Correlation study between bone metabolic markers, bone mineral density, and sarcopenia

OBJECTIVE

To investigate the correlation between bone metabolism markers, bone mineral density (BMD), and sarcopenia.

METHODS

A total of 331 consecutive patients aged ≥ 60 years who were hospitalized between November 2020 and December 2021 were enrolled. Participants were divided into sarcopenia and non-sarcopenia groups according to the Asian Working Group on Sarcopenia criteria (AWGS, 2019). The clinical data, bone metabolism markers (β-CTX, N-MID, and TP1NP), and BMD were compared between the two groups.

RESULTS

Age, β-CTX, and N-MID of the sarcopenia group were higher than those of the non-sarcopenia group (P < 0.05), but the BMD T values were lower than those of the non-sarcopenia group (P < 0.05). Binary logistic regression analysis showed that increased femoral neck BMD (FNBMD) was a protective factor for sarcopenia, while increased β-CTX was a risk factor. Pearson/Spearman correlation analysis showed that the diagnostic indices of sarcopenia were positively correlated with FNBMD and negatively correlated with β-CTX and N-MID. Multiple linear regression analysis revealed that BMI and FNBMD significantly positively affected muscle strength and appendicular skeletal muscle mass (ASM). The FNBMD significantly positively affected physical performance, while β-CTX significantly negatively affected muscle strength, ASM, and physical performance.

CONCLUSION

Increased FNBMD may be a protective factor against sarcopenia, and increased β-CTX may be a risk factor. The FNBMD significantly positively affected the diagnostic indices of sarcopenia, while β-CTX significantly negatively affected them. BMD and bone metabolism marker levels may be considered in early screening for sarcopenia.

[A multicenter randomized controlled study of bismuth-containing quadruple therapy followed by Jing-Hua-Wei-Kang in the treatment of patients newly diagnosed with Helicobacter pylori infection and dyspepsia]

Objective: To investigate the Helicobacter pylori (H. pylori) eradication rate and improvement of dyspepsia in patients who were newly diagnosed with H. pylori infection and dyspepsia and treated by bismuth-containing quadruple therapy followed by Jing-Hua-Wei-Kang(JHWK). Methods: Patients who were newly diagnosed with dyspepsia and H. pylori infection and treated in 16 medical centers in China between December 1, 2017 and September 30, 2019 were randomly divided into two groups. The experimental group received bismuth-containing quadruple therapy (esomeprazole+amoxicillin+furazolidone+colloidal bismuth pectin capsule, 14 days), followed by JHWK (30 days), and the course of treatment was 44 days in total. In the control group, the administration regimen was bismuth-containing quadruple therapy (esomeprazole+amoxicillin+furazolidone+colloidal bismuth pectin capsule, 14 days). The main outcome measure was H. pylori eradication rate, while the secondary outcome measures were dyspepsia symptom changes and adverse events during the treatment and the 1st month after treatment. Results: A total of 1 054 patients were included in the study. There were 522 cases enrolled in the experimental group, including 224(42.91%) men and 298(57.09%) women, and the age was 53(26, 73) years old; 532 cases enrolled in the control group, including 221(41.54%) men and 311(58.46%) women, and the age was 46(22, 71) years old. Based on PP analysis, it was found that the H. pylori eradication rate in the experimental group was significantly higher than those in the control group (93.85% vs 87.88%, P=0.001). In the group of all enrolled patients, the symptom dyspepsia after H. pylori eradication was significantly improved compared with that before treatment [4(4, 7) vs 15(10, 22), P<0.001], so was the superior and middle abdominal pain [1(1, 4) vs 4(1, 8), P<0.001], the postprandial fullness [1(1, 4) vs 4(4, 9), P<0.001], the early satiety [1(1, 1) vs 4(1, 4), P<0.001], and the heartburn [1(1, 1) vs 1(1, 4), P<0.001]. The symptom dyspepsia after treatment was significantly improved compared with that before treatment in the experimental, the control groups, the successful and the unsuccessful H. pylori eradication groups. The superior and middle abdominal pain after treatment was signifcantly improved than that before treatment [1(1, 2) vs 1(1, 4), P<0.001], so were the postprandial fullness [1(1, 3) vs 1(1, 4), P=0.002] and the dyspepsia[4(4, 7) VS 7(4, 10), P<0.001]. There was no statistically significant difference in the incidence of adverse events between the experimental group and the control group (1.34% vs 0.38%, P=0.09). Conclusions: Compared with bismuth-containing quadruple therapy, bismuth-containing quadruple therapy followed by JHWK significantly improves the H. pylori eradication rate without increasing the incidence of adverse events. H. pylori eradication therapy can improve symptoms of patients with H. pylori infection and dyspepsia.

[Effect of serum lipid level on prognosis of patients with small cell lung cancer at the initial treatment]

Objective: To investigate the effect of serum lipid level on prognosis of patients with small cell lung cancer (SCLC) at the initial treatment. Methods: The clinical data of patients with SCLC from 2012 to 2017 in our hospital were retrospectively analyzed. According to the standard of appropriate level and abnormal stratification of blood lipid in Chinese population, the lipids included total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDLC) and low-density lipoprotein cholesterol (LDLC) at the time of initial treatment were grouped. Then the relationship between different lipid levels and clinicopathological characteristics was analyzed. Finally, Cox proportional hazard model was used to analyze the independent prognostic factors of patients. Results: A total of 129 patients with SCLC were included in this study. At the time of initial treatment, there were 90 (69.8%) cases whose TC < 5.2 mmol/L, while 39 (30.2%) cases ≥5.2 mmol/L; 95 (73.6%) cases whose TG <1.7 mmol/L, while 34 (26.4%) cases ≥1.7 mmol/L; 27 (20.9%) cases whose HDLC <1.0 mmol/L while 102 cases (79.1%) ≥1.0 mmol/L; 90 (69.8%) cases whose LDLC <3.4 mmol/L while 39 cases (30.2%) ≥3.4 mmol/L. The patients' triglyceride initial treatment was associated with their body mass index (P<0.05). The median disease-free survival (PFS) of SCLC patients was related with their serum TC level and clinical stage (P<0.05) and the overall survival (OS) was related with clinical stage of SCLC patients (P<0.05). The median PFS of SCLC patients in the TC <1.7 mmol/L group at the initial treatment was 10.5 months, significantly longer than 8.8 months of the TC ≥1.7 mmol/L group (P=0.024). The median OS of SCLC patients in the TG <1.7 mmol/L group at the initial treatment was 20.2 months, marginally longer than 15.6 months of the TG ≥1.7 mmol/L group (P=0.097). Multivariate analysis result showed that, the TG level was an independent risk factor of SCLC progression at the time of initial treatment (P=0.024). There was no significant correlation of TC, HDLC, LDLC and SCLC prognosis (P>0.05). Conclusion: TG level is an independent risk factor for the progression of SCLC at the time of initial treatment, and the increase of TG level indicates rapid disease progression and poor prognosis.

[Hemodynamic changes in standing-up test of children and adolescents with postural tachycardia syndrome]

OBJECTIVE

To explore the hemodynamic changes in standing-up test of children and adolescents with postural tachycardia syndrome (POTS) and to compare hemodynamic parameters of POTS patients with decreased cardiac index (CI) and those with not-decreased CI.

METHODS

A retrospective study was conducted to show the trends of CI, total peripheral vascular resistance index (TPVRI), heart rate and blood pressure in standing-up test of 26 POTS patients and 12 healthy controls, and to compare them between the two groups. The POTS patients were divided into two groups based on CI decreasing or not in standing-up test, namely decreased CI group (14 cases) and not-decreased CI group (12 cases). The trends of the above mentioned hemodynamic parameters in standing-up test were observed and compared between decreased CI group and not-decreased CI group.

RESULTS

In standing-up test for all the POTS patients, CI (F=6.936, P=0.001) and systolic blood pressure (F=6.049, P<0.001) both decreased significantly, and heart rate increased obviously (F=113.926, P<0.001). However, TPVRI (F=2.031, P=0.138) and diastolic blood pressure (F=2.018, P=0.113) had no significant changes. For healthy controls, CI (F=3.646, P=0.016), heart rate (F=43.970, P<0.001), systolic blood pressure (F=4.043, P=0.020) and diastolic blood pressure (F=8.627, P<0.001) all increased significantly in standing-up test. TPVRI (F=1.688, P=0.190) did not change obviously. The changing trends of CI (F=6.221, P=0.001), heart rate (F=6.203, P<0.001) and systolic blood pressure (F=7.946, P<0.001) over time were significantly different between the patients and healthy controls, however, no difference was found in TPVRI and diastolic blood pressure (P > 0.05). Among the POTS patients, CI was significantly different between decreased CI group and not-decreased CI group (F=14.723, P<0.001). Systolic blood pressure of the former decreased obviously (F=8.010, P<0.001), but it did not change obviously in the latter (F=0.612, P=0.639). Furthermore, none of the changes of TPVRI, heart rate and diastolic blood pressure in standing-up test were significantly different between the two groups (P > 0.05). Age was an independent factor for decreased CI patients (P=0.013, OR=2.233; 95% CI, 1.183 to 4.216).

CONCLUSION

POTS patients experience vital hemodynamic changes in standing-up test, part of them suffering from decreased CI, but others from not-decreased CI. Age is an independent factor for patients suffering from decreased CI.

[Comparison of different serological methods in screening early gastric cancer]

Objective: To compare the consistency and detection rate of early gastric cancer (EGC) of three different methods including anti-Helicobacter pylori (Hp) antibody combined with pepsinogen (PG) (ABC method), serum PG combined with gastrin-17 (G-17) (new ABC method) and the new scoring system. Methods: Serological tests were performed in Zhejiang population, which divided the subjects into low risk, intermediate risk and high risk groups. High risk subjects were examined by endoscopic and pathological examination. SPSS19.0 were used to evaluate the consistency of three methods. According to the receiver operating characteristic (ROC) curve, the ratio of G-17 to PG (PGR) was calculated for the optimal diagnostic cut-off value of EGC. Results: A total of 30 126 subjects were recruited. Based on the data of ABC method, the proportions of low risk, intermediate risk and high risk group were 15 368 (51.01%), 13 246 (43.97%), and 1 512 (5.02%), respectively. These proportions by the new ABC method were 20 584 (68.32%), 8 990 (29.84%), 552 cases (1.83%), respectively. By new scoring system, these were 20 810 (69.08%), 8 059 (26.75%), and 1 257 (4.17%), respectively. Among them, 1 263 subjects underwent endoscopy and 22 cases (1.74%) were finally diagnosed as gastric cancer including 19 EGC (86.4%). There were 1 case (0.35%), 14 cases (1.84%), and 7 cases (3.21%) with gastric cancer in low risk, intermediate risk, and high risk groups by ABC methods, respectively. Gastric cancer patients were 7 (1.68%), 10 (1.38%), and 5 (4.10%) in three groups respectively by new ABC methods. Via new scoring system, gastric cancer were detected in 5 (0.66%), 9 (2.22%), and 8 (7.84%) patients of three risk groups respectively. The consistency of three screening methods was poor. The detection rate of gastric cancer in high risk group was higher than that in the other two (P<0.05). The area under the curve (AUC) for diagnosis of gastric cancer by G-17 and PGR was 0.588 and 0.729, respectively. According to the PGR cut-off value determined by the fitted model, the incidence of gastric cancer in the low, intermediate and high risk groups was 0.94%, 1.97%, and 6.31%, respectively. When the cut-off value is PGR<4.135, the sensitivity is 0.855 and the specificity is 0.545. Conclusion: The new scoring system has a better predictive value in EGC screening. The detection rate of EGC in high risk group is higher than that in low and intermediate risk groups.

[Clinical and prognostic significance of ABO promotor methylation level in adult leukemia and myelodydysplastic syndrome]

Objective: To investigate the clinical and prognostic significance of ABO promotor methylation level in adult patients with leukemia and myelodydysplastic syndrome(MDS). Methods: ABO promoter methylation level of 182 malignant hematological disease patients and 68 normal controls were detected by bisulfite sequencing PCR.Then clinical features and outcome were compared between hypermethylation group and hypomethylation group. Results: The median methylation rate of ABO promoter in newly diagnosed acute myeloid leukemia (AML) and acute lymphocytic leukemia (ALL) were 46.98% and 11.01% respectively, which were both higher than that in controls (2.30%, P<0.05). The methylation rates in remission AML and ALL were 1.58% and 2.30% respectively, which were comparable with that in normal group (P>0.05). As to relapse AML and ALL, methylation rates were 41.26% and 17.50% respectively, also significantly higher than that in controls (P<0.05).In patients with chronic myeloid leukemia (CML) chronic phase, the median methylation rate was 1.00%, which was similar to normal group. But a CML patient who transformed to ALL hadextremely high methylation rate 92.56%. The median methylation rate in patients with MDS significantly elevated as 5.81% compared with that in controls (P<0.05). The median overall survival (OS) of ALL and AML (non-M3) patients with hypermethylation were 12.5 months and 15.3 months, which were significantly shorter than those with hypomethylation (24.0 months and 20.0 months)(P<0.05).The median disease-free survival (DFS) of ALL and AML (non-M3) patients with hypermethylation were 9.9 months and 12.0 months, which were significantly shorter than those with hypomethylation (22.3 months and 18.5 months), (P<0.05). Multivariable analysis suggested that ABO promoter methylation level was an independent predictive factor of OS and DFS in ALL and AML (non-M(3)) patients. Conclusion: ABO promoter hypermethylation is closely related to genesis, development and prognosis of leukemia and MDS. Hypermethylationis related to a clinical poor prognosis compare with hypomethylation.

[Progress in diagnosis and management of syncope in children]

Syncope is a common emergency of children and adolescents, which has serious influence on the quality of life. Neurally-mediated syncope, including postural tachycardia syndrome, vasovagal syncope, orthostatic hypotension and orthostatic hypertension, is the main cause of syncope in children and adolescents. The main manifestations of neurally-mediated syncope are diverse, such as dizziness, headache, chest tightness, chest pain, pale complexion, fatigue, pre-syncope and syncope. Although the clinical manifestations are similar, each subtype of syncope has its hemodynamic feature and optimal treatment option. The diagnosis rate of syncope in children has been greatly improved on account of the development of the diagnostic procedures and methods. In recent years, with the promotion of head-up tilt test and drug-provocated head-up tilt test, the hemodynamic classification of neurally-mediated syncope gets continually refined. In recent years, with the effort of clinicians, an appropriate diagnostic protocol for children with syncope has been established. The initial evaluation consists of history taking, physical examination, standing test and standard electrocardiography. After the initial evaluation, some patients could be diagnosed definitely, such as postural tachycardia syndrome, orthostatic hypotension, and situational syncope. Those with a specific entity causing syncope need selective clinical and laboratory investigations. Patients for whom the cause of syncope remained undetermined should undergo head-up tilt test. The precise pathogenesis of neurally-mediated syncope is not entirely clear. In recent years, studies have shown that neurally-mediated syncope may be related to several factors, including hypovolemia, high catecholamine status, abnormal local vascular tension, decreased skeletal muscle pump activity and abnormal neurohumoral factors. Currently based on the possible pathogenesis, the individualized treatment of neurally-mediated syncope has also been studied in-depth. Generally, the management of neurally-mediated syncope includes non-pharmacological and pharmacological interventions. Patient education is the fundamental part above all. In addition to exercise training, the first-line treatments mainly include oral rehydration salts, beta adrenoreceptor blockers, and alpha adrenoreceptor agonists. By analyzing the patient's physiological indexes and biomarkers before treatment, the efficacy of medication could be well predicted. The individualized treatment will become the main direction in the future researches.

[Relationship between blood routine test parameters and syncopal recurrence of vasovagal syncope in children]

Objective: To explore the relationship between venous blood routine test parameters and syncopal recurrence of children with vasovagal syncope (VVS). Method: Sixty-three children (male 32, female 31) diagnosed as VVS in Department of Pediatrics, Peking University First Hospital from November 2010 to October 2015 were included in a case observational study.Their mean age was (11.2±2.7) years and basic treatment such as predisposing causes avoiding, standing training, autonomic nervous function exercise and oral rehydration salts were advised to them.The clinical data were obtained by out-patient visit and over telephone from December 2015 to January 2016, with a median follow-up period of 10 (4, 26) months. The effects of baseline venous blood routine test parameters, gender, age, and body mass index (BMI) on syncopal recurrence were studied via univariate and multivariate Cox regression analysis.Kaplan-Meier curve was used to evaluate the long-term prognosis. Result: Among the 63 VVS children in this study, 31 cases were diagnosed as VVS vasodepressor type, 4 cases as VVS cardioinhibitory type and 28 cases as VVS mixed type, 16 cases (25%) had experienced recurrence of syncope while 47 cases (75%) had not.The result of univariate analysis of Cox regression showed that baseline platelet count (PLT) (HR=1.012, 95%CI: 1.003-1.022) had a marked impact on the survival rate.And the result of multivariate analysis of Cox regression showed that baseline hemoglobin concentration (HGB) (HR=1.055, 95%CI: 1.007-1.105), mean corpuscular hemoglobin (MCH) (HR=0.612, 95%CI: 0.423-0.884) and PLT(HR=1.015, 95%CI: 1.006-1.024) had significant effects on survival rate of VVS children.In this study, the one-year, two-year, and three-year survival rate were 83% (52/63), 79% (50/63) and 75% (47/63), respectively. Conclusion: The baseline venous blood routine test parameters HGB, MCH and PLT might be the influencing factors of the syncopal recurrence of VVS children.

[Predictive value of upright blood pressure change for long-term prognosis of children with postural tachycardia syndrome treated with midodrine hydrochloride]

OBJECTIVE

To explore the predictive value of upright blood pressure change for long-term prognosis of children with postural tachycardia syndrome (POTS) treated with midodrine hydrochloride.

METHOD

A total of 90 children (male 41, female 49) were enrolled in this study. Their mean age was (11.8±2.7) years. They were diagnosed as POTS in Peking University First Hospital from 2005 to 2011. According to the upright change of blood pressure at the first visit, they were divided into two groups, effective group (n=55) and ineffective group(n=35). The follow-up time was 53-130 months. The orthostatic intolerance symptom score and symptom free survival rate were compared between the two groups.

RESULT

The change of systolic blood pressure and of diastolic blood pressure was lower in effective group than those in ineffective group (0(-6, 0) mmHg (1 mmHg=0.133 kPa) vs. 9(6, 11) mmHg, Z=-8.303, P<0.01; 0(0, 5) mmHg vs. 11(10, 16) mmHg, Z=-7.058, P<0.01). Two groups had no significant difference in symptom scores before treatment((4.8±0.9) points vs. (5.0±0.8) points, t=-0.53, P=0.595), while symptom scores were lower in effective group than that in ineffective group((1.3±0.9) points vs. (4.7±0.9) points, t=-15.60, P<0.01 ). The symptom free survival rate was higher in effective group than that in ineffective group (48/55(87.3%) vs. 23/35(65.7%), χ(2)=5.969, P<0.01).

CONCLUSION

The upright change of blood pressure has a good predictive value on the long-term survival of POTS children treated with midodrine hydrochloride.

[Hydrogen sulfide in cartilage and its inhibitory effect on matrix metalloproteinase 13 expression in chondrocytes induced by interlukin-1β]

OBJECTIVE

To investigate whether endogenous hydrogen sulfide (H2S) was involved in the pathogenesis of osteoarthritis (OA) and its underlying mechanism, to detect H2S and its synthases expression in knee cartilage in patients diagnosed with different severity of OA, and to explore the transcription and expression of gene MMP-13 in chondrocytes treated with IL-1β or H2S.

METHODS

Synovial fluids of the in-patients with different severity of OA hospitalized in Peking University First Hospital were collected for measurement of H2S content using methylene blue assay. Articular cartilages of the patients who underwent knee arthroplasty were collected for the cell culture of relatively normal chondrocytes. The chondrocytes were cultured to the P3 generation and H2S molecular probes were used for detection of endogenous H2S generation in the chondrocytes. Immunocytochemistry was used to detect the localization of H2S synthases including cystathionine β-synthase (CBS), cystathionine-γ-lyase (CSE), and mercaptopyruvate sulfurtransferase (MPST) in OA chondrocytes. Western blot was used to quantify the protein expressions of CSE, MPST, and CBS in cartilage tissues of the patients who were diagnosed with OA and underwent knee arthroplasty. The relatively normal human chondrocytes were cultured to passage 3 and then divided into 4 groups for different treatments: (1)the normal control group, no reagent was added; (2)the IL-1β group, 5 μg/L of IL-1β was added; (3)the IL-1β+H2S group, 200 μmol/L of NaHS was added 30 min before adding 5 μg/L of IL-1β;(4)the H2S group, 200 μmol/L of NaHS was added. The transcription and expression of gene MMP-13 in chondrocytes of each group were determined with Real-time PCR and Western blot, respectively. And the total NF-κB p65 and phosphorylated NF-κB p65 in chondrocytes were detected with Western blot.

RESULTS

The content of H2S in the synovial fluid of degenerative knee was (14.3±3.3) μmol/L. Expressions of endogenous H2S and its synthases including CBS, CSE and MPST were present in the cytoplasm of chondrocytes.CSE protein expression in Grade 3 (defined by outerbridge grading) cartilage tissues was significantly increased as compared with that of Grade 1 cartilage tissues (1.67±0.09 vs. 1.26±0.11, P< 0.05). However, no significant difference of CBS or MPST expression among the different groups was observed. The expression of MMP-13 protein in the IL-1βgroup was significantly higher than that in the normal chondrocytes (1.87±0.67 vs. 0.22±0.10, P<0.05), and that in the IL-1β+H2S group was significantly decreased than that in the IL-1β group (0.55±0.11 vs. 1.87±0.67, P< 0.05), and that in the H2S group had no significant difference compared with that in the normal control group. The transcription of MMP-13 protein in the IL-1β group was significantly higher than that in the normal chondrocytes (31.40±0.31 vs. 1.00±0.00, P<0.05), and that in the IL-1β+H2S group was significantly decreased than that in the IL-1β group (24.41±1.28 vs. 31.40±0.31, P<0.05), and that in the H2S group had no significant difference compared with that in the normal control group. The total NF-κB p65 in the IL-1β group was significantly higher than that in the normal chondrocytes (2.13±0.08 vs. 0.73±0.08, P< 0.05), and that in the IL-1β+H2S group was significantly decreased than that in the IL-1β group (1.24±0.13 vs. 2.13±0.08, P<0.05), and that in the H2S group had no significant difference compared with that in the normal control group. The phosphorylated NF-κB p65 in IL-1β group was significantly higher than that in the normal chondrocytes (1.30±0.13 vs. 0.19±0.04, P<0.05), and that in IL-1β+H2S group was significantly decreased than that in the IL-1β group (0.92±0.26 vs. 1.30±0.13, P<0.05), and that in the H2S group had no significant difference compared with that in the normal control group.

CONCLUSION

H2S affected the cartilage degeneration by partly inhibiting the degradation of extracellular matrix.

Expression of erythropoietin and its receptor in kidneys from normal and cyclosporine-treated rats

Long-term treatment with cyclosporine A (CsA) is associated with various types of complications; however, CsA-induced anemia has not been reported. The present study examined the impact of CsA on hematopoietic parameters and intrarenal expression of erythropoietin (EPO) and the EPO receptor (EPOR) in a rat model of chronic CsA nephrotoxicity. Sprague-Dawley rats were fed a low-salt diet (0.05% sodium) and were treated daily for 4 weeks with vehicle (olive oil 1 mL/kg subcutaneously) or CsA (15 mg/kg subcutaneously). The expression of EPO and EPOR was evaluated by immunohistochemistry and immunoblotting, and hematopoietic parameters were assessed by measuring blood hemoglobin and hematocrit levels, and these variables were compared between treatment groups. Renal function, oxidative stress, histopathology (tubulointerstitial fibrosis), apoptotic cell death, and expression of transforming growth factor β-inducible gene-h3 (βig-h3) were also compared between treatment groups. In kidneys from vehicle-treated rats, endogenous EPO and EPOR protein were expressed constitutively in the outer stripe of the outer medulla and the cortex. EPO protein expression decreased significantly in kidneys from CsA-treated rats. By contrast, EPOR expression was higher in kidneys from CsA-treated rats than in vehicle-treated rats. These changes were accompanied by decreases in serum hemoglobin and hematocrit levels and correlated with the number of cells positive for terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (r = -0.769, P = .003) and βig-h3 protein expression (r = -0.910, P < .001). Long-term treatment with CsA suppresses renal endogenous EPO expression, resulting in anemia. Increases in apoptotic cell death and βig-h3 expression are closely associated with inhibition of EPO expression in chronic CsA nephrotoxicity.

259 DNA HYPOMETHYLATION OF FETAL FIBROBLASTS IMPROVES DEVELOPMENTAL COMPETENCY AND GENE EXPRESSION PATTERN IN PORCINE EMBRYOS FOLLOWING NUCLEAR TRANSFER

The inhibition of methyl groups in the DNA of donor cells has been hypothesized to improve the potential reprogramming by the enucleated ooplasm after nuclear transfer (NT). Previously, we reported that treatment of porcine fetal fibroblasts (PFF) with an inhibitor of methylation, 5-azacytidine (5-azaC) at 0.5 �m, results in the retention of desirable characteristics with a relative reduction in methylation, making cells more conducive for reprogramming (Mohana Kumar et al. 2006 Cell Tissue Res. 325, 445-454). To understand these observations further, the present study investigated the developmental competence and expression pattern of gene transcripts in porcine NT embryos from PFF (control) and 0.5 �m 5-azaC-treated PFF (PFF + 5-azaC) at 4-cell, 8-cell, morula, and blastocyst stages, and compared these with those of IVF and in vivo embryos. Cleavage rate was significantly (P &lt; 0.05) higher in IVF than in NT embryos from PFF and PFF + 5-azaC (86.7 � 5.2% vs. 65.8 � 5.3% and 69.3 � 4.4%, respectively). Similarly, significantly (P &lt; 0.05) higher blastocyst rates were observed in IVF embryos (27.2 � 2.1%). However, NT embryos from PFF + 5-azaC showed enhanced developmental potential with significantly (P &lt; 0.05) higher rates of blastocysts (21.3 � 2.2%) than NT embryos from PFF (14.8 � 1.9%). NT embryos from PFF + 5-azaC (33.8 � 4.1) had significantly (P &lt; 0.05) higher total cell numbers than from PFF (24.6 � 3.5), but did not differ in the proportion of apoptotic cells (6.9 � 1.8% and 7.2 � 2.1%, respectively). However, the high total cell number and lower incidence of apoptosis were observed in IVF and in vivo embryos (45.3 � 3.8, 2.7 � 0.8%, and 53.9 � 3.5, 1.2 � 0.9%, respectively). Alterations in the expression pattern of genes implicated in transcription and pluripotency (Oct4 and Stat3), DNA methylation (DNA methyltransferases: Dnmt1, Dnmt2, Dnmt3a, and Dnmt3b), histone acetylation (histone acetyltransferase 1-HAT1), and histone deacetylation (histone deacetylases-Hdac1, Hdac2, and Hdac3) were observed in NT embryos from PFF and PFF + 5-azaC compared with that in IVF and in vivo counterparts. However, the expression of genes in PFF + 5-azaC-NT embryos closely followed those of in vivo-derived embryos compared with PFF-NT embryos, and, interestingly, there was lower variability in the expression of genes related to DNA methylation. Our findings demonstrate that remodeling of the epigenetic status by partial reduction of somatic DNA methylation from donor cells is beneficial in improving the developmental competency of porcine NT embryos. Further, hypomethylated donors may be more efficiently reprogrammed to re-activate the expression of early embryonic genes. This work was supported by Grant No. R05-2004-000-10702-0 from KOSEF, Republic of Korea.