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Irx5 is a vital transcription factor that establishes the transmural heterogeneity of ventricular myocyte contractility, thereby ensuring proper contractile function in the healthy heart. Regional differences in excitation-contraction coupling in the ventricular myocardium are primarily mediated through the inverse relationship between Irx5 and the fast transient outward K+ current ( Ito,f) across the ventricular wall.

The molecular mechanisms allowing hair follicles to periodically activate their stem cells (HFSCs) are incompletely characterized. Here, we identify the transcription factor IRX5 as a promoter of HFSC activation. Irx5-/- mice have delayed anagen onset, with increased DNA damage and diminished HFSC proliferation. Open chromatin regions form near cell cycle progression and DNA damage repair genes in Irx5-/- HFSCs. DNA damage repair factor BRCA1 is an IRX5 downstream target. Inhibition of FGF kinase signaling partially rescues the anagen delay in Irx5-/- mice, suggesting that the Irx5-/- HFSC quiescent phenotype is partly due to failure to suppress Fgf18 expression. Interfollicular epidermal stem cells also show decreased proliferation and increased DNA damage in Irx5-/-mice. Consistent with a role for IRX5 as a promoter of DNA damage repair, we find that IRX genes are upregulated in many cancer types and that there is a correlation between IRX5 and BRCA1 expression in breast cancer.

Supplementary Figures 1-3 from Multipotent CD15+ Cancer Stem Cells in Patched-1–Deficient Mouse Medulloblastoma

Supplementary Figure 9 from Multipotent CD15+ Cancer Stem Cells in Patched-1–Deficient Mouse Medulloblastoma

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Supplementary Figure 4 from Multipotent CD15+ Cancer Stem Cells in Patched-1–Deficient Mouse Medulloblastoma

Supplementary Figures 4-6 from Multipotent CD15+ Cancer Stem Cells in Patched-1–Deficient Mouse Medulloblastoma

Supplementary Figure 6 from Multipotent CD15+ Cancer Stem Cells in Patched-1–Deficient Mouse Medulloblastoma

Supplementary Figure 1 from Multipotent CD15+ Cancer Stem Cells in Patched-1–Deficient Mouse Medulloblastoma

Supplementary Figure 5 from Multipotent CD15+ Cancer Stem Cells in Patched-1–Deficient Mouse Medulloblastoma

Supplementary Figures 7-9 from Multipotent CD15+ Cancer Stem Cells in Patched-1–Deficient Mouse Medulloblastoma

Supplementary Figure 2 from Multipotent CD15+ Cancer Stem Cells in Patched-1–Deficient Mouse Medulloblastoma

Supplementary Figure 3 from Multipotent CD15+ Cancer Stem Cells in Patched-1–Deficient Mouse Medulloblastoma

Supplementary Figure 8 from Multipotent CD15+ Cancer Stem Cells in Patched-1–Deficient Mouse Medulloblastoma

Development of mammalian auditory epithelium, the organ of Corti, requires precise control of both cell cycle withdrawal and differentiation. Sensory progenitors (prosensory cells) in the cochlear apex exit the cell cycle first but differentiate last. Sonic hedgehog (Shh) signaling is required for the spatiotemporal regulation of prosensory cell differentiation, but the underlying mechanisms remain unclear. Here, we show that suppressor of fused (Sufu), a negative regulator of Shh signaling, is essential for controlling the timing and progression of hair cell (HC) differentiation. Removal of Sufu leads to abnormal Atoh1 expression and a severe delay of HC differentiation due to elevated Gli2 mRNA expression. Later in development, HC differentiation defects are restored in the Sufu mutant by the action of speckle-type PDZ protein (Spop), which promotes Gli2 protein degradation. Deletion of both Sufu and Spop results in robust Gli2 activation, exacerbating HC differentiation defects. We further demonstrate that Gli2 inhibits HC differentiation through maintaining the progenitor state of Sox2 + prosensory cells. Along the basal–apical axis of the developing cochlea, the Sox2 expression level is higher in the progenitor cells than in differentiating cells and is down-regulated from base to apex as differentiation proceeds. The dynamic spatiotemporal change of Sox2 expression levels is controlled by Shh signaling through Gli2. Together, our results reveal key functions of Gli2 in sustaining the progenitor state, thereby preventing HC differentiation and in turn governing the basal–apical progression of HC differentiation in the cochlea.

Irx1 and Irx2 (Irx1/2) are two closely linked and widely expressed members of the conserved Iroquois homeobox family of transcription factors. Despite mounting evidence suggesting the importance of homologs of these genes in many aspects of vertebrate development and function, the role of Irx1/2 in mammals has remained largely unknown. Here, we used mice carrying our newly generated Irx1flox and Irx1floxIrx2del mutant alleles to perform a stepwise genetic ablation of Irx1 and Irx2 levels. Our analysis revealed reduced postnatal growth and viability of Irx1KO mice with gross histological defects in the lung and gut and demonstrated that ablation of one copy of Irx2 in these mice results in neonatal lethality with exacerbated phenotypic defects. Conversely, while Irx2KO mice appear normal, ablation of one copy of Irx1 in these mutants leads to lethality at weaning. Furthermore, we found that homozygous deletion of both Irx1 and Irx2 results in embryonic lethality by mid-gestation with defective extraembryonic vasculature. Our results illustrate that Irx1 and Irx2 play distinct dose-dependent cooperative functions during both the early and late stages of mouse development.

Obesity is mainly due to excessive food intake. IRX3 and IRX5 have been suggested as determinants of obesity in connection with the intronic variants of FTO, but how these genes contribute to obesity via changes in food intake remains unclear. Here, we show that mice doubly heterozygous for Irx3 and Irx5 mutations exhibit lower food intake with enhanced hypothalamic leptin response. By lineage tracing and single-cell RNA sequencing using the Ins2-Cre system, we identify a previously unreported radial glia-like neural stem cell population with high Irx3 and Irx5 expression in early postnatal hypothalamus and demonstrate that reduced dosage of Irx3 and Irx5 promotes neurogenesis in postnatal hypothalamus leading to elevated numbers of leptin-sensing arcuate neurons. Furthermore, we find that mice with deletion of Irx3 in these cells also exhibit a similar food intake and hypothalamic phenotype. Our results illustrate that Irx3 and Irx5 play a regulatory role in hypothalamic postnatal neurogenesis and leptin response. Irx3 and Irx5 are effectors of the FTO locus, which is associated with obesity. Son et al. show regulation of hypothalamic neurogenesis by Irx3 and Irx5, uncovering a role for these genes in leptin response and energy homeostasis.

Childhood obesity is rapidly rising in China and effective diet interventions are needed. Here, we determine whether the Chinese government-recommended diet (GRD) or a modified diet of further restriction of sugar and ultra-processed food but without energy restriction, minimally processed diet (MPD) is effective on weight loss in children and adolescents with obesity/overweight.This open-label, randomized study included 60 children and adolescents between 5-18 years old with overweight/obesity. Participants were randomized 1:1 to the GRD or MPD and self-managed at home for 12 weeks. Both groups received general recommendations in physical activities. The changes were evaluated in body weight, fasting glucose and insulin, lipid metabolism and serum uric acid between baseline and week 12.The results indicated great reductions by time for BMI, BMI z-score, fat mass percentage and fat mass index in both groups. An obvious decrease by time for weight was found in the MPD group (p0.001) as well as fasting glucose (p=0.005), fasting insulin (p=0.001), total cholesterol (p=0.007) and serum uric acid (p=0.006). As for the amount of visceral fat, greater reduction by time was observed in MPD group compared with GRD group.A 12-week self-intervention combining the Chinese government-recommended diet with physical activities was effective on weight loss in children and adolescents with overweight/obesity. The minimally processed diet was more effective on decreasing visceral fat mass and may be beneficial to improving insulin resistance. Further studies are required to assess long-term outcomes of the general public.

Obesity, a leading cause of several metabolic abnormalities, is mainly caused by imbalanced energy homeostasis. IRX3 and IRX5 have been suggested as genetic determinants of obesity in connection with the intronic variants of the FTO gene, the strongest genetic risk factor of polygenic obesity in humans. Although the causal effects of Irx3 and its cooperation with Irx5 in obesity and associated metabolic abnormalities have been demonstrated in vivo, the function of Irx5 in energy homeostasis remains unclear. Here we aim to decipher the actions of Irx5 in the regulation of obesity and metabolic abnormalities.We employed a mouse model homozygous for an Irx5-knockout (Irx5Irx5Our study demonstrates that Irx5 is a genetic factor determining body mass/composition and obesity and regulates both energy expenditure and intake.

Hirschsprung disease (HSCR) is characterized by the absence of enteric neurons caused by the defects of enteric neural crest cells (ENCCs), leading to intestinal obstruction. Here, using iPSC-based models of HSCR and single-cell transcriptomic analysis, we identified a core gene set of 118 genes commonly dysregulated in all HSCR-ENCCs, with HDAC1 found to be a master regulator of these genes. Furthermore, upregulation of RNA splicing mediators and enhanced alternative splicing events were associated with severe form of HSCR. In particular, the higher inclusion rate of exon 9 in PTBP1 and the perturbed expression of a PTBP1-target, PKM, were significantly enriched in these HSCR-ENCCs, and associated with the defective oxidative-phosphorylation (OXPHOS) and impaired neurogenesis. Hedgehog-induced OXPHOS significantly enhanced the survival and differentiation capacity of HSCR-ENCCs. In sum, we have defined the core factors underpinning HSCR disease and demonstrated the implications of OXPHOS in ENCC development and HSCR pathogenesis.

Major obstacles in brain cancer treatment include the blood-tumor barrier (BTB), which limits the access of most therapeutic agents, and quiescent tumor cells, which resist conventional chemotherapy. Here, we show that Sox2

Stress urinary incontinence is of concern in both pediatric and adult population. Double mutant GLI family zinc finger Gli2We used 13 cluster of differentiation 1 (CD-1) mice (7-9 weeks) for demonstration of histology of the bladder and urethra. There were 3 Wild Gli2Gross and histologic appearance confirmed the previously reported widening of bladder outlet and hypoplasia of smooth muscles in female urethra and also established them in the male urethra of Gli2The histological changes in the bladder neck and urethra were consistent to those previously reported. While previous report described the findings in female mice only, we confirmed that these findings are also present in males as well as prostatic hypoplasia, a possible additional factor leading to stress incontinence. The most important finding in the present study however, was the detection of premature termination of spinal cord in the DKO Gli2The incontinence in male as well as female Gli2

The paraventricular nucleus of the hypothalamus (PVH) contains a heterogeneous cluster of Sim1-expressing neurons critical for feeding regulation. Sim1 haploinsufficiency results in hyperphagic obesity with disruption of PVH neurons, yet the molecular profiles of PVH neurons and the mechanism underlying the defects of Sim1 haploinsufficiency are not well understood. By single-cell RNA sequencing, we identified two major populations of Sim1+ PVH neurons, which are differentially affected by Sim1 haploinsufficiency. The Iroquois homeobox genes Irx3 and Irx5 have been implicated in the hypothalamic control of energy homeostasis. We found that Irx3 and Irx5 are ectopically expressed in the Sim1+ PVH cells of Sim1+/− mice. By reducing their dosage and PVH-specific deletion of Irx3, we demonstrate that misexpression of Irx3 and Irx5 contributes to the defects of Sim1+/− mice. Our results illustrate abnormal hypothalamic activities of Irx3 and Irx5 as a central mechanism disrupting PVH development and feeding regulation in Sim1 haploinsufficiency.

Description, Irx3 and Irx5 misexpression in paraventricular nucleus of the hypothalamus leads to hyperphagic obesity in Sim1 haploinsufficiency., The paraventricular nucleus of the hypothalamus (PVH) contains a heterogeneous cluster of Sim1-expressing neurons critical for feeding regulation. Sim1 haploinsufficiency results in hyperphagic obesity with disruption of PVH neurons, yet the molecular profiles of PVH neurons and the mechanism underlying the defects of Sim1 haploinsufficiency are not well understood. By single-cell RNA sequencing, we identified two major populations of Sim1+ PVH neurons, which are differentially affected by Sim1 haploinsufficiency. The Iroquois homeobox genes Irx3 and Irx5 have been implicated in the hypothalamic control of energy homeostasis. We found that Irx3 and Irx5 are ectopically expressed in the Sim1+ PVH cells of Sim1+/− mice. By reducing their dosage and PVH-specific deletion of Irx3, we demonstrate that misexpression of Irx3 and Irx5 contributes to the defects of Sim1+/− mice. Our results illustrate abnormal hypothalamic activities of Irx3 and Irx5 as a central mechanism disrupting PVH development and feeding regulation in Sim1 haploinsufficiency.

Obesity, a leading cause of several metabolic abnormalities, is mainly due to an imbalance of energy homeostasis. IRX3 and IRX5 have been suggested as determinants of obesity in connection with the intronic variants of FTO, the strongest genetic risk factor of polygenic obesity in humans. Although the causal effects of Irx3 on obesity and its related metabolic consequences have been demonstrated in vivo, the metabolic function of Irx5 remains unclear. In this study, using mice homozygous for an Irx5-knockout (Irx5KO) allele, we show a direct link between Irx5 expression and regulation of body mass/composition and energy homeostasis. Irx5KO mice are leaner and resistant to diet-induced obesity and associated metabolic abnormalities, primarily through the loss of adiposity with an increase in basal metabolic rate with adipose thermogenesis and lower food intake. Furthermore, our long-term feeding analysis found that Irx3 mutant mouse lines also have less food intake, indicating that lower caloric intake also contributes to their lean phenotype. Together, these results demonstrate that Irx5 is critical for energy homeostasis and regulation of body mass/composition and suggest that it likely acts in other tissues beyond adipocytes.

Stomach and intestinal stem cells are located in discrete niches called the isthmus and crypt, respectively. Recent studies have demonstrated a surprisingly conserved role for Wnt signaling in gastrointestinal development. Although intestinal stromal cells secrete Wnt ligands to promote stem cell renewal, the source of stomach Wnt ligands is still unclear. Here, by performing single cell analysis, we identify gastrointestinal stromal cell populations with transcriptome signatures that are conserved between the stomach and intestine. In close proximity to epithelial cells, these perictye-like cells highly express telocyte and pericyte markers as well as Wnt ligands, and they are enriched for Hh signaling. By analyzing mice activated for Hh signaling, we show a conserved mechanism of GLI2 activation of Wnt ligands. Moreover, genetic inhibition of Wnt secretion in perictye-like stromal cells or stromal cells more broadly demonstrates their essential roles in gastrointestinal regeneration and development, respectively, highlighting a redundancy in gastrointestinal stem cell niches., Wnt signals for intestinal stem cell self-renewal originate from the stroma and Paneth cells, but the source in stomach is unclear. Here the authors identify a conserved population of stromal cells adjacent to stomach epithelia where Gli2 activates Wnt ligands to promote gastrointestinal regeneration and development.

Summary Introduction and objective The effects estrogen and testosterone have on penile wound healing are still uncertain. This study evaluated the effects of these hormones on the wound healing process of penile and non-penile skin in wild-type (Mus musculus species) 4–5-week-old mice. Methodology Seventy wild-type Mus musculus species were randomly assigned to four groups control (n = 17), 1-week post-operative topical estrogen (n = 18), 1-week pre-operative testosterone (n = 17), and immediate post-operative testosterone (n = 18). Incisions were made on the ventrum of the penis and dorsal neck skin. On post-operative day 3, 7, and 14, incision sites were harvested. Evaluation was performed grossly for postsurgical penile edema and histologically for inflammatory cell concentration, presence of fibrinopurulent materials and distribution of collagen-fibroblastic cells. Each treatment group was compared at the three post-operative time points using the Fisher—Freeman--Halton exact test. CD34 and androgen receptor immunohistostaining was performed for between-group differences to assess microvascular density or vasodilatation and androgen receptor upregulation. Results In this study, the experiment noted significant penile edema on post-operative day 7 in the testosterone groups, whereas less edema in the estrogen group (P = 0.010; Figure). On histologic evaluation of the penile wounds, a significantly increased inflammatory cell concentration was noted for both pre-operative and post-operative testosterone groups on post-operative day 14 (P = 0.023). The estrogen group revealed significantly increased fibrinopurulent material on the 3rd and 7th post-operative days (P = 0.045 and P = 0.005, respectively). No significant between-group differences in the collagen-fibroblastic distribution were noted over the three-time phases. On histologic evaluation of the skin wounds, no significant differences were noted between the groups for inflammatory cell concentration and presence of fibrinopurulent materials. However, compared with the testosterone treatment groups, a significant higher collagen-fibroblast distribution was noted in the estrogen groups on post-operative day 3 and 14 (P = 0.001 and P = 0.044, respectively). Conclusion Sex hormones, when given peri-operatively, may affect the wound healing process in mice. Testosterone appears to stimulate a prolonged inflammatory effect on penile wounds. Conversely, estrogen induces a fibrinopurulent congregation early in the penile wound healing process. For general skin healing, estrogen induces earlier collagen and fibroblast distribution, whereas testosterone has a delayed effect. The findings of this study should be further investigated in larger animal model with longer follow-up period. Download : Download high-res image (472KB) Download : Download full-size image Summary Fig. .

Summary: Gut mesenchyme provides key stem cell niche signals such as Wnt ligands, but how these signals are regulated is unclear. Because Hedgehog (Hh) signaling is critical for gut mesenchymal development and tumorigenesis, we investigated Hh-mediated mechanisms by analyzing mice deleted for key negative regulators of Hh signaling, Sufu and/or Spop, in the gut mesenchyme, and demonstrated their dosage-dependent roles. Although these mutants exhibit abnormal mesenchymal cell growth and functionally defective muscle layers, villification is completed with proper mesenchymal clustering, implying a permissive role for Hh signaling. These mesenchymal defects are partially rescued by Gli2 reduction. Consistent with increased epithelial proliferation caused by abnormal Hh activation in development, Sufu reduction promotes intestinal tumorigenesis, whereas Gli2 heterozygosity suppresses it. Our analyses of chromatin and GLI2 binding genomic regions reveal its transcriptional regulation of stem cell niche signals through enhancers, providing mechanistic insight into the intestinal stem cell niche in development and tumorigenesis. : Coquenlorge et al. utilize various mouse models to investigate the mechanisms of gut stromal stem cell niche signals in development and cancer. This work demonstrates that Hh signaling in the gut stroma directly activates Wnt niche signals, and its dysregulation promotes epithelial proliferation and intestinal tumorigenesis. Keywords: Sufu, Spop, GLI2, villus formation, mesenchymal proliferation, WNT, intestinal tumorigenesis