fundamental underlying molecular pathology inherent in the disorder. Here, we studied the safety profile and therapeutic effects of a clinically relevant dose of a self-complementary adeno-associated viral (AAV) vector containing a major human brain isoform of FMRP after intrathecal injection into wild-type and fragile X-KO mice. Analysis of the cellular transduction in the brain indicated primarily neuronal transduction with relatively sparse glial expression, similar to endogenous FMRP expression in untreated wild-type mice. AAV vector-treated KO mice showed recovery from epileptic seizures, normalization of fear conditioning, reversal of slow-wave deficits as measured via electroencephalographic recordings, and restoration of abnormal circadian motor activity and sleep. Further assessment of vector efficacy by tracking and analyzing individual responses demonstrated correlations between the level and distribution of brain transduction and drug response. These preclinical findings further demonstrate the validity of AAV vector-mediated gene therapy for treating the most common genetic cause of cognitive impairment and autism in children.

Lgr5+ intestinal stem cells (ISCs) depend on niche factors for their proper function. However, the source of these ISC niche factors and how they support ISCs in vivo remain controversial. Here, we report that ISCs depend on lymphatic endothelial cells (LECs) and RSPO3+GREM1+ fibroblasts (RGFs). In the intestine and colon, LECs are surrounded by RGFs and are located near ISCs at the crypt base. Both LECs and RGFs provide the critical ISC niche factor RSPO3 to support ISCs, where RSPO3 loss in both cell types drastically compromises ISC numbers, villi length, and repair after injury. In response to injury, LEC and RGF numbers expand and produce greater amounts of RSPO3 and other growth/angiocrine factors to foster intestinal repair. We propose that LECs represent a novel niche component for ISCs, which together with RGFs serve as the major in vivo RSPO3 source for ISCs in homeostasis and injury-mediated regeneration.

Mycobacterium tuberculosis (Mtb) infects 25% of the world's population and causes tuberculosis (TB), which is a leading cause of death globally. A clear understanding of the dynamics of immune response at the cellular level is crucial to design better strategies to control TB. We use the single-cell RNA sequencing approach on lung lymphocytes derived from healthy and Mtb-infected mice. Our results show the enrichment of the type I IFN signature among the lymphoid cell clusters, as well as heat shock responses in natural killer (NK) cells from Mtb-infected mice lungs. We identify Ly6A as a lymphoid cell activation marker and validate its upregulation in activated lymphoid cells following infection. The cross-analysis of the type I IFN signature in human TB-infected peripheral blood samples further validates our results. These findings contribute toward understanding and characterizing the transcriptional parameters at a single-cell depth in a highly relevant and reproducible mouse model of TB.

The etiology of ulcerative colitis is poorly understood and is likely to involve perturbation of the complex interactions between the mucosal immune system and the commensal bacteria of the gut, with cytokines acting as important cross-regulators. Here we use IFN receptor-deficient mice in a dextran sulfate sodium (DSS) model of acute intestinal injury to study the contributions of type I and III interferons (IFN) to the initiation, progression and resolution of acute colitis. We find that mice lacking both types of IFN receptors exhibit enhanced barrier destruction, extensive loss of goblet cells and diminished proliferation of epithelial cells in the colon following DSS-induced damage. Impaired mucosal healing in double IFN receptor-deficient mice is driven by decreased amphiregulin expression, which IFN signaling can up-regulate in either the epithelial or hematopoietic compartment. Together, these data underscore the pleiotropic functions of IFNs and demonstrate that these critical antiviral cytokines also support epithelial regeneration following acute colonic injury.

BACKGROUND: Pemphigus vulgaris (PV) is a potentially life-threatening autoimmune blistering disease. PV autoantibodies disrupt desmosomal adhesion and cause acantholysis. Previous researches have shown that stem cells are indirectly involved as a result of desmoglein deficiency. Leucine-rich repeat-containing G protein-coupled receptor 5 (LGR5) as a follicular stem cell marker was evaluated in aim to correlate its intensity of expression with disease severity. OBJECTIVE: To correlate LGR5 intensity of expression with disease severity. PATIENT AND METHODS: This prospective cross sectional study was carried out on 20 PV patients. Patients were subjected to complete history taking, general, dermatological examination and assessment of disease severity by the Pemphigus Vulgaris Activity Score (PVAS), histopathological and immunohistochemical expression of LGR5 were done. RESULTS: All studied cases showed positive cytoplasmic basal LGR5 expression in patchy manner. 75% of cases had mild intensity of expression, 15% had moderate intensity and their Histo (H) score ranged from 50-130 with Mean ±SD 110±18.92. There were no significant correlation between PVAS scores ''skin, mucosa and total involvement'' and H score of LGR5 expression. CONCLUSION: The current study could shed a new light on the disease and its correlation with stem cells, LGR5 as a stem cell marker could be related to the healing process in PV. However, it didn't correlate PVAS scores either in skin, mucosa or total involvement.  

Non-thermal plasma (NTP) is widely used in the disinfection and surface modification of biomaterials.

To analyze the correlation between the inducing effect of Fusobacterium nucleatum (Fn) on the surface expression of the inhibitory receptor KIR2DL1 on CD8+ T cells in oesophageal squamous cell carcinoma (ESCC) and the clinicopathological features and survival prognosis and to explore its clinical significance.The inducing effect of Fn on CD8+ T cell surface inhibitory receptor KIR2DL1 expression was analyzed in a coculture system of human CD8+ T cells and ESCC cells infected with Fn. Fn infection and the expression of KIR2DL1 on CD8+ T cells were detected by RNAscope and immunohistochemistry in ESCC tissues, and the correlations between the inducing effect of Fn on KIR2DL1 expression on CD8+ T cells and clinicopathological features were analyzed. COX regression was used to analyze the influence of each factor on the prognosis of ESCC. Survival curves were plotted by the Kaplan-Meier method, and the effect of KIR2DL1 induction on survival time was analyzed by the log-rank test.In the coculture system, KIR2DL1 expression on the surface of CD8+ T cells increased with increasing Fn infection time. In ESCC tissues, Fn infection was significantly correlated with high KIR2DL1 expression on CD8+ T cells. The Fn + CD8+KIR2DL1 positive patients were predominantly males who were smokers and alcohol drinkers. Moreover, patients with Fn infection were characterized by poor tumour differentiation, advanced clinical stage, and a short survival time. Meanwhile, Fn + CD8+KIR2DL1 positive group was independent risk factor affecting the prognosis of ESCC patients.Long-term drinking and smoking lead to an extremely unhealthy oral environment in which Fn infection and colonization are more likely to occur, thus inducing high expression of KIR2DL1 on the surface of CD8+ T cells, which can weaken the antitumour immune response and promote the malignant progression of ESCC.HIGHLIGHTSFn induced high expression of KIR2DL1 CD8+ T cells in a time-dependent manner.Fn can reduce the response of tumour cells to CDDP.The inducing effect of Fn on CD8+ T cell surface KIR2DL1 expression was significantly associated with the poor prognosis of ESCC patients.

Few studies have focused on COVID-19 patients' hepatic histopathological features. Many of the described morphological landscapes are non-specific and possibly due to other comorbidities or to Sars-CoV-2-related therapies. We describe the hepatic histopathological findings of 3 liver biopsies obtained from living COVID-19 patients in which active SARS-CoV-2 infection was molecularly confirmed and biopsied because of significant alterations of liver function tests and 25 livers analyzed during COVID-19-related autopsies. Main histopathological findings were (i) the absence of significant biliary tree or vascular damages, (ii) mild/absent lymphocytic hepatitis; (iii) activation of (pigmented) Kupffer cells, (iv) hepatocellular regenerative changes, (v) the presence of steatosis, (vi) sinusoidal ectasia, micro-thrombosis and acinar atrophy in autopsy specimens No viral particle actively infecting the hepatic or endothelial cells was detected at in situ hybridization. The morphological features observed within the hepatic parenchyma are not specific and should be considered as the result of an indirect insult resulting from the viral infection or the adopted therapeutic protocols.

Type 2 diabetes (T2D) is associated with β-cell dedifferentiation. Aldehyde dehydrogenase 1 isoform A3 (ALHD1A3) is a marker of β-cell dedifferentiation and correlates with T2D progression. However, it is unknown whether ALDH1A3 activity contributes to β-cell failure, and whether the decrease of ALDH1A3-positive β-cells (A+) following pair-feeding of diabetic animals is due to β-cell restoration. To tackle these questions, we (i) investigated the fate of A+ cells during pair-feeding by lineage-tracing, (ii) somatically ablated ALDH1A3 in diabetic β-cells, and (iii) used a novel selective ALDH1A3 inhibitor to treat diabetes. Lineage tracing and functional characterization show that A+ cells can be reconverted to functional, mature β-cells. Genetic or pharmacological inhibition of ALDH1A3 in diabetic mice lowers glycemia and increases insulin secretion. Characterization of β-cells following ALDH1A3 inhibition shows reactivation of differentiation as well as regeneration pathways. We conclude that ALDH1A3 inhibition offers a therapeutic strategy against β-cell dysfunction in diabetes.

Along with functionally intact insulin, diabetes-associated insulin peptides are secreted by β cells. By screening the expression and functional characterization of olfactory receptors (ORs) in pancreatic islets, we identified Olfr109 as the receptor that detects insulin peptides. The engagement of one insulin peptide, insB:9-23, with Olfr109 diminished insulin secretion through Gi-cAMP signaling and promoted islet-resident macrophage proliferation through a β cell-macrophage circuit and a β-arrestin-1-mediated CCL2 pathway, as evidenced by β-arrestin-1-/- mouse models. Systemic Olfr109 deficiency or deficiency induced by Pdx1-Cre+/-Olfr109fl/fl specifically alleviated intra-islet inflammatory responses and improved glucose homeostasis in Akita- and high-fat diet (HFD)-fed mice. We further determined the binding mode between insB:9-23 and Olfr109. A pepducin-based Olfr109 antagonist improved glucose homeostasis in diabetic and obese mouse models. Collectively, we found that pancreatic β cells use Olfr109 to autonomously detect self-secreted insulin peptides, and this detection arrests insulin secretion and crosstalks with macrophages to increase intra-islet inflammation.