Objective To investigate the palmitoyltransferase (PATs) activity during different developmental stages of Plasmodium falciparum and to explore the impact of PATs activity on intra-erythrocytic replication and gametocytogenesis, so as to provide insights into development of novel antimalarial targets. Methods The PATs activity was measured using the click chemistry method during different developmental stages of P. falciparum, including rings, trophozoites, schizonts, and gametocytes. P. falciparum-infected erythrocytes were divided into three groups, including a control group, a dimethyl sulfoxide (DMSO) group, and a 2-bromopalmitate (2-BP) group. Erythrocytes in the control group were incubated in normal culture media, and cells in DMSO and 2-BP groups were exposed to DMSO or 2-BP at a final concentration of 10 μmol/L to examine the inhibitory effect of 2BP on the PATs activity. The growth curve analysis and gametocyte production assay were employed to investigate changes in asexual proliferation and gametocyte production of P. falciparum following inhibition of the PATs activity with 2-BP, and transcriptomics sequencing was performed to examine the impact of inhibition of the PATs activity with 2-BP on transcriptional levels of P. falciparum and possible mechanisms. Results The green fluorescence intensity of PATs varied across developmental stages of P. falciparum (F = 38.120, P < 0.001), with a higher fluorescence intensity seen in trophozoites (35.680 ± 8.439), merozoites (33.380 ± 9.030) and gametocytes (21.540 ± 8.654), and a lower intensity in ring bodies (10.720 ± 3.183) (all P values < 0.05). The green fluorescence intensities were 8.738 ± 1.576, 8.633 ± 1.827 and 4.911 ± 0.318 in the control group, DMSO group, and 2-BP group 4 days post-culture (schizont stage), respectively (F = 91.490, P < 0.001), and the PATs activity was significantly inhibited post-treatment with 2-BP (P < 0.05). The areas under the time curve for the parasitemias were 25.700 ± 0.696, 28.630 ± 3.062 and 8.370 ± 1.751 in the control group, DMSO group, and 2-BP group following inhibition of the PATs activity during the asexual stage of P. falciparum (F = 83.440, P < 0.001), and the parasitemia was lower in the 2-BP group than in the control group and the DMSO group (both P values < 0.001). In addition, the asexual stage development was delayed in the 2BP group, with abnormal morphology seen. The numbers of merozoites were 18.050 ± 4.362, 18.200 ± 3.517 and 14.020 ± 4.320 in each schizont in the control group, DMSO group and 2-BP group, respectively (H = 39.100, P < 0.001), and the merozoite number was significantly lower in the 2-BP group than in the control group and the DMSO group (both P_adjusted values < 0.001). The areas under the time curve for P. falciparum gametocyte production were 18.900 ± 0.384, 18.240 ± 0.177 and 7.507 ± 0.201 in the control group, the DMSO group, and the 2-BP group following inhibition of the PATs activity, respectively (F = 1 677.000, P < 0.001), and the proportion of gametocyte production was statistically lower in the 2-BP group than in the control group and DMSO group (both P values < 0.001). The formation and maturation of gametophytes were blocked in the 2-BP group, and most of them were arrested in the middle and late stages. Following 2-BP treatment, significantly down-regulated genes during the asexual stage of P. falciparum were significantly enriched in cell cycle regulation, mitosis, DNA damage/response and structural organization, and significantly down-regulated genes during the gametocyte stage were significantly enriched in biological processes of cell cycle (mitosis and G1/S transition), RNA regulation and metabolism (such as carbon catabolite repression 4-negative on TATA-less) and cell development and differentiation. Conclusion The palmitoylation modification plays an important role in the asexual reproduction and gametocyte generation and development of P. falciparum.

Objective:To carry out prenatal diagnosis for a fetus with Meckel syndrome(MKS) and explore its genetic basis.Methods:A pregnant woman presented at Suzhou Municipal Hospital in February 2018 was selected as the study subject. Clinical data was collected. Muscle tissue sample from the abortus and peripheral blood samples from the couple were collected. Genomic DNA was extracted and subjected to chromosomal microarray analysis (CMA) and whole exome sequencing. Candidate variant was verified by Sanger sequencing.Results:The fetus was found to have microcephaly, oligohydramnios, polycystic kidneys and banana-shaped cerebellum at 18 weeks of gestation. After induction of labor, it was found to have encephalocele, renal cysts and polydactyly. CMA has found no abnormality. Whole exome sequencing revealed novel compound heterozygous variants c. 296delA (p.Lys99SerfsTer6) and c. 1243G>A (p.Val415Met) in the TMEM67 gene. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the c. 296delA variant was predicted to be pathogenic (PVS1+ PM2_Supporting+ PP4), whilst the c. 1243G>A variant was predicted to be likely pathogenic (PM2_Supporting+ PM3+ PP3_Moderate+ PP4). Conclusion:The c. 296delA and c. 1243G>A compound heterozygous variants of the TMEM67 gene probably underlay the MKS in this fetus.

Objective:To investigate the expression level of small nucleolar RNA SNORD15A in bone marrow of patients with acute leukemia (AL) and its relationship with clinical characteristics and prognosis of patients.Methods:Bone marrow blood samples of 53 newly treated AL patients and 29 healthy subjects without clinical diagnosis of hematologic diseases or other malignant diseases (control group) at the Affiliated Hospital of Guangdong Medical University from March 2018 to December 2021 were collected. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the relative expression of SNORD15A in bone marrow blood mononuclear cells of the two groups. The median relative expression of SNORD15A (0.148) was used as the boundary, and AL patients were divided into low expression group (<0.148) and high expression group (≥0.148). The relationship between the expression level of SNORD15A and the clinical characteristics, clinical indicators and overall survival (OS) of AL patients was analyzed. Kaplan-Meier method was used for survival analysis and log-rank test was performed; Cox proportional hazards model was used for univariate and multivariate analyses of OS of patients.Results:The relative expression of SNORD15A was 0.148 (0.012-1.376) in newly treated AL patients and 0.921 (0.513-2.288) in the control group, and the difference was statistically significant ( Z = -6.85, P < 0.01). The differences in SNORD15A relative expression between patients with different prognostic stratification, efficacy and with or without fever and bleeding were statistically significant (all P < 0.05). The differences in platelet count, plateletcrit and albumin levels between SNORD15A low expression group and high expression group were statistically significant (all P < 0.05), and the differences in molecular biology and cytogenetic characteristics were not statistically significant (all P > 0.05). The patients in SNORD15A high expression group had better OS than the low expression group ( P < 0.05). The results of univariate Cox regression analysis showed that SNORD15A was an influencing factor for patients' OS ( HR = 0.063, 95% CI 0.005-0.766, P < 0.05); the results of multivariate Cox regression analysis showed that fatigue ( HR = 4.754, 95% CI 1.014-22.290), fever ( HR = 0.147, 95% CI 0.029-0.746) and hemoglobin ( HR = 0.970, 95% CI 0.944 -0.998) were independent influencing factors for OS (all P < 0.05). Conclusions:SNORD15A is lowly expressed in AL and may be an indicator for disease monitoring and prognostic assessment in AL patients.

Brain/diagnostic imaging* ; Head

Objective:To investigate the expression level of flap endonuclease 1 (FEN1) in bone marrow mononuclear cells of patients with acute myeloid leukemia (AML) and its relationship with clinicopathologic features and therapeutic effect, so as to provide a new direction for disease monitoring and targeted therapy in AML patients.Methods:The data of 57 newly treated AML patients and 26 healthy individuals (the healthy control) from the First Clinical College of Guangdong Medical University and Fujian Medical University Union Hospital from November 2018 to December 2020 were retrospectively analyzed. Bone marrow samples of all subjects were collected. Quantitative real-time fluorescence polymerase chain reaction (qRT-PCR) was used to detect FEN1 mRNA expression in bone marrow mononuclear cells of all subjects. Bone marrow samples from 9 newly-diagnosed AML patients and 4 healthy controls were collected, and FEN1 protein expression level was detected by using Western blotting. Differences in FEN1 mRNA expression in AML patients achieving different therapeutic effects were compared among AML patients whose data with evaluable efficacy. AML patients were divided into high FEN1 expression group (≥ critical value) and low FEN1 expression group (< critical value), taking the median relative expression level of FEN1 mRNA as the critical value. The correlation of FEN1 expression level with clinicopathologic features, laboratory indicators, cellular and molecular genetic changes in AML patients at initial diagnosis was analyzed.Results:The median relative expression of FEN1 mRNA in newly treated AML patients was higher than that in healthy controls [0.696 (0.025-3.661) vs. 0.246 (0.013-1.237), Z = 1.75, P = 0.041]. Western blotting showed that the expression level of FEN1 protein in AML patients was higher than that in healthy controls. The relative expression of FEN1 mRNA in 15 recurrent AML patients was higher than that in 19 patients patients achieving complete remission (CR) [1.153 (0.047-4.172) vs. 0.259 (0.023-1.148), Z = 2.71, P = 0.009]. The proportion of patients with French-American-British(FAB) type M 5, fever at initial diagnosis and lymph node enlargement in FEN1 high expression group (32 cases) was higher than that in FEN1 low expression group (25 cases) (all P < 0.05). There were no significant differences in the proportion of gender, age, fatigue, pale skin mucosa and large liver and spleen of patients between the two groups (all P > 0.05). At initial diagnosis, the white blood cell count, lactate dehydrogenase, C-reactive protein and bone marrow primitive cell proportion in FEN1 high expression group were higher than those in FEN1 low expression group (all P < 0.05), and the hemoglobin and platelet count in FEN1 high expression group were lower than those in FEN1 low expression group (all P < 0.05). There were no significant differences in procalcitonin level, the proportion of chromosome karyotype, cytogenetic prognosis grade and patients with or without gene mutation between the two groups (all P > 0.05). Conclusions:FEN1 expression is up-regulated in AML patients and further increased in relapsed patients. FEN1 expression in AML patients is associated with adverse clinicopathological features and poor detection results of laboratory indicators, which may become indicators for disease monitoring in AML patients.

Objective To observe the changes and significance of the protein expression levels of nuclear factor-κB p65 (NF-κB p65), transforming long factor-β1 (TGF-β1) and apoptosis-related factors Bcl-2 and Bax in myocardial tissue of Bama miniature pig model of diabetic cardiomyopathy (DCM). Methods Ten healthy male Guangxi Bama miniature pigs, aged 4 to 5 months old, were selected and divided into control group and model group according to the random number table method, with 5 pigs in each group. After 12 hours of fasting in the two groups, the DCM model was replicated by intravenous injection of streptozotocin (STZ) 150 mg/kg; for the Bama miniature pigs in the control group, citric acid-sodium citrate buffer 150 mg/kg was injected intravenously. After 10 months of modeling, the basic conditions of the two groups of animals were observed and their fasting blood glucose (FPG) levels were detected. The protein expression levels of NF-κB p65, TGF-β1, Bcl-2 and Bax in myocardial tissue of two groups were detected by Western Blot and the pathological changes of myocardial tissue were observed under electron microscope. Results In the model group, 4 models were successfully established, and 1 died. The model pigs had symptoms such as polydipsia, polyphagia, polyuria and decreased body weight. The FPG level in the model group was significantly higher than that in the control group (mmol/L: 25.53±3.75 vs. 4.68±0.77, P < 0.01). Compared with the control group, the protein expression levels of NF-κB p65, Bax and TGF-β1 in the myocardial tissue of model group were significantly increased (NF-κB p65/GAPDH: 0.46±0.05 vs. 0.38±0.02, Bax/GAPDH: 0.46±0.01 vs. 0.35±0.01, TGF-β1/GAPDH: 0.39±0.01 vs. 0.33±0.01, all P < 0.05) and the expression level of Bcl-2 protein was significantly decreased (Bcl-2/GAPDH: 0.33±0.01 vs. 0.42±0.01, P < 0.01). Electron microscopy results showed that the myofibrils of myocardial tissue in the DCM model group were disordered, and the number of mitochondria in the gap was significantly reduced. A large number of mitochondria with vacuolar degeneration were observed. Conclusions The DCM model of Bama miniature pigs can be successfully replicated after 10 months of high-dose STZ disposable ear vein injection. The DCM model miniature pigs have obvious glucose metabolism disorder, and their myocardial tissue has inflammatory reaction, cardiomyocyte apoptosis and fibrosis.

AIM:To investigate the role of nerve growth factor (NGF) and leukemia inhibitory factor (LIF) in the expression of IL-4 and IL-5 in the splenic lymphocytes of asthmatic rats. METHODS:Sixteen Sprague-Dawley rats were randomly divided into two groups:control group (n = 8) and asthma group (n = 8). The asthmatic model was set up by intraperitoneal injection of 100 mg ovalbumin and 100 mg aluminum hydroxide,and receiving nebulization aspiration of 1% ovalbumin solution 2 weeks later. The splenic lymphocytes from the control rats and asthmatic rats were isolated and cultured with exogenous NGF or LIF at different doses. The mRNA expression of IL-4 and IL-5 in the splenic lymphocytes was respectively detected by reverse transcription-polymerase chain reaction (RT-PCR). The secretions of IL-4 and IL-5 were respectively detected by ELISA. RESULTS:Compared to control group,the expression of IL-4 and IL -5 (P