Intestinal TLR4 deletion exacerbates acute pancreatitis through gut microbiota dysbiosis and Paneth cells deficiency.

Toll-like receptor 4 (TLR4) has been identified as a potentially promising therapeutic target in acute pancreatitis (AP). However, the role of intestinal TLR4 in AP and AP-associated gut injury remains unclear. This study aimed to explore the relationship between intestinal TLR4 and gut microbiota during AP. A mouse AP model was establish by intraperitoneal injection of L-arginine. Pancreatic injury and intestinal barrier function were evaluated in wild-type and intestinal epithelial TLR4 knockout (TLR4ΔIEC) mice. Gut microbiota was analyzed by 16S rRNA sequencing. Quadruple antibiotics were applied to induce microbiota-depleted mice. Differentially expressed genes in gut were detected by RNA sequencing. L. reuteri treatment was carried out in vivo and vitro study. Compared with wild-type mice, AP and AP-associated gut injury were exacerbated in TLR4ΔIEC mice in a gut microbiota-dependent manner. The relative abundance of Lactobacillus and number of Paneth cells remarkably decreased in TLR4ΔIEC mice. The KEGG pathway analysis derived from RNA sequencing suggested that genes affected by intestinal TLR4 deletion were related to the activation of nod-like receptor pathway. Furthermore, L. reuteri treatment could significantly improve the pancreatic and intestinal injury in TLR4ΔIEC mice through promoting Paneth cells in a NOD2-dependent manner. Loss of intestinal epithelial TLR4 exacerbated pancreatic and intestinal damage during AP, which might be attributed to the gut microbiota dysbiosis especially the exhausted Lactobacillus. L. reuteri might maintain intestinal homeostasis and alleviate AP via Paneth cells modulation.Abbreviations: AP Acute pancreatitis, TLR4 Toll-like receptor 4, IL-1ß Interleukin-1ß, IL-6 Interleukin-6, TNF-α Tumor necrosis factor-α, SIRS Systematic inflammatory response syndrome, LPS Lipopolysaccharides, SPF Specific pathogen-free, ZO-1 Zonula occludens-1, CON Control, H&E Hematoxylin and eosin, FISH Fluorescence in situ hybridization, DAPI 4',6-diamidino-2-phenylindole, PCoA Principal co-ordinates analysis, SCFA Short chain fatty acid, LEfSe Linear discriminant analysis Effect Size, ANOVA Analysis of variance, F/B Firmicutes/Bacteroidetes, PCA Principal component analysis, NOD2 Nod-like receptor 2, ABX antibiotics, PCNA proliferating cell nuclear antigen.

Efficacy and Recurrence Factors of Veneclax Combined with Aza- citidine in the Treatment of Acute Myeloid Leukemia / 中国实验血液学杂志

OBJECTIVE@#To observe the efficacy of veneclax combined with azacitidine in acute myeloid leukemia(AML) patients and explore the predictors of treatment response and recurrence.@*METHODS@#The clinical data of 30 AML patients who received venetecla combined with azacitidine in the Affiliated Hospital of Southwest Medical University from January 2021 to September 2022 were retrospectively analyzed, composite complete remission (CRc) rate, overall response rate(ORR), and disease free survival(DFS) of patients were observed.@*RESULTS@#After one course of trea- tment, CRc was 16 cases and ORR was 23/30. Patients with TP53 mutation had poor treatment response (P=0.009). After 1-2 courses, 25 patients reached CR/CRi. Finally, 24 patients who obtained CR/CRi were included to observe the duration of remission. 17 patients had relapse, with a median recurrence time of 3.9 (0.6-15.9) months. The Kaplan-Meier curve showed that MRD negative was a favorable factor for maintaining DFS status (HR=0.5647,95%CI:0.2179-1.464,P=0.007), while NRAS mutation was an adverse factor for maintaining DFS (HR=2.036,95%CI:0.6639-6.245,P=0.0003). Univariate combined multivariate cox regression analysis showed that NRAS mutation was an independent risk factor affecting DFS in patients (HR=5.569, P<0.05). In addition, the cases number of early recurrence in MRD negative group (n=8) and MRD non-negative group (n=9) was 0 and 5, respectively, the difference was statistically significant (P=0.012). There were 3 cases of early recurrence in the NRAS mutant group (n=4) and 2 cases in the NRAS wild-type group (n=13), the difference was statistically significant (P=0.022).@*CONCLUSION@#TP53 mutation is a predictor of poor response to veneclax in combination with azacitidine. With the conti-nuation of the combination chemotherapy regimen described above, NRAS mutation is an independent risk factor for DFS in patients. Moreover, the patients with non-negative MRD and NRAS mutations are at high risk of early recurrence.

Correlation between Expression of CXCL12, CXCR4, VEGF, MVD and Prognosis in Patients with Multiple Myeloma / 中国实验血液学杂志

OBJECTIVE@#To investigate the expressions of stromal cell-derived factor (CXCL12), stromal cell-derived factor receptor (CXCR4), vascular endothelial growth factor (VEGF) and microvessel density (MVD) in bone marrow microsputum of patients with multiple myeloma (MM) and their correlation with the prognosis.@*METHODS@#The expressions of CXCL12, CXCR4, VEGF and MVD in bone marrow microtubules of 57 newly diagnosed MM patients and 26 normal bone marrow samples were detected by immunohistochemistry. The rank sum test was used to compare the differences between the two groups. The clinical data of the patients were collected to analyze the correlation between the indicators of the MM group and the prognosis.@*RESULTS@#The expressions of CXCL12, CXCR4, VEGF and MVD in the bone marrow biopsy of the patients in MM group were significantly higher than those in the normal control group (P＜0.05). The expressions levels of CXCL12, CXCR4, VEGF and MVD were in the bone marrow of the patients in MM group were correlated with the ISS stage, risk stratification and the proportion of plasma cells in the bone marrow (P＜0.05). Univariate analysis showed that age, ISS stage, risk stratification, plasma cell ratio, expressions of CXCL12, CXCR4, VEGF, and MVD associated with the prognosis of patients with MM (P＜0.05). Multivariate analysis found that expressions of CXCR4, VEGF, MVD, age, and plasma cell ratio were independent prognostic factors.@*CONCLUSION@#The expressions of CXCL12, CXCR4, VEGF and MVD are increase in the bone marrow of patients with multiple myeloma, and their expressions levels are associate with the occurrence and development of multiple myeloma, and their high expression may indicate a poor prognosis.

Bivariate heritability estimation of resting heart rate and common chronic disease based on extended pedigrees / 北京大学学报(医学版)

OBJECTIVE@#To estimate the univariate heritability of resting heart rate and common chronic disease such as hypertension, diabetes, and dyslipidemia based on extended pedigrees in Fujian Tulou area and to explore bivariate heritability to test for the genetic correlation between resting heart rate and other relative phenotypes.@*METHODS@#The study was conducted in Tulou area of Nanjing County, Fujian Province from August 2015 to December 2017. The participants were residents with Zhang surname and their relatives from Taxia Village, Qujiang Village, and Nanou Village or residents with Chen surname and their relatives from Caoban Village, Tumei Village, and Beiling Village. The baseline survey recruited 1 563 family members from 452 extended pedigrees. The pedigree reconstruction was based on the family information registration and the genealogy booklet. Univariate and bivariate heritability was estimated using variance component models for continuous variables, and susceptibility-threshold model for binary variables.@*RESULTS@#The pedigree reconstruction identified 1 seven-generation pedigree, 2 five-generation pedigrees, 23 four-generation pedigrees, 186 three-generation pedigrees, and 240 two-generation pedigrees. The mean age of the participants was 57.2 years and the males accounted for 39.4%. The prevalence of hypertension, diabetes, dyslipidemia in this population was 49.2%, 10.0%, and 45.2%, respectively. The univariate heritability estimation of resting heart rate, hypertension, and dyslipidemia was 0.263 (95%CI: 0.120－0.407), 0.404 (95%CI: 0.135－0.673), and 0.799 (95%CI: 0.590－1), respectively. The heritability of systolic blood pressure, diastolic blood pressure, fasting glucose, total cholesterol, triglyceride, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol was 0.379, 0.306, 0.393, 0.452, 0.568, 0.852, and 0.387, respectively. In bivariate analysis, there were phenotypic correlations between resting heart rate with hypertension, diabetes, diastolic blood pressure, fasting glucose, and triglyceride. After taking resting heart rate into account, there were strong genetic correlations between resting heart rate with fasting glucose (genetic correlation 0.485, 95%CI: 0.120－1, P<0.05) and diabetes (genetic correlation 0.795, 95%CI: 0.181－0.788, P<0.05).@*CONCLUSION@#Resting heart rate was a heritable trait and correlated with several common chronic diseases and related traits. There was strong genetic correlation between resting heart rate with fasting glucose and diabetes, suggesting that they may share common genetic risk factors.

Effect of Microvascular Endothelial Cells on the Proliferation of Bone Marrow Hematopoietic Stem Cells under Different Culture Conditions / 中国实验血液学杂志

OBJECTIVE@#To investigate the effect of microvascular endothelial cells (MEC) on the proliferation of hematopoictic stem cells (HSC) under different culture conditions in vitro.@*METHODS@#The MEC from lung tissue of C57BL/6 mice and the HSC from bone marrow of GFP mice were used for non-contact co-culture, 2 D contact co-culture, at same time the single MEC and single HSC culture were seted up and were used as control group. The cell counting and CCK-8 method were used to detect and compare the proliferation levels of suspension cells in different groups on day 1, 3, 5 and 7.@*RESULTS@#MEC presented adherent growth. In process of cell culture in vitro, the number of suspension cells in MEC and HSC co-culture group and single HSC culture group increased, the suspension cells in 2D contact and non-contact co-culture groups more early gated into logarithmic growth phase as compared with suspension cells in control group, the proliferation level of suspention cells in 2D contact culture group was higher than that in non-contact co-culture group and single HSC culture group (P<0.05), the proliferation level of suspension cells in non-contact co-culture group was higher than that in single HSC culture group (P<0.05).@*CONCLUSION@#The culture of HSC in vitro can proliferate HSC, MEC can promote the proliferation of HSC, MEC also can promote the HSC proliferation by non-contact co-culture in vitro, which relates with the effect of cytokines secreted from MEC; the effect of MEC and HSC contact co-culture on the proliferation of HSC is stronger than that of non-contact co-culture, which relates with the regulation of cell-cell contact.

Coculture with mesenchymal stem cells facilitates the proliferation of hematopoietic stem cells under different coculture modes / 中国组织工程研究

BACKGROUND: Although a large number of related studies have been carried out, there is still a lack of practical methods to amplify hematopoietic stem cells(HSCs)in vitro.Mesenchymal stem cells(MSCs)secrete a variety of cytokines that promote the HSCs proliferation and inhibit their differentiation. These cytokines play an important role in maintaining the hematopoietic microenvironment and regulating HSCs function. OBJECTIVE:To investigate the effect of bone marrow MSCs on the proliferation of HSCs in vitro under different coculture modes. METHODS:Mesenchymal stem cells from the bone marrow of C57BL/6 mice were cultured in vitro using the whole bone marrow adherent culture. CD117+cells (HSCs) were sorted from passage 3 cells by using miniMACS magnetic beads sorting. Then, CD117+cells were co-cultured with MSCs under different coculture models, including single culture of HSCs (control group), Transwell coculture (upper chamber, HSCs; lower chamber, MSCs) and two-dimensional contact coculture (coculturing HSCs and MSCs in 24-well plates). The morphology of HSCs was observed under phase contrast microscope and fluorescence microscope, and the number of active cells of HSCs was counted at 1, 3, 5, and 7 days after coculture. RESULTS AND CONCLUSION: During the coculture of 1-7 days, the number of HSCs in the two groups was increased with culture time (P <0.05). After 3 days of coculture, HSCs in each group was grown into the logarithmic growth phase, and morphological changes in some HSCs were detected at 5 days of coculture. At 7 days of coculture, the viabilities of HSCs in different culture models were ranked as follows: single culture model < Transwell coculture model < two-dimensional contact coculture model (P < 0.05). These findings suggest that MSCs can effectively promote the proliferation of HSCs in vitro,and the promotion effect is increased under contact coculture conditions.

Effect of Shh and BM-MSC Synergism on the Proliferation of Hematopoietic Stem Cells / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To study the effect and mechanism of shh and mesenchymal stem cell（MSC）synergism on the proliferation of hematopoietic stem cells in noninvasive co-culture system in vitro.</p><p><b>METHODS</b>The mesenchymal stem cells were cultured in vitro，CD34 cells were sorted by mini MACS magnetic bead separator，flow cytometry was used to identify the purity of 2 cells. CD34 cells and MSCs were seeded to upper and low of transwell respecibely for non-contact coculture，and add exogenous shh protein for intervenece. The number of MSCs and HSCs，the total amount of RNA，the expression of ki67 and Tie-2 mRNA of HSC，the expression of VEGF and Ang-1 mRNA of MSC were detected for investigating the condition of cell proliferation and the expression of angiogenic factors.</p><p><b>RESULTS</b>The total number of cells，the total amount of RNA and the relative expression of ki67, Tie-2, VEGF and Ang-1 in non-contact co-culture group increased and showed the following trends on the 7th day：the above-mentioned indexes in group MSC + HSC, group shh + HSC were higher than those in group HSC, while those in MSC + shh + HSC Group was higher than those in MSC + HSC and shh + HSC group.</p><p><b>CONCLUSION</b>Angiogenic factors help MSC to proliferate HSC and amplify the CD34 hematopoietic stem/progenitor cells by shh and MSC synergism in vitro coculture system which may be related with angiogenic factors.</p>

Activity of lysozyme from Oncomelania hupensis and its role in inhibiting bacteria: a preliminary study / 中国地方病学杂志

Objective To study the lysozyme activity in Oncomelania hupensis and observe its inhibitory effect on bacterial growth.Methods Soft tissues of Oncomelania hupensis were initially homogenized and immersed in Tris-HCl-TritonX-114 buffer solution for 24 hours then the supernatant was collected after centrifugation at 10 000 × g for 10 minutes.The supernatant was incubated in a 37 ℃ water bath for 15 minutes and centrifuged again at 2000 × g for 10 minutes.The precipitate was put into ultrafiltration tube (relative retention molecular mass =3000) and centrifuged at 4 ℃,5 000 × g for 30 minute to obtain concentrated enzyme.The protein content,lysozyme activity and the antibacterial effect on Micrococcus lysodeikticus,Shigella dysenteriae,Staphylococcus aureus,Escherichia coli and Candida albicans were measured with bicinchonininc acid(BCA) method,turbidimetric method and agar diffusion (K-B) method,respectively.Results The antibacterial protein lysozyme was identified in gastropod protein concentration of the concentrated enzyme was 3.428 g/L.Average activity,total activity,and specific activity were (760 ± 120) × 103 U/L,(1520 ± 240) × 103 U/L and (221.70 ± 35.00)U/mg,respectively.The enzyme had produced exclusive inhibitory effects on growth of Micrococcus lysodeikticus and Shigella dysenteriae.Average inhibitory diameters were 10-12 and 12-15 mm,respectively.No inhibition zone was observed in saline control,Staphylococcus aureus,Escherichia coli and Candida albicans.Conclusions Lysozyme can be extracted from soft tissues of Oncomelania hupensis with Tris-HCl-TritonX-114 buffer solution,and the enzyme has inhibitory effect on growth of Micrococcus lysodeikticus and Shigella dysenteriae but has no antibacterial effect on Staphylococcus aureus,Escherichia coli and Candida albicans.

Experimental study of donor natural killer cells reducing graft-versus-host disease and enhancing engraftment / 中国实验血液学杂志

The purpose of this study was to investigate whether pretransplant infusion of reactive natural killer cells (NK cells) from donor or recipient can reduce graft-versus-host disease (GVHD) and enhance engraftment in bone marrow transplantation (BMT). Recipient BALB/c mice were divided into 4 groups after received 6.5 Gy total-body irradiation (TBI): control group 1 was treated with nothing, control group 2 received BMT alone, experiment group 1 received BMT and autoreactive NK cells, experiment group 2 received BMT and alloreactive NK cells. Life span, clinical and pathologic changes of GVHD and chimerism rate of each group were evaluated. The results showed that all mice were survival in control group 1. The life span was shorter in experiment group 1 than that in control group 2 (P < 0.05) and longer in experiment group 2 than that in control group 2 (P < 0.01). GVHD was higher in score of experiment group 1 than in control group 2 (P < 0.05) but lower in experiment group 2 than that in control group 2 (P < 0.01). The donor chimerism rate in both two experiment groups were higher than that in control group 2 (P < 0.05), however, the donor chimerism rate was higher in experiment group 2 than that in experiment group 1 (P < 0.01). It is concluded that pretransplant infusion of alloreactive donor NK cells can prolong life span, reduce the degree of GVHD and enhance engraftment. But autoreactive recipient NK cells can shorten life span, aggravate the degree of GVHD and also enhance engraftment, which is weaker than that using alloreactive donor NK cells.