Presence and significance of telocytes in cholelithiasis and biliary dilatation in benign biliary disorders.

Telocytes are closely associated with the regulation of tissue smooth muscle dynamics in digestive system disorders. They are widely distributed in the biliary system and exert their influence on biliary motility through mechanisms such as the regulation of CCK and their electrophysiological effects on smooth muscle cells. To investigate the relationship between telocytes and benign biliary diseases,such as gallbladder stone disease and biliary dilation syndrome, we conducted histopathological analysis on tissues affected by these conditions. Additionally, we performed immunohistochemistry and immunofluorescence double staining experiments for telocytes. The results indicate that the quantity of telocytes in the gallbladder and bile duct is significantly lower in pathological conditions compared to the control group. This reveals a close association between the decrease in telocyte quantity and impaired gallbladder motility and biliary fibrosis. Furthermore, further investigations have shown a correlation between telocytes in cholesterol gallstones and cholecystokinin-A receptor (CCK-AR), suggesting that elevated cholesterol levels may impair telocytes, leading to a reduction in the quantity of CCK-AR and ultimately resulting in impaired gallbladder motility.Therefore, we hypothesize that telocytes may play a crucial role in maintaining biliary homeostasis, and their deficiency may be associated with the development of benign biliary diseases, including gallstone disease and biliary dilation.

Rapid purification and scale-up of tilianin using counter-current chromatography with rectangular horizontal tubing.

In counter-current chromatography (CCC), linear scale-up is an ideal amplification strategy. However, when transferring from analytical to predictable preparative processes with high throughput, linear scale-up would be challenging due to limitations imposed by differences in instrument parameters, such as gravitational forces, tubing cross-section area, tubing length, column volume and flow rate. Some effective scale-up strategies have been studied for different instrument parameters, but so far, these scale-up works have only been tested on standard circular (SC) tubing. The previous research of our group found that rectangular horizontal (RH) tubing can double the separation efficiency compared with conventional SC tubing, and has industrial production potential. This paper used the separation of tilianin from Dracocephalum moldavica L. as an example to demonstrate how to scale up the optimized process from analytical SC tubing to preparative RH tubing. After systematic optimization of solvent systems, sample concentration and flow rate on the analytical CCC, the optimized parameters obtained were successfully transferred to the preparative CCC. The results showed that a crude sample of 2.07 g was successfully separated using a solvent system of n-hexane - ethyl acetate - ethanol - water (1:4:1:5, v/v/v/v) in reversed phase mode, and the three consecutive separations produced a total of 380 mg tilianin in 75 min with high purities of 98.3%, as analyzed by HPLC. The total throughput achieved from the analytical to semi-preparative scale was improved by 138 times (from 12 mg/h to 1.66 g/h), while the column volume was increased by only 46.5 times (from 15.5 mL to 720 mL). This is the successful application of CCC for the separation and purification of tilianin. Given that SC tubing is the traditional configuration for CCC columns, this study is a necessary step to prove the applicability of RH tubing columns for routine use and potential large-scale industrial applications.

Exploring the Immunomodulatory Properties of Red Onion (Allium cepa L.) Skin: Isolation, Structural Elucidation, and Bioactivity Study of Novel Onion Chalcones Targeting the A2A Adenosine Receptor.

Onions are versatile and nutritious food widely used in various cuisines around the world. In our ongoing pursuit of bioactive substances with health benefits from red onion (Allium cepa L.) skin, a comprehensive chemical investigation was undertaken. Consequently, a total of 44 compounds, including three previously unidentified chalcones (1-3) were extracted from red onion skin. Of these isolates, chalcones 1-4 showed high affinity to A2A adenosine receptor (A2AAR), and chalcone 2 displayed the best binding affinity to A2AAR, with the IC50 value of 33.5 nM, good A2AAR selectivity against A1AR, A2BAR, and A3AR, and high potency in the cAMP functional assay (IC50 of 913.9 nM). Importantly, the IL-2 bioassay and the cell-mediated cytotoxicity assay demonstrated that chalcone 2 could boost T-cell activation. Furthermore, the binding mechanism of chalcone 2 with hA2AAR was elucidated by molecular docking. This work highlighted that the active chalcones in red onion might have the potential to be developed as A2AAR antagonists used in cancer immunotherapy.

Pan-cancer analysis of oncogenic TNFAIP2 identifying its prognostic value and immunological function in acute myeloid leukemia.

BACKGROUND: Tumor necrosis factor alpha-induced protein 2 (TNFAIP2), a TNFα-inducible gene, appears to participate in inflammation, immune response, hematopoiesis, and carcinogenesis. However, the potential role of TNFAIP2 in the development of acute myeloid leukemia (AML) remains unknow yet. Therefore, we aimed to study the biological role of TNFAIP2 in leukemogenesis. METHODS: TNFAIP2 mRNA level, prognostic value, co-expressed genes, differentially expressed genes, DNA methylation, and functional enrichment analysis in AML patients were explored via multiple public databases, including UALCAN, GTEx portal, Timer 2.0, LinkedOmics, SMART, MethSurv, Metascape, GSEA and String databases. Data from The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO) and Beat AML database were used to determine the associations between TNFAIP2 expression and various clinical or genetic parameters of AML patients. Moreover, the biological functions of TNFAIP2 in AML were investigated through in vitro experiments. RESULTS: By large-scale data mining, our study indicated that TNFAIP2 was differentially expressed across different normal and tumor tissues. TNFAIP2 expression was significantly increased in AML, particularly in French-American-British (FAB) classification M4/M5 patients, compared with corresponding control tissues. Overexpression of TNFAIP2 was an independent poor prognostic factor of overall survival (OS) and was associated with unfavorable cytogenetic risk and gene mutations in AML patients. DNA hypermethylation of TNFAIP2 at gene body linked to upregulation of TNFAIP2 and inferior OS in AML. Functional enrichment analysis indicated immunomodulation function and inflammation response of TNFAIP2 in leukemogenesis. Finally, the suppression of TNFAIP resulted in inhibition of proliferation by altering cell-cycle progression and increase of cell death by promoting early and late apoptosis in THP-1 and U937AML cells. CONCLUSION: Collectively, the oncogenic TNFAIP2 can function as a novel biomarker and prognostic factor in AML patients. The immunoregulation function of TNFAIP2 warrants further validation in AML.

[Mechanism of combined treatment of rhein and emodin in Rhubarb for ulcerative colitis].

This study aimed to explore the efficacy and mechanism of combined rhein and emodin in the treatment of ulcerative colitis(UC) from the aspects of network pharmacology, animal inflammation improvement and molecular mechanism. Network pharmacology predicted that combined rhein and emodin acted on 52 potential targets, mainly participating in signaling pathways such as cancer, PI3 K/AKT, microRNAs in cancer and apoptosis. PI3 K/AKT signaling pathway has been reported to be closely related to UC, and the optimal candidate pathway for combined therapy. The UC mice model was established by dextran sodium sulfate, and then the modeled mice were randomly divided into control group, model group, rhein group, emodin group, rhein+emodin group and sulfasalazine group. After administration, compared with the conditions in model group, body weight, disease activity index(DAI) score, colon length, TNF-α, IL-6, IL-1ß and myeloperoxidase(MPO) of mice in rhein+emodin group were improved(P<0.01); colonic mucosal injury was significantly reduced; the expression of p-PI3 K/PI3 K and p-AKT/AKT proteins were down-regulated(P<0.01). All the above indices were better than those in the rhein/emodin group alone. The Jin's Q-values of the effect of combined rhein and emodin on colon length, TNF-α, IL-6, IL-1ß, MPO, p-PI3 K/PI3 K and p-AKT/AKT were all greater than 1.15, which indicated that there was obvious synergistic effect between rhein and emodin. In all, rhein and emodin have synergistic effect in the treatment of UC, and the mechanism may be related to the inhibition of PI3 K/AKT signaling pathway and the down-regulation of proinflammatory factors. They are the new components in the treatment of UC, which is worthy of attention.

Anti-inflammatory effect of Rhein on ulcerative colitis via inhibiting PI3K/Akt/mTOR signaling pathway and regulating gut microbiota.

This study aimed to analyze the therapeutic effect of Rhein on ulcerative colitis (UC) in mice and its possible mechanism. LPS-induced UC cell model and DSS-induced UC mouse model were used to analyze the antiinflammatory effect of Rhein on UC in vitro and in vivo, respectively. Network pharmacology analysis was conducted to identify potential signaling pathways involved in Rhein treating UC, and the results were further confirmed through western blotting assay. 16sRNA sequencing was performed to study the regulatory effect of Rhein on gut microbiota in UC mice. As indicated by the results, Rhein could significantly inhibit the production of pro-inflammatory cytokines (e.g., TNF-α, IL-6 and IL-1ß) in vivo and in vitro, and alleviate DSS-induced UC-associated symptoms in mice (e.g., colon shortening, weight loss, diarrhea and hematochezia). The PI3K/Akt/mTOR signaling pathway was predicted as the potential interacting protein of Rhein in the treatment of UC through network pharmacology analysis. It was found through western blotting assay that the Rhein treatment could significantly inhibit the PI3K/Akt/mTOR signaling pathway by decreasing the phosphorylated protein levels of PI3K, Akt, mTOR and p70S6K1. By 16sRNA gene sequencing analysis, Rhein administration could partially reverse the gut dysbacteriosis of mice induced by DSS and decrease pathogenic bacteria (e.g., Enterobacteriaceae and Turicibacter). It was positively correlated with the production of pro-inflammatory cytokines above, whereas the increase in probiotics (e.g., Unspecified-S24-7 and Rikenellaceae) was negatively correlated with the production of pro-inflammatory cytokines. In conclusion, Rhine had anti-UC efficacy, which was demonstrated by mitigating the UC symptoms and reducing intestinal inflammation by inhibiting the PI3K/Akt/mTOR signaling pathway and modulating gut microbiota.

A systematic review on botany, processing, application, phytochemistry and pharmacological action of Radix Rehmnniae.

ETHNOPHARMACOLOGICAL RELEVANCE: Radix Rehmanniae (RR) is the tuber root of Rehmannia glutionsa Libosch, which was firstly recorded in Shennong's Classic of Materia Medica (⟪⟫). RR is a non-toxic and wide used traditional Chinese medicine. RR has the effect of clearing heat, generating essence, cooling blood, stopping bleeding, nourishing yin and blood, and filling marrow. It is used in clinic in the form of processed decoction pieces, including Dry Radix Rehmnniae (DRR) and Rehmanniae Radix Praeparata (RRP). The application of RR in traditional Chinese medicine (TCM) prescriptions can treat various diseases, such as anemia, irregular menstruation, deficiency of liver yin, renal failure and so on. AIM OF REVIEW: This paper aims to provide a comprehensive and productive review of RR, which mainly contains botanical characteristics, processing methods, traditional application, chemical composition, quality control and pharmacological action. MATERIALS AND METHODS: Literature search was conducted through the Web of Science, Baidu Scholar, ScienceDirect, PubMed, CNKI, and WanFang DATA using the keywords "Radix Rehmnniae", "Rehmanniae Radix Praeparata", "processing", "clinical application", "chemical composition", "quality control", and "pharmacological action". In addition, information was collected from relevant textbooks, reviews, and documents. RESULTS: RR is a traditional Chinese herbal medicine with clinical value and rich resources. More than 100 components have been isolated and identified from RR. It has multiple pharmacological actions, such as hemostasis, antioxidation, anti-osteoporosis, lowering blood sugar, improving renal function, anti-inflammation, protecting neuronal function, antidepression and anti-anxiety. DRR and RRP are two different processed products of RR. After processing, there are great changes in property, taste, efficacy, clinical application, chemical composition and pharmacological action. At present, identifying chemical constituents of RR and its medicinal value has been deeply studied. However, there is a lack of research on the reasons for the differences in pharmacological effects between DRR and RRP. The reasons for these differences need to be further verified. Catalpol, the active component of RR, has been studied extensively in the literature, but the pharmacological effects of catalpol cannot represent the pharmacological effects of the whole RR. In the future, effective components such as rehmannioside D, polysaccharide, total glycosides, and effective parts in RR need to be further studied and developed. The pharmacodynamic material basis and mechanism of RR need to be further discussed. The scientific connotation and processing methods of RRP need to be studied and standardized.

Identification of the Ferroptosis-Associated Gene Signature to Predict the Prognostic Status of Endometrial Carcinoma Patients.

Endometrial carcinoma (EC) is one of the most common gynecological carcinomas. As previously described, ferroptosis was reported to exhibit a significant association with the development of malignant neoplasms. Nevertheless, there are few studies towards the association between the implication of ferroptosis-related genes (FRGs) and the prognostic status of patients with EC. Our study demonstrated that ferroptosis-related genes were evidently differently expressed in EC. Further analysis showed that SLC7A11, SAT1, CDKN1A, and TP5MC3 expression was linked to the low stage, grade of pTNM, and longer survival time. Bioinformatics analysis demonstrated that these ferroptosis-related regulators played a crucial role in EC by modulating multiple biological processes, such as cell cycle, citrate cycle (TCA cycle), metabolism-related pathways, ERK activation, p53 signaling pathway, cellular senescence, TAp63 pathway, and Notch signaling pathway. Of note, our results showed that ATP5MC3, CDKN1A, and SLC7A11 expression was dramatically positively related with the tumor mutational burden (TMB) score in EC. However, we did not observe a significant correlation between SAT1 and the TMB score in EC. These findings for the first time demonstrated that ferroptosis was displayed crucially in EC progression. We speculated that our findings offered novel targets and strategies for personalized treatment.

Network Pharmacology-Based Analysis of the Underlying Mechanism of Huajiao for Pain Relief.

OBJECTIVE: Pain is a common symptom among patients, and pain management is an important clinical practice topic. The mechanism of Huajiao (HJ; Zanthoxylum bungeanum Maxim.) and its effective components for treating pain was explored using network pharmacology and molecular docking to verify its pain relief function in traditional medical practice. METHODS: HJ's components were collected via the Traditional Chinese Medicine Systems Pharmacology platform and published studies. HJ-associated target proteins were predicted using the drug similarity rule via Swiss Target Prediction. Online Mendelian Inheritance in Man was used to search for pain-related genes and proteins, and the Database of Interacting Proteins was used to obtain the human interactive target proteins. The compound-target-disease network of HJ for pain relief was constructed with protein-protein interaction networks. The obtained target proteins were uploaded on the Database for Annotation, Visualization, and Integrated Discovery to annotate, visualize, and integrally discover the related signaling pathway, and semiflexible molecular docking by Autodock Vina was applied to verify the potential mechanism. RESULTS: A total of 157 molecules in HJ were obtained, and the top 20 active components or active groups were mainly focused on the amide alkaloids (e.g., [6RS]-[2E,7E,9E]-6-hydroxy-N-[2-hydroxy-2-methylpropyl]-11-oxo-2,7,9-dodecatrienamide and [2E,7E,9E]-N-[2-hydroxy-2-methylpropyl]-11-ethoxy-6-hydroxy-dodeca-2,7,9-trienamide). Also, the 66 main targets were filtered from 746 predicted targets and 928 pain-related targets through module Network Analyzer in Cytoscape 3.6.0. Finally, there were 3 critical signaling pathways, including mitogen-activated protein kinase, phosphoinositide 3-kinase-protein kinase B-mammalian target of rapamycin, and IκB kinase-nuclear factor κB-cyclooxygenase 2 based on integrated discovery with 54 enriched signaling pathways. CONCLUSIONS: HJ is used as a pain relief and has multicomponents, multitargets, and multiapproaches. Amide alkaloids are important substance bases, and HJ is more suitable for treating inflammatory pain.

Antisense techniques provide robust decrease in GnRH receptor expression with minimal cytotoxicity in GT1-7 cells.

The episodic pattern of gonadotropin-releasing hormone (GnRH) secretion from the hypothalamus is driven by an integrated network of cells termed the GnRH pulse generator. Cultured and immortalized GnRH neurons also produce a pulsatile pattern of GnRH secretions when grown in the absence of other cell types, suggesting the presence of an intrinsic oscillator mediating GnRH secretion. The mechanisms underlying such pulsatility comprise one of the most tantalizing problems in contemporary neuroendocrinology. In order to study the mechanism by which GnRH is produced in a pulsatile fashion, the autocrine effect of GnRH on GnRH-producing neurons must be eliminated. This may be performed by downregulating the expression of the GnRH receptor. Treatment with three 21-mer exogenous phosphorothioates and transient transfections with an inducible plasmid containing an antisense construct to the GnRH receptor gene decreased GnRH receptor expression further. This resulted in less cytotoxicity compared to inhibition of RNA or protein synthesis with actinomycin D, α-amanitin, puromycin, and cycloheximide. This study shows methods and optimized conditions established for the generation of a stable GT1-7 cell line containing an inducible construct allowing the downregulation of GnRH receptor expression. ABBREVIATIONS: ANOVA: analysis of the variance; DMEM: Dulbecco's modified Eagle's medium; GnRH: gonadotropin-releasing hormone; RXR: retinoid X receptor.

The Role of Hox Genes in Female Reproductive Tract Development, Adult Function, and Fertility.

HOX genes convey positional identity that leads to the proper partitioning and adult identity of the female reproductive track. Abnormalities in reproductive tract development can be caused by HOX gene mutations or altered HOX gene expression. Diethylstilbestrol (DES) and other endocrine disruptors cause Müllerian defects by changing HOX gene expression. HOX genes are also essential regulators of adult endometrial development. Regulated HOXA10 and HOXA11 expression is necessary for endometrial receptivity; decreased HOXA10 or HOXA11 expression leads to decreased implantation rates. Alternation of HOXA10 and HOXA11 expression has been identified as a mechanism of the decreased implantation associated with endometriosis, polycystic ovarian syndrome, leiomyoma, polyps, adenomyosis, and hydrosalpinx. Alteration of HOX gene expression causes both uterine developmental abnormalities and impaired adult endometrial development that prevent implantation and lead to female infertility.

Chemoattraction of bone marrow-derived stem cells towards human endometrial stromal cells is mediated by estradiol regulated CXCL12 and CXCR4 expression.

Bone marrow derived cells engraft to the uterine endometrium and contribute to endometriosis. The mechanism by which these cells are mobilized and directed to the endometrium has not been previously characterized. We demonstrate that human endometrial stromal cells (hESCs) produce the chemokine CXCL12 and that bone marrow cells (BMCs) express the CXCL12 receptor, CXCR4. Treatment with physiological levels of estradiol (E2) induced both CXCL12 and CXCR4 expression in hESCs and BMCs, respectively. BMCs migrated towards hESCs conditioned media; a CXCR4 antagonist blocked migration indicating that CXCL12 acting through its receptor, CXCR4, is necessary for chemoattraction of BM cells to human endometrial cells. E2 increased both CXCL12 expression in endometrial cells and CXCR4 expression in BM cells, further enhancing chemoattraction. E2 induced CXCL12/CXCR4 expression in endometrium and BM, respectively, drives migration of stem cells to the endometrium. The E2-CXCL12/CXCR4 signaling pathway may be useful in determining treatments for endometrial disorders, and may be antagonized to block stem cell migration to endometriosis.

Bone Marrow-Derived Stem Cell (BMDSC) transplantation improves fertility in a murine model of Asherman's syndrome.

Asherman's Syndrome is characterized by intrauterine adhesions or fibrosis resulting as a consequence of damage to the basal layer of endometrium and is associated with infertility due to loss of normal endometrium. We have previously shown that bone marrow derived stem cells (BMDSCs) engraft the endometrium in mice and humans and Ischemia/reperfusion injury of uterus promoted BMDSCs migration to the endometrium; however, the role of BMDSCs in Asherman's syndrome has not been characterized. Here a murine model of Asherman's syndrome was created by traumatizing the uterus. We evaluate stem cell recruitment and pregnancy after BMDSCs transplantation in a model of Asherman's syndrome. In the Asheman's syndrome model, after BMDSC transplant, the Y chromosome bearing CD45-cells represented less than 0.1% of total endometrial cells. Twice the number of Y+CD45- cells was identified in the damaged uterus compared to the uninjured controls. There was no significant difference between the damaged and undamaged uterine horns in mice that received injury to a single horn. In the BMDSC transplant group, 9 of the 10 mice conceived, while only 3 of 10 in the non-transplanted group conceived (Chi-Square p = 0.0225); all mice in an uninjured control group conceived. The time to conception and mean litter size were not different between groups. Taken together, BMDSCs are recruited to endometrium in response to injury. Fertility improves after BMDSC transplant in Asherman's Syndrome mice, demonstrating a functional role for these cells in uterine repair. BMDSC transplantation is a potential novel treatment for Asherman's Syndrome and may also be useful to prevent Asherman's syndrome after uterine injury.

Ischemia/reperfusion injury promotes and granulocyte-colony stimulating factor inhibits migration of bone marrow-derived stem cells to endometrium.

The endometrium is a dynamic tissue that undergoes repeated rounds of regeneration in each reproductive (estrous or menstrual) cycle. We have previously shown that bone marrow (BM)-derived stem cells engraft the endometrium in rodents and humans; however, it is not known if these cells contribute physiologically to uterine cyclic regeneration or alternatively are primarily involved in uterine repair in response to injury. Here we performed male-to-female BM transplant and tested the ability of uterine injury to recruit BM-derived cells to endometrium in the presence and absence of sex steroids. Uterine ischemia/reperfusion injury resulted in an ~2-fold increase in BM-derived stem cell recruitment to the endometrium. The effect was independent of sex steroids or the existence of an estrous cycle. BM-derived mesenchymal stem cells (MSCs) are involved in uterine repair after injury, but not the cyclic regeneration of the endometrium in the estrous/menstrual cycle. Granulocyte-colony stimulating factor (G-CSF) is used to increase BM mobilization for transplant and has been proposed as a means of mobilizing stem cells to the uterus. Here G-CSF treatment led to decreased BM engraftment of the uterus after injury, likely by favoring mobilization of hematopoietic stem cells over the MSCs. G-CSF is unlikely to be of benefit in repair of uterine injury in humans. Taken together, we demonstrate that ischemic injury drives BM MSC engraftment of the uterus, independent of estrous cycle, sex steroids, or G-CSF.

Endometrial stem cell transplantation restores dopamine production in a Parkinson's disease model.

Parkinson's disease (PD) is a neurodegenerative disorder caused by the loss of dopaminergic neurons. Adult human endometrial derived stem cells (HEDSC), a readily obtainable type of mesenchymal stem-like cell, were used to generate dopaminergic cells and for transplantation. Cells expressing CD90, platelet derived growth factor (PDGF)-Rß and CD146 but not CD45 or CD31 were differentiated in vitro into dopaminergic neurons that exhibited axon projections, pyramidal cell bodies and dendritic projections that recapitulate synapse formation; these cells also expressed the neural marker nestin and tyrosine hydroxylase, the rate-limiting enzyme in dopamine synthesis. Whole cell patch clamp recording identified G-protein coupled inwardly rectifying potassium current 2 channels characteristic of central neurons. A 1-methyl 4-phenyl 1,2,3,6-tetrahydro pyridine induced animal model of PD was used to demonstrate the ability of labelled HEDSC to engraft, migrate to the site of lesion, differentiate in vivo and significantly increase striatal dopamine and dopamine metabolite concentrations. HEDSC are a highly inducible source of allogenic stem cells that rescue dopamine concentrations in an immunocompetent PD mouse model.

HOXA10 inhibits Kruppel-like factor 9 expression in the human endometrial epithelium.

Kruppel-like factor 9 (KLF9) is a zinc finger transcription factor that regulates estrogen and progesterone action by modulating the activity of progesterone receptor (PGR). The transition from proliferative to secretory endometrial epithelium involves loss of estrogen receptor/PGR expression and loss of direct response to sex steroids. HOXA10 partially mediates progesterone responsiveness in the endometrium. Here, we demonstrate that HOXA10 directly regulates KLF9 in endometrial epithelial cells and not in stromal cells. Immunohistochemistry performed on endometrial tissue obtained from normal, reproductive-age women revealed that KLF9 expression was decreased in the secretory phase of the menstrual cycle compared to the proliferative phase. In vitro, HOXA10 transfection of human endometrial epithelial cells (Ishikawa), but not stromal cells (HESC), resulted in a greater than 50% decrease in KLF9 mRNA and protein expression. Reporter constructs driven by the KLF9 promoter were repressed by cotransfection with HOXA10. Electrophoretic mobility shift assay was used to demonstrate direct binding of HOXA10 to the KLF9 promoter. Targeted mutation of the HOXA10-binding site in the KLF9 promoter resulted in loss of HOXA10 binding and loss of repression by HOXA10 in reporter assays. HOXA10 directly and selectively repressed KLF9 expression in endometrial epithelial cells. HOXA10 repression of KLF9 likely contributes to the loss of sex steroid responsiveness in secretory-phase endometrial epithelium.

Stem cells and reproduction.

PURPOSE OF REVIEW: To review the latest developments in reproductive tract stem cell biology. RECENT FINDINGS: In 2004, two studies indicated that ovaries contain stem cells which form oocytes in adults and that can be cultured in vitro into mature oocytes. A live birth after orthotopic transplantation of cryopreserved ovarian tissue in a woman whose ovaries were damaged by chemotherapy demonstrates the clinical potential of these cells. In the same year, another study provided novel evidence of endometrial regeneration by stem cells in women who received bone marrow transplants. This finding has potential for the use in treatment of uterine disorders. It also supports a new theory for the cause of endometriosis, which may have its origin in ectopic transdifferentiation of stem cells. Several recent studies have demonstrated that fetal cells enter the maternal circulation and generate microchimerism in the mother. The uterus is a dynamic organ permeable to fetal stem cells, capable of transdifferentiation and an end organ in which bone marrow stem cells may differentiate. Finally stem cell transformation can be an underlying cause of ovarian cancer. SUMMARY: Whereas we are just beginning to understand stem cells, the potential implications of stem cells to reproductive biology and medicine are apparent.

3-Phosphoglycerate dehydrogenase expression is regulated by HOXA10 in murine endometrium and human endometrial cells.

3-Phosphoglycerate dehydrogenase (PHGDH, 3-PGDH) is an enzyme necessary for de novo l-serine biosynthesis. HOXA10 expression is required for endometrial receptivity; however, few target genes of HOXA10 regulation are known. Using a microarray we identified Phgdh as a target of HOXA10 regulation in murine endometrium and confirmed this regulatory relationship in human endometrial cells. PHGDH was downregulated 2.0-fold by HOXA10 and upregulated 4.4-fold by HOXA10 antisense in vivo. In human endometrial cells, real-time PCR results show that pcDNA3.1/HOXA10 transfection decreased PHGDH mRNA expression to 40% of pretreatment level (P<0.05), while PHGDH mRNA expression was increased 2.1-fold (P<0.05) by HOXA10 siRNA. Western blot results confirmed the regulatory relationship in both primary human endometrial stromal and epithelial cells, as well as in human endometrial stromal cells and Ishikawa cells. In human cycling endometrial tissue, immunohistochemical results showed that PHGDH expression is relatively high in the proliferative phase in glandular cells and lower in the secretory phase. Here we report novel expression and regulation of PHGDH in murine and human endometrium. PHGDH is expressed in both endometrial epithelial and stromal cells. HOXA10 represses endometrial PHGDH expression. PHGDH is necessary for serine biosynthesis, which serves as a substrate for protein synthesis. One mechanism by which HOXA10 regulates cellular differentiation may involve limiting protein synthesis in the secretary phase.

Stem cells and female reproduction.

Several recent findings in stem cell biology have resulted in new opportunities for the treatment of reproductive disease. Endometrial regeneration can be driven by bone marrow derived stem cells. This finding has potential implications for the treatment of uterine disorders. It also supports a new theory for the etiology of endometriosis. The ovaries have been shown to contain stem cells that form oocytes in adults and can be cultured in vitro to develop mature oocytes. Stem cells from the fetus have been demonstrated to lead to microchimerism in the mother and implicated in several maternal diseases. Additionally the placenta may be another source of hematopoietic stem cell. Finally endometrial derived stem cells have been demonstrated to differentiate into non-reproductive tissues. While we are just beginning to understand stem cells and many key questions remain, the potential advantages of stem cells in reproductive biology and medicine are apparent.

Experimental murine endometriosis induces DNA methylation and altered gene expression in eutopic endometrium.

The eutopic endometrium in women with endometriosis demonstrates diminished endometrial receptivity and altered gene expression. It is unknown if the endometrium being defective gives rise to a predisposition toward endometriosis and infertility or, alternatively, if endometriosis causes the altered endometrial receptivity. Here we created experimental endometriosis in mice and examined the expression of several markers of endometrial receptivity in the eutopic endometrium. Methylation of Hoxa10 was also evaluated as a potential mechanism responsible for altered gene expression. Expression of each gene was measured using quantitative real-time RT-PCR at 14 wk after induction of endometriosis. Expression of Hoxa10 and Hoxa11, which are necessary for endometrial receptivity, were decreased in the endometriosis group. Insulin-like growth factor binding protein-1 (Igfbp1) mRNA was decreased in the endometriosis group. However, there was no change in Integrin beta3 (Itgb3) mRNA expression. Total progesterone receptor (Pgr-AB) was increased in the endometriosis group and the ratio of Pgr-B to Pgr-AB was increased, indicating a shift from Pgr-A to Pgr-B expression. Basic transcription element-binding protein-1 (Bteb1), official symbol and name Klf9, Kruppel-like factor 9, which functionally interacts with Pgr in endometrium, was also decreased in the endometriosis group. In addition, hypermethylation of Hoxa10 in the endometriosis group was shown by methylation-specific PCR and confirmed by bisulfite sequencing. These findings demonstrate that normal endometrium, when placed in an ectopic location to create experimental endometriosis, led to characteristic changes in gene expression in eutopic endometrium. These data suggest the existence of a signal conduction pathway from endometriosis that alters endometrial gene expression through altered Pgr signaling and epigenetic programming.