Transcriptional regulation and post-translational modifications in the glycolytic pathway for targeted cancer therapy.

Cancer cells largely rely on aerobic glycolysis or the Warburg effect to generate essential biomolecules and energy for their rapid growth. The key modulators in glycolysis including glucose transporters and enzymes, e.g. hexokinase 2, enolase 1, pyruvate kinase M2, lactate dehydrogenase A, play indispensable roles in glucose uptake, glucose consumption, ATP generation, lactate production, etc. Transcriptional regulation and post-translational modifications (PTMs) of these critical modulators are important for signal transduction and metabolic reprogramming in the glycolytic pathway, which can provide energy advantages to cancer cell growth. In this review we recapitulate the recent advances in research on glycolytic modulators of cancer cells and analyze the strategies targeting these vital modulators including small-molecule inhibitors and microRNAs (miRNAs) for targeted cancer therapy. We focus on the regulation of the glycolytic pathway at the transcription level (e.g., hypoxia-inducible factor 1, c-MYC, p53, sine oculis homeobox homolog 1, N6-methyladenosine modification) and PTMs (including phosphorylation, methylation, acetylation, ubiquitination, etc.) of the key regulators in these processes. This review will provide a comprehensive understanding of the regulation of the key modulators in the glycolytic pathway and might shed light on the targeted cancer therapy at different molecular levels.

[The influence of family structure on depression and anxiety symptoms in adolescents: the mediating role of emotional neglect]. / å®¶åº­ç»“æž„å¯¹é’å°‘å¹´æŠ‘éƒå’Œç„¦è™‘ç—‡çŠ¶çš„å½±å“ï¼šæƒ æ„Ÿå¿½è§†çš„ä¸­ä»‹ä½œç”¨.

OBJECTIVES: To study the influence of family structure on depression and anxiety symptoms in adolescents and its mechanism. METHODS: The cluster sampling method was used to select the students from seven middle schools in Shanghai, China. An online questionnaire survey was conducted using a self-made general status questionnaire, Childhood Trauma Questionnaire, Children's Depression Inventory, and Screen for Child Anxiety Related Emotional Disorders. The methods including one-way analysis of variance, chi-square test, binary logistic regression analysis, and mediating effect analysis were used to evaluate depression and anxiety symptoms in adolescents and the difference in childhood trauma and its mediating effect. RESULTS: Compared with the adolescents from nuclear families, the adolescents from three-generation lineal families had a lower risk of depression symptoms (OR=0.794, 95%CI: 0.649-0.972, P<0.05), while those from host families had a higher risk of depression symptoms (OR=4.548, 95%CI: 1.113-18.580, P<0.05). The adolescents from inter-generational families and host families had a significantly higher score on the Childhood Trauma Questionnaire subscale of emotional neglect (P<0.05). Emotional neglect played a mediating role in the influence of inter-generational families and host families on depression symptoms in adolescents. CONCLUSIONS: Parents and grandparents have a certain positive effect in family structures. Separation from parents may make adolescents perceive more emotional neglect, which may increase the occurrence of depression symptoms.

Genome-wide TCP transcription factors analysis provides insight into their new functions in seasonal and diurnal growth rhythm in Pinus tabuliformis.

BACKGROUND: Pinus tabuliformis adapts to cold climate with dry winter in northern China, serving as important commercial tree species. The TEOSINTE BRANCHED 1, CYCLOIDEA, and PROLIFERATING CELL FACTOR family(TCP)transcription factors were found to play a role in the circadian clock system in Arabidopsis. However, the role of TCP transcription factors in P. tabuliformis remains little understood. RESULTS: In the present study, 43 TCP genes were identified from P. tabuliformis genome database. Based on the phylogeny tree and sequence similarity, the 43 TCP genes were classified into four groups. The motif results showed that different subfamilies indeed contained different motifs. Clade II genes contain motif 1, clade I genes contain motif 1, 8, 10 and clade III and IV contain more motifs, which is consistent with our grouping results. The structural analysis of PtTCP genes showed that most PtTCPs lacked introns. The distribution of clade I and clade II on the chromosome is relatively scattered, while clade III and clade IV is relatively concentrated. Co-expression network indicated that PtTCP2, PtTCP12, PtTCP36, PtTCP37, PtTCP38, PtTCP41 and PtTCP43 were co-expressed with clock genes in annual cycle and their annual cycle expression profiles both showed obvious seasonal oscillations. PtTCP2, PtTCP12, PtTCP37, PtTCP38, PtTCP40, PtTCP41, PtTCP42 and PtTCP43 were co-expressed with clock genes in diurnal cycle. Only the expression of PtTCP42 showed diurnal oscillation. CONCLUSIONS: The TCP gene family, especially clade II, may play an important role in the regulation of the season and circadian rhythm of P. tabuliformis. In addition, the low temperature in winter may affect the diurnal oscillations.

MADS-box transcription factors MADS11 and DAL1 interact to mediate the vegetative-to-reproductive transition in pine.

The reproductive transition is an important event that is crucial for plant survival and reproduction. Relative to the thorough understanding of the vegetative phase transition in angiosperms, a little is known about this process in perennial conifers. To gain insight into the molecular basis of the regulatory mechanism in conifers, we used temporal dynamic transcriptome analysis with samples from seven different ages of Pinus tabuliformis to identify a gene module substantially associated with aging. The results first demonstrated that the phase change in P. tabuliformis occurred as an unexpectedly rapid transition rather than a slow, gradual progression. The age-related gene module contains 33 transcription factors and was enriched in genes that belong to the MADS (MCMl, AGAMOUS, DEFICIENS, SRF)-box family, including six SOC1-like genes and DAL1 and DAL10. Expression analysis in P. tabuliformis and a late-cone-setting P. bungeana mutant showed a tight association between PtMADS11 and reproductive competence. We then confirmed that MADS11 and DAL1 coordinate the aging pathway through physical interaction. Overexpression of PtMADS11 and PtDAL1 partially rescued the flowering of 35S::miR156A and spl1,2,3,4,5,6 mutants in Arabidopsis (Arabidopsis thaliana), but only PtMADS11 could rescue the flowering of the ft-10 mutant, suggesting PtMADS11 and PtDAL1 play different roles in flowering regulatory networks in Arabidopsis. The PtMADS11 could not alter the flowering phenotype of soc1-1-2, indicating it may function differently from AtSOC1 in Arabidopsis. In this study, we identified the MADS11 gene in pine as a regulatory mediator of the juvenile-to-adult transition with functions differentiated from the angiosperm SOC1.

LINC02381, a sponge of miR-21, weakens osteogenic differentiation of hUC-MSCs through KLF12-mediated Wnt4 transcriptional repression.

INTRODUCTION: Human umbilical cord blood-derived MSCs (hUC-MSCs) have the potential to differentiate into osteoblasts. This study investigated the function and potential mechanisms of a novel lncRNA LINC02381 in hUC-MSC osteogenic differentiation. MATERIALS AND METHODS: hUC-MSCs were maintained in osteogenic differentiation medium. RT-qPCR assay was performed to assess LINC02381 expression. Alizarin Red S (ARS) and alkaline phosphatase (ALP) staining were performed to evaluate osteogenic differentiation. The interaction between miR-21 and LINC0238/KLF12 was determined by luciferase reporter and RNA immunoprecipitation (RIP) assays. Chromatin immunoprecipitation (ChIP) assay was used to confirm the transcriptional regulation of KLF12 on Wnt4 promoter. The nuclear translocation of ß-catenin was evaluated using immunofluorescence. hUC-MSCs seeded on Bio-Oss Collagen scaffolds were transplanted into nude mice to assess in vivo osteogenesis. Bone formation was observed by H&E and Masson's trichrome staining. OSX and OPN levels were assessed by immunohistochemistry. RESULTS: LINC02381 was up-regulated in the clinical samples of osteoporotic patients. However, LINC02381 expression was reduced during osteogenic differentiation of hUC-MSCs. Enforced expression of LINC02381 suppressed the osteogenic differentiation of hUC-MSCs. Mechanistically, LINC02381 sponged miR-21 to enhance KLF12 expression, which led to the inactivation of Wnt/ß-catenin signaling pathway. Furthermore, miR-21 mimics or KLF12 silencing counteracted LINC02381-induced inhibition of osteogenic differentiation, whereas IWP-4 (an inhibitor of Wnt pathway) abolished this effect. CONCLUSION: In summary, LINC02381 repressed osteogenic differentiation of hUS-MSCs through sponging miR-21 to enhance KLF12-mediated inactivation of Wnt/ß-catenin pathway, indicating that LINC02381 might be a therapeutic target for osteoporosis.

Relationship between the Height of Alveolar Bone Resorption and Sex and Age in Adolescents.

OBJECTIVES: To explore the relationship between the height of alveolar bone resorption and sex and age in the adolescent dentition. METHODS: Multi-slice computed tomography (MSCT) was used to measure the height of alveolar bone resorption at labial, lingual, mesial and distal sites of teeth in 149 adolescents aged from 10 to 20 years. SPSS 25.0 software was used to analyze the relationship between the height of alveolar bone resorption and sex and age. RESULTS: There was no significant difference in the height of alveolar bone resorption between sex (P>0.05). The height of alveolar bone resorption was positively correlated with age in all types of teeth. The model constructed by combining the alveolar bone resorption height data of four sites (y=2.569x1+3.106x2+4.108x3+1.451x4-0.082, R2max=0.756)had a better ability to infer age than that of combining two sites (y=5.942x1+4.489x2+0.612, R2max=0.706) and a single site (R2max=0.638). CONCLUSIONS: The height of alveolar bone resorption is positively correlated with the age of adolescents. The combination of four sites has a stronger ability to infer the relationship between the height of alveolar bone resorption and age in adolescents and has higher accuracy in practical application.

Gibberellin Signaling Is Required for Far-Red Light-Induced Shoot Elongation in Pinus tabuliformis Seedlings.

Gibberellin (GA) is known to play an important role in low red/far-red (R:FR) light ratio-mediated hypocotyl and petiole elongation in Arabidopsis (Arabidopsis thaliana). However, the regulatory relationship between low R:FR and GAs remains unclear, especially in gymnosperms. To increase our understanding of the molecular basis of low R:FR-mediated shoot elongation in pines and to determine whether there is an association between low R:FR and GAs action, we explored the morphological and transcriptomic changes triggered by low R:FR, GAs, and paclobutrazol (PAC), a GAs biosynthesis inhibitor, in Pinus tabuliformis seedlings. Transcriptome profiles revealed that low R:FR conditions and GAs have a common set of transcriptional targets in P. tabuliformis We provide evidence that the effect of low R:FR on shoot elongation in P. tabuliformis is at least partially modulated by GAs accumulation, which can be largely attenuated by PAC. GAs are also involved in the cross talk between different phytohormones in the low R:FR response. A GA biosynthesis gene, encoding ent-kaurenoic acid oxidase (KAO), was strongly stimulated by low R:FR without being affected by GAs feedback regulation or the photoperiod. We show that GA signaling is required for low R:FR-induced shoot elongation in P tabuliformis seedlings, and that there are different regulatory targets for low R:FR-mediated GA biosynthesis between conifers and angiosperms.

Comparative transcriptome analyses reveal two distinct transcriptional modules associated with pollen shedding time in pine.

BACKGROUND: Seasonal flowering time is an ecologically and economically important trait in temperate trees. Previous studies have shown that temperature in many tree species plays a pivotal role in regulating flowering time. However, genetic control of flowering time is not synchronised in different individual trees under comparable temperature conditions, the underlying molecular mechanism is mainly to be investigated. RESULTS: In the present study, we analysed the transcript abundance in male cones and needles from six early pollen-shedding trees (EPs) and six neighbouring late pollen-shedding trees (LPs) in Pinus tabuliformis at three consecutive time points in early spring. We found that the EPs and LPs had distinct preferred transcriptional modules in their male cones and, interestingly, the expression pattern was also consistently maintained in needles even during the winter dormancy period. Additionally, the preferred pattern in EPs was also adopted by other fast-growing tissues, such as elongating new shoots. Enhancement of nucleic acid synthesis and stress resistance pathways under cold conditions can facilitate rapid growth and maintain higher transcriptional activity. CONCLUSIONS: During the cold winter and early spring seasons, the EPs were more sensitive to relatively warmer temperatures and showed higher transcriptomic activity than the LPs, indicating that EPs required less heat accumulation for pollen shedding than LPs. These results provided a transcriptomic-wide understanding of the temporal regulation of pollen shedding in pines.

A Modified Technique Using Levator Aponeurosis-Müller Muscle-Reinforced Plication for Blepharoptosis Correction.

BACKGROUND: Blepharoptosis is a common and challenging clinical problem for oculoplastic surgeons, and various surgical techniques have been used to correct ptosis. The aims of this study were to present the clinical results of a modified technique using levator aponeurosis-Müller muscle-reinforced plication for blepharoptosis correction and to demonstrate its advantages over conventional advancement or plication methods. METHODS: This study was conducted in the Plastic Surgery Department of Sir Run Run Shaw Hospital between April 2017 and September 2018. By using this modified technique, the levator-Müller complex was reinforced with a plication suture that pierced under and through the levator-Müller complex, and the posterior and lower part of the levator-Müller complex was advanced to the tarsus, which provided permanent, reliable adhesion. The primary outcome was marginal reflex distance 1 preoperatively and postoperatively. Secondary outcomes were the cosmetic outcome, complications, and operative time. RESULTS: Eighty-six patients (169 eyelids) underwent this modified surgery. Patients' average age was 26 ± 7.6 years, and the median follow-up was 14 months. The preoperative and postoperative mean marginal reflex distance 1 values were 1.72 ± 0.32 and 3.69 ± 0.28 mm, respectively. The amount of plication ranged from 4 to 15 mm. The overall surgical success rate was 88.17%. Some complications were observed including undercorrection (5.92%), asymmetry (4.73%), lagophthalmos (0.59%), and conjunctival prolapse (0.59%). CONCLUSIONS: The modified technique provided good functional and cosmetic outcomes for blepharoptosis correction by avoiding unpredicted adhesion, and it has its advantages including simplicity, easy adjustment of the eyelid height intraoperatively, minimal edema formation, and high success rate.

Copper-catalyzed fluoroalkylation of alkynes, and alkynyl & vinyl carboxylic acids with fluoroalkyl halides.

Copper-catalyzed fluoroalkylation of alkynes and alkynyl carboxylic acids has been achieved with high functional-group tolerance and excellent regio- and stereoselectivities. A variety of fluoroalkyl halides including ethyl bromodifluoroacetate can be employed. Additionally, an unprecedented decarboxylative fluoroalkylation of α, ß-unsaturated carboxylic acids has been achieved via a radical pathway.

Transition-metal-free C-H oxidative activation: persulfate-promoted selective benzylic mono- and difluorination.

An operationally simple and selective method for the direct conversion of benzylic C-H to C-F to obtain mono- and difluoromethylated arenes using Selectfluor™ as a fluorine source is developed. Persulfate can be used to selectively activate benzylic hydrogen atoms toward C-F bond formation without the aid of transition metal catalysts.

CHARACTERISTICS AND FACTORS INFLUENCING UNPROTECTED ANAL INTERCOURSE AMONG MEN WHO HAVE SEX WITH MEN IN FUYANG, CHINA.

Men who have sex with men (MSM) are at risk for contracting hu- man immunodeficiency virus (HIV) infection. The objective of this study was to explore the characteristics and factors influencing unprotected anal intercourse (UAI) among MSM in Fuyang, China in order to develop an intervention program to prevent the spread of HIV infection among MSM. We conducted this cross sectional study among 413 MSM in 2013. Participants completed an interviewer- administered questionnaire and were tested for HIV and syphilis infections. Three hundred fifty of 413 subjects reported sexual activity with a male partner during the previous 6 months; of these 27(7.7%) had unprotected sex. Forty-four subjects had sex with a female partner during the previous 6 months; of these 25 (58.1%) had unprotected sex. The frequency of having unprotected sex with a female was significantly greater than with a male (χ2 = 84.52, p < 0.001). Multivariate logistic analysis showed education level (OR = 0.45, p = 0.003), length of time of current residence (OR = 0.47, p = 0.014), knowledge about HIV infection (OR = 0.09, p = 0.022) and integrated interventions (OR = 0.32, p < 0.001) were all significantly associated with UAI. High-risk sex behavior was common among the study population. A targeted interventions needs to be developed urgently.

Venous thromboembolism risk and erythropoiesis-stimulating agents for the treatment of cancer-associated anemia: a meta-analysis.

Erythropoiesis-stimulating agents (ESAs) reduce anemia in patients with cancer and could improve their quality of life, but ESA-related safety concerns exist. To evaluate the overall risk of venous thromboembolism (VTE) associated with the use of ESAs, a systematic review and meta-analysis of published randomized controlled trials (RCTs) was performed. The databases of PubMed and Web of Science and the abstracts presented at the American Society of Clinical Oncology conferences were searched to identify relevant clinical trials. Summary incidence rates, relative risks (RRs), and 95% confidence intervals (CIs) were calculated. A total of 12,115 patients with a variety of cancer types from 51 RCTs were identified and included in the meta-analysis. Among patients receiving ESAs, the summary incidence of all-grade VTE was 7.78%. Patients with cancer who received ESAs had increased VTE risks (484 events among 6,301 patients treated with ESA vs. 276 events among 5,814 control patients; RR = 1.75 [95% CI, 1.50­2.05]). The highest risk of VTE was found in patients with ovarian and cervical cancers (RR = 2.45 [CI = 1.12­5.33]). The VTE risk among hematologic malignancies was higher than that among solid tumors. The administration of ESAs was significantly associated with an increased risk of developing VTE in cancer patients receiving these drugs. The risks of VTE may vary with various tumor types, including hematologic malignancies.

Prognostic significance of VEGF-C immunohistochemical expression in breast cancer: a meta-analysis.

Vascular endothelial growth factor-C (VEGF-C) is considered as a prime mediator of lymphangiogenesis and has been implicated in carcinogenesis and metastasis. Various studies examined the relationship between VEGF-C protein overexpression with the clinical outcome in patients with breast cancer but yielded conflicting results. Electronic databases updated to April 2013 were searched to find relevant studies. A meta-analysis was conducted with eligible studies which quantitatively evaluated the relationship between VEGF-C overexpression and survival of patients with breast cancer. Survival data were aggregated and quantitatively analyzed. We performed a meta-analysis of 11 studies (n = 1,357 patients) that evaluated the correlation between VEGF-C overexpression detected by immunohistochemistry and survival in patients with breast cancer. Combined hazard ratios suggested that VEGF-C overexpression was not associated with poor prognosis of disease-free survival (HR [hazard ratio] = 0.80, 95 % CI [confidence interval]: 0.51-1.09), overall survival (OS) (HR = 1.08, 95 % CI: 0.37-1.78) in patients with breast cancer. In the stratified analysis by patient source, significantly risks were not found among Asians or non-Asians. No significant heterogeneity was observed among all studies. VEGF-C overexpression was not associated with poor disease-free survival or overall survival in breast cancer.

[Treating lupus nephritis by a drug pair of radix astragali and rehmanniae radix combined with glucocorticoid: a preliminary clinical study].

OBJECTIVE: To observe the therapeutic effect of a drug pair of Radix Astragali and Rehmanniae Radix combined with glucocorticoid (GC) in treating lupus nephritis (LN) patients and its influence on some experimental indices. METHODS: Totally 52 LN patients were randomly assigned to the treatment group (treated by routine Western medicine and a drug pair of Radix Astragali and Rehmanniae Radix, 25 cases) and the control group (treated by Western medicine, mainly by GC and cyclophosphamide, 27 cases). All patients received 6-month therapy. The GC dosage, the withdrawal and reduction dosage of GC, clinical efficacy, systemic lupus erythematosus disease activity index (SLEDAI) score, adverse reactions, and laboratory indicators were recorded. RESULTS: (1) All patients got relieved to some degree with the dosage of GC reduced. The total withdrawal and reduction dosage of GC was slightly higher in the treatment group than in the control group [(50.23 +/- 12.43) mg vs (48.76 +/- 13.61) mg, P > 0.05]. Besides, the prednisone dosage in the treatment group was lower than that in the control group, but without statistical difference (P > 0.05). The ratio of patients in need of adding prednisone for aggravating disease was 24.0%, significantly lower than that in the control group (44.44%, P < 0.05). (2) There was no statistical difference in the SLEDAI score, inflammatory indicators, liver and renal functions, blood electrolytes, blood glucose, blood and urine routines between the two groups (P > 0.05). The 24-h urinary protein count was (1.06 +/- 0.22) g/L in the treatment group, obviously lower than that in the control group (1.43 +/- 0.55 g/L, P < 0.05). (3) There was no statistical difference in the incidence rate of infection, gastrointestinal hemorrhage, psychoneuroses, Cushing's syndrome, cardiovascular anomalies, and femoral head necrosis between the two groups (P > 0.05). But the incidence of adverse reactions such as insomnia, tidal fever, spontaneous sweat, and obesity was less in the treatment group than in the control group (P < 0.05). CONCLUSIONS: Using a drug pair of Radix Astragali and Rehmanniae Radix combined with GC in treating LN could withdraw the dosage of GC and relieve symptoms it induced. It was advantageous in reducing the dosage of GC and stabilizing patients' conditions.

Prognostic value of cyclin E expression in breast cancer: a meta-analysis.

Cyclin E is an important regulator of cell cycle progression. Various studies examined the relationship between cyclin E overexpression with the clinical outcome in patients with breast cancer but yielded conflicting results. Electronic databases updated to May 2013 were searched to find relevant studies. A meta-analysis was conducted with eligible studies which quantitatively evaluated the relationship between cyclin E overexpression and survival of patients with breast cancer. Survival data were aggregated and quantitatively analyzed. We conducted a final analysis of 7,759 patients from 23 eligible studies and evaluated the correlation between cyclin E overexpression and survival in patients with breast cancer. Combined hazard ratios suggested that cyclin E overexpression had an unfavorable impact on overall survival (OS) (hazard ratio (HR) = 1.30, 95% confidence interval (CI), 1.12-1.49) and breast cancer-specific survival (BCSS) (HR = 1.48, 95% CI, 1.03-1.93), but not disease-free survival (HR = 1.11; 95% CI, 0.96-1.27) in patients with breast cancer. Significantly, risks were found among stage I-II breast cancer for (HR = 1.75; 95% CI, 1.30-2.19). Cyclin E overexpression is associated with poor OS and BCSS in breast cancer.

Modular pathways for editing non-cognate amino acids by human cytoplasmic leucyl-tRNA synthetase.

To prevent potential errors in protein synthesis, some aminoacyl-transfer RNA (tRNA) synthetases have evolved editing mechanisms to hydrolyze misactivated amino acids (pre-transfer editing) or misacylated tRNAs (post-transfer editing). Class Ia leucyl-tRNA synthetase (LeuRS) may misactivate various natural and non-protein amino acids and then mischarge tRNA(Leu). It is known that the fidelity of prokaryotic LeuRS depends on multiple editing pathways to clear the incorrect intermediates and products in the every step of aminoacylation reaction. Here, we obtained human cytoplasmic LeuRS (hcLeuRS) and tRNA(Leu) (hctRNA(Leu)) with high activity from Escherichia coli overproducing strains to study the synthetic and editing properties of the enzyme. We revealed that hcLeuRS could adjust its editing strategy against different non-cognate amino acids. HcLeuRS edits norvaline predominantly by post-transfer editing; however, it uses mainly pre-transfer editing to edit α-amino butyrate, although both amino acids can be charged to tRNA(Leu). Post-transfer editing as a final checkpoint of the reaction was very important to prevent mis-incorporation in vitro. These results provide insight into the modular editing pathways created to prevent genetic code ambiguity by evolution.

A Novel Manner of Anchoring Cobalt Phthalocyanine on Edge-Defected Carbon for Highly Electrocatalytic CO2 Reduction.

Cobalt phthalocyanine anchored on carbon material has attracted an enormous amount of attention due to its superior performance in electrocatalytic CO2 reduction. However, the interaction between cobalt phthalocyanine and the carbon substrate remains problematic, and the role of intrinsic carbon defects is unfortunately ignored in the anchoring of cobalt phthalocyanine on carbon. Herein, new interactions between the bridging N atoms of cobalt phthalocyanine and the edge defects of carbon have been discovered, which result in a novel model of anchoring of cobalt phthalocyanine on ketjen black carbon. Such anchored cobalt phthalocyanine has been found to be responsible for superior catalysis for electrochemical reduction of CO2 to CO with high selectivity and low overpotential.

Clinical guideline on magnetically controlled capsule gastroscopy (2021 edition).

With the development and generalization of endoscopic technology and screening, clinical application of magnetically controlled capsule gastroscopy (MCCG) has been increasing. In recent years, various types of MCCG are used globally. Therefore, establishing relevant guidelines on MCCG is of great significance. The current guidelines containing 23 statements were established based on clinical evidence and expert opinions, mainly focus on aspects including definition and diagnostic accuracy, application population, technical optimization, inspection process, and quality control of MCCG. The level of evidence and strength of recommendations were evaluated. The guidelines are expected to guide the standardized application and scientific innovation of MCCG for the reference of clinicians.

Retinoic acid synthesis and metabolism are concurrent in the mouse uterus during peri-implantation.

Vitamin A (retinol) and its active metabolite, retinoic acid (RA), serve dual roles in the female reproductive tract. Cytochrome P450 26A1 (Cyp26a1), an RA-metabolizing enzyme, is involved in mammalian early pregnancy. In order to investigate the role of RA synthesis and metabolism during embryo implantation, we first investigated the spatiotemporal expression of RA-signal in the mouse uterus during the peri-implantation period. RA-signal-related molecules, including binding proteins, synthesizing enzymes, catabolizing enzymes and receptors, were all expressed in the mouse uterus during embryo implantation. The locations of the RA synthetic system (Aldh1a1, Aldh1a2, CRBP1) and catabolizing enzyme (Cyp26a1) were distinctive in the mouse uterus during the peri-implantation period. Aldh1a1 was located in the gland epithelium, whereas Aldh1a2 and CRBP1 were located in the stroma and Cyp26a1 was expressed in the luminal and glandular epithelium. These results demonstrate that RA synthesis occurs in the stroma, whereas RA metabolism takes place in the endometrial epithelium. When endometrial epithelial cells were isolated on day 4.5 of pregnancy and treated with E(2) (17beta-estradiol) or a combination of E(2) and progesterone, all-trans-RA (10 µM) significantly down-regulated the expression of LIF, HB-EF and CSF-1 in these cells in vitro. Taken together, these results suggest that the accumulation of RA in the stroma during mouse embryo implantation has an inhibitory effect on the expression of the three implantation-essential genes, LIF, HB-EGF and CSF-1. Therefore, the expression of Cyp26a1 in luminal and glandular epithelium might block the adverse effect of RA in order to promote successful embryo implantation.