[miR-185-5p alleviates the inflammatory response of acute gouty arthritis by inhibiting of IL-1ß].

Objective To investigate the relationship between interleukin-1ß (IL-1ß) and miR-185-5p in the process of joint injury in acute gouty arthritis (AGA). Methods The serum miR-185-5p levels of 89 AGA patients and 91 healthy volunteers were detected by real-time quantitative PCR. The correlation between miR-185-5p expression level and VAS score or IL-1ß expression level was evaluated by Pearson correlation coefficient method. Receiver operating characteristic (ROC) curve was used to evaluate the diagnostic value of miR-185-5p in AGA. THP-1 cells were induced by sodium urate (MSU) to construct an in vitro acute gouty inflammatory cell model. After the expression level of miR-185-5p in THP-1 cells was upregulated or downregulated by transfection of miR-185-5p mimics or inhibitors in vitro, inflammatory cytokines of THP-1 cells, such as IL-1ß, IL-8 and tumor necrosis factor α (TNF-α), were detected by ELISA. The luciferase reporter gene assay was used to determine the interaction between miR-185-5p and the 3'-UTR of IL-1ß. Results Compared with the healthy control group, the expression level of serum miR-185-5p in AGA patients was significantly reduced. The level of serum miR-185-5p was negatively correlated with VAS score and IL-1ß expression level. The area under the curve (AUC) was 0.905, the sensitivity was 80.17% and the specificity was 83.52%. Down-regulation of miR-185-5p significantly promoted the expression of IL-1ß, IL-8 and tumor necrosis factor (TNF-α), while overexpression of miR-185-5p showed the opposite results. Luciferase reporter gene assay showed that IL-1ß was the target gene of miR-185-5p, and miR-185-5p negatively regulated the expression of IL-1ß. Conclusion miR-185-5p alleviates the inflammatory response in AGA by inhibiting IL-1ß.

IGF2BP1/IMP1 Deletion Enhances a Facultative Stem Cell State via Regulation of MAP1LC3B.

BACKGROUND & AIMS: The intestinal epithelium interfaces with a diverse milieu of luminal contents while maintaining robust digestive and barrier functions. Facultative intestinal stem cells are cells that survive tissue injury and divide to re-establish the epithelium. Prior studies have shown autophagic state as functional marker of facultative intestinal stem cells, but regulatory mechanisms are not known. The current study evaluated a post-transcriptional regulation of autophagy as an important factor for facultative stem cell state and tissue regeneration. METHODS: We evaluated stem cell composition, autophagic vesicle content, organoid formation, and in vivo regeneration in mice with intestinal epithelial deletion of the RNA binding protein IGF2 messenger RNA binding protein 1 (IMP1). The contribution of autophagy to resulting in vitro and in vivo phenotypes was evaluated via genetic inactivation of Atg7. Molecular analyses of IMP1 modulation of autophagy at the protein and transcript localization levels were performed using IMP1 mutant studies and single-molecule fluorescent in situ hybridization. RESULTS: Epithelial Imp1 deletion reduced leucine rich repeat containing G protein coupled receptor 5 cell frequency but enhanced both organoid formation efficiency and in vivo regeneration after irradiation. We confirmed prior studies showing increased autophagy with IMP1 deletion. Deletion of Atg7 reversed the enhanced regeneration observed with Imp1 deletion. IMP1 deletion or mutation of IMP1 phosphorylation sites enhanced expression of essential autophagy protein microtubule-associated protein 1 light chain 3ß. Furthermore, immunofluorescence imaging coupled with single-molecule fluorescent in situ hybridization showed IMP1 colocalization with MAP1LC3B transcripts at homeostasis. Stress induction led to decreased colocalization. CONCLUSIONS: Depletion of IMP1 enhances autophagy, which promotes intestinal regeneration via expansion of facultative intestinal stem cells.

Intestinal transit-amplifying cells require METTL3 for growth factor signaling and cell survival.

Intestinal epithelial transit-amplifying cells are essential stem progenitors required for intestinal homeostasis, but their rapid proliferation renders them vulnerable to DNA damage from radiation and chemotherapy. Despite these cells' critical roles in intestinal homeostasis and disease, few studies have described genes that are essential to transit-amplifying cell function. We report that RNA methyltransferase-like 3 (METTL3) is required for survival of transit-amplifying cells in the murine small intestine. Transit-amplifying cell death after METTL3 deletion was associated with crypt and villus atrophy, loss of absorptive enterocytes, and uniform wasting and death in METTL3-depleted mice. Sequencing of polysome-bound and methylated RNAs in enteroids and in vivo demonstrated decreased translation of hundreds of methylated transcripts after METTL3 deletion, particularly transcripts involved in growth factor signal transduction such as Kras. Further investigation verified a relationship between METTL3 and Kras methylation and protein levels in vivo. Our study identifies METTL3 as an essential factor supporting the homeostasis of small intestinal tissue via direct maintenance of transit-amplifying cell survival. We highlight the crucial role of RNA modifications in regulating growth factor signaling in the intestine with important implications for both homeostatic tissue renewal and epithelial regeneration.

APC and P53 mutations synergise to create a therapeutic vulnerability to NOTUM inhibition in advanced colorectal cancer.

OBJECTIVE: Colorectal cancer (CRC) is a leading cause of cancer-related deaths, with the majority of cases initiated by inactivation of the APC tumour suppressor. This results in the constitutive activation of canonical WNT pathway transcriptional effector ß-catenin, along with induction of WNT feedback inhibitors, including the extracellular palmitoleoyl-protein carboxylesterase NOTUM which antagonises WNT-FZD receptor-ligand interactions. Here, we sought to evaluate the effects of NOTUM activity on CRC as a function of driver mutation landscape. DESIGN: Mouse and human colon organoids engineered with combinations of CRC driver mutations were used for Notum genetic gain-of-function and loss-of-function studies. In vitro assays, in vivo endoscope-guided orthotopic organoid implantation assays and transcriptomic profiling were employed to characterise the effects of Notum activity. Small molecule inhibitors of Notum activity were used in preclinical therapeutic proof-of-principle studies targeting oncogenic Notum activity. RESULTS: NOTUM retains tumour suppressive activity in APC-null adenomas despite constitutive ß-catenin activity. Strikingly, on progression to adenocarcinoma with P53 loss, NOTUM becomes an obligate oncogene. These phenotypes are Wnt-independent, resulting from differential activity of NOTUM on glypican 1 and 4 in early-stage versus late-stage disease, respectively. Ultimately, preclinical mouse models and human organoid cultures demonstrate that pharmacological inhibition of NOTUM is highly effective in arresting primary adenocarcinoma growth and inhibiting metastatic colonisation of distal organs. CONCLUSIONS: Our findings that a single agent targeting the extracellular enzyme NOTUM is effective in treating highly aggressive, metastatic adenocarcinomas in preclinical mouse models and human organoids make NOTUM and its glypican targets therapeutic vulnerabilities in advanced CRC.

Intestinal transit amplifying cells require METTL3 for growth factor signaling, KRAS expression, and cell survival.

Intestinal epithelial transit amplifying cells are essential stem progenitors required for intestinal homeostasis, but their rapid proliferation renders them vulnerable to DNA damage from radiation and chemotherapy. Despite their critical roles in intestinal homeostasis and disease, few studies have described genes that are essential to transit amplifying cell function. We report that the RNA methyltransferase, METTL3, is required for survival of transit amplifying cells in the murine small intestine. Transit amplifying cell death after METTL3 deletion was associated with crypt and villus atrophy, loss of absorptive enterocytes, and uniform wasting and death in METTL3-depleted mice. Ribosome profiling and sequencing of methylated RNAs in enteroids and in vivo demonstrated decreased translation of hundreds of unique methylated transcripts after METTL3 deletion, particularly transcripts involved in growth factor signal transduction such as Kras. Further investigation confirmed a novel relationship between METTL3 and Kras methylation and protein levels in vivo. Our study identifies METTL3 as an essential factor supporting the homeostasis of small intestinal tissue via direct maintenance of transit amplifying cell survival. We highlight the crucial role of RNA modifications in regulating growth factor signaling in the intestine, with important implications for both homeostatic tissue renewal and epithelial regeneration.

Intestinal epithelial autophagy is required for the regenerative benefit of calorie restriction.

Calorie restriction can enhance the regenerative capacity of the injured intestinal epithelium. Among other metabolic changes, calorie restriction can activate the autophagy pathway. Although independent studies have attributed the regenerative benefit of calorie restriction to downregulation of mTORC1, it is not known whether autophagy itself is required for the regenerative benefit of calorie restriction. We used mouse and organoid models with autophagy gene deletion to evaluate the contribution of autophagy to intestinal epithelial regeneration following calorie restriction. In the absence of injury, mice with intestinal epithelial-specific deletion of autophagy gene Atg7 (Atg7ΔIEC) exhibit weight loss and histological changes similar to wild-type mice following calorie restriction. Conversely, calorie-restricted Atg7ΔIEC mice displayed a significant reduction in regenerative crypt foci after irradiation compared with calorie-restricted wild-type mice. Targeted analyses of tissue metabolites in calorie-restricted mice revealed an association between calorie restriction and reduced glycocholic acid (GCA) in wild-type mice but not in Atg7ΔIEC mice. To evaluate whether GCA can directly modulate epithelial stem cell self-renewal, we performed enteroid formation assays with or without GCA. Wild-type enteroids exhibited reduced enteroid formation efficiency in response to GCA treatment, suggesting that reduced availability of GCA during calorie restriction may be one mechanism by which calorie restriction favors epithelial regeneration in a manner dependent upon epithelial autophagy. Taken together, our data support the premise that intestinal epithelial Atg7 is required for the regenerative benefit of calorie restriction, due in part to its role in modulating luminal GCA with direct effects on epithelial stem cell self-renewal.NEW & NOTEWORTHY Calorie restriction is associated with enhanced intestinal regeneration after irradiation, but the requirement of autophagy for this process is not known. Our data support the premise that intestinal epithelial autophagy is required for the regenerative benefit of calorie restriction. We also report that luminal levels of primary bile acid glycocholic acid are modulated by epithelial cell autophagy during calorie restriction with direct effects on epithelial stem cell function.

Construction and comprehensive analysis of the biological network related to rheumatoid arthritis-related interstitial lung disease.

OBJECTIVE: Interstitial lung disease (ILD) is a severe manifestation of rheumatoid arthritis (RA), which is characterized by low survival time post-diagnosis. Thus, it is important to explore the role of gene regulation related with ILD. METHOD: Constructed a RA-ILD-related long chain noncoding RNA - messenger RNA (lncRNA-mRNA) network (ILD-LMN), based on ILD- and RA-related genes. We analyzed the topological properties of the resulting network. RESULT: The results for network modularization and functional analysis showed that ILD-LMN performed basic and specific functions in ILD pathology. Furthermore, differential expression and correlation analysis of hub nodes revealed highly correlated competitive endogenous RNA regulatory relationships with important roles in pathological regulation. Following this, statistical analysis of disease-related single nucleotide polymorphisms (SNPs) in hub lncRNAs revealed that some of transcription factor-related SNPs were significantly associated with the expression of lncRNA. In fact, these SNPs exhibited significant differential expression in disease and normal samples. CONCLUSION: These results suggest that ILD-LMN has important implications in the study of disease. Altogether, the study of RA- and ILD-related lncRNA and genes on the basis of biological network would assist in providing better treatment opportunities for ILD patients. Additionally, it would promote further research on treatment of the disease.

Research on Impermeability of Underwater Non-Dispersible Concrete in Saline Soil.

The permeability of different strength grades of submerged non-dispersible concrete with different granulated slag admixtures in a saline soil environment simulated by different erosion solutions was investigated. The variation patterns of the chloride ion diffusion coefficient and pore characteristics were tested using NEL and MIP. The microscopic morphology of the specimens in different erosion environments and with slag doping was observed using SEM. The results showed that the impermeability of concrete in sulfate and complex salt environments was significantly reduced. The resistance of concrete to chloride ion penetration increased with the increase in strength grade, and the Cl- diffusion coefficient of C35 was 5-30% lower than those of C30 and C25 underwater non-dispersible concrete at 360 d. Meanwhile, the admixture of granulated blast-furnace slag optimized the pore size distribution and improved the matrix compactness and permeability.

The phagosomal solute transporter SLC15A4 promotes inflammasome activity via mTORC1 signaling and autophagy restraint in dendritic cells.

Phagocytosis is the necessary first step to sense foreign microbes or particles and enables activation of innate immune pathways such as inflammasomes. However, the molecular mechanisms underlying how phagosomes modulate inflammasome activity are not fully understood. We show that in murine dendritic cells (DCs), the lysosomal histidine/peptide solute carrier transporter SLC15A4, associated with human inflammatory disorders, is recruited to phagosomes and is required for optimal inflammasome activity after infectious or sterile stimuli. Dextran sodium sulfate-treated SLC15A4-deficient mice exhibit decreased colon inflammation, reduced IL-1ß production by intestinal DCs, and increased autophagy. Similarly, SLC15A4-deficient DCs infected with Salmonella typhimurium show reduced caspase-1 cleavage and IL-1ß production. This correlates with peripheral NLRC4 inflammasome assembly and increased autophagy. Overexpression of constitutively active mTORC1 rescues decreased IL-1ß levels and caspase1 cleavage, and restores perinuclear inflammasome positioning. Our findings support that SLC15A4 couples phagocytosis with inflammasome perinuclear assembly and inhibition of autophagy through phagosomal content sensing. Our data also reveal the previously unappreciated importance of mTORC1 signaling pathways to promote and sustain inflammasome activity.

Psoralen induces hepatotoxicity by covalently binding to glutathione-S-transferases and the hepatic cytochrome P450.

BACKGROUND: Psoraleae Fructus has been widely used in China and its surroundings; however, Psoraleae Fructus and its compound preparation have been reported recently to cause liver injury in clinics. Thus, its safe use has attracted increasing attention. The possible mechanism is related to the metabolism of psoralen, but it still needs further clarification. PURPOSE: The present study was designed to evaluate the toxicity of psoralen and investigate the potentially related molecular mechanisms using chemical biology methods combined with animal experiments to provide evidence for the rational clinical use of psoralen. METHODS: An in vivo experiment was conducted with a time series of 20-80 mg/kg psoralen to verify its toxic performance. Target capture and click reactions were used to investigate direct targets of psoralen. Selectivity for different glutathione-S-transferase (GST) subtypes in the liver and inhibition of cytochrome P450 (CYP450) were also detected. RESULTS: Psoralen build-up in the liver is the primary cause of liver damage. Our study revealed the mechanism by which psoralen induces liver injury. Psoralen can bind directly to CYP2D6, CYP3A4, GST-α, and GST-µ and inhibit their activities, causing the depletion of glutathione (GSH) in vivo, which in turn induces hepatic damage. The special structure of α,ß-unsaturated lactones in psoralen facilitates its attachment to its target; therefore, complementing psoralen with GSH can efficiently protect the liver from damage. CONCLUSIONS: Psoralen causes a disorder in drug metabolism by inhibiting the activity of CYPs and GSTs, causing exhaustion of GSH, and subsequently leading to liver damage. The co-administration of GSH and psoralen is an effective way to avoid liver injury in clinical settings.

Epidermis-Intrinsic Transcription Factor Ovol1 Coordinately Regulates Barrier Maintenance and Neutrophil Accumulation in Psoriasis-Like Inflammation.

Skin epidermis constitutes the exterior barrier that protects the body from dehydration and environmental assaults. Barrier defects underlie common inflammatory skin diseases, but the molecular mechanisms that maintain barrier integrity and regulate epidermal-immune cell cross-talk in inflamed skin are not fully understood. In this study, we show that skin epithelia-specific deletion of Ovol1, which encodes a skin disease‒linked transcriptional repressor, impairs the epidermal barrier and aggravates psoriasis-like skin inflammation in mice in part by enhancing neutrophil accumulation and abscess formation. Through molecular studies, we identify IL-33, a cytokine with known pro-inflammatory and anti-inflammatory activities, and Cxcl1, a neutrophil-attracting chemokine, as potential weak and strong direct targets of Ovol1, respectively. Furthermore, we provide functional evidence that elevated Il33 expression reduces disease severity in imiquimod-treated Ovol1-deficient mice, whereas persistent accumulation and epidermal migration of neutrophils exacerbate it. Collectively, our study uncovers the importance of an epidermally expressed transcription factor that regulates both the integrity of the epidermal barrier and the behavior of neutrophils in psoriasis-like inflammation.

CircASH2L facilitates tumor-like biologic behaviours and inflammation of fibroblast-like synoviocytes via miR-129-5p/HIPK2 axis in rheumatoid arthritis.

BACKGROUND: Previous study showed that circular RNA Absent-Small-Homeotic-2--Like protein (circASH2L) was higher in rheumatoid arthritis (RA) patients. However, the roles and mechanisms of circASH2L in RA progression remain unclear. METHODS: Levels analysis was conducted using western blot and qRT-PCR. The proliferation, apoptosis, cell cycle progression, migration, invasiveness, and inflammation of RA fibroblast-like synoviocytes (RA-FLSs) were determined via MTT, flow cytometry, western blot, transwell, and ELISA assays. RESULTS: CircASH2L knockdown in RA-FLSs suppressed cell proliferative, migratory, and invasive capacities, triggered cell cycle arrest, promoted apoptosis, and inhibited inflammation. Mechanistically, circASH2L targeted miR-129-5p, and repression of miR-129-5p abolished the functions of circASH2L silencing on the growth, motility, and inflammation of RA-FLSs. Besides, miR-129-5p was found to directly target HIPK2, and suppressed the tumor-like biologic behaviors and inflammation of RA-FLSs via regulating HIPK2. Importantly, we proved that circASH2L could modulate HIPK2 expression via miR-129-5p. CONCLUSION: CircASH2L promoted RA-FLS growth, motility, and inflammation through miR-129-5p/HIPK2 axis.

Colonoids From Patients With Pediatric Inflammatory Bowel Disease Exhibit Decreased Growth Associated With Inflammation Severity and Durable Upregulation of Antigen Presentation Genes.

BACKGROUND: Defining epithelial cell contributions to inflammatory bowel disease (IBD) is essential for the development of much needed therapies for barrier repair. Children with very early onset (VEO)-IBD have more extensive, severe, and refractory disease than older children and adults with IBD and, in some cases, have defective barrier function. We therefore evaluated functional and transcriptomic differences between pediatric IBD (VEO and older onset) and non-IBD epithelium using 3-dimensional, biopsy-derived organoids. METHODS: We measured growth efficiency relative to histopathological and clinical parameters in patient enteroid (ileum) and colonoid (colon) lines. We performed RNA-sequencing on patient colonoids and subsequent flow cytometry after multiple passages to evaluate changes that persisted in culture. RESULTS: Enteroids and colonoids from pediatric patients with IBD exhibited decreased growth associated with histological inflammation compared with non-IBD controls. We observed increased LYZ expression in colonoids from pediatric IBD patients, which has been reported previously in adult patients with IBD. We also observed upregulation of antigen presentation genes HLA-DRB1 and HLA-DRA, which persisted after prolonged passaging in patients with pediatric IBD. CONCLUSIONS: We present the first functional evaluation of enteroids and colonoids from patients with VEO-IBD and older onset pediatric IBD, a subset of which exhibits poor growth. Enhanced, persistent epithelial antigen presentation gene expression in patient colonoids supports the notion that epithelial cell-intrinsic differences may contribute to IBD pathogenesis.

The Msi1-mTOR pathway drives the pathogenesis of mammary and extramammary Paget's disease.

Mammary and extramammary Paget's Diseases (PD) are a malignant skin cancer characterized by the appearance of Paget cells. Although easily diagnosed, its pathogenesis remains unknown. Here, single-cell RNA-sequencing identified distinct cellular states, novel biomarkers, and signaling pathways - including mTOR, associated with extramammary PD. Interestingly, we identified MSI1 ectopic overexpression in basal epithelial cells of human PD skin, and show that Msi1 overexpression in the epidermal basal layer of mice phenocopies human PD at histopathological, single-cell and molecular levels. Using this mouse model, we identified novel biomarkers of Paget-like cells that translated to human Paget cells. Furthermore, single-cell trajectory, RNA velocity and lineage-tracing analyses revealed a putative keratinocyte-to-Paget-like cell conversion, supporting the in situ transformation theory of disease pathogenesis. Mechanistically, the Msi1-mTOR pathway drives keratinocyte-Paget-like cell conversion, and suppression of mTOR signaling with Rapamycin significantly rescued the Paget-like phenotype in Msi1-overexpressing transgenic mice. Topical Rapamycin treatment improved extramammary PD-associated symptoms in humans, suggesting mTOR inhibition as a novel therapeutic treatment in PD.

A mutation in MAP2 is associated with prenatal hair follicle density.

Hairlessness is usually a rare trait in pigs; however, in this study, we found hairless (HR) pigs at a relatively high frequency in 1 pig herd. We observed that, the lower hair shaft density of HR pigs could be mainly attributed to the lower hair follicle density, and during the embryonic period, d 39-45 were a critical stage for the formation of the hair follicle. In this regard, d 41 during gestation was a particularly important point. Hair follicle morphogenesis occurring at an early stage of embryo development is similar to humans and mice. Further analyses of association studies based on single-nucleotide polymorphism chip as well as sequence data, mRNA sequencing, immunohistochemistry, and comparative genomics demonstrated that microtubule-associated protein 2 (MAP2) is a key gene responsible for hair follicle density and 1 missense mutation of A-to-G at rs328005415 in MAP2, causing a valine-to-methionine substitution leads to the HR phenotype. Considering the high homology between pigs and humans, our research has some significance for the study of the mechanisms of skin development, hair morphogenesis, and hair loss in humans by showing that the pig may be a more appropriate model in which to study these processes.-Jiang, Y., Jiang, Y., Zhang, H., Mei, M., Song, H., Ma, X., Jiang, L., Yu, Z., Zhang, Q., Ding, X. A mutation in MAP2 is associated with prenatal hair follicle density.

An Ovol2-Zeb1 transcriptional circuit regulates epithelial directional migration and proliferation.

Directional migration is inherently important for epithelial tissue regeneration and repair, but how it is precisely controlled and coordinated with cell proliferation is unclear. Here, we report that Ovol2, a transcriptional repressor that inhibits epithelial-to-mesenchymal transition (EMT), plays a crucial role in adult skin epithelial regeneration and repair. Ovol2-deficient mice show compromised wound healing characterized by aberrant epidermal cell migration and proliferation, as well as delayed anagen progression characterized by defects in hair follicle matrix cell proliferation and subsequent differentiation. Epidermal keratinocytes and bulge hair follicle stem cells (Bu-HFSCs) lacking Ovol2 fail to expand in culture and display molecular alterations consistent with enhanced EMT and reduced proliferation. Live imaging of wound explants and Bu-HFSCs reveals increased migration speed but reduced directionality, and post-mitotic cell cycle arrest. Remarkably, simultaneous deletion of Zeb1 encoding an EMT-promoting factor restores directional migration to Ovol2-deficient Bu-HFSCs. Taken together, our findings highlight the important function of an Ovol2-Zeb1 EMT-regulatory circuit in controlling the directional migration of epithelial stem and progenitor cells to facilitate adult skin epithelial regeneration and repair.

MiR-31 Mediates Inflammatory Signaling to Promote Re-Epithelialization during Skin Wound Healing.

Wound healing is essential for skin repair after injury, and it consists of hemostasis, inflammation, re-epithelialization, and remodeling phases. Successful re-epithelialization, which relies on proliferation and migration of epidermal keratinocytes, requires a reduction in tissue inflammation. Therefore, understanding the molecular mechanism underlying the transition from inflammation to re-epithelialization will help to better understand the principles of wound healing. Currently, the in vivo functions of specific microRNAs in wound healing are not fully understood. We observed that miR-31 expression is strongly induced in wound edge keratinocytes, and is directly regulated by the activity of NF-κB and signal transducer and activator of transcription 3 signaling pathways during the inflammation phase. We used miR-31 loss-of-function mouse models to demonstrate that miR-31 promotes keratinocyte proliferation and migration. Mechanistically, miR-31 activates the Ras/mitogen-activated protein kinase signaling by directly targeting Rasa1, Spred1, Spred2, and Spry4, which are negative regulators of the Ras/mitogen-activated protein kinase pathway. Knockdown of these miR-31 targets at least partially rescues the delayed scratch wound re-epithelialization phenotype observed in vitro in miR-31 knockdown keratinocytes. Taken together, these findings identify miR-31 as an important cell-autonomous mediator during the transition from inflammation to re-epithelialization phases of wound healing, suggesting a therapeutic potential for miR-31 in skin injury repair.

Stress responsive miR-31 is a major modulator of mouse intestinal stem cells during regeneration and tumorigenesis.

Intestinal regeneration and tumorigenesis are believed to be driven by intestinal stem cells (ISCs). Elucidating mechanisms underlying ISC activation during regeneration and tumorigenesis can help uncover the underlying principles of intestinal homeostasis and disease including colorectal cancer. Here we show that miR-31 drives ISC proliferation, and protects ISCs against apoptosis, both during homeostasis and regeneration in response to ionizing radiation injury. Furthermore, miR-31 has oncogenic properties, promoting intestinal tumorigenesis. Mechanistically, miR-31 acts to balance input from Wnt, BMP, TGFß signals to coordinate control of intestinal homeostasis, regeneration and tumorigenesis. We further find that miR-31 is regulated by the STAT3 signaling pathway in response to radiation injury. These findings identify miR-31 as a critical modulator of ISC biology, and a potential therapeutic target for a broad range of intestinal regenerative disorders and cancers.

Effect of Shenmai injection on preventing the development of nitroglycerin-induced tolerance in rats.

Long-term nitroglycerin (NTG) therapy causes tolerance to its effects attributing to increased oxidative stress and endothelial dysfunction. Shenmai injection (SMI), which is clinically used to treat cardiovascular diseases, consists of two herbal medicines, Ginseng Rubra and Ophiopogonjaponicas, and is reported to have antioxidant effects. The present study was designed to investigate the potential preventive effects of Shenmai injection on development of nitroglycerin-induced tolerance. The present study involves both in vivo and in vitro experiments to investigate nitroglycerin-induced tolerance. We examined the effect of Shenmai injection on the cardiovascular oxidative stress by measuring the serum levels of malondialdehyde (MDA) and superoxide dismutase (SOD). Endothelial dysfunction was determined by an endothelium-dependent vasorelaxation method in aortic rings and NOS activity. Inhibition of the cGMP/cGK-I signalling pathway was determined from released serum levels of cGMP and the protein expression levels of sGC, cGK-I, PDE1A and P-VASP by western blot. Here, we showed that SMI ameliorated the decrease in AV Peak Vel, the attenuation in the vasodilation response to nitroglycerin and endothelial dysfunction. SMI also reduced the cardiovascular oxidative stress by reducing the release of MDA and increasing the activity of SOD. Shenmai injection further ameliorated inhibition of the cGMP/cGK-I signalling pathway triggered by nitroglycerin-induced tolerance through up-regulating the protein expression of sGC, cGK-I, and P-VASP and down- regulating the proteins expression of PDE1A. In vitro studies showed that Shenmai injection could recover the attenuated vasodilation response to nitroglycerin following incubation (of aortic rings) with nitroglycerin via activating the enzymes of sGC and cGK-I. Therefore, we conclude that Shenmai injection could prevent NTG nitroglycerin-induced tolerance at least in part by decreasing the cardiovascular oxidative stress, meliorating the endothelial dysfunction and ameliorating the inhibition of the cGMP/cGK-I signalling pathway. These findings indicate the potential of Shenmai injection (SMI) as a promising medicine for preventing the development of nitroglycerin-induced tolerance.

Msi2 Maintains Quiescent State of Hair Follicle Stem Cells by Directly Repressing the Hh Signaling Pathway.

Hair follicles (HFs) undergo precisely regulated cycles of active regeneration (anagen), involution (catagen), and relative quiescence (telogen). Hair follicle stem cells (HFSCs) play important roles in regenerative cycling. Elucidating mechanisms that govern HFSC behavior can help uncover the underlying principles of hair development, hair growth disorders, and skin cancers. RNA-binding proteins of the Musashi (Msi) have been implicated in the biology of different stem cell types, yet they have not been studied in HFSCs. Here we utilized gain- and loss-of-function mouse models to demonstrate that forced MSI2 expression retards anagen entry and consequently delays hair growth, whereas loss of Msi2 enhances hair regrowth. Furthermore, our findings show that Msi2 maintains quiescent state of HFSCs in the process of the telogen-to-anagen transition. At the molecular level, our unbiased transcriptome profiling shows that Msi2 represses Hedgehog signaling activity and that Shh is its direct target in the hair follicle. Taken together, our findings reveal the importance of Msi2 in suppressing hair regeneration and maintaining HFSC quiescence. The previously unreported Msi2-Shh-Gli1 pathway adds to the growing understanding of the complex network governing cyclic hair growth.