Unveiling the mechanism of source-sink rebalancing in cucumber-pumpkin heterografts: the buffering roles of rootstock cotyledon.

Grafting onto pumpkin rootstock is widely applied in cucumber production to improve growth and yield, as well as to overcome soil-borne diseases and enhance resistance to abiotic stresses. In this study, we constructed the cucumber-pumpkin heterografts with the one-cotyledon grafting method, and examined the effects of heterografting on biomass allocation and sugar partitioning, with cucumber and pumpkin self-grafts used as control. Compared with cucumber self-grafts, heterografting onto pumpkin rootstock promoted photosynthesis in cucumber scion, and led to higher sucrose contents in the 1st true leaf (source) and newly emerged leaf (sink). Thereby, the scion part of heterografts accumulated more biomass than cucumber self-grafts. In contrast, when compared to pumpkin self-grafts, grafting with cucumber scion reduced root vigor and biomass but promoted cotyledon growth in pumpkin rootstock. The roots (sink) of heterografts contained less sucrose and hexoses, and showed reduced sucrose synthase (SuSy) and hexokinase (HXK) activities. However, the rootstock cotyledon (source) contained more sucrose and starch, and showed higher activities of HXK, cell-wall invertase (CWIN), and enzymes for starch synthesis and degradation. Furthermore, removal or shade of rootstock cotyledon led to reduced growth of root and scion. Silencing of CmoMEX1a gene in rootstock cotyledon inhibited maltose export and reduced root growth of heterografts. These results indicated that rootstock cotyledon, especially its starch content, played a buffering role in the growth regulation of cucumber-pumpkin heterografts. Taken together, our results provided a major contribution to our understanding of source-sink sugar partitioning and scion-rootstock growth balancing in cucumber-pumpkin heterografts.

Identifying Key Genes and Functionally Enriched Pathways in Osteoporotic Patients by Weighted Gene Co-Expression Network Analysis.

Osteoporosis is a systemic bone disease characterized by low bone mineral density and bone microstructure damage, resulting in increased bone fragility and fracture risk. The present study aimed to identify key genes and functionally enriched pathways in osteoporotic patients. Weighted Gene Co-expression Network Analysis (WGCNA) was applied to microarray datasets of blood samples of osteoporotic patients from the Sao Paulo Ageing & Health [SPAH] study (26 osteoporotic samples and 31 normal samples) to construct co-expression networks and identify hub gene. The results showed that HDGF, AP2M1, DNAJC6, TMEM183B, MFSD2B, IGKV1-5, IGKV1-8, IGKV3-7, IGKV3D-11, and IGKV1D-42 are genes which were associated with the disease status of osteoporosis. Differentially expressed genes are enriched in proteasomal protein catabolic process, ubiquitin ligase complex, and ubiquitin-like protein transferase activity. Functional enrichment analysis demonstrated that genes in the tan module were enriched in immune-related functions, indicating that the immune system plays a critical role in osteoporosis. Validation assay demonstrated that the HDGF, AP2M1, TMEM183B, and MFSD2B levels were decreased in osteoporosis samples compared with healthy controls, while the levels of IGKV1-5, IGKV1-8, and IGKV1D-42 were increased in osteoporosis samples compared with healthy controls. In conclusion, our data identified and validated the association of HDGF, AP2M1, TMEM183B, MFSD2B, IGKV1-5, IGKV1-8, and IGKV1D-42 with osteoporosis in elderly women. These results suggest that these transcripts have potential clinical significance and may help to explain the molecular mechanisms and biological functions of osteoporosis.

ABA-responsive AREB1/ABI3-1/ABI5 cascade regulates IAA oxidase gene SlDAO2 to inhibit hypocotyl elongation in tomato.

Hypocotyl elongation is dramatically influenced by environmental factors and phytohormones. Indole-3-acetic acid (IAA) plays a prominent role in hypocotyl elongation, whereas abscisic acid (ABA) is regarded as an inhibitor through repressing IAA synthesis and signalling. However, the regulatory role of ABA in local IAA deactivation remains largely uncharacterized. In this study, we confirmed the antagonistic interplay of ABA and IAA during the hypocotyl elongation of tomato (Solanum lycopersicum) seedlings. We identified an IAA oxidase enzyme DIOXYGENASE FOR AUXIN OXIDATION2 (SlDAO2), and its expression was induced by both external and internal ABA signals in tomato hypocotyls. Moreover, the overexpression of SlDAO2 led to a reduced sensitivity to IAA, and the knockout of SlDAO2 alleviated the inhibitory effect of ABA on hypocotyl elongation. Furthermore, an ABA-responsive regulatory SlAREB1/SlABI3-1/SlABI5 cascade was identified to act upstream of SlDAO2 and to precisely control its expression. SlAREB1 directly bound to the ABRE present in the SlDAO2 promoter to activate SlDAO2 expression, and SlABI3-1 enhanced while SlABI5 inhibited the activation ability of SlAREB1 by directly interacting with SlAREB1. Our findings revealed that ABA might induce local IAA oxidation and deactivation via SlDAO2 to modulate IAA homoeostasis and thereby repress hypocotyl elongation in tomato.

A Phase I Study to Evaluate the Safety and Pharmacokinetics of SHR0302 Base Ointment in Healthy Adult Volunteers.

INTRODUCTION: SHR0302 is a highly selective JAK1 inhibitor. This study aimed to investigate the safety, tolerability, and pharmacokinetics of single and multiple-dose topical skin application of SHR0302 base ointment in healthy adult subjects. METHODS: This phase I clinical trial (registration number: CTR20192188) consisted of two parts. Part 1 was a single-dose ascending study with four dose levels in 32 healthy Australian adults (8 subjects in each dose group). All Australian subjects were randomized 3:1 to a single-dose topical skin application of SHR0302 base ointment or placebo. The dose escalated from 1% SHR0302 base ointment on 3% of body surface area (BSA) to 2% SHR0302 base ointment on 20% of BSA. Part 2 combined single and multiple-dose ascension studies with two dose levels in 20 healthy Chinese adults (10 subjects in each dose group). All Chinese subjects were randomized 4:1 to a combination of single and multiple doses for consecutive 10 days of topical application of 1% SHR0302 base ointment on 20% BSA or 2% SHR0302 base ointment on 20% BSA. The safety and pharmacokinetics of the SHR0302 base ointment were evaluated. RESULTS: The incidence of treatment-emergent adverse events (TEAEs) in both parts was comparable between the SHR0302 base ointment group and the vehicle group (part 1: 33.3% vs. 37.5%; part 2: 56.3% vs. 75.0%). All TEAEs were transient, recovered, and equally well-tolerated in the two racial groups. The overall absorption of the SHR0302 base ointment was slow after topical application, with Tmax>10 h. After a single dose of the SHR0302 base ointment, drug exposure in healthy Australian and Chinese subjects increased nonlinearly with the increase in the administration area and drug content. Drug exposure increased in a less-than-dose-proportional manner within the dose range tested. Due to differences in the clinical practice of topical application, the Tmax of the drug in Australian subjects was earlier than in Chinese subjects, but the overall extent of absorption seemed comparable in Australian and Chinese subjects (with comparable AUC0-t). CONCLUSION: The SHR0302 base ointment (either single or multiple doses) was well tolerated and safe, with no racial disparity. KEY MESSAGE: The SHR0302 base ointment (either single or multiples doses) was well tolerated and safe.

[Construction and Exploration of Simulative Virtual Curriculum of Laparoscopy for Standardized Surgical Residency Training]. / å¤–ç§‘ä½é™¢åŒ»å¸ˆåŸ¹è®­çš„è ¹è ”é•œæ¨¡æ‹Ÿè™šæ‹Ÿè¯¾ç¨‹å»ºè®¾æŽ¢ç´¢.

Laparoscopic operations have become an indispensable therapeutic measure in surgical treatment due to the emerging trends of minimal invasiveness and precision in the field of surgery. Laparoscopic skills have gradually become part of the essential skills for young surgeons and hospitals at all levels are giving high priority to laparoscopic skills training. The innovation and development of simulative and virtual medical technology has given rise to effective ways and platforms for the training of laparoscopy surgeons in China. Based on the laparoscopy simulative virtual technology, our hospital gradually developed a systematic training and evaluation system for the laparoscopy training of surgical residents by offering theory courses on laparoscopy, conducting simulative and virtual systematic training, and developing assessment criteria for the training. Herein, we presented and shared our experience in applying laparoscopy simulative virtual technology in the training of surgical residents in order to promote the standardized residency training of laparoscopic skills in China and to provide reference for the implementation of standardized training of laparoscopic skills.

Differential MC5R loss in whales and manatees reveals convergent evolution to the marine environment.

Melanocortin 5 receptor (MC5R), which is expressed in the terminally differentiated sebaceous gland, is a G protein-coupled receptor (GPCR). MC5R exists mostly in mammals but is completely lost in whales; only the relic of MC5R can be detected in manatees, and phenotypically, they have lost sebaceous glands. Interestingly, whales and manatees are both aquatic mammals but have no immediate common ancestors. The loss of MC5R and sebaceous glands in whales and manatees is likely to be a result of convergent evolution. Here, we find that MC5R in whales and manatees are lost by two different mechanisms. Homologous recombination of MC5R in manatees and the insertion of reverse transcriptase in whales lead to the gene loss, respectively. On one hand, in manatees, there are two "TTATC" sequences flanking MC5R, and homologous recombination of the segments between the two "TTATC" sequences resulted in the partial loss of the sequence of MC5R. On the other hand, in whales, reverse transcriptase inserts between MC2R and RNMT on the chromosome led to the loss of MC5R. Based on these two different mechanisms for gene loss in whales and manatees, we finally concluded that MC5R loss might be the result of convergent evolution to the marine environment, and we explored the impact on biological function that is significant to environmental adaptation.

Peripheral immunophenotypes associated with the flare in the systemic lupus erythematosus patients with low disease activity state.

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by clinical heterogeneity and flare unpredictability. It was still unclear for the association between SLE flare and immunophenotypes. Flow cytometric analysis defined the B and T subsets of the low disease activity state (LDAS) patients and healthy controls. Principal components analysis (PCA) and cluster analysis (CA) distinguished the immunophenotypes. Compared with the 66 healthy controls, the 93 LDAS patients had higher proportions of plasma cells, double negative B cells, naïve B cells and CD8+T cells, and lower proportions of unswitched memory B cells and CD4+T cells. PCA showed the abnormalities of T and B cell axes. CA divided the patients into 3 groups. The memory B cells group had the lower flare risk compared with the non-memory B cells group (including naïve B cells group and T cells group). The immunophenotypes were associated with SLE flare in the LDAS patients.

Alterations of peripheral blood B cell subsets in Chinese patients with adult idiopathic inflammatory myopathies.

OBJECTIVES: Abnormalities and hyperactivation of B cells have been described in idiopathic inflammatory myopathies (IIM). However, little is known about changes in the homeostasis of peripheral blood B cells in adult IIM patients. The aim of this study was to identify phenotypic alterations of B cell subsets and their relation to the overall clinical profile. METHODS: Blood samples were collected from 25 adult IIM patients and 15 healthy controls. Peripheral B cell subsets were classified into non-switched memory B cells (CD19+CD27+lgD+), switched memory B cells (CD19+CD27+lgD-), double-negative (DN) memory B cells (CD19+CD27-lgD-) and naïve B cells (CD19+CD27-lgD+) based on their surface phenotype as measured by flow cytometry. The clinical profile of IIM and its correlation with B cell subsets was further evaluated. RESULTS: Frequencies of CD19+ B cells and naïve B cells were increased in adult IIM patients compared with healthy controls (p=0.005 and p<0.001, respectively) and the frequency of memory B cells was decreased (p<0.001). Moreover, patients with a rash had lower non-switched memory B cells proportion (p=0.032). Patients with anti-MDA5+ antibodies had higher CD19+ B cells proportion than anti-ARS+ patients (p=0.046). Patients who were not receiving treatment had elevated levels of CD19+ B cells and naïve B cells along with reduced non-switched memory B cells compared with patients who were receiving treatment (p=0.021, p=0.036 and p=0.032, respectively). CONCLUSIONS: Our findings demonstrate abnormalities in the homeostasis of the B cell subsets present in adult IIM patients, characterised by expanded CD19+ B cells and naïve B cells but reduced memory B cells. Phenotypic abnormalities of B cell subsets are associated with the presence of a rash, with anti-MDA5 positivity and with treatment.

Impact of background music on the performance of laparoscopy teams.

BACKGROUND: Acoustic conditions in the operating room have different impacts on surgeon's performance. Their effects on the performance of surgical teams are not well documented. We investigated if laparoscopic teams operating under pleasant acoustic conditions would perform better than under noisy conditions. METHODS: We recruited 114 surgical residents and built 57 two-person teams. Each team was required to perform two laparoscopic tasks (object transportation and collaborative suturing) on a simulation training box under music, neutral, and noisy acoustic conditions. Data were extracted from video recordings of each performance for analysis. Task performance was measured by the duration of time to complete a task and the total number of errors, and objective performance scores. The measures were compared over the three acoustic conditions. RESULTS: A music environment elicited higher performance scores than a noisy environment for both the object transportation (performance score: 66.3 ± 8.6 vs. 57.6 ± 11.2; p < 0.001) and collaborative suturing tasks (78.6 ± 5.4 vs. 67.2 ± 11.1; p < 0.001). Task times in the music and noisy environments was subtracted to produce a music-noisy difference time. Pearson correlation coefficient analysis showed a significant negative relationship between the team experience score and the music-noisy difference time on the object transportation (r = - 0.246, p = 0.046) and collaborative suturing tasks (r = - 0.248, p = 0.044). CONCLUSIONS: As to individuals, music enhances the performance of a laparoscopy team while a noisy environment worsens performance. The negative correlation between team experience and music-noisy difference time suggests that laparoscopy teams composed of experienced surgeons are less likely affected by an acoustic distraction than the noisy teams. Team resistance to acoustic distraction may lead to a new way for assessing team skills.

Celastrol Exerts Cardioprotective Effect in Rheumatoid Arthritis by Inhibiting TLR2/HMGB1 Signaling Pathway-Mediated Autophagy.

OBJECTIVE: Rheumatoid arthritis (RA) is a kind of chronic inflammatory disease characterized by the release of inflammatory cytokines and cardiomyocyte apoptosis, which lead to increased riskfor heart diseases. This study aims to explore the possible effect and mechanism of Celastrol on RA induced cardiac impairments in rats. METHODS: Collagen induced RA wistar rat models (CIA) were established for the measurement on secondary foot swelling degree, polyarthritis index score, spleen and thymus index. Pathological morphology was observed using H&E staining. Heart fibrosis was measured after Sirius red staining, while cell apoptosis was determined by TUNEL staining. For in vitro experiments, rat cardiomyocytes were isolated to determine the inflammatory cytokine secretion and cell apoptosis using ELISA and flow cytometry, respectively. Protein expressions of related index and autophagy were detected by Western blot and immunofluorescence. RESULTS: CIA rat model was successfully established and characterized by severe secondary foot swelling degree, and increased polyarthritis index score and spleen and thymus index. Synovial hyperplasia, disordered cardiomyocytes, cell infiltration and fibrosis were also observed in CIA rat model. Compared with CIA model, Celastrol treatment could suppress the release of inflammatory cytokines, including TNF-α, IL-6, IL-1ß, as well as inhibiting the expressions of Bax, cleaved caspase3, collagen I, collagen III and α-SMA. In addition to that, Celastrol treatment can attenuate cell apoptosis and fibrosis of cardiomyocytes and elevate Bcl-2 expression. RA induced cell autophagy can be suppressed by Celastrol through inhibiting the activation of TLR2/HMGB1 signal pathway. CONCLUSION: Celastrol can regulate TLR2/HMGB1 signal pathway to suppress autophagy and therefore exert cardioprotective effect in RA.

Uncoupled bone remodeling is characteristic of bone damage in premenopausal women with new-onset systemic lupus erythematosus.

OBJECTIVE: To investigate the mechanism underlying systemic lupus erythematosus (SLE)-related bone loss by evaluating the bone mineral density (BMD) and bone turnover markers (BTMs) in premenopausal patients with new-onset SLE without any treatment. METHODS: BMD and BTMs of 106 premenopausal patients with new-onset SLE and 64 gender-, age- and body mass index (BMI)-matched healthy controls were analyzed. BMD was determined using dual energy X-ray absorptiometry (DXA). Serum BTMs were measured. RESULTS: Hip and lumbar spine BMD in premenopausal patients with new-onset SLE was significantly decreased compared with healthy controls. Higher rate of osteoporosis was observed in new-onset SLE patients (25% vs. 1%). Moreover, uncoupled bone remodeling evidenced by an increase in bone resorption marker ß-CTX (685.9 ± 709.6 pg/mL vs. 395.4 ± 326.0 pg/mL, P < 0.05) and decrease in bone formation markers PINP (37.4 ± 33.0 ng/mL vs. 46.1 ± 20.9 ng/mL, P < 0.05) and OC (11.4 ± 9.8 ng/mL vs. 18.2 ± 8.6 ng/mL, P < 0.05) was observed in premenopausal patients with new-onset SLE compared with healthy controls. Univariate correlation analyses showed negative correlations between OC and SLE Disease Activity Index (SLEDAI), and positive correlations between ß-CTX and SLEDAI. SLE patients positive for dsDNA, nucleosome showed lower OC and higher ß-CTX. CONCLUSION: Premenopausal patients with new-onset SLE had decreased BMD and abnormal bone metabolism with increased ß-CTX and decreased OC and P1NP levels, indicating uncoupled bone remodeling in new-onset SLE patients. Disease activity and abnormal immunity, especially the amount of antibodies in SLE patients, were strongly associated with abnormality of bone metabolism.

Cav 1.3 damages the osteogenic differentiation in osteoporotic rats by negatively regulating Spred 2-mediated autophagy-induced cell senescence.

Cav 1.3 can affect the classical osteoclast differentiation pathway through calcium signalling pathway. Here, we performed cell transfection, real-time fluorescence quantitative PCR (qPCR), flow cytometry, SA-ß-Gal staining, Alizarin Red S staining, ALP activity test, immunofluorescence, Western blot and cell viability assay to analyse cell viability, cell cycle, osteogenesis differentiation and autophagy activities in vitro. Meanwhile, GST-pull down and CHIP experiments were conducted to explore the influence of Cav 1.3 and Sprouty-related EVH1 domain 2 (Spred 2) on bone marrow-derived mesenchymal stem cells (BMSCs). The results showed that OS lead to the decreased of bone mineral density and differentiation ability of BMSCs in rats. Cav 1.3 was up-regulated in OS rats. Overexpression of Cav 1.3 inhibited the activity of BMSCs, the expression of alkaline phosphatase (ALP), runt-related transcription factor 2 (RUNX2) and osteocalcin (OCN), as well as promoted the cell cycle arrest and senescence. Furthermore, the negative correlation between Cav 1.3 and Spred 2 was found through GST-pull down and CHIP. Overexpression of Spred 2 increased the expressions of microtubule-associated protein 1 light chain 3 (LC3) and Beclin 1 of BMSCs, which ultimately promoted the cell activity of BMSCs and ALP, RUNX2, OCN expression. In conclusion, Cav 1.3 negatively regulates Spred 2-mediated autophagy and cell senescence, and damages the activity and osteogenic differentiation of BMSCs in OS rats.

Unraveling the molecular mechanism of BNC105, a phase II clinical trial vascular disrupting agent, provides insights into drug design.

Microtubules are made up of tubulin protein and play a very important part in numerous cellular events of eukaryotic cells, which is why they are seen as attractive targets for tumor chemotherapy. BNC105, a known vascular targeting agent, has entered in phase II clinical trials. It has previously been confirmed that BNC105 is an effective microtubule targeting agent for various cancers. BNC105 exhibits selectivity for tumor cells, elicits vascular disrupting effects, and inhibits tumor growth. However, the molecular mechanism of BNC105 is still elusive. Herein, the crystal structure of BNC105 in complex with tubulin protein is revealed, demonstrating the its interaction with the colchicine binding site. In order to thoroughly evaluate its molecular mechanism from a structural-activity-relationship standpoint, the binding mode of tubulin to BNC-105 is compared with colchicine, CA-4 and other BNC-105 derivatives. Our study not only confirms the detailed interactions of the BNC105-tubulin complex, but also offer substantial structural foundation for the design and development of novel benzo[b]furan derivatives as microtubule targeting agents.

[Capability-based assessment promotes the innovation and development of online education of basic medical sciences in the post-COVID-19 era].

Assessment and evaluation are major teaching activities which are essential to achieve the goal of medical education. During COVID-19 pandemic, a novel assessment and evaluation system has been developed in the School of Basic Medical Sciences, Peking University, and aimed at increasing the competence of students. We established a unique evaluation method for commonly used lecture-based teaching, experiment-based teaching and group discussion learning. The comprehensive assessment of the pre-clinical stage was set up to reflect the whole learning effects. Guided by the student-centered and learning outcome-improving rationale, the new assessment and evaluation system of the online teaching during COVID-19 pandemic was utilized together with the classical offline onsite teaching evaluation system. The establishment of the novel online teaching evaluation system provides a solid platform for the transformation of medical education from traditional offline teaching to mixed offline and online teaching in the post-COVID-19 era.

Cav1.3 is upregulated in osteoporosis rat model and promotes osteoclast differentiation from preosteoclast cell line RAW264.7.

BACKGROUND: Osteoporosis (OP) is a systemic osteopathy with increased bone fragility and increased risk of fracture. Osteoclasts (OC) are the key target cells in the treatment of osteoporosis. We aimed to research the role of L-type calcium channel protein Cav1.3 in OC differentiation in this study. METHODS: OP rat model was established to detect the expression level of Cav1.3. Tartrate-resistant acid phosphatase assay was used to measure the differentiation of osteoclast during receptor activator of nuclear factor κ-Β ligand (RANKL)-induced osteoclasts formation. The expression of bone differentiation-related proteins were detected by western blot analysis. RESULTS: Cav1.3 is upregulated in OP rats. Knockdown of Cav1.3 inhibits the differentiation of RAW264.7. Cav1.3 regulates the cell differentiation and bone resorption of RAW264.7 during RANKL-induced osteoclasts formation, which is accompanied by upregulation of CaMK II, p-CERB, AP-1, NFATC1, and NF-κB. CONCLUSION: Cav1.3 plays an important role in osteoporosis and the differentiation of osteoclast, which might be involved with the bone differentiation-related proteins.

Influence of critical thinking disposition on the learning efficiency of problem-based learning in undergraduate medical students.

BACKGROUND: Problem-based learning (PBL), a pedagogical approach, is widely accepted in medical education. Manipulated by many factors, the internal motivation of learner is the most crucial determinant that affects the nature of the outcome, in which the influences of critical thinking (CT) remained elusive. METHODS: One hundred two third-year undergraduate medical students at Peking University were involved in this study. A Chinese version of the Critical Thinking Disposition Inventory (CTDI-CV) was used to assess the CT disposition, and the performance scores of students in PBL tutorials were compiled. A parametric bivariate correlation analysis was performed between the students' CT scores and their PBL average scores. The PBL scores were compared between the strong and weak CT disposition groups using independent t-test. The analysis of numerical data was conducted using SPSS 16.0. RESULTS: CT disposition of third-year undergraduate medical students at Peking University was at a positive level, with an average score of 297.72. The total CT scores had a positive correlation with the scores of the PBL performance and its five dimensions significantly. In the majority, students with Strong-CT disposition obtained higher scores in PBL tutorials compared with students with Weak-CT disposition. The performance of these two groups was significantly different in the Late-Half but not in the Early-Half PBL tutorials. Furthermore, a significant improvement was observed in the students with strong CT but not weak CT dispositions. CONCLUSION: CT disposition positively correlates to a students' PBL performance. Students with stronger CT dispositions perform better in the PBL process and obtain higher scores. Our work suggested that the open-mindedness of the CT disposition is the primary factor that determines the improvement of the preparation dimensions in the PBL process.

[The Development of Huaxi Intelligent Endoscopic Skill Training and Assessment System].

OBJECTIVE: To develop a novel objective standardized endoscopic skill training and assessment system based on artificial intelligence technology. METHODS: By designing five basic skill parts of endoscopic operation including vision location, clamping, delivering, shearing and suturing, we achieved objective standardized indexes which gained automatically with image recognition and refined perception. RESULTS: With Huaxi intelligent endoscopic skill training system, the accurate rates of vision location, clamping, delivering, shearing and suturing were 90%, 95%, 99%, 90%, and 89%, respectively. The response and performance time were 8-10 s, <1 s, <1 s, 1-3 s, and <1 s, respectively. CONCLUSION: Huaxi intelligent endoscopic skill training and assessment system has preliminarily possessed the capability to assess the endoscopic skills of surgeons objectively.

Effect of 1,25-(OH)2D3 on Proliferation of Fibroblast-Like Synoviocytes and Expressions of Pro-Inflammatory Cytokines through Regulating MicroRNA-22 in a Rat Model of Rheumatoid Arthritis.

OBJECTIVE: This study aims to investigate the regulatory mechanism of 1,25-(OH)2D3 on the proliferation of fibroblast-like synoviocytes (FLS) and expressions of pro-inflammatory cytokines in rheumatoid arthritis (RA) rats via microRNA-22 (miR-22). METHODS: A rat model of RA was established with a subcutaneous injection of type II collagen. After treated with different concentrations of 1,25-(OH)2D3 the proliferation of FLS was estimated by the MTT method, and the optimal concentration of 1,25-(OH)2D3 was selected for further experiments. Cell proliferation was detected by MTT. Cell cycle and apoptosis were analyzed by FCM. The IL-1ß, IL-6, IL-8, and PGE2 protein expressions were determined by ELISA, and MMP-3, INOS, and Cox-2 mRNA expressions were measured by qRT-PCR. RESULTS: The rat model of RA was successfully established. Compared with the blank group, the 1,25-(OH)2D3 and miR-22 inhibitors groups exhibited higher proliferation inhibition and apoptosis rates, lower levels of pro-inflammatory cytokines (IL-1ß, IL-6, IL-8, and PGE2), and decreased mRNA expressions of MMP-3, INOS, and Cox-2. The miR-22 mimics group had lower proliferation inhibition and apoptosis rates, elevated expressions of pro-inflammatory cytokines and MMP-3, INOS, and Cox-2 than the blank group. In contrast to the 1,25-(OH)2D3 group, the proliferation inhibition and apoptosis rates were down-regulated, and the expressions of pro-inflammatory cytokines and MMP-3, INOS, and Cox-2 were up-regulated in the 1,25-(OH)2D3 + miR-22 mimics group. CONCLUSION: Our study demonstrated that 1,25-(OH)2D3 inhibits the proliferation of FLS and alleviates inflammatory response in RA rats by down-regulating miR-22.

Quantitative analysis of single-nucleotide polymorphisms by pyrosequencing with di-base addition.

We have developed and validated a novel method for quantitative detection of SNPs by using pyrosequencing with di-base addition (PDBA). Based on the principle that the signal intensity is proportional to the template concentration within a linear concentration range, linear formula (Y = AX + B) for each genotype is established, and the relationship between two genotypes of a single SNP can be resolved by corresponding linear formulas. Here, PDBA assays were developed to detect variants rs6717546 and rs4148324, and the linear formulas for each genotype of rs6717546 and rs4148324 were established. The method allowed to quantitatively determine each genotype and showed 100% accordant results against a panel of defined mixtures. A set of 24 template fragments containing variants rs6717546 or rs4148324 was tested to evaluate the method. Our results showed that allele frequency of each genotype was accurately quantified, with results comparable to those of conventional pyrosequencing. Furthermore, this method was capable of detecting alleles with frequencies as low as 3%, which was more sensitive than ∼5 to ∼7% level detected by conventional pyrosequencing. This method offers high sensitivity, reproducibility, and relatively low costs, and thus could provide a much-needed approach for quantitative analysis of SNPs in clinical samples.