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Dysregulated glucose metabolism is associated with many chronic diseases such as obesity and type 2 diabetes mellitus (T2DM), and strategies to restore and maintain glucose homeostasis are essential to health. The incretin hormone of glucagon-like peptide-1 (GLP-1) is known to play a critical role in regulating glucose homeostasis and dietary nutrients are the primary stimuli to the release of intestinal GLP-1. However, the GLP-1 producing enteroendocrine L-cells are mainly distributed in the distal region of the gastrointestinal tract where there are almost no nutrients to stimulate the secretion of GLP-1 under normal situations. Thus, a dietary strategy to sustain the release of GLP-1 was proposed, and the slow digestion property and dipeptidyl peptidase IV (DPP-IV) inhibitory activity of food components, approaches to reduce the rate of food digestion, and mechanisms to sustain the release of GLP-1 were reviewed. A slow digestion-oriented dietary approach through encapsulation of nutrients, incorporation of viscous dietary fibers, and enzyme inhibitors of phytochemicals in a designed whole food matrix will be implemented to efficiently reduce the digestion rate of food nutrients, potentiate their distal deposition and a sustained secretion of GLP-1, which will be beneficial to improved glucose homeostasis and health.

There are individual differences in the tolerance to hypoxia and stress. Stress can contribute to the development of various diseases, including inflammatory bowel disease. It was found that inflammatory bowel diseases in animals susceptible to hypoxia runs more severe course than in tolerant animals. We studied morphofunctional changes in the colon under conditions of modeled cold stress in male C57BL/6 mice susceptible and tolerant to hypoxia. The animals were daily subjected to cold stress (20 min at -20°C) for 2 weeks. Cold stress was followed by an increase in the volume fraction of goblet cells in the colon and production of mucins by these cells in mice tolerant to hypoxia and an increase in cell content in the lamina propria of the colon mucous membrane in animals susceptible to hypoxia. The number of serotoninproducing endocrine cells increased in both groups, but these changes were more pronounced in mice susceptible to hypoxia.

International audience; The gastrointestinal tract harbors an intrinsic neuronal network, the enteric nervous system (ENS). The ENS controls motility, fluid homeostasis and blood flow, but also interacts with other components of the intestine such as epithelial and immune cells. Recent studies indicate that gut microbiota diversification occurring concomitantly to postnatal ENS maturation could be critical for ENS development and function. Here we discuss the possibility that this functional relationship starts in utero, whereby the maternal microbiota would prime the developing ENS and shape its physiology. We review the ENS/microbiota interactions and their modulation in physiological and pathophysiological contexts. While the microbial modulation of ENS physiology is now well established, further studies are required to understand the contribution of the gut microbiota to the ENS development and pathologies and to reveal the precise mechanisms underlying microbiota-to-ENS communications.

The current COVID-19 pandemic, which continues to spread across the globe, is caused by severe acute respiratory syndrome coronavirus (SARS-Cov-2). Soon after the pandemic emerged in China, it became clear that the receptor-binding domain (RBD) of angiotensin-converting enzyme 2 (ACE2) serves as the primary cell surface receptor for SARS-Cov-2. Subsequent work has shown that diabetes and hyperglycemia are major risk factors for morbidity and mortality in COVID-19 patients. However, data on the pattern of expression of ACE2 on human pancreatic β cells remain contradictory. Additionally, there is no consensus on whether the virus can directly infect and damage pancreatic islets and hence exacerbate diabetes. In this mini-review, we highlight the role of ACE2 receptor and summarize the current state of knowledge regarding its expression/co-localization in human pancreatic endocrine cells. We also discuss recent data on the permissiveness of human pancreatic β cells to SARS-Cov-2 infection.

Regeneration of epithelia is crucial for maintaining the intestinal barrier and homeostasis. Our previous work showed that exopolysaccharides from Lactobacillus plantarum NCU116 (EPS116) regulated the barrier function and homeostasis of the intestine; however, the relevant mechanisms remain obscure. Therefore, we sought to explore the role of EPS116 in promoting intestinal epithelial regeneration. Our data showed that the administration of EPS116 markedly ameliorated inflammatory bowel disease-related phenotypes and promoted the regeneration of crypts in the colon of colitis mice. The results of immunofluorescence and reverse transcription-quantitative polymerase chain reaction experiments indicated that EPS116 strikingly increased the number of intestinal stem cells (ISCs) and the expression of differentiation markers for goblet cells, enterocytes, and enteroendocrine cells in the mouse colon. Intestinal microbiota analysis showed that EPS116 increased microbial populations associated with intestinal regeneration and glycan metabolism. Therefore, the present study revealed a novel model that EPS116 promoted the intestinal homeostasis through modulating the proliferation and differentiation of ISCs and altering the gut microbiota profile.

Work in recent decades has established that metabolic hormones released by endocrine cells and diverse other cell types serve to regulate nutrient intake and energy homeostasis. Tsukushi (TSK) is a leucine-rich repeat-containing protein secreted primarily by the liver that exerts an inhibitory effect on brown fat sympathetic innervation and thermogenesis. Despite this, physiological regulation of TSK and the mechanisms underlying its effects on energy balance remain poorly understood. Here we show that hepatic expression and plasma concentrations of TSK are induced by feeding and regulated by melanocortin-4 receptor (MC4R) signaling. We generated TSK and MC4R–double-knockout mice to elucidate the nature of cross talk between TSK and the central regulatory circuit of energy balance. Remarkably, TSK inactivation restores energy balance, ameliorates hyperphagia, and improves metabolic health in MC4R-deficient mice. TSK ablation enhances thermogenic gene expression in brown fat, dampens obesity-association inflammation in the liver and adipose tissue, and protects MC4R-null mice from diet-induced nonalcoholic steatohepatitis. At the cellular level, TSK deficiency augments feeding-induced c-Fos expression in the paraventricular nucleus of the hypothalamus. These results illustrate physiological cross talk between TSK and the central regulatory circuit in maintaining energy balance and metabolic homeostasis.

Enteroendocrine cells (EECs) in both invertebrates and vertebrates derive from intestinal stem cells (ISCs) and are scattered along the digestive tract, where they function in sensing various environmental stimuli and subsequently secrete neurotransmitters or neuropeptides to regulate diverse biological and physiological processes. To fulfill these functions, EECs are specified into multiple subtypes that occupy specific gut regions. With advances in single-cell technology, organoid culture experimental systems, and CRISPR/Cas9 mediated genomic editing, rapid progress has been made towards characterization of EEC subtypes in mammals. Additionally, studies of genetic model organisms-especially Drosophila melanogaster-have also provided insights about the molecular processes underlying EEC specification from ISCs and about the establishment of diverse EEC subtypes. In this review we compare the regulation of EEC specification and function in mammals and Drosophila, with a focus on EEC subtype characterization, on how internal and external regulators mediate EEC subtype specification, and on how EEC-mediated intra- and inter-organ communications affect gastrointestinal physiology and pathology.

The objective of this study was to investigate the plasma concentrations of insulin-like growth factor-2 (IGF-2) as well as its expression in the uterus and ovary of healthy dogs and those with cystic endometrial hyperplasia (CEH)–pyometra complex. Group 1 (n = 10) included bitches with open cervix pyometra, while Group 2 (n = 7) consisted of clinically healthy bitches in dioestrus. The number of IGF-2 immunopositive interstitial cells was significantly higher in Group 1, whereas in Group 2 there were only two cases in which a few cells were IGF-2 immunopositive. IGF-2 immunopositivity was observed in the endometrial glandular epithelium in both groups. Additionally, interstitial fibroblasts and macrophages in the endometrium were also positive in Group 1. The concentration of plasma IGF-2 was higher in Group 1 than in Group 2 (P < 0.05). The concentration was positively correlated with IGF-2 expression in the endometrial glands (r = 0.926; P < 0.001) in Group 1. However, a negative correlation was present between plasma IGF-2 concentration and IGF-2 expression in the interstitial endocrine cells of the ovary in Group 1 (r = −0.652; P < 0.05). The results suggest that IGF-2 plays an important role during the inflammatory process occurring in bitches with CEH–pyometra complex as well as in the endometrium of healthy bitches in dioestrus.

The death of endocrine cells is involved in type 1 diabetes mellitus, autoimmunity, adrenopause and hypogonadotropism. Insights from research on basic cell death have revealed that most pathophysiologically important cell death is necrotic in nature, whereas regular metabolism is maintained by apoptosis programmes. Necrosis is defined as cell death by plasma membrane rupture, which allows the release of damage-associated molecular patterns that trigger an immune response referred to as necroinflammation. Regulated necrosis comes in different forms, such as necroptosis, pyroptosis and ferroptosis. In this Perspective, with a focus on the endocrine environment, we introduce these cell death pathways and discuss the specific consequences of regulated necrosis. Given that clinical trials of necrostatins for the treatment of autoimmune conditions have already been initiated, we highlight the therapeutic potential of such novel therapeutic approaches that, in our opinion, should be tested in endocrine disorders in the future., Studies have shown that the three pathways of regulated necrosis, namely necroptosis, pyroptosis and ferroptosis, can be therapeutically targeted. This Perspective summarizes existing data on the newly characterized cell death pathways in endocrine disorders.

Conventional methods for obtaining pancreatic β cells are based on simulating the embryonic development phase of endocrine cells via hierarchical differentiation of pluripotent stem cells (PSCs). Accordingly, we attempted to modify the protocols for obtaining insulin-secreting cells (ISCs) by sequential differentiation of a human embryonic stem cell (hESC), using the HS181 cell line. Furthermore, we hypothesize that actual pancreatic endocrine cells may arise from trans-differentiation of mature ductal cells after the embryonic developmental stage and throughout the rest of life. According to the hypothesis, ductal cells are trans-differentiated into endocrine and exocrine cells, undergoing a partial epithelial to mesenchymal transition (EMT). To address this issue, we developed two new protocols based on hESC differentiation to obtain ductal cells and then induce EMT in cells to obtain hormone-secreting islet-like cells (HSCs). The ductal (pre-EMT exocrine) cells were then induced to undergo partial EMT by treating with Wnt3a and activin A, in hypoxia. The cell derived from the latter method significantly expressed the main endocrine cell-specific markers and also β cells, in particular. These experiments not only support our hypothetical model but also offer a promising approach to develop new methods to compensate β cell depletion in patients with type 1 diabetes mellitus (T1DM). Although this protocol of generating islet-like cells from ductal cells has a potential to treat T1DM, this strategy may be exploited to optimize the function of these cells in an animal model and future clinical applications.

Despite the connection of secretory cells, including goblet and enteroendocrine (EEC) cells, to distinct mucus-containing colorectal cancer histologic subtypes, their role in colorectal cancer progression has been underexplored. Here, our analysis of The Cancer Genome Atlas (TCGA) and single-cell RNA-sequencing data demonstrates that EEC progenitor cells are enriched in BRAF-mutant colorectal cancer patient tumors, cell lines, and patient-derived organoids. In BRAF-mutant colorectal cancer, EEC progenitors were blocked from differentiating further by DNA methylation and silencing of NEUROD1, a key gene required for differentiation of intermediate EECs. Mechanistically, secretory cells and the factors they secrete, such as trefoil factor 3, promoted colony formation and activation of cell survival pathways in the entire cell population. Lysine-specific demethylase 1 (LSD1) was identified as a critical regulator of secretory cell specification in vitro and in a colon orthotopic xenograft model, where LSD1 loss blocks formation of EEC progenitors and reduces tumor growth and metastasis. These findings reveal an important role for EEC progenitors in supporting colorectal cancer. Significance: This study establishes enteroendocrine progenitors as a targetable population that promotes BRAF-mutant colorectal cancer and can be blocked by LSD1 inhibition to suppress tumor growth.

Dispersed single cells from pancreatic islets can configure the 3D islet-like architecture (pseudo-islets) with insulin secretion potential and controllable size through their aggregation property. The present study was designed to investigate whether cryopreservation of islets or islet cells can contribute to the efficient pseudo-islet fabrication in the rat model. In control group (CT), islet single cells were prepared by trypsin digestion of 50-400-µm o fresh control islets, and then cultured for 3 days in the U-bottom micro-well to fabricate pseudo-islets. In vitrification-warming group (VW), islet single cells were prepared from post-warm islets cryopreserved by vitrification on nylon mesh device, and then cultured for 3 days. In freezing group (FR), islet single cells originated from fresh islets were subjected to a conventional Bicell® freezing, and post-thaw cells were cultured for 3 days. To generate 1 IEQ pseudo-islets (150 µm o) by the sphere culture, 1250 CT cells, 1250 VW cells, and 1500 FR cells were seeded to each micro-well. The viability of the pseudo-islets was comparable among the three groups (93.9-96.9%). Furthermore, the insulin secretion assay showed that those pseudo-islets responded sufficiently to the high glucose stimulation. Immunostaining for insulin and glucagon showed that the endocrine cell arrangement of those pseudo-islets is similar to that of native and isolated islets. These islets/pseudo-islets had the β-cells in core and the α-cells in mantle, which was typical characteristic of the rodent islets. However, some clusters of α-cells were observed inside the FR pseudo-islets. Interestingly, the VW pseudo-islets had significantly fewer α-cells than the CT or FR pseudo-islets. These results suggest that the sphere culture of islet cells is useful tool to generate the pseudo-islets with the customized size and normal functionality, even after islet cryopreservation. This article is protected by copyright. All rights reserved.

Single-cell RNA sequencing combined with spatial information on landmark genes enables reconstruction of spatially-resolved tissue cell atlases. However, such approaches are challenging for rare cell types, since their mRNA contents are diluted in the spatial transcriptomics bulk measurements used for landmark gene detection. In the small intestine, enterocytes, the most common cell type, exhibit zonated expression programs along the crypt-villus axis, but zonation patterns of rare cell types such as goblet and tuft cells remain uncharacterized. Here, we present ClumpSeq, an approach for sequencing small clumps of attached cells. By inferring the crypt-villus location of each clump from enterocyte landmark genes, we establish spatial atlases for all epithelial cell types in the small intestine. We identify elevated expression of immune-modulatory genes in villus tip goblet and tuft cells and heterogeneous migration patterns of enteroendocrine cells. ClumpSeq can be applied for reconstructing spatial atlases of rare cell types in other tissues and tumors., Combining scRNA-seq with spatial information to enable the reconstruction of spatially-resolved cell atlases is challenging for rare cell types. Here the authors present ClumpSeq, an approach for sequencing small clumps of tissue attached cells, and apply it to establish spatial atlases for all secretory cell types in the small intestine.

The literature review highlights the questions of the interaction of Helicobacter pylori and the human body. Modern data on the structure of the pathogenicity island in the Helicobacter pylori genome are presented. There is given a detailed description of both well-known virulence and pathogenicity factors of the infection (genes encoding the formation of urease subunits, in particular urel, cytotoxin associated gene A, vacuolating cytotoxin gen A, blood group associated binding adhesion, induced by contact with epithelium) and less studied ones (sialic acid-binding adhesion, adhesion-associated lipoprotein A and B, adhesin gene of Helicobacter pylori, Hp outer membrane protein). The significance of individual genes and proteins encoded by them in the development of chronic inflammatory process in diseases of the upper digestive tract, as well as in ulcer and carcinogenesis is analyzed. Mechanisms of interaction of bacteria with epithelial cells of the gastric mucosa, adhesive and cytotoxic effects of Helicobacter pylori, factors of biofilm formation are described. The influence of the genetic structure of Infect on cytological composition of the gastric glands in the form of reduction of specialized glandular cells chief and parietal cells of pyloric glands and the increase of endocrine cells in the pool is assessed. It is shown that colonization of the gastric mucosa by highly pathogenic strains of Helicobacter pylori contributes to the development of widespread pronounced and active inflammation in it, the appearance of morphological signs of atrophy. The role of the genetic characteristics of the infection in the failure of anti-helicobacter therapy is emphasized. Separately, the question of the effect of combined infection of the gastric mucosa with highly pathogenic strains of Helicobacter pylori and Epstein-Barr virus is highlighted.

Three synthetic peptides, ILAP, LLAP and MAGVDHI, derived from a Palmaria palmata protein hydrolysate were assessed for their antidiabetic potential in vitro and in vivo. In addition to inhibiting dipeptidyl peptidase-IV in a cell-based in situ assay all three peptides significantly increased the half-life of the incretin hormone glucagon-like peptide-1 (GLP-1). ILAP and LLAP mediated a significant increase (p –6 M). A significant increase in the concentration of cyclic adenosine monophosphate production in BRIN-BD11 cells mediated by ILAP (p Palmaria palmata peptides studied herein have prospective antidiabetic activity and have the potential to act as agents that can be used alone or in combination with drugs, to aid in the prevention and management of Type 2 diabetes mellitus.

Our understanding about the epidemiological aspects, pathogenesis, molecular diagnosis, and targeted therapies of neuroendocrine neoplasms (NENs) have drastically advanced in the past decade. Gastroenteropancreatic (GEP) NENs originate from the enteroendocrine cells of the embryonic gut which share common endocrine and neural differentiation factors. Most NENs are well-differentiated, and slow growing. Specific neuroendocrine biomarkers that are used in the diagnosis of functional NENs include insulin, glucagon, vasoactive intestinal polypeptide, gastrin, somatostatin, adrenocorticotropin, growth hormone releasing hormone, parathyroid hormone-related peptide, serotonin, histamine, and 5-hydroxy indole acetic acid (5-HIAA). Biomarkers such as pancreatic polypeptide, human chorionic gonadotrophin subunits, neurotensin, ghrelin, and calcitonin are used in the diagnosis of non-functional NENs. 5-HIAA levels correlate with tumour burden, prognosis and development of carcinoid heart disease and mesenteric fibrosis, however several diseases, medications and edible products can falsely elevate the 5-HIAA levels. Organ-specific transcription factors are useful in the differential diagnosis of metastasis from an unknown primary of well-differentiated NENs. Emerging novel biomarkers include circulating tumour cells, circulating tumour DNA, circulating micro-RNAs, and neuroendocrine neoplasms test (NETest) (simultaneous measurement of 51 neuroendocrine-specific marker genes in the peripheral blood). NETest has high sensitivity (85%-98%) and specificity (93%-97%) for the detection of gastrointestinal NENs, and is useful for monitoring treatment response, recurrence, and prognosis. In terms of management, surgery, radiofrequency ablation, symptom control with medications, chemotherapy and molecular targeted therapies are all considered as options. Surgery is the mainstay of treatment, but depends on factors including age of the individual, location, stage, grade, functional status, and the heredity of the tumour (sporadic vs inherited). Medical management is helpful to alleviate the symptoms, manage inoperable lesions, suppress postoperative tumour growth, and manage recurrences. Several molecular-targeted therapies are considered second line to somatostatin analogues. This review is a clinical update on the pathophysiological aspects, diagnostic algorithm, and management of GEP NENs.

Precise regulation of circulating glucose is crucial for human health and ensures a sufficient supply to the brain, which relies almost exclusively on glucose for metabolic energy. Glucose homeostasis is coordinated by hormone-secreting endocrine cells in the pancreas, as well as glucose utilization and production in peripheral metabolic tissues including the liver, muscle, and adipose tissue. Glucose-regulatory tissues receive dense innervation from sympathetic, parasympathetic, and sensory fibers. In this review, we summarize the functions of peripheral nerves in glucose regulation and metabolism. Dynamic changes in peripheral innervation have also been observed in animal models of obesity and diabetes. Together, these studies highlight the importance of peripheral nerves as a new therapeutic target for metabolic disorders.

Wasting marmoset syndrome (WMS) is a serious disease in captive common marmoset (Callithrix jacchus) colonies. Because of the high mortality rates, elucidation of the underlying mechanisms is essential. In this study, we compared the histopathology, the number of each epithelial cell in the jejunum and colon, and the expression patterns of some molecular markers between healthy and WMS-affected marmosets. Atrophy of villi in the jejunum and mononuclear cell infiltration in the lamina propria were observed in the intestinal tract of WMS-affected marmosets. Although the numbers of transient amplifying cells and tuft cells were increased, the number of goblet cells was obviously decreased in the jejunum and colon of WMS-affected marmosets compared to healthy marmosets. In addition, the number of enterocytes in the jejunum was decreased in WMS animals. There was no apparent difference in the numbers of stem cells, enteroendocrine cells, or Paneth cells. The expression of β-catenin and Tcf7l2 was increased in WMS, and the co-existence of β-catenin and Tcf7l2/Cyclin D1 was observed around the crypts in WMS-affected marmosets. These findings suggest that cell proliferation continues, but cell differentiation is halted in the intestinal tract due to the enhanced β-catenin/Tcf7l2/Cyclin D1signaling pathway in WMS, which results in malfunction of the villus and mucosa.

Proprotein convertase (PC) deficiency is a rare autosomal recessive disorder caused by mutations in proprotein convertase subtilisin/kexin type 1 (PCSK1). It is characterized by severe malabsorptive early-onset diarrhea, obesity, and systemic endocrinopathies. Only few cases have been reported in the literature; we have add two female sisters with some difference in clinical progress. Herein, we describe two sisters with congenital osmotic diarrhea diagnosed with PC1/3 deficiency, causing malabsorptive diarrhea and enteroendocrine dysfunction, who presented with chronic enteropathy with hypernatremia but with different expressivity. PC1/3 deficiency presents with symptoms and signs that mimic glucose-galactose malabsorption. Because of the clinical paucity and heterogeneity of congenital enteropathies, whole-exome sequencing may be of great help towards early diagnosis and effective treatment.

Endocrine cells can be fully functional after heterotopic transplantation into mammals, which makes them a promising tool for regenerative medicine. However, to date, cellular therapy for endocrine diseases is limited by the inability to efficiently and stably obtain endocrine cells in vitro. The review focuses on current knowledge of the molecular genetic mechanisms involved in embryonic development of mouse and human endocrine tissues, as well as the key genetic factors regulating the differentiation of pluripotent stem cells (PSCs) into the endocrine lineage in vitro, using the example of parathyroid cells. The data presented make it possible to suggest an alternative approach to the PSCs differentiation toward parathyroid cells based on genetic engineering by inducing endogenous expression of key differentiation factors.

Secretogranin III (SgIII) is a granin protein involved in secretory granule formation in peptide-hormone-producing endocrine cells. In this study, we analyzed the expression of the LacZ reporter in the SgIII knockout mice produced by gene trapping ( SgIII-gtKO) for the purpose of comprehensively clarifying the expression patterns of SgIII at the cell and tissue levels. In the endocrine tissues of SgIII-gtKO mice, LacZ expression was observed in the pituitary gland, adrenal medulla, and pancreatic islets, where SgIII expression has been canonically revealed. LacZ expression was extensively observed in brain regions, especially in the cerebral cortex, hippocampus, hypothalamic nuclei, cerebellum, and spinal cord. In peripheral nervous tissues, LacZ expression was observed in the retina, optic nerve, and trigeminal ganglion. LacZ expression was particularly prominent in astrocytes, in addition to neurons and ependymal cells. In the cerebellum, at least four cell types expressed SgIII under basal conditions. The expression of SgIII in the glioma cell lines C6 and RGC-6 was enhanced by excitatory glutamate treatment. It also became clear that the expression level of SgIII varied among neuron and astrocyte subtypes. These results suggest that SgIII is involved in glial cell function, in addition to neuroendocrine functions, in the nervous system

Purpose Many studies about bariatric surgery have analyzed the effect of sleeve gastrectomy (SG) on glucose improvement, beta-cell mass, and islet size modification. The effects of SG on the other endocrine cells of the pancreas, such as the alpha-cell population, and their regulatory mechanisms remain less studied. Materials and Methods We focused our work on the changes in the alpha-cell population after SG in a healthy model of Wistar rats. We measured alpha-cell mass, glucose tolerance, and insulin release after oral glucose tolerance tests and plasma glucagon secretion patterns after insulin infusion. Three Wistar rat groups were employed: SG-operated, surgical control (Sham), and fasting control. Results The results obtained showed significant increases in the alpha-cell population after SG. The result was an increase in beta-cell transdifferentiation; it was shown by some expressed molecules (the loss of expression of Pdx-1 and the increase in Arx and Pax6 cells/mm2 of islet). The serum results were enhanced plasma glucagon secretion pattern after insulin infusion assays and normal glucose tolerance and insulin release after OGTT. Conclusion We concluded that SG leads to an expansion of the alpha-cell population, at expense of beta-cell; this expansion of alpha-cells is related to transdifferentiation. Plasma glucose level was not affected due to an increased glucagon response.

Recent studies have demonstrated that genes related to bitter taste receptors (TAS2Rs) on various chromosomes are expressed in extra-oral organs of various animals. The bitter taste receptor TAS2R14 is conserved among primate species and shows broad ligand sensitivity. Mice have a number of orthologues to primate TAS2R14 located in tandem on chromosome 16; however, their expression patterns are not unique. We characterized the expression of TAS2R14 in various cell types in the intestines of the rhesus macaque and evaluated its role in hormone production in the gut. TAS2R14 expression was examined in the intestines of rhesus macaques, a common non-human primate model, by RT-qPCR and immunohistochemical staining. Mean expression levels of TAS2R14 in the duodenum, ileum, and colon were similar to each other and were lower than those in circumvallate papillae. An immunohistochemical analysis revealed TAS2R14 immunoreactivity in enteroendocrine cells positive for cholecystokinin, serotonin, and the G protein GNAT3. These results suggest that primate TAS2R14 is broadly expressed in the intestine, mainly in enteroendocrine cells, and promotes gut hormone secretion in response to bitter stimuli.

5-HT containing enteroendocrine cells (EEC), the most abundant type of EEC in the gut, regulate many functions including motility, secretion and inflammatory responses. We examined the morphologies of 5-HT cells from stomach to rectum, patterns of hormone co-expression in the stomach and colon, and the relationship of 5-HT cells with nerve fibres. We also reviewed some of the relevant literature. The morphologies of 5-HT cells were distinct, depending on their location in the gut. A noticeable feature of some 5-HT cells in the antrum and colon was their long basal processes, which resembled processes of neurons, whereas 5-HT cells in the small intestinal mucosa lacked basal processes. In the stomach, numerous 5-HT cells, including cells with basal processes, were identified as enterochromaffin-like cells by their expression of histidine decarboxylase. In the colon, we observed a small number of 5-HT cells that were in close contact with, but distinct from, oxyntomodulin (OXM) and PYY immunoreactive EEC. We did not find specific relationships between nerve fibres and the processes of colonic 5-HT cells. We conclude that five major features, i.e., gut region, morphology, hormone content, receptor repertoire and cell lineage, can be used to define 5-HT cells.

Serotonin (5-HT)-containing gastrointestinal endocrine cells contribute to regulation of numerous bodily functions, but whether these functions are related to differences in cell shape is not known. The current study identified morphologies and localization of subtypes of 5-HT-containing enteroendocrine cells in the mouse large intestine. 5-HT cells were most frequent in the proximal colon compared with cecum and distal colon. The large intestine harbored both open (O) cells, with apical processes that reached the lumen, and closed (C) cells, not contacting the lumen, classified into O1, O2, and O3 and C1, C2, and C3 cells, by the lengths of their basal processes. O1 and C1 cells, with basal processes sometimes longer that 100 µm, were most common in the distal colon. Their long basal processes ran against the inner surfaces of the mucosal epithelial cells and were strongly immunoreactive for 5-HT; these processes are ideally placed to communicate with the epithelium and to react to mechanical forces. O2 and C2 cells that had similar but shorter basal processes were also most common in the distal colon. O3 and C3 cells had no or very short basal processes. The O3 open type 5-HT cells were abundant in the proximal colon, particularly at the luminal surface, where they could release 5-HT into the lumen to act on luminal 5-HT receptors. Numerous O3 type 5-HT cells occurred in the lower (submucosal) region of the crypts in all segments and might release 5-HT to influence cell renewal in the crypt proliferative zones.

The allocation and specification of pancreatic endocrine lineages are tightly regulated by transcription factors. Disturbances in differentiation of these lineages contribute to the development of various metabolic diseases, including diabetes. The insulinoma-associated protein 1 (Insm1), which encodes a protein containing one SNAG domain and five zinc fingers, plays essential roles in pancreatic endocrine cell differentiation and in mature β-cell function. In the current study, we compared the differentiation of pancreatic endocrine cells between Insm1 null and Insm1 SNAG domain mutants (Insm1delSNAG) to explore the specific function of the SNAG domain of Insm1. We show that the δ-cell number is increased in Insm1delSNAG but not in Insm1 null mutants as compared with the control mice. We also show a less severe reduction of the β-cell number in Insm1delSNAG as that in Insm1 null mutants. In addition, similar deficits are observed in α-, PP, and ε-cells in Insm1delSNAG and Insm1 null mutants. We further identified that the increased δ-cell number is due to β- to δ-cell transdifferentiation. Mechanistically, the SNAG domain of Insm1 interacts with Lsd1, the demethylase of H3K4me1/2. Mutation in the SNAG domain of Insm1 results in impaired recruitment of Lsd1 and increased H3K4me1/2 levels at hematopoietically expressed homeobox (Hhex) loci that are bound by Insm1, thereby promoting the transcriptional activity of the δ-cell–specific gene Hhex. Our study has identified a novel function of the SNAG domain of Insm1 in the regulation of pancreatic endocrine cell differentiation, particularly in the repression of β- to δ-cell transdifferentiation.

Studies on localization and distribution of enteroendocrine cells (EECs) are important for better understanding of their role in the ontogenetic development of intestines. Information about the distribution of the most important endocrine cells in the digestive tract of the ostrich is very limited; therefore, the aim of the present study was to identify gastrin and somatostatin EECs in the small intestine of the ostrich (Struthio camelus var. domesticus) chicks at different ages. Six embryos along with 42 ostriches of both sexes from hatching up to 60 days post-hatching, including six embryos, were obtained from an ostrich farm in Latvia. Duodenum, jejunum and ileum were investigated using routine histology and immunohistochemistry methods. Gastrin and somatostatin EECs were examined in 10 microscopic fields of the intestinal mucosa in each tissue sample. The cells were detected in all age groups as well as the embryos. The number of both types of EEC in the mucosa of the ileum was significantly lower (p

This paper overviews the development and differentiation of the hypothalamus and pituitary gland from embryonic stem (ES) and induced pluripotent stem (iPS) cells. It is important to replicate the developmental process in vivo to create specific cells/organoids from ES/iPS cells. We also introduce the latest findings and discuss future issues for clinical application. Neuroectodermal progenitors are induced from pluripotent stem cells by strictly removing exogenous patterning factors during the early differentiation period. The induced progenitors differentiate into rostral hypothalamic neurons, in particular magnocellular vasopressin+ neurons. In three-dimensional cultures, the ES/iPS cells differentiate into hypothalamic neuroectoderm as well as non-neural head ectoderm back to back. Rathke's pouch-like structures self-organize at the interface between the two layers and generated various endocrine cells, including corticotrophs and somatotrophs from the Rathke's pouch-like structures. Our next objective is to sophisticate our stepwise methodology to establish the novel transplantation treatment for hypopituitarism and to apply it to developmental disease models.

Therapeutic approaches to the treatment of type 2 diabetes mellitus that are designed to increase insulin secretion either directly target β-cells or indirectly target gastrointestinal enteroendocrine cells (EECs), which release hormones that modulate insulin secretion (for example, incretins). Given that β-cells and EECs both express a large array of G protein-coupled receptors (GPCRs) that modulate insulin secretion, considerable research and development efforts have been undertaken to design therapeutic drugs targeting these GPCRs. Among them are GPCRs specific for free fatty acid ligands (lipid GPCRs), including free fatty acid receptor 1 (FFA1, otherwise known as GPR40), FFA2 (GPR43), FFA3 (GPR41) and FFA4 (GPR120), as well as the lipid metabolite binding glucose-dependent insulinotropic receptor (GPR119). These lipid GPCRs have demonstrated important roles in the control of islet and gut hormone secretion. Advances in lipid GPCR pharmacology have led to the identification of a number of synthetic agonists that exert beneficial effects on glucose homeostasis in preclinical studies. Yet, translation of these promising results to the clinic has so far been disappointing. In this Review, we present the physiological roles, pharmacology and clinical studies of these lipid receptors and discuss the challenges associated with their clinical development for the treatment of type 2 diabetes mellitus.

Adenomatous polyposis coli (APC), a well-known anti-oncogene, is considered to have multiple functions through its several binding domains. We have continuingly studied APC1638T/1638T mice (APC1638T mice) to elucidate the functions of APC other than tumor suppression. A distinctive feature of the APC1638T mice is they are tumor free and live as long as APC+/+ mice (WT mice). Previously, we found the length of crypt-villus axis in the jejunum was significantly elongated in APC1638T mice compared with that of WT mice. The populations of goblet cells, Paneth cells, and enteroendocrine cells were also disordered in APC1638T mice. Here, we further analyzed the intestinal dyshomeostasis in APC1638T mice, focusing on the proliferation and differentiation of intestinal stem cell (ISC) lineages, and apoptotic cell shedding at the villus tips. We found that the proliferation of ISC lineages was normally controlled; however, the shedding process of apoptosis cells was significantly delayed in the APC1638T mouse jejunum. Furthermore, the number of microfold cells (M cells) was significantly increased in the APC1638T mouse jejunum. Our data suggested both differentiation process of ISCs and turnover process of intestinal epithelia were disturbed in APC1638T mice, and that contributed to the villus elongation in the APC1638T mouse jejunum.

Purpose of review Enteroendocrine cells (EECs) are scattered chemosensory cells in the intestinal epithelium that release hormones with a wide range of actions on intestinal function, food intake and glucose homeostasis. The mechanisms by which gut hormones are secreted postprandially, or altered by antidiabetic agents and surgical interventions are of considerable interest for future therapeutic development. Recent findings EECs are electrically excitable and express a repertoire of G-protein coupled receptors that sense nutrient and nonnutrient stimuli, coupled to intracellular Ca2+ and cyclic adenosine monophosphate. Our knowledge of EEC function, previously developed using mouse models, has recently been extended to human cells. Gut hormone release in humans is enhanced by bariatric surgery, as well as by some antidiabetic agents including sodium-coupled glucose transporter inhibitors and metformin. Summary EECs are important potential therapeutic targets. A better understanding of their chemosensory mechanisms will enhance the development of new therapeutic strategies to treat metabolic and gastrointestinal diseases.

ContextMaturity-onset diabetes of the young (MODY) 8 is a rare form of monogenic diabetes characterized by a mutation in CEL (carboxyl ester lipase) gene, which leads to exocrine pancreas dysfunction, followed by β cell failure. Induced pluripotent stem cells can differentiate into functional β cells. Thus, β cells from MODY8 patients can be generated in vitro and used for disease modelling and cell replacement therapy.MethodsA genetic study was performed in a patient suspected of monogenic diabetes.ResultsA novel heterozygous pathogenic variant in CEL (c.1818delC) was identified in the proband, allowing diagnosis of MODY8. Three MODY8-iPSC (induced pluripotent stem cell) clones were reprogrammed from skin fibroblasts of the patient, and their pluripotency and genomic stability confirmed. All 3 MODY8-iPSC differentiated into β cells following developmental stages. MODY8-iPSC–derived β cells were able to secrete insulin upon glucose dynamic perifusion. The CEL gene was not expressed in iPSCs nor during any steps of endocrine differentiation.ConclusioniPSC lines from a MODY8 patient with a novel pathogenic variant in the CEL gene were generated; they are capable of differentiation into endocrine cells, and β cell function is preserved in mutated cells. These results set the basis for in vitro modelling of the disease and potentially for autologous β cell replacement.

Taking excessive sodium fluoride may cause female reproductive dysfunction, but underlying molecular mechanism is unclear. The ovarian granulosa cells are the key endocrine cells releasing reproductive hormones. The miRNAs in the granulosa cells play an important function in regulating reproduction. The aim of this study is to explore the role of miRNAs in granulosa cell apoptosis and autophagy, as well as estradiol (E2) release in response to excessive sodium fluoride. The ovarian granulosa cells (KGN cells) were treated in vitro by different concentrations of sodium fluoride (NaF) for 24 h. The level of estradiol (E2) in the incubation medium was measured by ELISA kits. The total RNA and protein were collected and purified from KGN cells. The expression of miRNAs was detected by the real-time PCR. The signal molecules involved in cell apoptosis and autophagy were detected by the real-time PCR and Western blotting. Six miRNAs in granulosa cells were significantly up- or downregulated by NaF and selected for real-time PCR analysis. The miR-378d was the most significantly upregulated one dose dependently by NaF. It was positively correlated to the extent of apoptosis but negatively correlated to the level of autophagy in KGN cells in response to NaF. In addition, miR-378d promoted E2 release in response to 1 and 2 mM NaF but reduced E2 release in response to 4 and 8 mM NaF treatments. It is concluded that expression of miR-378d in ovarian granulosa cells is negatively correlated to the autophagy and E2 release and positively correlated to cell apoptosis under the influence of NaF.

Aims/hypothesis We hypothesised that human beta cells are structurally and functional polarised with respect to the islet capillaries. We set out to test this using confocal microscopy to map the 3D spatial arrangement of key proteins and live-cell imaging to determine the distribution of insulin granule fusion around the cells. Methods Human pancreas samples were rapidly fixed and processed using the pancreatic slice technique, which maintains islet structure and architecture. Slices were stained using immunofluorescence for polarity markers (scribble, discs large [Dlg] and partitioning defective 3 homologue [Par3]) and presynaptic markers (liprin, Rab3-interacting protein [RIM2] and piccolo) and imaged using 3D confocal microscopy. Isolated human islets were dispersed and cultured on laminin-511-coated coverslips. Live 3D two-photon microscopy was used on cultured cells to image exocytic granule fusion events upon glucose stimulation. Results Assessment of the distribution of endocrine cells across human islets found that, despite distinct islet-to-islet complexity and variability, including multi-lobular islets, and intermixing of alpha and beta cells, there is still a striking enrichment of alpha cells at the islet mantle. Measures of cell position demonstrate that most beta cells contact islet capillaries. Subcellularly, beta cells consistently position polar determinants, such as Par3, Dlg and scribble, with a basal domain towards the capillaries and apical domain at the opposite face. The capillary interface/vascular face is enriched in presynaptic scaffold proteins, such as liprin, RIM2 and piccolo. Interestingly, enrichment of presynaptic scaffold proteins also occurs where the beta cells contact peri-islet capillaries, suggesting functional interactions. We also observed the same polarisation of synaptic scaffold proteins in islets from type 2 diabetic patients. Consistent with polarised function, isolated beta cells cultured onto laminin-coated coverslips target insulin granule fusion to the coverslip. Conclusions/interpretation Structural and functional polarisation is a defining feature of human pancreatic beta cells and plays an important role in the control of insulin secretion. Graphical abstract

Psychobiotics are a special class of probiotics, which deliver mental health benefits to individuals. They differ from conventional probiotics in their ability to produce or stimulate the production of neurotransmitters, short-chain fatty acids, enteroendocrine hormones and anti-inflammatory cytokines. Owing to this potential, psychobiotics have a broad spectrum of applications ranging from mood and stress alleviation to being an adjuvant in therapeutic treatment for various neurodevelopment and neurodegenerative disorders. The common psychobiotic bacteria belong to the family Lactobacilli, Streptococci, Bifidobacteria, Escherichia and Enterococci. The two-way crosstalk between the brain and the gastrointestinal system is influenced by these bacteria. The neurons present in the enteric nervous system interact directly with the neurochemicals produced by microbiota of the gut, thereby influencing the signaling to central nervous system. The present review highlights the scope and advancements made in the field, enlisting numerous commercial psychobiotic products that have flooded the market. In the latter part we discuss the potential concerns with respect to psychobiotics, such as the effects due to withdrawal, compatibility with immunocompromised patients, and the relatively unregulated probiotic market.

A detailed understanding of intestinal stem cell (ISC) self-renewal and differentiation is required to treat chronic intestinal diseases. However, the different models of ISC lineage hierarchy1–6 and segregation7–12 are subject to debate. Here, we have discovered non-canonical Wnt/planar cell polarity (PCP)-activated ISCs that are primed towards the enteroendocrine or Paneth cell lineage. Strikingly, integration of time-resolved lineage labelling with single-cell gene expression analysis revealed that both lineages are directly recruited from ISCs via unipotent transition states, challenging the existence of formerly predicted bi- or multipotent secretory progenitors7–12. Transitory cells that mature into Paneth cells are quiescent and express both stem cell and secretory lineage genes, indicating that these cells are the previously described Lgr5+ label-retaining cells7. Finally, Wnt/PCP-activated Lgr5+ ISCs are molecularly indistinguishable from Wnt/β-catenin-activated Lgr5+ ISCs, suggesting that lineage priming and cell-cycle exit is triggered at the post-transcriptional level by polarity cues and a switch from canonical to non-canonical Wnt/PCP signalling. Taken together, we redefine the mechanisms underlying ISC lineage hierarchy and identify the Wnt/PCP pathway as a new niche signal preceding lateral inhibition in ISC lineage priming and segregation. Polarity cues regulate intestinal stem cell fate. Bottcher et al. demonstrate that mouse intestinal stem cells, which express the Wnt/planar cell polarity reporter Flattop, are primed either towards the enteroendocrine or Paneth cell lineage.

Cholecystokinin (CCK) is secreted from enteroendocrine I cells in response to fat, carbohydrate, and protein ingestion. Gene expression of nutrient-sensing molecules in I cells remains unclear, primarily due to the difficulty in distinguishing I cells from intestinal epithelial cells in vivo. In this study, we generated CCK reporter male mice in which the red fluorescence protein tdTomato (Tomato) is produced by activation of the native murine Cck promoter. Fluorescence microscopy revealed the presence of Tomato-positive cells in upper small intestine (SI), lower SI, and colon. Flow cytometer analysis revealed that Tomato-positive cells among epithelial cells of upper SI, lower SI, and colon occurred at the rate of 0.95, 0.54, and 0.06%, respectively. In upper SI and lower SI, expression levels of Cck mRNA were higher in Tomato-positive cells than those in Tomato-negative cells. The fatty acid receptors Gpr120, Gpr40, and Gpr43 and the oleoylethanolamide receptor Gpr119 were highly expressed in Tomato-positive cells isolated from SI, but were not found in Tomato-positive cells from colon. The glucose and fructose transporters Sglt1, Glut2, and Glut5 were expressed in both Tomato-positive cells and -negative cells, but these expression levels tended to be decreased in Tomato-positive cells from upper SI to colon. The peptide transporter Pept1 and receptor Gpr93 were expressed in both Tomato-positive cells and -negative cells, whereas Casr was expressed only in Tomato-positive cells isolated from SI. Thus, this transgenic mouse reveals that I cell number and gene expression in I cells vary according to region in the gastrointestinal tract.

Pituitary proliferative lesions derived from the endocrine cells of the pars distalis are frequently encountered and adenomas/carcinomas are a common cause of death in standard 2-year carcinogenicity studies using various rat strains, especially Sprague-Dawley. This report describes the immunohistochemical characteristics of pituitary tumors derived from the pars distalis in rats. Prolactin (PRL)-containing tumors are the most common, with PRL/growth hormone (GH) dual positive tumor masses (PRL/GH co-positive tumor masses) being more prevalent than only PRL-positive tumor masses (PRL single-positive tumor masses). GH-containing tumors are relatively numerous and many of these are also PRL/GH co-positive tumor masses. TSH-containing tumors are common in females. PRL-containing tumors have been shown to increase the incidence of hyperlactation in males and mammary adenomas/adenocarcinomas in females, suggesting that these masses are functional tumors.

The intestines have been recognized as important tissues for metabolic regulation, including glycemic control, but their vital role in promoting the anti-diabetic effects of bitter melon, the fruit of Momordica charantia L, has seldom been characterized, nor acknowledged. Evidence suggests that bitter melon constituents can have substantial interactions with the intestinal epithelial cells before circulating to other tissues. We therefore characterized the effects of bitter melon extract (BME) on intestinal epithelial cells. BME was found to contain substantial amounts of carbohydrates, proteins, and triterpenoids. TNF-α induced insulin resistance in an enterocyte cell line of IEC-18 cells, and BME promoted glucose utilization of the insulin-resistant cells. Further analysis suggested that the increased glucose consumption was a result of the combined effects of insulin sensitizing and insulin substitution functions of BME. The functions of insulin substitution were likely generated due to the activation of AMP-activated protein kinase. Meanwhile, BME acted as a glucagon-like peptide 1 (GLP-1) secretagogue on enteroendocrine cells, which may be mediated by the activation of bitter-taste receptors. Therefore, BME possesses insulin sensitizing, insulin substitution, and GLP-1 secretagogue functions upon intestinal cells. These effects of BME on intestinal cells likely play a significant part in the anti-diabetic action of bitter melon.

Background & Aims Congenital tufting enteropathy (CTE) is an intractable diarrheal disease of infancy caused by mutations of epithelial cell adhesion molecule (EpCAM). The cellular and molecular basis of CTE pathology has been elusive. We hypothesized that the loss of EpCAM in CTE results in altered lineage differentiation and defects in absorptive enterocytes thereby contributing to CTE pathogenesis. Methods Intestine and colon from mice expressing a CTE-associated mutant form of EpCAM (mutant mice) were evaluated for specific markers by quantitative real-time polymerase chain reaction, Western blotting, and immunostaining. Body weight, blood glucose, and intestinal enzyme activity were also investigated. Enteroids derived from mutant mice were used to assess whether the decreased census of major secretory cells could be rescued. Results Mutant mice exhibited alterations in brush-border ultrastructure, function, disaccharidase activity, and glucose absorption, potentially contributing to nutrient malabsorption and impaired weight gain. Altered cell differentiation in mutant mice led to decreased enteroendocrine cells and increased numbers of nonsecretory cells, though the hypertrophied absorptive enterocytes lacked key features, causing brush border malfunction. Further, treatment with the Notch signaling inhibitor, DAPT, increased the numbers of major secretory cell types in mutant enteroids (graphical abstract 1). Conclusions Alterations in intestinal epithelial cell differentiation in mutant mice favor an increase in absorptive cells at the expense of major secretory cells. Although the proportion of absorptive enterocytes is increased, they lack key functional properties. We conclude that these effects underlie pathogenic features of CTE such as malabsorption and diarrhea, and ultimately the failure to thrive seen in patients., Graphical abstract

Background & Aims Helicobacter pylori infection in humans typically begins with colonization of the gastric antrum. The initial Th1 response occasionally coincides with an increase in gastrin secretion. Subsequently, the gastritis segues to chronic atrophic gastritis, metaplasia, dysplasia and distal gastric cancer. Despite these well characterized clinical events, the link between inflammatory cytokines and non-cardia gastric cancer remains difficult to study in mouse models. Prior studies have demonstrated that overexpression of the Hedgehog (HH) effector GLI2 induces loss of gastrin (atrophy) and antral hyperplasia. To determine the link between specific cytokines, HH signaling and pre-neoplastic changes in the gastric antrum. Methods Mouse lines were created to conditionally direct IL1β or IFN-γ to the antrum using the Gastrin-CreERT2 and Tet activator. Primary cilia, which transduces HH signaling, on G cells were disrupted by deleting the ciliary motor protein KIF3a. Phenotypic changes were assessed by histology and western blots. A subclone of GLUTag enteroendocrine cells selected for gastrin expression and the presence of primary cilia was treated with recombinant SHH, IL1β or IFN-γ with or without kif3a siRNA. Results IFN-γ increased gastrin and induced antral hyperplasia. However, antral expression of IL1β suppressed tissue and serum gastrin, while also inducing antral hyperplasia. IFN-γ treatment of GLUTAg cells suppressed GLI2 and induced gastrin, without affecting cilia length. By contrast, IL1β treatment doubled primary cilia length, induced GLI2 and suppressed gastrin gene expression. Knocking down kif3a in GLUTAg cells mitigated SHH or IL1β suppression of gastrin. Conclusions Overexpression of IL1β in the antrum was sufficient to induce antral hyperplasia coincident with suppression of gastrin via primary cilia. ORCID: #0000-0002-6559-8184

The gastrointestinal tract in the adult Drosophila serves as a model system for exploring the mechanisms underlying digestion, absorption and excretion, stem cell plasticity, and inter-organ communication, particularly through the gut-brain axis. It is also useful for studying the cellular and adaptive responses to dietary changes, alterations in microbiota and immunity, and systematic and endocrine signals. Despite the various cell types and distinct regions in the gastrointestinal tract, few tools are available to target and manipulate the activity of each cell type and region, and their gene expression. Here, we report 353 GAL4 lines and several split-GAL4 lines that are expressed in enteric neurons (ENs), progenitors (ISCs and EBs), enterocytes (ECs), enteroendocrine cells (EEs), or/and other cell types that are yet to be identified in distinct regions of the gut. We had initially collected approximately 600 GAL4 lines that may be expressed in the gut based on RNA sequencing data, and then crossed them to UAS-GFP to perform immunohistochemistry to identify those that are expressed selectively in the gut. The cell types and regional expression patterns that are associated with the entire set of GAL4 drivers and split-GAL4 combinations are annotated online at http://kdrc.kr/index.php (K-Gut Project). This GAL4 resource can be used to target specific populations of distinct cell types in the fly gut, and therefore, should permit a more precise investigation of gut cells that regulate important biological processes.

Epithelial regeneration is essential for homeostasis and mucosal barrier repair. In this study, we aimed to define the effect of IL-10 on mucosal healing. Intestinal stem cells (ISCs) cultures and mice were treated with recombinant mice IL-10 (rmIL-10). The level of cell proliferation, differentiation, death and related signaling pathways for self-renewal of ISCs were measured in vitro and in vivo. It was uncovered that rmIL-10 increased the size and death, but reduced the total number of organoids. In addition, rmIL-10 depleted Lgr5+ ISCs and reduced epithelial proliferation, but enhanced the differentiation of epithelial cells and expanded numbers of transit-amplifying (TA) cells. These changes are related to the decrease of Wnt and Notch signals in vivo and in vitro. Meanwhile, increased expression of Paneth cells and decreased expression of enteroendocrine cells and goblet cells were induced by rmIL-10. Thus, our data indicate that IL-10 reduces the survival of Lgr5+ ISCs and proliferation of epithelial cells by inhibiting Notch and Wnt signaling, but promotes enhanced the differentiation of epithelial cells and expanded numbers of TA cells. Therefore, IL-10 acts as an anti-inflammatory factor, but may damage intestinal mucosa repair and maybe a potential target for the treatment of intestinal injury.

Human intestinal organoids (HIOs) are a promising in vitro model consisting of different intestinal cell types with a 3D microarchitecture resembling native tissue. In the current study, we aimed to assess the expression of the most common intestinal CYP enzymes in a human induced pluripotent stem cell (hiPSC)-derived HIO model, and the suitability of that model to study chemical-induced changes in CYP expression and activity. We compared this model with the commonly used human colonic adenocarcinoma cell line Caco-2 and with a human primary intestinal epithelial cell (IEC)-based model, closely resembling in vivo tissue. We optimized an existing protocol to differentiate hiPSCs into HIOs and demonstrated that obtained HIOs contain a polarized epithelium with tight junctions consisting of enterocytes, goblet cells, enteroendocrine cells and Paneth cells. We extensively characterized the gene expression of CYPs and activity of CYP3A4/5, indicating relatively high gene expression levels of the most important intestinal CYP enzymes in HIOs compared to the other models. Furthermore, we showed that CYP1A1 and CYP1B1 were induced by β-naphtoflavone in all three models, whereas CYP3A4 was induced by phenobarbital and rifampicin in HIOs, in the IEC-based model (although not statistically significant), but not in Caco-2 cells. Interestingly, CYP2B6 expression was not induced in any of the models by the well-known liver CYP2B6 inducer phenobarbital. In conclusion, our study indicates that hiPSC-based HIOs are a useful in vitro intestinal model to study biotransformation of chemicals in the intestine. Electronic supplementary material The online version of this article (10.1007/s00204-020-02953-6) contains supplementary material, which is available to authorized users.

The Drosophila adult midgut is a model epithelial tissue composed of a few major cell types with distinct regional identities. One of the limitations to its analysis is the lack of tools to manipulate gene expression based on these regional identities. To overcome this obstacle, we applied the intersectional split-GAL4 system to the adult midgut and report 653 driver combinations that label cells by region and cell type. We first identified 424 split-GAL4 drivers with midgut expression from ∼7300 drivers screened, and then evaluated the expression patterns of each of these 424 when paired with three reference drivers that report activity specifically in progenitor cells, enteroendocrine cells, or enterocytes. We also evaluated a subset of the drivers expressed in progenitor cells for expression in enteroblasts using another reference driver. We show that driver combinations can define novel cell populations by identifying a driver that marks a distinct subset of enteroendocrine cells expressing genes usually associated with progenitor cells. The regional cell type patterns associated with the entire set of driver combinations are documented in a freely available website, providing information for the design of thousands of additional driver combinations to experimentally manipulate small subsets of intestinal cells. In addition, we show that intestinal enhancers identified with the split-GAL4 system can confer equivalent expression patterns on other transgenic reporters. Altogether, the resource reported here will enable more precisely targeted gene expression for studying intestinal processes, epithelial cell functions, and diseases affecting self-renewing tissues.