Catalytic Regio- and Enantioselective Remote Hydrocarboxylation of Unactivated Alkenes with CO2.

The catalytic regio- and enantioselective hydrocarboxylation of alkenes with carbon dioxide is a straightforward strategy to construct enantioenriched α-chiral carboxylic acids but remains a big challenge. Herein we report the first example of catalytic highly enantio- and site-selective remote hydrocarboxylation of a wide range of readily available unactivated alkenes with abundant and renewable CO2 under mild conditions enabled by the SaBOX/Ni catalyst. The key to this success is utilizing the chiral SaBOX ligand, which combines with nickel to simultaneously control both chain-walking and the enantioselectivity of carboxylation. This process directly furnishes a range of different alkyl-chain-substituted or benzo-fused α-chiral carboxylic acids bearing various functional groups in high yields and regio- and enantioselectivities. Furthermore, the synthetic utility of this methodology was demonstrated by the concise synthesis of the antiplatelet aggregation drug (R)-indobufen from commercial starting materials.

Combining serum microRNAs and machine learning algorithms for diagnosing infectious fever after HSCT.

Infection post-hematopoietic stem cell transplantation (HSCT) is one of the main causes of patient mortality. Fever is the most crucial clinical symptom indicating infection. However, current microbial detection methods are limited. Therefore, timely diagnosis of infectious fever and administration of antimicrobial drugs can effectively reduce patient mortality. In this study, serum samples were collected from 181 patients with HSCT with or without infection, as well as the clinical information. And more than 80 infectious-related microRNAs in the serum were selected according to the bulk RNA-seq result and detected in the 345 time-pointed serum samples by Q-PCR. Unsupervised clustering result indicates a close association between these microRNAs expression and infection occurrence. Compared to the uninfected cohort, more than 10 serum microRNAs were identified as the combined diagnostic markers in one formula constructed by the Random Forest (RF) algorithms, with a diagnostic accuracy more than 0.90. Furthermore, correlations of serum microRNAs to immune cells, inflammatory factors, pathgens, infection tissue, and prognosis were analyzed in the infection cohort. Overall, this study demonstrates that the combination of serum microRNAs detection and machine learning algorithms holds promising potential in diagnosing infectious fever after HSCT.

Catalytic Regio- and Enantioselective Boracarboxylation of Arylalkenes with CO2 and Diboron.

Catalytic asymmetric carboxylation of readily available alkenes with CO2, an abundant and sustainable one-carbon building block, that gives access to value-added α-stereogenic carboxylic acids in an atom- and step-economic manner is highly attractive. However, it has remained a formidable challenge for the synthetic community. Here, the first example of Cu-catalyzed highly regio- and enantioselective boracarboxylation reaction on various arylalkenes with diboron under an atmospheric pressure of CO2 is described, which afforded a variety of chiral ß-boron-functionalized α-aryl carboxylic acids with up to 87% yield and 97% ee under mild conditions. Importantly, α-substituted arylalkenes could also be subject to this protocol with excellent enantiopurities, thereby rendering an efficient approach for the generation of enantioenriched carboxylic acids with an α-chiral all-carbon quaternary center. Moreover, high functional group tolerance, scalable synthesis, and facile access to bioactive compounds, like (-)-scopolamine, (-)-anisodamine, and (-)-tropicamide, further demonstrated the synthetic utility of this strategy.

Mucosal-associated invariant T cells predict increased acute graft-versus-host-disease incidence in patients receiving allogeneic hematopoietic stem cell transplantation.

BACKGROUND: Mucosal-associated invariant T (MAIT) cells are innate-like T cells, some studies have reported that the number of circulating MAIT cells reduced in patients with acute graft-versus-host-disease (aGVHD) development. However, the role of donor MAIT cells on aGVHD development and subsequent functional change still remain unclear. METHODS: The study recruited 86 patients with hematological malignancies who underwent allogeneic hematopoietic cell transplantation (HCT) from May 1, 2018 to June 30, 2019. MAIT cells, their subset, and cytokine levels were measured by flow cytometry. Gray's test was used to assess the impact of graft MAIT cell proportion and number on aGVHD incidence. The Cox proportional hazard model was used in the multivariate analysis. The comparison for continuous variables was assessed using Mann-Whitney analysis. RNA-sequencing was performed to investigate the possible molecular pathway changes. RESULTS: Our study showed that the proportion of MAIT cells in grafts was not different from normal controls, but the CD4/8 subsets were altered. Taking the median of the proportion and number of MAIT cells in the graft as the threshold, the results showed that the incidence of grade B-D aGVHD in patients with MAIT cell proportion ≥ 3.03% was significantly higher than that in patients with MAIT cell proportion < 3.03% (56.3%, 95% CI 37.1-71.2 versus 23.1%, 95% CI 13.8-46.2; P = 0.038).The number of MAIT cells in the graft was not associated with aGVHD development (P = 0.173), however, when the graft contained more CD4 positive, CD8 positive, and CD4/CD8 double-positive MAIT cells, the incidence of aGVHD was significantly increased (P = 0.019, P = 0.035 and P = 0.027, respectively). Besides, reduced frequencies and counts of circulating MAIT cells were observed in patients with aGVHD when compared to patients without aGVHD, accompanied by enhanced production of Tumor necrosis factor-α, Interferon-γ and upregulated programmed death-1, CXC Chemokine Receptor-6 (CXCR6) and CD38 expression. Gene set enrichment analysis of MAIT cell RNA-seq data showed interferon-α response pathway upregulated in aGVHD patients when compared with patients without aGVHD and healthy controls. CONCLUSIONS: Our study shows that MAIT cells in grafts and peripheral blood are both closely related to the aGVHD development post allogeneic HCT. Interferon-α response pathway perhaps is a critical regulation mechanism for the MAIT cell involvement in aGVHD development.

Single-cell transcriptomic landscape of human blood cells.

High throughput single-cell RNA-seq has been successfully implemented to dissect the cellular and molecular features underlying hematopoiesis. However, an elaborate and comprehensive transcriptome reference of the whole blood system is lacking. Here, we profiled the transcriptomes of 7551 human blood cells representing 32 immunophenotypic cell types, including hematopoietic stem cells, progenitors and mature blood cells derived from 21 healthy donors. With high sequencing depth and coverage, we constructed a single-cell transcriptional atlas of blood cells (ABC) on the basis of both protein-coding genes and long noncoding RNAs (lncRNAs), and showed a high consistence between them. Notably, putative lncRNAs and transcription factors regulating hematopoietic cell differentiation were identified. While common transcription factor regulatory networks were activated in neutrophils and monocytes, lymphoid cells dramatically changed their regulatory networks during differentiation. Furthermore, we showed a subset of nucleated erythrocytes actively expressing immune signals, suggesting the existence of erythroid precursors with immune functions. Finally, a web portal offering transcriptome browsing and blood cell type prediction has been established. Thus, our work provides a transcriptional map of human blood cells at single-cell resolution, thereby offering a comprehensive reference for the exploration of physiological and pathological hematopoiesis.

Single-cell transcriptome profiling reveals neutrophil heterogeneity in homeostasis and infection.

The full neutrophil heterogeneity and differentiation landscape remains incompletely characterized. Here, we profiled >25,000 differentiating and mature mouse neutrophils using single-cell RNA sequencing to provide a comprehensive transcriptional landscape of neutrophil maturation, function and fate decision in their steady state and during bacterial infection. Eight neutrophil populations were defined by distinct molecular signatures. The three mature peripheral blood neutrophil subsets arise from distinct maturing bone marrow neutrophil subsets. Driven by both known and uncharacterized transcription factors, neutrophils gradually acquire microbicidal capability as they traverse the transcriptional landscape, representing an evolved mechanism for fine-tuned regulation of an effective but balanced neutrophil response. Bacterial infection reprograms the genetic architecture of neutrophil populations, alters dynamic transitions between subpopulations and primes neutrophils for augmented functionality without affecting overall heterogeneity. In summary, these data establish a reference model and general framework for studying neutrophil-related disease mechanisms, biomarkers and therapeutic targets at single-cell resolution.

Synthesis of the Alleged Structures of Fortisterol and Herbarulide and Structural Revision of Herbarulide.

The alleged structures of 5,6-epoxy-5,6-secosteroids fortisterol and herbarulide differ only in the stereoconfiguration of C24. Applying insights into the hypothetical biosynthesis of this class of natural products, we devised a short synthetic access (four and eight steps, respectively) starting from commercial ergosterol and featuring an alkoxy radical rearrangement. The comparison of nuclear magnetic resonance spectroscopic data revealed herbarulide having the proposed structure of fortisterol, whereas synthesis of another two diastereomers could not conclusively prove the true structure of fortisterol. Along the way, a high-yielding and scalable access to the infamous Burawoy's ketone not requiring chromium(VI) reagents was developed.

Conditioning Regimen of 5-Day Decitabine Administration for Allogeneic Stem Cell Transplantation in Patients with Myelodysplastic Syndrome and Myeloproliferative Neoplasms.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a potentially curative treatment for patients with myelodysplastic syndromes (MDS) and myelodysplastic/myeloproliferative neoplasms (MDS/MPN). However, post-HSCT relapse remains a major cause of treatment failure. Here we assessed the efficacy of a new conditioning regimen comprising decitabine (Dec), busulfan (Bu), cyclophosphamide (Cy), fludarabine (Flu), and cytarabine (Ara-c) for allo-HSCT in patients with MDS and MDS/MPN. A total of 48 patients were enrolled, including 44 with MDS and 4 with chronic myelomonocytic leukemia (CMML). Patients received Dec 20 mg/m2/day on days -9 to -5, combined with a Bu/Cy/Flu/Ara-c-modified preparative regimen. At a median follow-up of 522 days (range, 15 to 1313 days), the overall survival (OS) was 86%, relapse incidence was 12%, and nonrelapse mortality was 12%. The incidence of severe acute (grade III-IV) graft-versus-host disease (GVHD) was 23% and that of chronic GVHD was 15%. At 2 years, OS was 74% and 86%, respectively for high-risk and very-high-risk patients with MDS. Survival was promising in patients with poor-risk gene mutations, such as TP53 and ASXL1 (88%), and in those with ≥3 gene mutations (79%). Results of immunomonitoring studies revealed that proper natural killer cells made essential contributions to these favorable clinical outcomes. Overall, this new regimen was associated with a low relapse rate, low incidence and severity of GVHD, and satisfactory survival in allo-HSCT recipients with MDS and MDS/MPN.

Palladium-Catalyzed Oxidative Cross-Coupling of Conjugated Enynones with Allylarenes: Synthesis of Furyl-Substituted 1,3-Dienes.

A new method for the synthesis of furyl-substituted 1,3-dienes via palladium-catalyzed oxidative cross-coupling of conjugated enynones with allylarenes is developed. This reaction shows broad substrate scope and good functional group tolerance. Palladium carbene migratory insertion is proposed as the key step for this transformation with conjugated enynones serving as the carbene precursors.

Posaconazole oral suspension as salvage therapy for invasive fungal disease in patients with hematological diseases.

Aim: Posaconazole (POS) is an extended-spectrum triazole approved for treatment of refractory invasive fungal disease. Outcome analysis of POS salvage therapy is of great clinical significance. Methods: We retrospectively reviewed data for 113 patients who received POS oral suspension as salvage therapy between December 2013 and May 2018. Results: Cumulative success rate at 12 weeks was 53.1% (60/113) with a rapid increase within the first 3-4 weeks and a plateau at 6 weeks after POS initiation. Multivariate logistic regression analysis showed that disseminated infection, prolonged neutropenia, severe graft-versus-host disease and high-dose steroid use were independent risk factors of response. Conclusion: POS oral suspension is effective as a salvage therapy for invasive fungal disease.

[The Effect of Serum Cytokine Levels prior Transplantation on the Outcome of Severe Aplastic Anemia Patients Received Allogeneic Hematopoietic Stem Cell Transplantation].

OBJECTIVE: To identify the role of serum cytokine levels prior allogeneic hematopoietic stem cell trans-plantation (allo-HSCT) in the outcome of severe aplastic anemia (SAA) patients received allo-HSCT treatment. METHODS: The clinical data of 117 SAA patients received allo-HSCT were enrolled in this study. The overall survival (OS), graft versus host disease (GVHD) incidence and relationship of serum cytokines with OS and major transplantation complications were retrospectively analyzed. RESULTS: The patients enrolled in this study included 78(66.7%) cases received HSCT matched sibling donors (MSD), 12(10.2%) HSCT of unrelated donors (MUD) and 27 cases received HSCT of haploidentical donors (HID). The 5-years OS was 76.0%(95% CI: 64.4-87.5%); aGVHD cumulative incidence was 49.6%(95% CI: 40.4%-58.8%) and cumulative incidence cGVHD was 31.6%(95% CI:23.1%-40.2%). MSD allo-HSCT had a significantly higher 5-years OS as compared with the other donors(82.3%±6.6% vs 61.3%±11.7%, P<0.05). HLA matching, donor's age, cytomegalovirus/ Epstein-Barr virus (CMV/EBV) infection were important factors of affecting occurence of aGVHD. The patients with higher serum IL-6 had reduced platelet recovery time after transplantation (14.6±1.8 vs 18.3±2.6 d)(P=0.050) and higher serum TNF-α level accompanied by a lower incidence of CMV/EBV infection (37.8%±11.1% vs 58.8±16.8%)(P<0.05). CONCLUSION: MSD allo-HSCT is the effective treatment for SAA patients. Donor's type remains the strong predictor of survival. The serum levels IL-6 and TNF-α before transplantation associate with platelet recovery and CMV/EBV infection.

Pre-transplantation thymic function is associated with the risk of acute graft versus host disease and cytomegalovirus viremia after allogeneic hematopoietic stem cell transplantation.

OBJECTIVES: To analyze the kinetics of T-cell subsets and thymic function reconstitution after allogeneic hematopoietic stem cell transplantation (AHSCT); to determine whether sjTREC (signal joint TCR rearrangement excision circle) and CD31-positive recent thymic emigrant (CD31 + RTE) are correlated with acute graft versus host disease (aGVHD) or CMV (cytomegalovirus) viremia after AHSCT. METHODS: Forty-nine patients who underwent AHSCT in our institution were prospectively enrolled. Periphery blood samples were collected before conditioning and at 1, 2, 3 months after AHSCT. T-cell subsets were analyzed with flow cytometry. Genomic DNA was purified from peripheral blood mononuclear cells (PBMCs), and sjTREC was quantified by real-time PCR. Impact of sjTREC and CD31 + RTE on aGVHD and CMV viremia was evaluated by univariate and multivariate Cox regression analyses. RESULTS: The analyzed T-cell subsets and sjTREC of patients before AHSCT were all significantly lower than those of healthy donors (p < 0.05). sjTREC and CD31 + RTE were remarkably decreased in 3 months after AHSCT (p < 0.05). Patients with lower pre-transplantation sjTREC and CD31 + RTE level had higher incidence of CMV viremia after AHSCT (p < 0.05). sjTREC/106 PBMCs was negatively correlated with aGVHD (p = 0.024). CONCLUSION: Thymic function was impaired before transplantation, and was consistently decreased in 3 months after AHSCT. Patients who had lower pre-transplantation sjTREC level were at high risk of aGVHD and CMV viremia after AHSCT, low pre-transplantation CD31 + RTE was correlated with CMV viremia after AHSCT.

Efficacy and safety of posaconazole in hematopoietic stem cell transplantation patients with invasive fungal disease.

AIM: Invasive fungal disease (IFD) is a significant cause of morbidity and mortality in hematopoietic stem cell transplantation (HSCT) patients. This study reports real-world efficacy and safety of posaconazole (POS) in HSCT recipients with IFD. PATIENTS & METHODS: We performed a retrospective study to investigate the efficacy and safety of POS oral suspension in 45 HSCT patients with IFD from December 2013 to December 2016. RESULTS: The success rate at 12 weeks after POS treatment was 57.8%. Multivariate logistic regression analysis showed that persistent neutropenia, severe graft-versus-host disease, high-dose steroid and cytomegalovirus infection were independently associated with inferior responses to POS. POS caused some adverse effects of mild or moderate severity that were of short duration. CONCLUSION: This study provides encouraging data regarding the efficacy and safety of POS in HSCT recipients. Neutropenia, graft-versus-host disease, steroid use and cytomegalovirus infection are possibly associated with inferior responses to POS therapy.

[Influence of MicroRNA-382 on Biological Properties of Human Umbilical Cord-Derived Mesenchymal Stem Cells].

OBJECTIVE: To investigate the effect of microRNA-382 (miR-382) on the biological properties of human umbilical cord-derived mesenchymal stem cells (hUC-MSC). METHODS: The mimics and inhibitor of miR-382 were transfected into hUC-MSC with lipo2000. Inverted microscopy was used to observe the morphology change of hUC-MSC. The proliferation of hUC-MSC was detected by CCK-8. Oil red O and alizarin red staining were applied to assess the adipogenic and osteogenic differentiation of hUC-MSC. Cetylpyridinium chloride was used to the quantitative analysis of osteogenic differentiation. The expression of Runx2 and some cytokines were detected by RT-PCR. RESULTS: miR-382 did not influence the morphology, proliferation and adipogenic differentiation of hUC-MSC miR-382 inhibited the expression of Runx2, thus could inhibit the osteogenesis of hUC-MSC, being confirmed by alizarin red stain; miR-382 could influence the expression of key cytokines secreted from hUC-MSC, such as IL-6, IDO1, G-CSF, M-CSF, GM-CSF. CONCLUSION: miR-382 decreases the expression of Runx2 and inhibites the osteogenesis of hUC-MSC. In addition, it also affects the expression of some key cytokines secreted from hUC-MSC.