[Effect and safety of 10-day decitabine-containing conditioning regimen for allogeneic hematopoietic stem cell transplantation in 31 patients with acute myeloid leukemia/myelodysplastic syndrome]

Objective: To investigate the early effect and safety of allogeneic hematopoietic stem cell transplantation (allo-HSCT) with a 10-day decitabine-containing conditioning regimen in the treatment of acute myeloid leukemia (AML) /myelodysplastic syndrome (MDS) . Methods: From April 2021 to May 2022, 31 AML/MDS patients who received allo-HSCT with a 10-day decitabine-containing conditioning regimen were analyzed. Results: AML (n=10), MDS-AML (n=6), CMML-AML (n=1), and MDS (n=14) were identified in 31 patients, 16 males, and 15 females, with a median age of 41 (20-55) yr. Neutrophils and platelets were successfully implanted in 31 patients (100%), with a median implantation duration of 12 (9-30) and 14 (9-42) days, respectively. During the preconditioning period, 16 patients (51.6%) developed oral mucositis, with 15 cases of Ⅰ/Ⅱ grade (48.4%) and one case of Ⅲ grade (3.2%). After transplantation, 13 patients (41.9%) developed CMV viremia, six patients (19.4%) developed hemorrhagic cystitis, and four patients (12.9%) developed a local infection. The median time of acute graft versus host disease (aGVHD) following transplantation was 33 (12-111) days. The cumulative incidence of aGVHD and Ⅲ/Ⅳ grade aGVHD was 41.9% (95% CI 26.9%-61.0%) and 22.9% (95% CI 13.5%-47.5%), respectively. There was no severe cGVHD, and mild and moderate chronic GVHD (cGVHD) incidence was 23.5% (95% CI 12.1%-43.6%). As of November 30, 2022, only one of the 31 patients had relapsed, with a 1-yr cumulative relapse rate (CIR) of 3.2% (95% CI 0.5%-20.7%). There was only one relapse patient death and no non-relapse deaths. The 1-yr overall survival (OS) and disease-free survival (DFS) rates were 92.9% (95% CI 80.3%-100%) and 96.8% (95% CI 90.8%-100%), respectively. Conclusions: A 10-day decitabine-containing conditioning regimen for allo-HSCT reduced relapse and was safe and feasible in treating AML/MDS.

[Mechanism study of platelet derived growth factor receptor alpha on the bidirectional differentiation regulation of glioma-associated oncogene homolog 1-positive mesenchymal stem cells in mice]

Objective: To investigate the role of platelet derived growth factor receptor alpha (PDGFRα) on bidirectional differentiation of glioma-associated oncogene homolog 1-positive mesenchymal stem cells (Gli1+-MSC). Methods: Breeding double reporter transgenic mice ROSAmT/mG/Gli1-Cre^ERt2/PDGFRα^fl (Experimental group) and ROSA^mT/mG/Gli1-Cre^ERt2 (Control group), 20 mice in each of the two groups at four weeks of age were selected, MSC were isolated from the mouse aortic epithelium. After tamoxifen inducement, the two groups of Gli1⁺-MSC were screened by green fluorescent protein (GFP) labeling and flow cytometry sorting. PDGFRα was conditionally knocked out in the experimental group, and the control group Gli1⁺-MSC expressed PDGFRα normally. The two groups of Gli1⁺-MSC were subjected to adipogenic induction and fibrogenic induction, the Western blotting was performed to detect PDGFRα, adipocyte markers [perilipin and CCAAT/enhancer binding protein alpha (C/EBPα)] and fibrogenic markers [alpha smooth muscle actin (α-SMA) and fibroblast-specific protein 1 (FSP-1)] and semi-quantitative analysis was performed. The degree of cellular adipose differentiation after bidirectional induction of Gli1+-MSC in both groups was observed by oil red O staining and analyzed semi-quantitatively. Results: After tamoxifen induction, Gli1⁺-MSC could be accurately isolated from flow cytometry by GFP labeling. Via adipogenic differentiation, the expression of PDGFRα in the experimental group (0.017±0.002) was significantly lower than that in the control group (0.184±0.012) (t=25.48，P=0.002). The protein expressions of perilipin (3.138±0.414) and C/EBPα (3.565±0.289) were significantly higher than those in the control group (2.312±0.218 and 2.179±0.103, respectively) (t=6.21，P=0.025；t=6.69，P=0.022). Thus, the knock-out of PDGFRα enhanced the adipogenic differentiation ability of Gli1⁺-MSC. After fibrogenesis induction, the protein expressions of PDGFRα, α-SMA and FSP-1 in the experimental group (0.030±0.001, 0.932±0.177 and 0.276±0.020, respectively) were significantly lower than those in the control group (0.439±0.006, 1.352±0.170 and 0.835±0.097, respectively) (t=149.40, P<0.001; t=66.38,P<0.001; t=11.41,P<0.08). This suggested that the knock-out of PDGFRα significantly inhibited Gli1⁺-MSC differentiation toward fibroblasts. After bidirectional induction, significantly less adipocyte formation was seen in the control group and more in the experimental group. Quantitative analysis showed that the amount of oil red O staining in the experimental group (0.461±0.042) was significantly higher than that in the control group (0.017±0.007) after bidirectional induction (t=23.20, P<0.01). Conclusions: PDGFRα plays an important role in the regulation of bidirectional differentiation of vascular adventitial Gli1+-MSC.

Faecalibaculum rodentium remodels retinoic acid signaling to govern eosinophil-dependent intestinal epithelial homeostasis

The intestinal epithelium plays critical roles in sensing and integrating dietary and microbial signals. How microbiota and intestinal epithelial cell (IEC) interactions regulate host physiology in the proximal small intestine, particularly the duodenum, is unclear. Using single-cell RNA sequencing of duodenal IECs under germ-free (GF) and different conventional microbiota compositions, we show that specific microbiota members alter epithelial homeostasis by increasing epithelial turnover rate, crypt proliferation, and major histocompatibility complex class II (MHCII) expression. Microbiome profiling identified Faecalibaculum rodentium as a key species involved in this regulation. F. rodentium decreases enterocyte expression of retinoic-acid-producing enzymes Adh1, Aldh1a1, and Rdh7, reducing retinoic acid signaling required to maintain certain intestinal eosinophil populations. Eosinophils suppress intraepithelial-lymphocyte-mediated production of interferon-γ that regulates epithelial cell function. Thus, we identify a retinoic acid-eosinophil-interferon-γ-dependent circuit by which the microbiota modulates duodenal epithelial homeostasis.

Diet posttranslationally modifies the mouse gut microbial proteome to modulate renal function

Associations between chronic kidney disease (CKD) and the gut microbiota have been postulated, yet questions remain about the underlying mechanisms. In humans, dietary protein increases gut bacterial production of hydrogen sulfide (H2S), indole, and indoxyl sulfate. The latter are uremic toxins, and H2S has diverse physiological functions, some of which are mediated by posttranslational modification. In a mouse model of CKD, we found that a high sulfur amino acid-containing diet resulted in posttranslationally modified microbial tryptophanase activity. This reduced uremic toxin-producing activity and ameliorated progression to CKD in the mice. Thus, diet can tune microbiota function to support healthy host physiology through posttranslational modification without altering microbial community composition.

The Taste Receptor TAS1R3 Regulates Small Intestinal Tuft Cell Homeostasis

Tuft cells are an epithelial cell type critical for initiating type 2 immune responses to parasites and protozoa in the small intestine. To respond to these stimuli, intestinal tuft cells use taste chemosensory signaling pathways, but the role of taste receptors in type 2 immunity is poorly understood. In this study, we show that the taste receptor TAS1R3, which detects sweet and umami in the tongue, also regulates tuft cell responses in the distal small intestine. BALB/c mice, which have an inactive form of TAS1R3, as well as Tas1r3-deficient C57BL6/J mice both have severely impaired responses to tuft cell–inducing signals in the ileum, including the protozoa Tritrichomonas muris and succinate. In contrast, TAS1R3 is not required to mount an immune response to the helminth Heligmosomoides polygyrus, which infects the proximal small intestine. Examination of uninfected Tas1r3^−/− mice revealed a modest reduction in the number of tuft cells in the proximal small intestine but a severe decrease in the distal small intestine at homeostasis. Together, these results suggest that TAS1R3 influences intestinal immunity by shaping the epithelial cell landscape at steady-state. ImmunoHorizons, 2020, 4: 23–32.

[Antibacterial effectiveness of calcium silicate-based root canal sealer against Enterococcus faecalis biofilms in infected dentinal tubules in vitro]

Objective: To evaluate the antiseptic effect of combined using of 5% sodium hypochlorite and calcium silicate-based root canal sealer against Enterococcus faecalis (Ef) biofilms in infected dentinal tubules in vitro. Methods: Cells of Ef were inoculated into the dentinal tubules of single-rooted teeth (without caries, periapical lesions and malformations extracted due to periodontal disease or orthodontic reasons; collected from Department of Maxillofacial Surgery, The First Affiliated Hospital of Zhengzhou University) with centrifugation and incubated in brain-heart infusion (BHI) to form 3-week-old biofilms. The infected samples were subjected to sodium hypochlorite or sterile water bathing for 10 minutes followed by calcium silicate-based root canal sealer (iRoot SP) (calcium silicate-based group), Gutta-percha group and sterile water group placed on the root canal wall for 1, 4 and 12 weeks. There were two samples in each treatment at each point. The antiseptic effectiveness of combined use of sodium hypochlorite and calcium silicate-based root canal sealer was analyzed by laser scanning confocal microscope (LSCM), ANOVA and LSD-t test. Results: After treatment with 5% sodium hypochlorite, in calcium silicate-based group for 4 and 12 weeks more Ef biofilm cells [(75.3±3.5)% and (74.8±3.8)%] were killed than in Gutta-percha group [(65.9±4.1)% and (63.0±3.7)%] and sterile water group [(63.9±4.0)% and (64.2±3.5)%] (P<0.05). After being treated with sterile water, the proportion of dead bacterial cells in calcium silicate-based group for 1, 4 and 12 weeks [(27.5±4.6)%, (43.0±4.4)% and (40.3±6.1)%] were more than those in Gutta-percha group and sterile water group (P<0.05). After being treated with 5% sodium hypochlorite or sterile water, more biofilm bacteria were killed in calcium silicate-based group for 4 and 12 weeks than in calcium silicate-based group for 1 week (P<0.05). Conclusions: The combined use of sodium hypochlorite and calcium silicate-based root canal sealer kills more biofilm cells in infected dentinal tubules.

[Killing activity of nonequilibrium plasma against young and old Enterococcus faecalis biofilms with long-term exposure in infected root canals in vitro]

Objective: To evaluate the antimicrobial activity of nonequilibrium plasma against Enterococcus faecalis (Ef) biofilms in vitro and to obtain novel evidence of root canal disinfection with nonequilibrium plasma. Methods: Sterile cover slips and single-rooted canals were filled with Ef and incubated to form 1-week-old and 3-week-old biofilms, respectively. The infected samples were subjected to nonequilibrium plasma, 2% chlorhexidine digluconate (CHX) and saline for 3, 10 and 30 minutes, respectively. After treatment, the killing effectiveness of nonequilibrium plasma was analyzed by using laser scanning confocal microscopy (LSCM) and colony forming unit (CFU) counting. Results: The 3-dimentional reconstruction LSCM images showed that about 48.3%-79.8% of 1-week-old Ef biofilm cells and 40.0%-67.4% of 3-week-old biofilm cells were killed by nonequilibrium plasma and 2% CHX compared to saline (P<0.05). The proportion of killing activity was lower after 3 minutes (40.0%-50.9% killing) than after 10 minutes (65.3%-77.8% killing) and 30 minutes (66.4%-79.8% killing) (P<0.05). And the killing of biofilm bacteria was fastest during the first 3 minutes (13.3%-17.0% killing per minute) and slow down greatly after 10 minutes. Remarkably more bacteria were killed in 1-week-old Ef biofilms (48.3%-79.8% killing) than in 3-week-old biofilms (P<0.05). Conclusions: The nonequilibrium plasma killed more Ef biofilm cells in infected root canals showed promotional as an additional approach against bacterial biofilms during root canal disinfection.

Macrophage function in tissue repair and remodeling requires IL-4 or IL-13 with apoptotic cells

Tissue repair is a subset of a broad repertoire of interleukin-4 (IL-4)- and IL-13-dependent host responses during helminth infection. Here we show that IL-4 or IL-13 alone was not sufficient, but IL-4 or IL-13 together with apoptotic cells induced the tissue repair program in macrophages. Genetic ablation of sensors of apoptotic cells impaired the proliferation of tissue-resident macrophages and the induction of anti-inflammatory and tissue repair genes in the lungs after helminth infection or in the gut after induction of colitis. By contrast, the recognition of apoptotic cells was dispensable for cytokine-dependent induction of pattern recognition receptor, cell adhesion, or chemotaxis genes in macrophages. Detection of apoptotic cells can therefore spatially compartmentalize or prevent premature or ectopic activity of pleiotropic, soluble cytokines such as IL-4 or IL-13.

Depinning dynamics of two-dimensional magnetized colloids on a random substrate

We perform Langevin simulations on the depinning dynamics of two-dimensional magnetized colloids on a random substrate. On increasing the magnetic field strength, we find for the first time a crossover from plastic to smectic flows as well as a crossover from smectic to elastic crystal flows above depinning. For both the smectic and elastic crystal flows, a power-law scaling relationship could be obtained between the average velocity and applied driving force. The scaling exponent is found to be larger than 1 for smectic flow. But, for the elastic crystal flow, the scaling exponent is found to be less than 1. For the plastic flow, no power-law scaling relationship between the average velocity and applied driving force can be derived and history dependence of the depinning occurs. Within the crossover from plastic to smectic flows, a sudden decrease in the critical driving force is observed, and a sudden increase is found in the critical driving force across the crossover from smectic to elastic crystal flows, accompanied by a crossing of the curves of average velocity versus driving force.

Identification and characterization of phospholipase D and its association with drought susceptibilities in peanut (Arachis hypogaea)

Preharvest aflatoxin contamination has been identified by the peanut industry as a serious issue in food safety and human health because of the carcinogenic toxicity. Drought stress is the most important environmental factor exacerbating Aspergillus infection and aflatoxin contamination in peanut. The development of drought-tolerant peanut cultivars could reduce aflatoxin contamination and would represent a major advance in the peanut industry. In this study, we identified a novel PLD gene in peanut (Arachis hypogaea), encoding a putative phospholipase D (PLD, EC 3.1.4.4). The completed cDNA sequence was obtained by using the consensus-degenerated hybrid oligonucleotide primer strategy. The deduced amino acid sequence shows high identity with known PLDs, and has similar conserved domains. The PLD gene expression under drought stress has been studied using four peanut lines: Tifton 8 and A13 (both drought tolerant) and Georgia Green (moderate) and PI 196754 (drought sensitive). Northern analysis showed that PLD gene expression was induced faster by drought stress in the drought-sensitive lines than the drought tolerance lines. Southern analysis showed that cultivated peanut has multiple copies (3 to 5 copies) of the PLD gene. These results suggest that peanut PLD may be involved in drought sensitivity and tolerance responses. Peanut PLD gene expression may be useful as a tool in germplasm screening for drought tolerance.

[Construction of a genetic map and location of quantitative trait loci for yield component traits in maize by SSR markers]

Using 230 F2:3 lines derived from the hybrid of ND3138, a SSR genetic linkage map of maize (Zea mays L.) was constructed on which 80 markers distribute among 10 linkage groups and spanning maize genome about 2033.4 cM with average distance between markers being 25.42 cM. The 230 F2:3 lines were grown in a random design of one-row plot with three replication, and evaluated for ear length, bared tip, ear diameter, row number, kernel number row-1, one thousand grains weight, ear weight and grain weight plant-1. With interval mapping procedure, 30 QTLs were revealed for all traits, which distributed on 9 of 10 chromosomes of maize except chromosome 6 and accounted for from 9.5% to 55.3% of the total phenotypic variation. Genetic effects and gene action were also determined.