SARS-CoV-2 infection aggravates cigarette smoke-exposed cell damage in primary human airway epithelia.

BACKGROUND: The coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has become a worldwide pandemic with over 627 million cases and over 6.5 million deaths. It was reported that smoking-related chronic obstructive pulmonary disease (COPD) might be a crucial risk for COVID-19 patients to develop severe condition. As cigarette smoke (CS) is the major risk factor for COPD, we hypothesize that barrier dysfunction and an altered cytokine response in CS-exposed airway epithelial cells may contribute to increased SARS-CoV-2-induced immune response that may result in increased susceptibility to severe disease. The aim of this study was to evaluate the role of CS on SARS-CoV-2-induced immune and inflammatory responses, and epithelial barrier integrity leading to airway epithelial damage. METHODS: Primary human airway epithelial cells were differentiated under air-liquid interface culture. Cells were then exposed to cigarette smoke medium (CSM) before infection with SARS-CoV-2 isolated from a local patient. The infection susceptibility, morphology, and the expression of genes related to host immune response, airway inflammation and damages were evaluated. RESULTS: Cells pre-treated with CSM significantly caused higher replication of SARS-CoV-2 and more severe SARS-CoV-2-induced cellular morphological alteration. CSM exposure caused significant upregulation of long form angiotensin converting enzyme (ACE)2, a functional receptor for SARS-CoV-2 viral entry, transmembrane serine protease (TMPRSS)2 and TMPRSS4, which cleave the spike protein of SARS-CoV-2 to allow viral entry, leading to an aggravated immune response via inhibition of type I interferon pathway. In addition, CSM worsened SARS-CoV-2-induced airway epithelial cell damage, resulting in severe motile ciliary disorder, junctional disruption and mucus hypersecretion. CONCLUSION: Smoking led to dysregulation of host immune response and cell damage as seen in SARS-CoV-2-infected primary human airway epithelia. These findings may contribute to increased disease susceptibility with severe condition and provide a better understanding of the pathogenesis of SARS-CoV-2 infection in smokers.

ORMDL3 regulates cigarette smoke-induced endoplasmic reticulum stress in airway smooth muscle cells.

BACKGROUND: Orosomucoid 1-like protein 3 (ORMDL3), a transmembrane protein localized in the endoplasmic reticulum (ER), has been genetically associated with chronic obstructive pulmonary disease (COPD), in addition to childhood-onset asthma. However, the functional role of ORMDL3 in the pathogenesis of COPD is still unknown. OBJECTIVE: Because cigarette smoke is the major risk factor for COPD, we aimed to investigate the role of ORMDL3 in cigarette smoke-induced human airway smooth muscle cell (HASMC) injury. METHODS: The mRNA and protein expression of ORMDL3 was examined in HASMCs from nonsmokers and smokers without or with COPD. Knockdown of ORMDL3 in primary healthy HASMCs was performed using small interfering RNA before exposure to cigarette smoke medium (CSM) for 24 hours. Inflammatory, proliferative/apoptotic, ER stress, and mitochondrial markers were evaluated. RESULTS: Elevation of ORMDL3 mRNA and protein expression was observed in HASMCs of smokers without or with COPD. CSM caused significant upregulation of ORMDL3 expression in healthy nonsmokers. ORMDL3 knockdown regulated CSM-induced inflammation, cell proliferation, and apoptosis. Silencing ORMDL3 led to reduction of CSM-induced ER stress via inhibition of unfolded protein response pathways such as activating transcription factor 6 and protein kinase RNA-like ER kinase. ORMDL3 was also involved in CSM-induced mitochondrial dysfunction via the mitochondrial fission process. CONCLUSIONS: We report the induction of ORMDL3 in HASMCs after cigarette smoke exposure. ORMDL3 may mediate cigarette smoke-induced activation of unfolded protein response pathways during airway smooth muscle cell injury.

Clinical risk score for predicting invasive fungal disease after allogeneic hematopoietic stem cell transplantation: Analysis of the China Assessment of Antifungal Therapy in Hematological Diseases (CAESAR) study.

BACKGROUND AND OBJECTIVE: Invasive fungal disease (IFD) is associated with a high mortality for patients with hematological malignancies undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT). This study aimed not only to develop a proven/probable IFD risk-scoring model but to identify high-risk populations that would benefit from anti-fungal prophylaxis. METHODS: Data from the China Assessment of Antifungal Therapy in Hematological Diseases (CAESAR) study were retrieved, and all patients (n = 1053) undergoing allo-HSCT were randomly divided into the training set (n = 685) for model development and the validation set (n = 368) for model verification. A weighted risk score for proven or probable IFD was established through multivariate logistic regression analysis. RESULTS: The study population had a mean age of 28.95 years and the majority underwent myeloablative transplantation in complete remission 1 (53.4%). Five risk factors of IFD were identified, namely neutropenia lasting longer than 14 days, corticosteroid use, diabetes, haploidentical donor, and unrelated donor. Based on the risk score for IFD, the patients were categorized into three groups: low risk (score 0-4, 1.5%-4.0%), intermediate risk (score 5-8, 9.8%), and high risk (score>8, 24.7%-14.0%). Anti-fungal prophylaxis may provide benefits for patients with intermediate (8.5% vs. 18.5%, P = .0085) or high risk (19.4% vs. 30.8%, P = .4651) but not low risk (2.1% vs. 3.8%, P = .6136) of IFD. CONCLUSION: A practical weighted risk score for IFD in patients receiving allo-HSCT was established, which can aid decision-making regarding the administration of anti-fungal prophylaxis.

Current Treatment Patterns of Aplastic Anemia in China: A Prospective Cohort Registry Study.

Aplastic anemia (AA) is a hematologic disease characterized by pancytopenia and hypocellular bone marrow, potentially leading to chronic anemia, hemorrhage, and infection. The China Aplastic Anemia Committee and British Committee for Standards in Haematology guidelines recommend hematopoietic stem-cell transplantation (HSCT) or immunosuppressive therapy (IST) comprising antithymocyte globulin (ATG) with cyclosporine (CsA) as initial treatment for AA patients. With limited epidemiological data on the clinical management of AA in Asia, a prospective cohort registry study involving 22 AA treatment centers in China was conducted to describe the disease characteristics of newly diagnosed AA patients and investigate real-world treatment patterns and patient outcomes. Of 340 AA patients, 72.9, 12.6, and 3.5% were receiving IST, traditional Chinese medicine, and HSCT, respectively, at baseline; only 22.2% of IST-treated patients received guideline-recommended ATG with CsA initially. Almost all patients received supportive care (95.6%) as blood transfusion (97.8%), antibiotics (63.7%), and/or hematopoietic growth factors (58.2%). Overall, 64.8% achieved a partial or complete response, and 0.9% experienced relapse. No new safety concerns were identified; serious adverse events were largely unrelated to the treatment regimen. These results demonstrate the need to identify and minimize treatment barriers to standardize and align AA management in China with treatment guideline recommendations and further improve patient outcomes.

Plerixafor and granulocyte-colony-stimulating factor for mobilization of hematopoietic stem cells for autologous transplantation in Chinese patients with non-Hodgkin's lymphoma: a randomized Phase 3 study.

BACKGROUND: This Phase 3 randomized, double-blind study evaluated the efficacy and safety of plerixafor plus granulocyte-colony-stimulating factor for the mobilization of hematopoietic stem cells in Chinese patients with non-Hodgkin's lymphoma. STUDY DESIGN AND METHODS: Adults (ages 18-75 years) with non-Hodgkin's lymphoma in first or second complete or partial remission, without previous hematopoietic stem cell mobilization or autologous transplant, were included. Patients received granulocyte-colony-stimulating factor 10 µg/kg/day from Days 1 through 4 before they were randomized (1:1) to receive either plerixafor 0.24 mg/kg/day or placebo subcutaneously on Days 4 through 7 plus continued granulocyte-colony-stimulating factor on Days 5 through 8. Apheresis began on Day 5 and continued for no more than 4 days. The primary endpoint was collection of 5 × 106 CD34+ cells/kg or greater over no more than 4 days of apheresis. Other endpoints included the collection of 2 × 106 CD34+ cells/kg or greater and safety. RESULTS: Overall, 101 patients were enrolled, and 50 were randomized to each group. More patients in the plerixafor group achieved 5 × 106 CD34+ cells/kg or greater (62 vs. 20%; p < 0.0001) or 2 × 106 CD34+ cells/kg or greater (88 vs. 66%) and underwent transplantation (88 vs. 68%) compared with those in the placebo group. The most common plerixafor-related adverse events were nausea (7.8%) and diarrhea (3.9%). CONCLUSION: Plerixafor plus granulocyte-colony-stimulating factor is superior to placebo plus granulocyte-colony-stimulating factor for the mobilization of CD34+ cells for autologous transplantation and is generally well tolerated in Chinese patients with non-Hodgkin's lymphoma.

Recent advance on genome editing for therapy of ß-hemoglobinopathies.

ß-hemoglobinopathies are one of six groups of common illnesses affecting human health. Although the genetic mechanisms have been elucidated for several decades, curable treatment options, other than allogeneic bone marrow transplantation, are still lacking. In recent years, rapid development in genome editing technologies and their clinical applications have opened up new directions for treatment of ß-hemoglobinopathies. Genome editing technologies, as applied in autologous CD34 + hematopoietic stem and progenitor cells, represents a promising remedial means for the ß-globin disorders. Hemoglobin gene mutations could be corrected with homologous recombination-mediated DNA repair pathway to repair the genetic defects, while the nonhomologous end-joining pathway may be used to silence the key repressor of fetal globin expression and reactivate fetal hemoglobin expression, thereby alleviating the clinical symptoms of ß-hemoglobinopathies in patients. This review summarizes the recent advances on genome editing of ß-hemoglobinopathies from the bench design to the establishment of clinical translational platforms, thereby providing critical insights and references on the application of genome editing technologies for the development of therapeutic strategies for ß-hemoglobinopathies.

iPSC-derived mesenchymal stem cells exert SCF-dependent recovery of cigarette smoke-induced apoptosis/proliferation imbalance in airway cells.

Mesenchymal stem cells (MSCs) have emerged as a potential cell-based therapy for pulmonary emphysema in animal models. Our previous study demonstrated that human induced pluripotent stem cell-derived MSCs (iPSC-MSCs) were superior over bone marrow-derived MSCs (BM-MSCs) in attenuating cigarette smoke (CS)-induced airspace enlargement possibly through mitochondrial transfer. This study further investigated the effects of iPSC-MSCs on inflammation, apoptosis, and proliferation in a CS-exposed rat model and examined the effects of the secreted paracrine factor from MSCs as another possible mechanism in an in vitro model of bronchial epithelial cells. Rats were exposed to 4% CS for 1 hr daily for 56 days. At days 29 and 43, human iPSC-MSCs or BM-MSCs were administered intravenously. We observed significant attenuation of CS-induced elevation of circulating 8-isoprostane and cytokine-induced neutrophil chemoattractant-1 after iPSC-MSC treatment. In line, a superior capacity of iPSC-MSCs was also observed in ameliorating CS-induced infiltration of macrophages and neutrophils and apoptosis/proliferation imbalance in lung sections over BM-MSCs. In support, the conditioned medium (CdM) from iPSC-MSCs ameliorated CS medium-induced apoptosis/proliferation imbalance of bronchial epithelial cells in vitro. Conditioned medium from iPSC-MSCs contained higher level of stem cell factor (SCF) than that from BM-MSCs. Deprivation of SCF from iPSC-MSC-derived CdM led to a reduction in anti-apoptotic and pro-proliferative capacity. Taken together, our data suggest that iPSC-MSCs may possess anti-apoptotic/pro-proliferative capacity in the in vivo and in vitro models of CS-induced airway cell injury partly through paracrine secretion of SCF.

The long-term outcome of reduced-intensity allogeneic stem cell transplantation from a matched related or unrelated donor, or haploidentical family donor in patients with leukemia: a retrospective analysis of data from the China RIC Cooperative Group.

This study compared 6-year follow-up data from patients undergoing reduced-intensity conditioning (RIC) transplantation with an HLA-matched related donor (MRD), an HLA-matched unrelated donor (MUD), or an HLA-haploidentical donor (HID) for leukemia. Four hundred and twenty-seven patients from the China RIC Cooperative Group were enrolled, including 301 in the MRD, 79 in the HID, and 47 in the MUD groups. The conditioning regimen involved fludarabine combined with anti-lymphocyte globulin and cyclophosphamide. Graft-versus-host disease (GVHD) prophylaxis was administered using cyclosporin A (CsA) and mycophenolate mofetil (MMF). Four hundred and nineteen patients achieved stable donor chimerism. The incidence of stage II-IV acute GVHD in the HID group was 44.3 %, significantly higher than that in the MRD (23.6 %) and MUD (19.1 %) groups. The 1-year transplantation-related mortality (TRM) rates were 44.3, 17.6, and 21.3, respectively. Event-free survival (EFS) at 6 years in the HID group was 36.7 %, significantly lower than that of the MRD and MUD groups (59.1 and 66.0 %, P < 0.001 and P = 0.001, respectively). For advanced leukemia, the relapse rate of the HID group was 18.5 %, lower than that of the MRD group (37.5 %, P = 0.05), but the EFS at 6 years was 31.7 and 30.4 % (P > 0.05), respectively. RIC transplantation with MRD and MUD had similar outcome in leukemia which is better than that with HID. RIC transplantation with HID had lower relapsed with higher TRM and GVHD rate, particularly in advanced leukemias. RIC transplantation with MRD and MUD had similar outcomes in leukemia and they were better than those with HID. RIC transplantation with HID had a lower relapse rate but higher TRM and GVHD rates, particularly in cases of advanced leukemia.

Hyperglycemia-induced PATZ1 negatively modulates endothelial vasculogenesis via repression of FABP4 signaling.

Vascular endothelial dysfunction, a central hallmark of diabetes, predisposes diabetic patients to numerous cardiovascular complications. The POZ/BTB and AT-hook-containing zinc finger protein 1 (PATZ1), is an important transcriptional regulatory factor and regulates divergent pathways depending on the cellular context, but its role in endothelial cells remains poorly understood. Herein, we report for the first time that endothelial PATZ1 expression was abnormally upregulated in diabetic endothelial cells (ECs) regardless of diabetes classification. This stimulatory effect was further confirmed in the high glucose-treated human umbilical vein endothelial cells (HUVECs). From a functional standpoint, transgenic overexpression of PATZ1 in endothelial colony forming cells (ECFCs) blunted angiogenesis in vivo and rendered endothelial cells unresponsive to established angiogenic factors. Mechanistically, PATZ1 acted as a potent transcriptional corepressor of fatty acid-binding protein 4 (FABP4), an essential convergence point for angiogenic and metabolic signaling pathways in ECs. Taken together, endothelial PATZ1 thus potently inhibits endothelial function and angiogenesis via inhibition of FABP4 expression, and abnormal induction of endothelial PATZ1 may contribute to multiple aspects of vascular dysfunction in diabetes.

Endothelium-targeted human Delta-like 1 enhances the regeneration and homing of human cord blood stem and progenitor cells.

BACKGROUND: Umbilical cord blood (UCB) is becoming an alternative cell source for hematopoietic stem cell transplantation (HSCT). However, umbilical cord blood transplantation (UCBT) has been severely limited by low and finite numbers of hematopoietic stem cells and their delayed engraftment. New strategies are needed to improve ex vivo expansion efficiency and in vivo haematopoietic recovery. METHODS: We produced an endothelium-targeted soluble Notch ligand, the Delta-Serrate-Lag-2 (DSL) domain of human Delta-like 1 fused with a RGD motif (hD1R), and tested the effects of this protein on human umbilical cord blood hematopoietic stem and progenitor cell (UCB-HSPC) ex vivo and in vivo. RESULTS: hD1R-mediated ex vivo expansion system was able to significantly increase the absolute number of UCB-HSPCs. The hD1R-expanded cells had the enhanced homing and maintained long-term hematopoietic stem cell repopulation capacity in the bone marrow of immunodeficient nonobese diabetic-severe combined immunodeficient (NOD/SCID) mice. Moreover, systemic administration of hD1R promoted the in vivo regeneration of donor cells in recipient mice and accelerated hematopoietic recovery, particularly in settings wherein the HSPCs dose was limiting. CONCLUSIONS: Our results indicated that hD1R might be applied in improving hematopoietic recovery and HSC engraftment in human UCBT.

Rituximab plus chemotherapy as first-line treatment in Chinese patients with diffuse large B-cell lymphoma in routine practice: a prospective, multicentre, non-interventional study.

BACKGROUND: The efficacy and safety of rituximab-based chemotherapy (R-chemo), the standard regimen for patients with diffuse large B-cell lymphoma (DLBCL), which is more common in Asia than in Western countries, are well confirmed in randomized controlled trials (RCTs). However, the safety and effectiveness of R-chemo in patients who are largely excluded from RCTs have not been well characterized. This real-world study investigated the safety and effectiveness of R-chemo as first-line treatment in Chinese patients with DLBCL. METHODS: Treatment-naive DLBCL patients who were CD20 positive and eligible to receive R-chemo were enrolled with no specific exclusion criteria. Data collected at baseline included age, gender, disease stage, international prognostic index (IPI), B symptoms, extranodal involvement, performance status, and medical history. In the present study, data on safety, treatment effectiveness, and HBV infection management were collected 120 days after the last R-chemo administration. RESULTS: Overall, R-chemo was well tolerated. The safety profile of R-chemo in patients with a history of heart or liver disease was well described without any additional unexpected safety concerns. The overall response rate (ORR) in the Chinese patients from this study was 94.2 % (complete response [CR], 55.0 %; CR unconfirmed [CRu] 18.2 %; and partial response [PR], 20.9 %). Compared to patients with no history of disease, the CR and PR rates of patients with a history of heart or liver disease were lower and higher, respectively; this tendency could be in part explained by treatment interruptions in patients with heart or liver diseases. HBsAg positivity and a maximum tumor diameter of ≥7.5 cm negatively correlated with CR + CRu, whereas age and HBsAg positivity negatively correlated with CR. CONCLUSIONS: This study further validated the safety and effectiveness of R-chemo in Chinese patients with DLBCL. Patients with a history of heart or liver disease may further benefit from R-chemo if preventive measures are taken to reduce hepatic and cardiovascular toxicity. In addition to IPI and tumor diameter, HBsAg positivity could also be a poor prognostic factor for CR in Chinese patients with DLBCL. TRIAL REGISTRATION: ClinicalTrials.gov # NCT01340443 , April 20, 2011.

Invasive fungal infection in patients receiving chemotherapy for hematological malignancy: a multicenter, prospective, observational study in China.

This stud y examined the epidemiology, risk factors, management, and outcome of invasive fungal infection (IFI) in patients receiving chemotherapy for hematological malignancy in China. IFI risk factors were analyzed using univariate analysis and multivariate logistic regression. In total, 4,192 patients receiving 4,889 chemotherapy courses were enrolled [mean age 40.7 years, 58.4% male, 16.9% children (<18 years)]. The most common hematological diseases were acute myeloid leukemia (AML, 28.5%), non-Hodgkin lymphoma (NHL, 26.3%), and acute lymphoblastic leukemia (ALL, 20.2%). Severe neutropenia (absolute neutrophil count [ANC] <500/mm(3)) occurred after one third (1,633/4,889, 33.4%) of chemotherapy courses. Incidence of proven/probable IFI was 2.1% per chemotherapy course and higher in patients with myelodysplastic syndrome (MDS, 4.94%), acute hyperleukocytic leukemia (AHL, 4.76%), AML (3.83%), or induction chemotherapy. Risk factors included ANC <500/mm(3) [odds ratio (OR) 3.60], AML or MDS (OR 1.97), induction chemotherapy (OR 2.58), previous IFI (OR 3.08), and being male (OR 1.74). Antifungal agents, prescribed in one quarter (1,211/4,889, 24.8%) of chemotherapy courses, included primary/secondary prophylaxis (n = 827, 16.9%) and/or treatment (n = 655, 13.4%; 86.9 % triazoles), which was empirical (84.3%), pre-emptive (8.6%), or targeted (7.1%). Overall mortality following each chemotherapy course (1.5%) increased in proven/probable (11.7%) and possible IFI (8.2%). In summary, IFI was more common in MDS, AHL, AML, or induction chemotherapy, and substantially increased mortality. Neutropenic patients receiving induction chemotherapy for AML or MDS and those with previous IFI were at particular risk. Antifungal prophylaxis showed an independent protective effect but was not commonly used, even in high-risk patients. By contrast, empiric antifungals were widely used.

Mitochondrial transfer of induced pluripotent stem cell-derived mesenchymal stem cells to airway epithelial cells attenuates cigarette smoke-induced damage.

Transplantation of mesenchymal stem cells (MSCs) holds great promise in the repair of cigarette smoke (CS)-induced lung damage in chronic obstructive pulmonary disease (COPD). Because CS leads to mitochondrial dysfunction, we aimed to investigate the potential benefit of mitochondrial transfer from human-induced pluripotent stem cell-derived MSCs (iPSC-MSCs) to CS-exposed airway epithelial cells in vitro and in vivo. Rats were exposed to 4% CS for 1 hour daily for 56 days. At Days 29 and, human iPSC-MSCs or adult bone marrow-derived MSCs (BM-MSCs) were administered intravenously to CS-exposed rats. CS-exposed rats exhibited severe alveolar destruction with a higher mean linear intercept (Lm) than sham air-exposed rats (P < 0.001) that was attenuated in the presence of iPSC-MSCs or BM-MSCs (P < 0.01). The attenuation of Lm value and the severity of fibrosis was greater in the iPSC-MSC-treated group than in the BM-MSC-treated group (P < 0.05). This might have contributed to the novel observation of mitochondrial transfer from MSCs to rat airway epithelial cells in lung sections exposed to CS. In vitro studies further revealed that transfer of mitochondria from iPSC-MSCs to bronchial epithelial cells (BEAS-2B) was more effective than from BM-MSCs, with preservation of adenosine triphosphate contents. This distinct mitochondrial transfer occurred via the formation of tunneling nanotubes. Inhibition of tunneling nanotube formation blocked mitochondrial transfer. Our findings indicate a higher mitochondrial transfer capacity of iPSC-MSCs than BM-MSCs to rescue CS-induced mitochondrial damage. iPSC-MSCs may thus hold promise for the development of cell therapy in COPD.

FHL1C induces apoptosis in Notch1-dependent T-ALL cells through an interaction with RBP-J.

BACKGROUND: Aberrantly activated Notch signaling has been found in more than 50% of patients with T-cell acute lymphoblastic leukemia (T-ALL). Current strategies that employ γ-secretase inhibitors (GSIs) to target Notch activation have not been successful. Many limitations, such as non-Notch specificity, dose-limiting gastrointestinal toxicity and GSI resistance, have prompted an urgent need for more effective Notch signaling inhibitors for T-ALL treatment. Human four-and-a-half LIM domain protein 1C (FHL1C) (KyoT2 in mice) has been demonstrated to suppress Notch activation in vitro, suggesting that FHL1C may be new candidate target in T-ALL therapy. However, the role of FHL1C in T-ALL cells remained unclear. METHODS: Using RT-PCR, we amplified full-length human FHL1C, and constructed full-length and various truncated forms of FHL1C. Using cell transfection, flow cytometry, transmission electron microscope, real-time RT-PCR, and Western blotting, we found that overexpression of FHL1C induced apoptosis of Jurkat cells. By using a reporter assay and Annexin-V staining, the minimal functional sequence of FHL1C inhibiting RBP-J-mediated Notch transactivation and inducing cell apoptosis was identified. Using real-time PCR and Western blotting, we explored the possible molecular mechanism of FHL1C-induced apoptosis. All data were statistically analyzed with the SPSS version 12.0 software. RESULTS: In Jurkat cells derived from a Notch1-associated T-ALL cell line insensitive to GSI treatment, we observed that overexpression of FHL1C, which is down-regulated in T-ALL patients, strongly induced apoptosis. Furthermore, we verified that FHL1C-induced apoptosis depended on the RBP-J-binding motif at the C-terminus of FHL1C. Using various truncated forms of FHL1C, we found that the RBP-J-binding motif of FHL1C had almost the same effect as full-length FHL1C on the induction of apoptosis, suggesting that the minimal functional sequence in the RBP-J-binding motif of FHL1C might be a new drug candidate for T-ALL treatment. We also explored the molecular mechanism of FHL1C overexpression-induced apoptosis, which suppressed downstream target genes such as Hes1 and c-Myc and key signaling pathways such as PI3K/AKT and NF-κB of Notch signaling involved in T-ALL progression. CONCLUSIONS: Our study has revealed that FHL1C overexpression induces Jurkat cell apoptosis. This finding may provide new insights in designing new Notch inhibitors based on FHL1C to treat T-ALL.

Deletion of RBP-J in dendritic cells compromises TLR-mediated DC activation accompanied by abnormal cytoskeleton reorganization.

Dendritic cells (DCs) are professional antigen presenting cells that activate and modulate immune responses, but the mechanisms underlying DC activation have not been fully understood. In this study, we investigated the role of Notch signaling in DC activation by using murine bone marrow-derived DCs. Triggering of Toll-like receptors (TLRs) of DCs led to upregulated expression of Notch ligands. Disruption of Notch signaling by the deletion of RBP-J, the critical transcription factor mediating the canonical signaling from all Notch receptors, resulted in a reduced capacity of DCs in activating T cells. Moreover, RBP-J deficiency altered the polarization of T cell activation, as manifested by downregulated interferon-γ and upregulated interleukin-4 and -10 expressions after LPS or Poly(I:C) stimulation. Furthermore, we found that RBP-J(-/-) DCs had reduced intracellular calcium after TLR-triggering. Immunofluorescent staining showed that RBP-J deficient DCs exhibited attenuated cytoskeleton reorganization when contacting T cells. In summary, our results suggested that the canonical Notch signaling promotes the cytoskeleton reorganization and the TLR-mediated DC activation.

Interactions of Inhaled Liposome with Macrophages and Neutrophils Determine Particle Biofate and Anti-Inflammatory Effect in Acute Lung Inflammation.

Since most current studies have focused on exploring how phagocyte internalization of drug-loaded nanovesicles by macrophages would affect the function and therapeutic effects of infiltrated neutrophils or monocytes, research has evaluated the specificity of the inhaled nanovesicles for targeting various phagocytes subpopulations. In this study, liposomes with various charges (including neutral (L1), anionic (L2), and cationic at inflammatory sites (L3)) were constructed to investigate how particle charge determined their interactions with key phagocytes (including macrophages and neutrophils) in acute lung injury (ALI) models and to establish correlations with their biofate and overall anti-inflammatory effect. Our results clearly indicated that neutrophils were capable of rapidly sequestering L3 with a 3.2-fold increase in the cellular liposome distribution, compared to that in AMs, while 70.5% of L2 were preferentially uptaken by alveolar macrophages (AMs). Furthermore, both AMs and the infiltrated neutrophils performed as the potential vesicles for the inhaled liposomes to prolong their lung retention in ALI models, whereas AMs function as sweepers to recognize and process liposomes in the healthy lung. Finally, inhaled roflumilast-loaded macrophage or neutrophil preferential liposomes (L2 or L3) exhibited optimal anti-inflammatory effect because of the decreased AMs phagocytic capacity or the prolonged circulation times of neutrophils. Such findings will be beneficial in exploiting a potential pathway to specifically manipulate lung phagocyte functions in lung inflammatory diseases where these cells play crucial roles.

The effects of intermittent hypoxia on hepatic expression of fatty acid translocase CD36 in lean and diet-induced obese mice.

BACKGROUND: Both obstructive sleep apnea (OSA) and non-alcoholic fatty liver disease (NAFLD) are prevalent within obese individuals. We aimed to investigate the effects of intermittent hypoxia (IH), a clinical feature of OSA, on hepatic expression of fatty acid translocase (CD36) in relation to liver injury in lean and diet-induced obese mice. METHODS: Four-week-old male C57BL/6J mice were randomized to standard diet (SD) or high fat (HF) diet groups. At 13-week-old, all mice were exposed to either air or IH (IH30; thirty hypoxic episodes per hour) for four weeks. We assessed liver injury through lipid profile, oxidative and inflammatory stress, histological scoring and hepatic CD36 expression. RESULTS: In lean mice, IH elevated serum and hepatic triglyceride and free fatty acid (FFA) levels, in line with upregulation of hepatic CD36 expression and myeloperoxidase (MPO)-positive cells in support of inflammatory infiltrates along with increase in serum malondialdehyde (MDA), C-X-C motif chemokine ligand 1(CXCL-1) and monocyte chemoattractant protein-1 (MCP-1). In diet-induced obese mice, an increase in hepatic alanine transaminase (ALT) activity, serum and hepatic levels of lipid parameters and inflammatory markers, serum MDA level, hepatic expressions of CD36 and α-smooth muscle actin (α-SMA), and MPO-positive cells was observed. IH potentiated hepatic ALT activity, serum CXCL-1 and hepatic interleukin-6 (IL-6), in line with inflammatory infiltrates, but paradoxically, reduced hepatic FFA level and hepatic CD36 expression, compared to obese mice without IH exposure. However, IH further augmented diet-induced liver steatosis and fibrosis as shown by histological scores. CONCLUSION: This study contributes to support that IH featuring OSA may lead to liver injury via differential regulation of hepatic CD36 expression in lean and diet-induced obese mice.

PD-L1 expression levels in mesenchymal stromal cells predict their therapeutic values for autoimmune hepatitis.

BACKGROUND: Autoimmune hepatitis is a chronic inflammatory hepatic disorder with no effective treatment. Mesenchymal stromal cells (MSCs) have emerged as a promising treatment owing to their unique advantages. However, their heterogeneity is hampering use in clinical applications. METHODS: Wharton's jelly derived MSCs (WJ-MSCs) were isolated from 58 human donors using current good manufacturing practice conditions. Gene expression profiles of the WJ-MSCs were analyzed by transcriptome and single-cell RNA-sequencing (scRNA-seq), and subsequent functional differences were assessed. Expression levels of programmed death-ligand 1 (PD-L1) were used as an indicator to screen WJ-MSCs with varied immunomodulation activities and assessed their corresponding therapeutic effects in a mouse model of concanavalin A-induced autoimmune hepatitis. RESULTS: The 58 different donor-derived WJ-MSCs were grouped into six gene expression profile clusters. The gene in different clusters displayed obvious variations in cell proliferation, differentiation bias, trophic factor secretion, and immunoregulation. Data of scRNA-seq revealed four distinct WJ-MSCs subpopulations. Notably, the different immunosuppression capacities of WJ-MSCs were positively correlated with PD-L1 expression. WJ-MSCs with high expression of PD-L1 were therapeutically superior to WJ-MSCs with low PD-L1 expression in treating autoimmune hepatitis. CONCLUSION: PD-L1 expression levels of WJ-MSCs could be regarded as an indicator to choose optimal MSCs for treating autoimmune disease. These findings provided novel insights into the quality control of MSCs and will inform improvements in the therapeutic benefits of MSCs.

Myc induced miR-144/451 contributes to the acquired imatinib resistance in chronic myelogenous leukemia cell K562.

Imatinib resistance remains the big hurdle for CML therapy. Previous study reveals that c-myc is important for bcr-abl CML cell proliferation, while its role in imatinib resistance is largely unknown. In this study, we first found that c-myc expression is upregulated in imatinib resistant K562R cells, which in turn enhances the expression of miR-144/451. Knockdown of c-myc or restoration of miR-144/451 in the K562R cells sensitizes K562R cells to imatinib therapy. Our study here reveals an regulatory pathway between myc and miR-144/451 and highlights that targeting either myc or miR-144/451 might be valuable for eliminating the imatinib resistant CML cells.