Critical Role of Tripartite Fusion and LBD Truncation in Certain RARA- and all RARG-Related Atypical APL.

Atypical acute promyelocytic leukemia (aAPL) presents a complex landscape of retinoic acid receptor (RAR) fusion genes beyond the well-known PML::RARA fusion. Among these, 31 individually rare RARA and RARG fusion genes have been documented, often reported in the canonical X::RAR bipartite fusion form. Intriguingly, some artificially mimicked bipartite X::RAR fusions respond well to all-trans retinoic acid (ATRA) in vitro, contrasting with the ATRA resistance observed in patients. To unravel the underlying mechanisms, we conducted a comprehensive molecular investigation into the fusion transcripts in 27 RARA fusion gene-positive aAPL (RARA-aAPL) and 21 RARG-aAPL cases. Our analysis revealed an unexpected novel form of X::RAR::X or X::RAR::Y-type tripartite fusions in certain RARA- and all RARG-aAPL cases, with shared features and notable differences between these two disease subgroups. In RARA-aAPL cases, the occurrence of RARA 3' splices was associated with their 5' fusion partner genes, mapping across the coding region of helix 11_12 (H11_12) within the ligand-binding domain (LBD), resulting in LBD-H12 or H11_12 truncation. In RARG-aAPL cases, RARG 3' splices were consistently localized to the terminus of exon 9, leading to LBD-H11_12 truncation. Significant differences were also observed between RARA and RARG 5' splice patterns. Our analysis also revealed extensive involvement of transposable elements in constructing RARA and RARG 3' fusions, suggesting transposition mechanisms for fusion gene ontogeny. Both protein structural analysis and experimental results highlighted the pivotal role of LBD-H11_12/H12 truncation in driving ATRA unresponsiveness and leukemogenesis in tripartite fusion-positive aAPL, through a protein allosteric dysfunction mechanism.

Atypical BCR-ABL1 transcript in mixed phenotype acute leukemia with bone marrow necrosis.

Mixed phenotype acute leukemia (MPAL) is a type of acute leukemia in which encompasses mixed features of myeloid, T-lymphoid, and/or B-lymphoid differentiation. Philadelphia chromosome-positive (Ph+) MPAL is a rare subgroup with a poor prognosis and accounts for ＜1% of adult acute leukemia. Until now, there is still no consensus on how to best treat Ph+ MPAL. Here, we report a 62-year-old male with Ph+ (atypical e13a2 BCR-ABL1 fusion protein) MPAL. This patient presented with recurrent and intense bone pain due to bone marrow necrosis (BMN). Besides, he did not achieve a complete remission for the first two chemotherapies, until he received flumatinib combined with hyper-CVAD (B) (a dose-intensive regimen include methotrexate and cytarabine). To our knowledge, this is the first report to describe the coexistence of BMN and atypical e13a2 BCR-ABL1 transcripts in patients with MPAL. This finding will bring new understandings in the diagnosis and treatment of Ph+ MPAL.

Detection rates of abnormalities in over 10,000 amniotic fluid samples at a single laboratory.

BACKGROUND: A growing number of cytogenetic techniques have been used for prenatal diagnosis. This study aimed to demonstrate the usefulness of karyotyping, BACs-on-Beads (BoBs) assay and single nucleotide polymorphism (SNP) array in prenatal diagnosis during the second trimester based on our laboratory experience. METHODS: A total of 10,580 pregnant women with a variety of indications for amniocentesis were enrolled in this retrospective study between January 2015 and December 2020, of whom amniotic fluid samples were analysed in 10,320 women. The main technical indicators of participants in the three different technologies were summarized, and cases of chromosome abnormalities were further evaluated. RESULTS: The overall abnormality detection rate of karyotyping among all the amniotic fluid samples was 15.4%, and trisomy 21 was the most common abnormality (20.9%). The total abnormality detection rate of the BoBs assay was 5.6%, and the diagnosis rate of microdeletion/microduplication syndromes that were not identified by karyotyping was 0.2%. The detection results of the BoBs assay were 100.0% concordant with karyotyping analysis in common aneuploidies. Seventy (87.5%) cases of structural abnormalities were missed by BoBs assay. The total abnormality detection rate of the SNP array was 21.6%. The detection results of common aneuploidies were exactly the same between SNP array and karyotyping. Overall, 60.1% of structural abnormalities were missed by SNP array. The further detection rate of pathogenic significant copy number variations (CNVs) by SNP was 1.4%. CONCLUSIONS: Karyotyping analysis combined with BoBs assay or SNP array for prenatal diagnosis could provide quick and accurate results. Combined use of the technologies, especially with SNP array, improved the diagnostic yield and interpretation of the results, which contributes to genetic counselling. BoBs assay or SNP array could be a useful supplement to karyotyping.

Developing a rapid and highly efficient cowpea regeneration, transformation and genome editing system using embryonic axis explants.

Cowpea (Vigna unguiculata (L.) Walp.) is one of the most important legume crops planted worldwide, but despite decades of effort, cowpea transformation is still challenging due to inefficient Agrobacterium-mediated transfer DNA delivery, transgenic selection and in vitro shoot regeneration. Here, we report a highly efficient transformation system using embryonic axis explants isolated from imbibed mature seeds. We found that removal of the shoot apical meristem from the explants stimulated direct multiple shoot organogenesis from the cotyledonary node tissue. The application of a previously reported ternary transformation vector system provided efficient Agrobacterium-mediated gene delivery, while the utilization of spcN as selectable marker enabled more robust transgenic selection, plant recovery and transgenic plant generation without escapes and chimera formation. Transgenic cowpea plantlets developed exclusively from the cotyledonary nodes at frequencies of 4% to 37% across a wide range of cowpea genotypes. CRISPR/Cas-mediated gene editing was successfully demonstrated. The transformation principles established here could also be applied to other legumes to increase transformation efficiencies.

Gene activation via Cre/lox-mediated excision in cowpea (Vigna unguiculata).

KEY MESSAGE: Expression of Cre recombinase by AtRps5apro or AtDD45pro enabled Cre/lox-mediated recombination at an early embryonic developmental stage upon crossing, activating transgenes in the hybrid cowpea and tobacco. Genetic engineering ideally results in precise spatiotemporal control of transgene expression. To activate transgenes exclusively in a hybrid upon fertilization, we evaluated a Cre/lox-mediated gene activation system with the Cre recombinase expressed by either AtRps5a or AtDD45 promoters that showed activity in egg cells and young embryos. In crosses between Cre recombinase lines and transgenic lines harboring a lox-excision reporter cassette with ZsGreen driven by the AtUbq3 promoter after Cre/lox-mediated recombination, we observed complete excision of the lox-flanked intervening DNA sequence between the AtUbq3pro and the ZsGreen coding sequence in F1 progeny upon genotyping but no ZsGreen expression in F1 seeds or seedlings. The incapability to observe ZsGreen fluorescence was attributed to the activity of the AtUbq3pro. Strong ZsGreen expression in F1 seeds was observed after recombination when ZsGreen was driven by the AtUbq10 promoter. Using the AtDD45pro to express Cre resulted in more variation in recombination frequencies between transgenic lines and crosses. Regardless of the promoter used to regulate Cre, mosaic F1 progeny were rare, suggesting gene activation at an early embryo-developmental stage. Observation of ZsGreen-expressing tobacco embryos at the globular stage from crosses with the AtRps5aproCre lines pollinated by the AtUbq3prolox line supported the early activation mode.

Evaluation of triage strategies for high-risk human papillomavirus-positive women in cervical cancer screening: A multicenter randomized controlled trial in different resource settings in China.

Objective: We aimed to evaluate the effectiveness of different triage strategies for high-risk human papillomavirus (hrHPV)-positive women in primary healthcare settings in China. Methods: This study was undertaken in 11 rural and 9 urban sites. Women aged 35-64 years old were enrolled. HrHPV-positive women were randomly allocated to liquid-based cytology (LBC), visual inspection with acetic acid and Lugol's iodine (VIA/VILI) (rural only) triage, or directly referred to colposcopy (direct COLP). At 24 months, hrHPV testing, LBC and VIA/VILI were conducted for combined screening. Results: In rural sites, 1,949 hrHPV-positive women were analyzed. A total of 852, 218 and 480 women were randomly assigned to direct COLP, LBC and VIA/VILI. At baseline, colposcopy referral rates of LBC or VIA/VILI triage could be reduced by 70%-80%. LBC (n=3 and n=7) or VIA/VILI (n=8 and n=26) could significantly decrease the number of colposcopies needed to detect one cervical intraepithelial neoplasia (CIN) 2 or worse and CIN3+ compared with direct COLP (n=14 and n=23). For the 24-month cumulative detection rate of CIN2+, VIA/VILI triage was 0.50-fold compared with LBC triage and 0.46-fold with the direct COLP. When stratified by age, baseline LBC triage+ performed best (P<0.001), peaking among women aged 35-44 years (Ptrend=0.002). In urban sites, 1,728 women were hrHPV genotyping test positive. A total of 408, 571 and 568 women were randomly assigned to direct COLP for HPV16/18+, direct COLP for other hrHPV subtypes+, and LBC triage for other hrHPV subtypes+. LBC (n=12 and n=31) significantly decreased the number of colposcopies needed to detect one CIN2+ and CIN3+ compared with direct COLP (n=14 and n=44). HPV16/18+ increased the 24-month cumulative detection rate of CIN2+ (17.89%, P<0.001). Conclusions: LBC triage for hrHPV-positive women in rural settings and direct COLP for HPV16/18+ women and LBC triage for other hrHPV subtype+ women in urban settings might be feasible strategies.

Association of neutrophil to lymphocyte ratio, platelet to lymphocyte ratio, mean platelet volume with the risk of gestational diabetes mellitus.

OBJECTIVE: In the present study, we aimed to investigate the correlation of neutrophil to lymphocyte ratio, platelet to lymphocyte ratio, mean platelet volume with the risk of gestational diabetes mellitus. METHODS: The study enrolled 120 pregnant women who were the 24th and 28th weeks of gestation, including GDM group (n = 58), the control group (n = 62). The NLR, PLR and MPV levels were measured. RESULTS: NLR, PLR and MPV were significantly higher in GDM compared with control group. Logistic regression analysis showed that elevated WBC, NLR, PLR and MPV was an independent variable for predicting GDM in pregnancy. The OR and 95% CI was (OR: 1.6, 95% CI: 1.2-2.5), (OR: 4.1, 95% CI: 1.3-13.1), (OR: 5.5, 95% CI: 1.5-20.0), (OR: 4.0, 95% CI: 1.2-12.0), respectively. CONCLUSION: Increased WBC, PLR, NLR, MPV were independent predictors of GDM.

Changes of Serum Sex Hormone-Binding Globulin, Homocysteine, and Hypersensitive CRP Levels during Pregnancy and Their Relationship with Gestational Diabetes Mellitus.

BACKGROUND: Inflammatory response state is related to the pathogenesis of gestational diabetes mellitus (GDM). OBJECTIVE: To investigate the changes of serum sex hormone-binding globulin (SHBG), homocysteine (Hcy), and hypersensitive CRP (hs-CRP) levels during pregnancy and their relationship with GDM. METHODS: The nested case-control study method was used. Sixty nonobese single pregnant women diagnosed with GDM were divided into the GDM group (GDM, n = 60), together with another 60 pregnant women with normal glucose tolerance who were matched in the same period and divided into the control group (control, n = 60). The serum Hcy, hs-CRP, and SHBG levels were measured. RESULTS: The serum levels of Hcy and hs-CRP were significantly higher in the GDM group compared with the control group, and serum levels of SHBG was significantly lower in the GDM group compared with the control group at different stages of pregnancy. The serum levels of Hcy and hs-CRP in pregnant women increased with the increase of gestational age, and serum levels of SHBG decreased with the increase of gestational age. Increased Hcy and hs-CRP levels in the second trimester and decreased SHBG levels in the first trimester were related to GDM. The odds ratio (OR) and 95% confidence interval (CI) were as follows: OR: 4.5, 95% CI: 1.5-13.0; OR: 4.2, 95% CI: 1.5-10.1; and OR: 0.4, 95% CI: 0.3-0.7, respectively. CONCLUSION: Increased Hcy and hs-CRP in the second trimester and decreased SHBG in the first trimester were independent predictors of GDM, which provides a new idea for early prevention and treatment of GDM.

Fetal birthweight prediction with measured data by a temporal machine learning method.

BACKGROUND: Birthweight is an important indicator during the fetal development process to protect the maternal and infant safety. However, birthweight is difficult to be directly measured, and is usually roughly estimated by the empirical formulas according to the experience of the doctors in clinical practice. METHODS: This study attempts to combine multiple electronic medical records with the B-ultrasonic examination of pregnant women to construct a hybrid birth weight predicting classifier based on long short-term memory (LSTM) networks. The clinical data were collected from 5,759 Chinese pregnant women who have given birth, with more than 57,000 obstetric electronic medical records. We evaluated the prediction by the mean relative error (MRE) and the accuracy rate of different machine learning classifiers at different predicting periods for first delivery and multiple deliveries. Additionally, we evaluated the classification accuracies of different classifiers respectively for the Small-for-Gestational-age (SGA), Large-for-Gestational-Age (LGA) and Appropriate-for-Gestational-Age (AGA) groups. RESULTS: The results show that the accuracy rate of the prediction model using Convolutional Neuron Networks (CNN), Random Forest (RF), Linear-Regression, Support Vector Regression (SVR), Back Propagation Neural Network(BPNN), and the proposed hybrid-LSTM at the 40th pregnancy week for first delivery were 0.498, 0.662, 0.670, 0.680, 0.705 and 0.793, respectively. Among the groups of less than 39th pregnancy week, the 39th pregnancy week and more than 40th week, the hybrid-LSTM model obtained the best accuracy and almost the least MRE compared with those of machine learning models. Not surprisingly, all the machine learning models performed better than the empirical formula. In the SGA, LGA and AGA group experiments, the average accuracy by the empirical formula, logistic regression (LR), BPNN, CNN, RF and Hybrid-LSTM were 0.780, 0.855, 0.890, 0.906, 0.916 and 0.933, respectively. CONCLUSIONS: The results of this study are helpful for the birthweight prediction and development of guidelines for clinical delivery treatments. It is also useful for the implementation of a decision support system using the temporal machine learning prediction model, as it can assist the clinicians to make correct decisions during the obstetric examinations and remind pregnant women to manage their weight.

Downregulation of lncRNA ZFAS1 and upregulation of microRNA-129 repress endocrine disturbance, increase proliferation and inhibit apoptosis of ovarian granulosa cells in polycystic ovarian syndrome by downregulating HMGB1.

OBJECTIVE: The objective was to find the role of long-non-coding RNA zinc finger antisense 1 (lncRNA ZFAS1)/microRNA (miR)-129/high-mobility group box protein 1 (HMGB1) axis in polycystic ovary syndrome (PCOS). METHODS: Ovarian granulosa cells from non-PCOS patients and PCOS patients were collected, and HMGB1, miR-129 and lncRNA ZFAS1 expression were detected. Ovarian granulosa cells were transfected with si-ZFAS1 or miR-129 mimics to verify their roles in P4 and E2 secretion, and the biological functions of ovarian granulosa cells. RESULTS: LncRNA ZFAS1 and HMGB1 were elevated, while miR-129 was down-regulated in ovarian granulosa cells of PCOS patients. Down-regulated lncRNA ZFAS1 or overexpressed miR-129 could decrease HMGB1 expression, increase P4 and E2 secretion, promote proliferation activity while inhibit apoptosis of ovarian granulosa cells in PCOS. CONCLUSION: LncRNA ZFAS1 could bind to miR-129 to promote HMGB1 expression, thereby affecting the endocrine disturbance, proliferation and apoptosis of ovarian granulosa cells in PCOS.

Heat shock protein 90 alpha and 14-3-3η in postmenopausal osteoporotic rats with varying levels of serum FSH.

PURPOSE: This study compared the severity of osteoporosis and screened differentially expressed proteins in postmenopausal osteoporotic rats with varying levels of serum follicle stimulating hormone (FSH). METHODS: Thirty-six Sprague Dawley female rats were divided into four groups: sham operation (sham) group, ovariectomy (OVX) group, FSH and ovariectomy (OVX + FSH) group, and Leuprorelin (LE) and ovariectomy group (OVX + LE). Body weight, serum estradiol, FSH, tartrate-resistant acid phosphatase, alkaline phosphatase, and bone mineral density were measured. We randomly selected six rats each from the OVX and OVX + FSH groups to detect differentially expressed proteins by data-independent acquisition, and we verified the results in the remaining six rats by enzyme-linked immunosorbent assay (ELISA). RESULTS: Nineteen proteins were upregulated and 36 proteins were downregulated in the OVX + FSH group. The expression of heat shock protein 90 alpha (Hsp90α) and 14-3-3η protein was significantly different between the OVX and OVX + FSH groups, and both were linearly correlated with bone trabecular area. Results were verified by ELISA and were found to be consistent with the results of data-independent acquisition. DISCUSSION: In rats with high serum FSH, expression of Hsp90α protein was increased and expression of 14-3-3η protein was decreased. Both changes in protein expression were strongly correlated with bone trabecular area.

New cut-off values for screening of trisomy 21, 18 and open neural tube defects (ONTD) during the second trimester in pregnant women with advanced maternal age.

BACKGROUND: To determine whether advanced maternal age (AMA) causes changes in the maternal serum markers of Trisomy 21, 18 and open neural tube defects (ONTD) during the second trimester of pregnancy. Our research aims to develop new cut-off values for AMA in order to reduce the need for further invasive testing. METHODS: This retrospective cohort study involved 12,739 pregnant women with AMA and 197,101 pregnant women with non-AMA. We then compared the two groups with respect to the positive rate and positive predictive value (PPV) of Trisomy 21, 18 and ONTD. Pregnant women with Trisomy 21, 18 and ONTD were diagnosed by karyotyping the amniotic fluid and by ultrasound diagnosis. RESULTS: Compared to the non-AMA group, the multiple of the median (MOM) of free beta- human chorionic gonadotropin (free ß-hCG), alpha-fetoprotein (AFP), and the risk value forTrisomy 21, were significantly higher in the AMA group (all P < 0.001). The positive rates of Trisomy 21, 18, and ONTD in the AMA group were significantly higher than those in the control group (all P < 0.001). In the AMA group, the PPVs for Trisomy 21 and other deformities were significantly higher (all P < 0.001), although the PPVs for Trisomy 18 and ONTD were similar to those of the non-AMA group. The area under the curve (AUC) values for the AMA group were higher than the non-AMA group, based on free ß-hCG MoM, AFP MoM, and the risk value of Trisomy 21. The cut-off value for the risk value of Trisomy 21 was 1/172 for the AMA, group and 1/780 for the non-AMA group. CONCLUSIONS: The positive rates for Trisomy 21, 18 and ONTD, and the PPV for Trisomy 21 and other deformities were significantly higher in the AMA group. It is essential for pregnant women with AMA to be tested using appropriate cut-off values of serum markers screening for Trisomy 21 during the second trimester of pregnancy to improve the efficacy of prenatal screening and reduce the need for further invasive testing.

The influence of educational level in peri-menopause syndrome and quality of life among Chinese women.

Objective: To investigate the influence of education level in the peri-menopausal symptoms and quality of life (QoL) among Chinese women.Methods: We carried out a cross-sectional study of 1632 peri-menopausal women (age 40-60 y) who visited Hangzhou Women's Hospital from November 2018 to November 2019. The menopausal symptoms were evaluated by modified Kupperman index (KI). World Health Organization Quality of Life (WHOQOL-BREF) questionnaire was used to evaluate the QoL.Result: In total, 1501 women were included in the analysis. The mean age of natural menopause was 49.63 years in China. The five most frequent symptoms in menopausal women were Hot flash (75.53%), sexual problems (72.62%), insomnia (67.29%), fatigue (65.56%), and irritability (61.89%). Natural menopausal age, parity, BMI, bone mineral density, depression, skin formication, total score of KI, and the score of WHOQOL-BREF questionnaire were different in different educational background women (p < .05).Conclusions: The results of the study suggest that education level is associated with the age of natural menopause and menopausal symptoms. A high educational level is correlated with a better score of WHOQOL-BREF in peri-menopause women.

Follicle stimulating hormone, its association with glucose and lipid metabolism during the menopausal transition.

AIM: Accumulative evidence shows that follicle stimulating hormone (FSH) is associated with metabolic disorders. We aimed to ascertain the relationship between FSH, blood glucose and lipid metabolism in general perimenopausal women. METHODS: This cross-sectional study analyzed 2121 perimenopausal women aged 40-54 years in Zhejiang Province from January 2016 to December 2018. Regression analysis was performed to assess the relationship between FSH and metabolic parameters. RESULTS: Serum FSH had a significant inverse association with fasting plasma glucose (P < 0.05) and triglycerides (TG) (P < 0.01) in perimenopausal women. However, after adjusting for body mass index, there was no significant association between FSH and fasting plasma glucose. In a model fully adjusted for demographic variables, estradiol, body mass index, high-density lipoprotein, low-density lipoprotein, homocysteine, systolic blood pressure and blood viscosity, a significant association still existed between FSH and TG (standardized ß = -0.095; R2 = 0.155; P = 0.002). CONCLUSION: Overall, FSH is negatively associated with metabolic parameters, especially TG, in perimenopausal women. These results indicated that FSH might be a biomarker for the primary prevention of disorders with lipid metabolism during the menopausal period.

Clostridium difficile toxins A and B: Receptors, pores, and translocation into cells.

The most potent toxins secreted by pathogenic bacteria contain enzymatic moieties that must reach the cytosol of target cells to exert their full toxicity. Toxins such as anthrax, diphtheria, and botulinum toxin all use three well-defined functional domains to intoxicate cells: a receptor-binding moiety that triggers endocytosis into acidified vesicles by binding to a specific host-cell receptor, a translocation domain that forms pores across the endosomal membrane in response to acidic pH, and an enzyme that translocates through these pores to catalytically inactivate an essential host cytosolic substrate. The homologous toxins A (TcdA) and Toxin B (TcdB) secreted by Clostridium difficile are large enzyme-containing toxins that for many years have eluded characterization. The cell-surface receptors for these toxins, the non-classical nature of the pores that they form in membranes, and mechanism of translocation have remained undefined, exacerbated, in part, by the lack of any structural information for the central ∼1000 amino acid translocation domain. Recent advances in the identification of receptors for TcdB, high-resolution structural information for the translocation domain, and a model for the pore have begun to shed light on the mode-of-action of these toxins. Here, we will review TcdA/TcdB uptake and entry into mammalian cells, with focus on receptor binding, endocytosis, pore formation, and translocation. We will highlight how these toxins diverge from classical models of translocating toxins, and offer our perspective on key unanswered questions for TcdA/TcdB binding and entry into mammalian cells.

A neutralizing antibody that blocks delivery of the enzymatic cargo of Clostridium difficile toxin TcdB into host cells.

Clostridium difficile infection is the leading cause of hospital-acquired diarrhea and is mediated by the actions of two toxins, TcdA and TcdB. The toxins perturb host cell function through a multistep process of receptor binding, endocytosis, low pH-induced pore formation, and the translocation and delivery of an N-terminal glucosyltransferase domain that inactivates host GTPases. Infection studies with isogenic strains having defined toxin deletions have established TcdB as an important target for therapeutic development. Monoclonal antibodies that neutralize TcdB function have been shown to protect against C. difficile infection in animal models and reduce recurrence in humans. Here, we report the mechanism of TcdB neutralization by PA41, a humanized monoclonal antibody capable of neutralizing TcdB from a diverse array of C. difficile strains. Through a combination of structural, biochemical, and cell functional studies, involving X-ray crystallography and EM, we show that PA41 recognizes a single, highly conserved epitope on the TcdB glucosyltransferase domain and blocks productive translocation and delivery of the enzymatic cargo into the host cell. Our study reveals a unique mechanism of C. difficile toxin neutralization by a monoclonal antibody, which involves targeting a process that is conserved across the large clostridial glucosylating toxins. The PA41 antibody described here provides a valuable tool for dissecting the mechanism of toxin pore formation and translocation across the endosomal membrane.

Impacts of macrophage colony-stimulating factor (M-CSF) on the expression of natriuretic peptide precursor type C (NPPC) and regulation of meiotic resumption.

In mammalian follicles, oocytes are arrested at the diplotene stage of prophase I until meiotic resumption following the LH surge. C-type natriuretic peptide (CNP), encoded by natriuretic peptide precursor type C (NPPC), was found to be reduced by the LH surge in the follicle, and then lead to meiotic resumption by decreasing the level of cAMP in the oocyte. As a wide-spread cytokine, macrophage colony-stimulating factor (M-CSF) takes part in the oocyte development to maturation and ovulation. Our study describes the expression curve of M-CSF and its receptor and investigates the impact on the levels of CNP/NPPC to explore the possible mechanism for meiotic resumption in both vivo and vitro. The result shows after the LH/HCG surge, the expressions of M-CSF and its receptors decline significantly inside ovarian follicles, thus leading to transduction of a range of signals. Consequently, the expression of CNP reaches the peak at 2 h and immediately declines to a relatively low level.

Effects of dipeptidyl peptidase-4 inhibitors on transforming growth factor-ß1 signal transduction pathways in the ovarian fibrosis of polycystic ovary syndrome rats.

AIM: Examine the effects of dipeptidyl peptidase-4 (DPP4) inhibitor Sitagliptin on the transforming growth factor-ß1 (TGF-ß1) signal transduction pathway in polycystic ovary syndrome (PCOS) rats with ovarian fibrosis. METHODS: Thirty rats were divided randomly into the PCOS model group, Sitagliptin treatment group and blank control group. Dehydroepiandrosterone was administered to the model group and treatment group to establish the models. Then, the phenotype of rats was recorded, and the serum sex hormone levels were measured. The pathological structures of the rat ovaries were observed. The protein and mRNA expression levels of DPP4, connective tissue growth factor (CTGF), TGF-ß1 and Smad2/3 in the ovaries were analyzed. RESULTS: There was no statistically difference in fasting body weight and blood glucose among the three groups before Sitagliptin treatment (P > 0.05). The fasting blood glucose level was significantly decreased after the administration of Sitagliptin (P < 0.05). The level of testosterone in the model group was reduced remarkably after Sitagliptin treatment (P < 0.001). The protein expression levels of DPP4, CTGF and TGF-ß1 in the ovarian stroma were lower in the treatment group than in the model group (P < 0.01, P < 0.001, P < 0.05). The mRNA levels of DPP4, CTGF and TGF-ß1 in the model group also greatly declined after Sitagliptin treatment (P < 0.05, P < 0.001, P < 0.01). CONCLUSION: The DPP4 inhibitor Sitagliptin lowers fasting blood glucose, relieves the high androgen state of PCOS rats and delays the process of ovarian fibrosis, which may be related to reducing the levels of factors related to the TGF-ß1/Smad2/3 signaling pathway.

Functional defects in Clostridium difficile TcdB toxin uptake identify CSPG4 receptor-binding determinants.

Clostridium difficile is a major nosocomial pathogen that produces two exotoxins, TcdA and TcdB, with TcdB thought to be the primary determinant in human disease. TcdA and TcdB are large, multidomain proteins, each harboring a cytotoxic glucosyltransferase domain that is delivered into the cytosol from endosomes via a translocation domain after receptor-mediated endocytosis of toxins from the cell surface. Although there are currently no known host cell receptors for TcdA, three cell-surface receptors for TcdB have been identified: CSPG4, NECTIN3, and FZD1/2/7. The sites on TcdB that mediate binding to each receptor are not defined. Furthermore, it is not known whether the combined repetitive oligopeptide (CROP) domain is involved in or required for receptor binding. Here, in a screen designed to identify sites in TcdB that are essential for target cell intoxication, we identified a region at the junction of the translocation and the CROP domains that is implicated in CSPG4 binding. Using a series of C-terminal truncations, we show that the CSPG4-binding site on TcdB extends into the CROP domain, requiring three short repeats for binding and for full toxicity on CSPG4-expressing cells. Consistent with the location of the CSPG4-binding site on TcdB, we show that the anti-TcdB antibody bezlotoxumab, which binds partially within the first three short repeats, prevents CSPG4 binding to TcdB. In addition to establishing the binding region for CSPG4, this work ascribes for the first time a role in TcdB CROPs in receptor binding and further clarifies the relative roles of host receptors in TcdB pathogenesis.