Probes for INS

Adult stem cells play an essential role in adult organ physiology and tissue repair and regeneration. While much has been learnt about the property and function of various adult stem cells, the mechanisms of their development remain poorly understood in mammals. Earlier studies suggest that the formation of adult mouse intestinal stem cells takes place during the first few weeks after birth, the postembryonic period when plasma thyroid hormone (T3) levels are high. Furthermore, deficiency in T3 signaling leads to defects in adult mouse intestine, including reduced cell proliferation in the intestinal crypts, where stem cells reside. Our earlier studies have shown that protein arginine methyltransferase 1 (PRMT1), a T3 receptor coactivator, is highly expressed during intestinal maturation in mouse.We have analyzed the expression of PRMT1 by immunohistochemistry and studied the effect of tissue-specific knockout of PRMT1 in the intestinal epithelium.We show that PRMT1 is expressed highly in the proliferating transit amplifying cells and crypt base stem cells. By using a conditional knockout mouse line, we have demonstrated that the expression of PRMT1 in the intestinal epithelium is critical for the development of the adult mouse intestine. Specific removal of PRMT1 in the intestinal epithelium results in, surprisingly, more elongated adult intestinal crypts with increased cell proliferation. In addition, epithelial cell migration along the crypt-villus axis and cell death on the villus are also increased. Furthermore, there are increased Goblet cells and reduced Paneth cells in the crypt while the number of crypt base stem cells remains unchanged.Our finding that PRMT1 knockout increases cell proliferation is surprising considering the role of PRMT1 in T3-signaling and the importance of T3 for intestinal development, and suggests that PRMT1 likely regulates pathways in addition to T3-signaling to affect intestinal development and/or homeostasis, thus affecting cell proliferating and epithelial turn over in the adult.

Olfactomedin 4 (OLFM4) has been demonstrated to be upregulated in various cancers and involved in many cellular processes such as cell adhesion, apoptosis, and cell proliferation. In gastric cancer, clinicopathological relevance of OLFM4 expression has been reported. However, there are few studies showing how expression of OLFM4 evolves during multistep gastric carcinogenesis. In this study, we investigated OLFM4 expression during gastric carcinogenesis using RNA in situ hybridization (ISH). We found that OLFM4 expression is absent in normal gastric mucosa, begins to appear at the isthmus region in gastric glands in chronic gastritis, and is remarkably increased in intestinal metaplasia (IM). Interestingly, gastric-type glands around IM frequently expressed OLFM4 before CDX2 was expressed, suggesting that OLFM4 might be involved in regulating CDX2 expression. However, overexpression of OLFM4 failed to induce CDX2 transcription. All gastric adenomas were strongly positive for OLFM4. OLFM4 expression was higher in intestinal type, well to moderately differentiated and early-stage adenocarcinomas, and decreased in poorly differentiated and advanced-stage gastric cancer (GC). Although OLFM4 expression had no prognostic value for GC overall (P = 0.441), it was associated with poor survival of GC in stage II, III, and IV (P = 0.018), suggesting that OLFM4 expression has prognostic significance for late-stage GC. Our findings suggest that OLFM4 is not only involved in early stages of gastric carcinogenesis but also a useful prognostic marker for advanced GC, which is encouraging for further studies exploring OLFM4 as a potential target for therapy of GC.

Lateral flight membranes, or patagia, have evolved repeatedly in diverse mammalian lineages. While little is known about patagium development, its recurrent evolution may suggest a shared molecular basis. By combining transcriptomics, developmental experiments, and mouse transgenics, we demonstrate that lateral Wnt5a expression in the marsupial sugar glider (Petaurus breviceps) promotes the differentiation of its patagium primordium. We further show that this function of Wnt5a reprises ancestral roles in skin morphogenesis predating mammalian flight and has been convergently used during patagium evolution in eutherian bats. Moreover, we find that many genes involved in limb development have been redeployed during patagium outgrowth in both the sugar glider and bat. Together, our findings reveal that deeply conserved genetic toolkits contribute to the evolutionary transition to flight in mammals.

Gastric intestinal metaplasia (IM) is a highly prevalent preneoplastic lesion; however, the molecular mechanisms regulating its development remain unclear. We have previously shown that a population of cells expressing the intestinal stem cell (ISC) marker LGR5 increases remarkably in IM. In this study, we further investigated the molecular characteristics of these LGR5+ cells in IM by examining the expression profile of several ISC markers. Notably, we found that ISC markers-including OLFM4 and EPHB2-are positively associated with the CDX2 expression in non-tumorous gastric tissues. This finding was confirmed in stomach lesions with or without metaplasia, which demonstrated that OLFM4 and EPHB2 expression gradually increased with metaplastic progression. Moreover, RNA in situ hybridization revealed that LGR5+ cells coexpress several ISC markers and remained confined to the base of metaplastic glands, reminiscent to that of normal intestinal crypts, whereas those in normal antral glands expressed none of these markers. Furthermore, a large number of ISC marker-expressing cells were diffusely distributed in gastric adenomas, suggesting that these markers may facilitate gastric tumorigenesis. In addition, Barrett's esophagus (BE)-which is histologically similar to intestinal metaplasia-exhibited a similar distribution of ISC markers, indicating the presence of a stem cell population with intestinal differentiation potential. In conclusion, we identified that LGR5+ cells in gastric IM and BE coexpress ISC markers, and exhibit the same expression profile as those found in normal intestinal crypts. Taken together, these results implicate an intestinal-like stem cell population in the pathogenesis of IM, and provide an important basis for understanding the development and maintenance of this disease.

Background Orofacial clefts are the most common birth defects affecting 1 in 750 live births worldwide. Various genetic loci to be involved in nonsyndromic cleft lip and palate has been identified with a variation among populations. Wnt5a is expressed in the frontonasal prominence and maxillary process, which fuse to form the primary palate. Therefore, its dysregulation can lead to certain birth defects along with other diseases. Single nucleotide polymorphism (rs566926) in Wnt5A shows a significant association with nonsyndromic cleft lip and palate in Brazilian and European American populations. Objective The aim of the present study was to describe single nucleotide polymorphism (SNP; rs566926) in patients with nonsyndromic cleft lip and palate in a Pakistani population. Methods This study was conducted on 120 patients with nonsyndromic cleft lip and palate. Demographics and phenotypes were noted. Blood samples were collected in ethylenediaminetetraacetic acid vials. DNA was extracted followed by conventional polymerase chain reaction. SNP (566926) was determined by Sanger sequencing. Data were analyzed using NCBI Blast and SPSS (24.0). Results The mean age of n = 30 patients was 51.33 ± 61.33 months. Sixty percent were male and 40% were female. Regarding cleft types, 70% were both cleft lip and palate, 26% cleft lip only, and 3.3% cleft palate only. Heterozygous polymorphism (T/G) was seen in 33.3% of patients with both cleft lip and palate with bilateral involvement and heterozygous polymorphism (T) was seen in 16.6%. Conclusions SNP in the WNT5A gene is associated with cleft lip and palate, supporting its involvement in pathogenesis of cleft lip and palate. Further studies are recommended to determine the role of Wnt5a genes during craniofacial development.

Acute intestinal mucositis is a common off-target effect of chemotherapy, leading to co-morbidities such as vomiting, diarrhea, sepsis, and death. We previously demonstrated that the presence of enteric bacteria modulates the extent of jejunal epithelial damage induced by doxorubicin (DXR) in mice. Despite conventional thinking of the crypt as a sterile environment, recent evidence suggests that bacterial signaling influences aISC function. In this study, we labeled aISCs using transgenic Lgr5-driven fluorescence or with immunostaining for OLFM4. We examined the effect of DXR in both germ free (GF) mice and mice depleted of microbiota using an established antimicrobial treatment protocol (AMBx). We found differences in DXR-induced loss of aISCs between GF mice and mice treated with AMBx. aISCs were decreased after DXR in GF mice, whereas AMBx mice retained aISC expression after DXR. Neither group of mice exhibited an inflammatory response to DXR, suggesting the difference in aISC retention was not due to differences in local tissue inflammation. Therefore, we suspected that there was a protective microbial signal present in the AMBx mice that was not present in the GF mice. 16S rRNA sequencing of jejunal luminal contents demonstrated that AMBx altered the fecal and jejunal microbiota. In the jejunal contents, AMBx mice had increased abundance of Ureaplasma and Burkholderia. These results suggest pro-survival signaling from microbiota in AMBx-treated mice to the aISCs, and that this signaling maintains aISCs in the face of chemotherapeutic injury. Manipulation of the enteric microbiota presents a therapeutic target for reducing the severity of chemotherapy-associated mucositis.

Abstract Aims Intestinal stem cell (ISC) markers such as LGR5, ASCL2, EPHB2 and OLFM4 and their clinical implications have been extensively studied in colorectal cancers (CRCs). However, little is known about their expression in precancerous lesions of CRCs. Here, we investigated the expression and distribution of ISC markers in serrated polyps and conventional adenomas. Methods and results RT-PCR analysis revealed that all ISC markers were significantly upregulated in conventional adenomas with low grade dysplasia (CALGs) compared with other lesions. RNA in situ hybridization confirmed that CALGs exhibited strong and diffuse expression of all ISC markers, which indicate a stem cell-like phenotype. However, normal colonic mucosa hyperplastic polyps and sessile serrated adenomas harbored LGR5+ cells that were confined to the crypt base and demonstrated an organized expression of ISC markers. Notably, in traditional serrated adenomas, expression of LGR5 and ASCL2 was localized to the ectopic crypts as in the normal crypts, but expression of EPHB2 and OLFM4 was distributed in a diffuse manner, which is suggestive of a progenitor-like features. Conclusions The expression and distribution profile of ISC markers possibly provides insights into the organization of stem and progenitor-like cells in each type of precancerous lesion of CRC

In mammalian ovaries, immature oocytes are reserved in primordial follicles until their activation for potential ovulation. Precise control of primordial follicle activation (PFA) is essential for reproduction, but how this is achieved is unclear. Here, we show that canonical wingless-type MMTV integration site family (WNT) signaling is pivotal for pre-granulosa cell (pre-GC) activation during PFA. We identified several WNT ligands expressed in pre-GCs that act in an autocrine manner. Inhibition of WNT secretion from pre-GCs/GCs by conditional knockout (cKO) of the wntless (Wls) gene led to female infertility. In Wls cKO mice, GC layer thickness was greatly reduced in growing follicles, which resulted in impaired oocyte growth with both an abnormal, sustained nuclear localization of forkhead box O3 (FOXO3) and reduced phosphorylation of ribosomal protein S6 (RPS6). Constitutive stabilization of β-catenin (CTNNB1) in pre-GCs/GCs induced morphological changes of pre-GCs from a squamous into a cuboidal form, though it did not influence oocyte activation. Our results reveal that canonical WNT signaling plays a permissive role in the transition of pre-GCs to GCs, which is an essential step to support oocyte growth.

The cervical epithelium undergoes changes in proliferation, differentiation, and function that are critical to ensure fertility and maintain pregnancy. Here, we identify cervical epithelial subtypes in non-pregnant, pregnant, and in labor mice using single-cell transcriptome and spatial analysis. We identify heterogeneous subpopulations of epithelia displaying spatial and temporal specificity. Notably in pregnancy, two goblet cell subtypes are present in the most luminal layers with one goblet population expanding earlier in pregnancy than the other goblet population. The goblet populations express novel protective factors and distinct mucosal networks. Single-cell analysis in a model of cervical epithelial barrier disruption indicates untimely basal cell proliferation precedes the expansion of goblet cells with diminished mucosal integrity. These data demonstrate how the cervical epithelium undergoes continuous remodeling to maintain dynamic states of homeostasis in pregnancy and labor, and provide a framework to understand perturbations in epithelial health that increase the risk of premature birth.

Runting stunting syndrome (RSS) in broiler chickens is characterized by altered intestinal morphology and gene expression and stunted growth. The objective of this study was to conduct a retrospective study of gene expression in stem and differentiated cells in the small intestine of RSS chicks. Two different models of RSS were analyzed: broiler chicks that were experimentally infected and broiler chicks that were naturally infected. Experimentally infected chicks were exposed to litter from infected flocks (RSS-litter chicks) or infected with astrovirus (RSS-astrovirus chicks). Intestinal samples from naturally infected chicks showing clinical signs of RSS were acquired from commercial farms in Georgia and were brought into a poultry diagnostic lab (RSS-clinical-GA) and from farms in Brazil that had a history of RSS (RSS-clinical-BR). The RSS-clinical-BR chicks were separated into those that were positive or negative for gallivirus based on DNA sequencing. Intestinal morphology and intestinal cell type were identified in archived formalin-fixed, paraffin-embedded tissues. In situ hybridization for cell-specific mRNA was used to identify intestinal stem cells expressing olfactomedin 4 (Olfm4), proliferating cells expressing Ki67, absorptive cells expressing sodium glucose cotransporter 1 (SGLT1) and peptide transporter 1 (PepT1), and goblet cells expressing mucin 2 (Muc2). RSS-litter and RSS-clinical-GA chicks showed 4% to 7.5% cystic crypts, while gallivirus-positive RSS-clinical-BR chicks showed 11.7% cystic crypts. RSS-astrovirus and gallivirus-negative RSS-clinical-BR chicks showed few cystic crypts. RSS-litter and gallivirus-positive RSS-clinical-BR chicks showed an increase in crypt depth compared to control or gallivirus-negative chicks, respectively. There was no expression of Olfm4 mRNA in the stem cells of RSS-litter and RSS-clinical-GA chicks, in contrast to the normal expression of Olfm4 mRNA in RSS-astrovirus and RSS-clinical-BR chicks. All chicks regardless of infection status showed normal expression of Ki67 mRNA in crypt cells, Muc2 mRNA in goblet cells, and SGLT1 or PepT1 mRNA in enterocytes. These results demonstrate that RSS, which can be induced by different etiologies, can show differences in the expression of the stem cell marker Olfm4.

Dietary signals are known to modulate stemness and tumorigenicity of intestinal progenitors; however, the impact of a high-fat diet (HFD) on the intestinal stem cell (ISC) niche and its association with colorectal cancer remains unclear. Thus, we aimed to investigate how a HFD affects the ISC niche and its regulatory factors.Mice were fed a purified diet (PD) or HFD for 2 months. The expression levels of ISC-related markers, ISC-supportive signals, and Wnt2b were assessed with real-time quantitative polymerase chain reaction, in situ hybridization, and immunofluorescence staining. RNA sequencing and metabolic function were analyzed in mesenchymal stromal cells (MSCs) from PD- and HFD-fed mice. Fecal microbiota were analyzed by 16s rRNA sequencing. Bile salt hydrolase activity and bile acid (BA) levels were measured.We found that expression of CD44 and Wnt signal-related genes was higher in the colonic crypts of HFD-fed mice than in those fed a PD. Within the ISC niche, MSCs were expanded and secreted predominant levels of Wnt2b in the colon of HFD-fed mice. Of note, increased energy metabolism and cancer-associated fibroblast (CAF)-like properties were found in the colonic MSCs of HFD-fed mice. Moreover, colonic MSCs from HFD-fed mice promoted the growth of tumorigenic properties and accelerated the expression of cancer stem cell (CSC)-related markers in colon organoids. In particular, production of primary and secondary BAs was increased through the expansion of bile salt hydrolase-encoding bacteria in HFD-fed mice. Most importantly, BAs-FXR interaction stimulated Wnt2b production in colonic CAF-like MSCs.HFD-induced colonic CAF-like MSCs play an indispensable role in balancing the properties of CSCs through activation of the BAs-FXR axis.