Paliarin, F;Duplantis, C;Jones, AF;Cucinello-Ragland, J;Basavanhalli, S;Blaze, E;Doré, E;Neel, AI;Sun, H;Chen, R;Edwards, S;Gilpin, NW;Messing, RO;Maiya, R;
PMID: 37364995 | DOI: 10.1523/ENEURO.0043-23.2023
Here we describe the generation and characterization of a Cre knockin mouse line which harbors a Cre insertion in the 3'UTR of the kappa opioid receptor gene (Oprk1) locus and provides genetic access to populations of kappa opioid receptor (KOR)-expressing neurons throughout the brain. Using a combination of techniques including RNA in situ hybridization and immunohistochemistry, we report that Cre is expressed with high fidelity in KOR-expressing cells throughout the brain in this mouse line. We also provide evidence that Cre insertion does not alter basal KOR function. Baseline anxiety-like behaviors and nociceptive thresholds are unaltered in Oprk1-Cre mice. Chemogenetic activation of KOR-expressing cells in the basolateral amygdala (BLAKOR cells) resulted in several sex-specific effects on anxiety-like and aversive behaviors. Activation led to decreased anxiety-like behavior on the elevated plus maze and increased sociability in female but not in male Oprk1-Cre mice. Activation of BLAKOR cells also attenuated KOR-agonist induced conditioned place aversion (CPA) in male Oprk1-Cre mice. Overall, these results suggest a potential role for BLAKOR cells in regulating anxiety-like behaviors and KOR-agonist mediated CPA. In summary, these results provide evidence for the utility of the newly generated Oprk1-Cre mice in assessing localization, anatomy, and function of KOR circuits throughout the brain.Significance statementHere we report the generation and characterization of a Oprk1-Cre mouse line that harbors Cre insertion in the 3'UTR of the Oprk1 locus. There is high fidelity of Cre expression to KOR expressing cells throughout the brain in this mouse line and Cre insertion does not impair KOR function. Chemogenettic activation of BLAKORs led to sex-specific effects on anxiety-like behaviors and attenuated KOR-agonist induced conditioned place aversion (CPA). These results provide evidence for the utility of the newly generated Oprk1-Cre mice to interrogate KOR function in discreet circuits.
Molecular Metabolism (2019)
Pan W, Allison MB, Sabatini P, Rupp A, Adams J, Patterson C, Jones JC, Olson DP, Myers MG.
| DOI: doi:10.1016/j.molmet.2019.01.007
Abstract Objectives Leptin acts via its receptor LepRb on specialized neurons in the brain to modulate food intake, energy expenditure, and body weight. LepRb activates signal transducers and activators of transcription (STATs, including STAT1, STAT3, and STAT5) to control gene expression. Methods Because STAT3 is crucial for physiologic leptin action, we used TRAP-seq to examine gene expression in LepRb neurons of mice ablated for Stat3 in LepRb neurons (Stat3LepRbKO mice), revealing the STAT3-dependent transcriptional targets of leptin. To understand roles for STAT proteins in leptin action, we also ablated STAT1 or STAT5 from LepRb neurons and expressed a constitutively-active STAT3 (CASTAT3) in LepRb neurons. Results While we also found increased Stat1 expression and STAT1-mediated transcription of leptin-regulated genes in Stat3LepRbKO mice, ablating Stat1 in LepRb neurons failed to alter energy balance (even on the Stat3LepRbKO background); ablating Stat5 in LepRb neurons also failed to alter energy balance. Importantly, expression of a constitutively-active STAT3 (CASTAT3) in LepRb neurons decreased food intake and body weight and improved metabolic parameters in leptin-deficient (ob/ob) mice, as well as in wild-type animals. Conclusions Thus, STAT3 represents the unique STAT protein required for leptin action and STAT3 suffices to mediate important components of leptin action in the absence of other LepRb signals.
Protein arginine methyltransferase 1 regulates cell proliferation and differentiation in adult mouse adult intestine
Xue, L;Bao, L;Roediger, J;Su, Y;Shi, B;Shi, YB;
PMID: 34158114 | DOI: 10.1186/s13578-021-00627-z
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.
Virchows Arch. 2015 Jun 13.
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.
PLoS One. 2015 May 21;10(5):e0127300.
Jang BG, Lee BL, Kim WH.
PMID: 26015511 | DOI: clincanres.3357.2014.
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.
Samineni VK, Grajales-Reyes JG, Copits BA, O’Brien DE, Trigg SL, Gomez AM, Bruchas MR, Gereau RW.
PMID: - | DOI: 10.1523/ENEURO.0129-16.2017
The ventrolateral periaqueductal gray (vlPAG) constitutes a major descending pain modulatory system and is a crucial site for opioid-induced analgesia. A number of previous studies have demonstrated that glutamate and GABA play critical opposing roles in nociceptive processing in the vlPAG. It has been suggested that glutamatergic neurotransmission exerts antinociceptive effects, whereas GABAergic neurotransmission exert pro-nociceptive effects on pain transmission, through descending pathways. The inability to exclusively manipulate subpopulations of neurons in the PAG has prevented direct testing of this hypothesis. Here we demonstrate the different contributions of genetically-defined glutamatergic and GABAergic vlPAG neurons in nociceptive processing by employing cell type-specific chemogenetic approaches in mice. Global chemogenetic manipulation of vlPAG neuronal activity suggests that vlPAG neural circuits exert tonic suppression of nociception, consistent with previous pharmacological and electrophysiological studies. However, selective modulation of GABAergic or glutamatergic neurons demonstrates an inverse regulation of nociceptive behaviors by these cell populations. Selective chemogenetic activation of glutamatergic neurons, or inhibition of GABAergic neurons, in vlPAG suppresses nociception. In contrast, inhibition of glutamatergic neurons, or activation of GABAergic neurons, in vlPAG facilitates nociception. Our findings provide direct experimental support for a model in which excitatory and inhibitory neurons in the PAG bidirectionally modulate nociception.
Significance Statement The PAG is a midbrain region critical for the modulation of pain. However, the roles played by the distinct cell types within the PAG in nociceptive processing are poorly understood. This work addresses the divergent roles of glutamatergic and GABAergic PAG neuronal subpopulations in nociceptive processing. We demonstrate that activation of glutamatergic neurons or inhibition of GABAergic neurons suppresses nociception. Whereas inhibition of glutamatergic neuronal activity or activation of GABAergic neuronal activity potentiates nociception. This report identifies distinct roles for these neuronal populations in modulating nociceptive processing.
Sheahan, BJ;Theriot, CM;Cortes, JE;Dekaney, CM;
PMID: 35012435 | DOI: 10.1080/19490976.2021.2018898
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.
Parekh PK, Logan RW, Ketchesin KD, Becker-Krail D, Shelton MA, Hildebrand MA, Barko K, Huang YH, McClung CA.
PMID: 30962277 | DOI: 10.1523/JNEUROSCI.2233-18.2019
The circadian transcription factor neuronal PAS domain 2 (NPAS2) is linked to psychiatric disorders associated with altered reward sensitivity. The expression of Npas2 is preferentially enriched in the mammalian forebrain, including the nucleus accumbens (NAc), a major neural substrate of motivated and reward behavior. Previously, we demonstrated that down-regulation of NPAS2 in the NAc reduces the conditioned behavioral response to cocaine in mice. We also showed that Npas2 is preferentially enriched in dopamine receptor 1 containing medium spiny neurons (D1R-MSNs) of the striatum. To extend these studies, we investigated the impact of NPAS2 disruption on accumbal excitatory synaptic transmission and strength, along with the behavioral sensitivity to cocaine reward in a cell-type specific manner. Viral-mediated knockdown of Npas2 in the NAc of male and female C57BL/6J mice increased the excitatory drive onto MSNs. Using Drd1a-tdTomato mice in combination with viral knockdown, we determined these synaptic adaptations were specific to D1R-MSNs relative to non-D1R-MSNs. Interestingly, NAc-specific knockdown of Npas2 blocked cocaine-induced enhancement of synaptic strength and glutamatergic transmission specifically onto D1R-MSNs. Lastly, we designed, validated, and employed a novel Cre-inducible short-hairpin RNA virus for MSN-subtype specific knockdown of Npas2 Cell-type specific Npas2 knockdown in D1R-MSNs, but not D2R-MSNs, in the NAc reduced cocaine conditioned place preference. Together, our results demonstrate that NPAS2 regulates excitatory synapses of D1R-MSNs in the NAc and cocaine reward-related behavior.SIGNIFICANCE STATEMENTDrug addiction is a widespread public health concern often comorbid with other psychiatric disorders. Disruptions of the circadian clock can predispose or exacerbate substance abuse in vulnerable individuals. We demonstrate a role for the core circadian protein, NPAS2, in mediating glutamatergic neurotransmission at medium spiny neurons (MSNs) in the nucleus accumbens (NAc), a region critical for reward processing. We find that NPAS2 negatively regulates functional excitatory synaptic plasticity in the NAc and is necessary for cocaine-induced plastic changes in MSNs expressing the dopamine 1 receptor (D1R). We further demonstrate disruption of NPAS2 in D1R-MSNs produces augmented cocaine preference. These findings highlight the significance of cell-type specificity in mechanisms underlying reward regulation by NPAS2 and extend our knowledge of its function.
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
Cooley, A;Madhukaran, S;Stroebele, E;Colon Caraballo, M;Wang, L;Akgul, Y;Hon, GC;Mahendroo, M;
PMID: 36718364 | DOI: 10.1016/j.isci.2023.105953
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.
Cloft, SE;Kinstler, SR;Reno, KE;Sellers, HS;Franca, M;Ecco, R;Lee, MD;Maurer, JJ;Wong, EA;
PMID: 35191652 | DOI: 10.1637/21-00109
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.
Physiol Behav. 2014 Apr 2. pii: S0031-9384(14)00173-5.
Smith JA, Wang L, Hiller H, Taylor CT, de Kloet AD, Krause EG.
PMID: 24704193 | DOI: 10.1016/j.physbeh.2014.03.027.
Previous investigation by our laboratory found that acute hypernatremia potentiates an oxytocinergic tone that inhibits parvocellular neurosecretory neurons in the paraventricular nucleus of the hypothalamus (PVN), attenuates restraint-induced surges in corticosterone (CORT), and reduces anxiety-like behavior in male rats. To investigate the neural mechanisms mediating these effects and extend our findings to a more versatile species, we repeated our studies using laboratory mice. In response to 2.0M NaCl injections, mice had increased plasma sodium concentrations which were associated with a blunted rise in CORT subsequent to restraint challenge relative to 0.15M NaCl injected controls. Immunofluorescent identification of the immediate early gene product Fos found that 2.0M NaCl treatment increased the number of activated neurons producing oxytocin in the PVN. To evaluate the effect of acute hypernatremia on PVN neurons producing corticotropin-releasing hormone (CRH), we used the Cre-lox system to generate mice that produced the red fluorescent protein, tdTomato, in cells that had Cre-recombinase activity driven by CRH gene expression. Analysis of brain tissue from these CRH-reporter mice revealed that 2.0M NaCl treatment caused a dramatic reduction in Fos-positive nuclei specifically in CRH-producing PVN neurons. This altered pattern of activity was predictive of alleviated anxiety-like behavior as mice administered 2.0M NaCl spent more time exploring the open arms of an elevated-plus maze than 0.15M NaCl treated controls. Taken together, these results further implicate an oxytocin-dependent inhibition of CRH neurons in the PVN and demonstrate the impact that slight elevations in plasma sodium have on the hypothalamic-pituitary-adrenocortical axis output and anxiety-like behavior.
