64 research outputs found

    Pharmacological Inhibition of Caspase and Calpain Proteases: A Novel Strategy to Enhance the Homing Responses of Cord Blood HSPCs during Expansion

    Get PDF
    Background: Expansion of hematopoietic stem/progenitor cells (HSPCs) is a well-known strategy employed to facilitate the transplantation outcome. We have previously shown that the prevention of apoptosis by the inhibition of cysteine proteases, caspase and calpain played an important role in the expansion and engraftment of cord blood (CB) derived HSPCs. We hypothesize that these protease inhibitors might have maneuvered the adhesive and migratory properties of the cells rendering them to be retained in the bone marrow for sustained engraftment. The current study was aimed to investigate the mechanism of the homing responses of CB cells during expansion. Methodology/Principal Findings: CB derived CD34 + cells were expanded using a combination of growth factors with and without Caspase inhibitor-zVADfmk or Calpain 1 inhibitor- zLLYfmk. The cells were analyzed for the expression of homingrelated molecules. In vitro adhesive/migratory interactions and actin polymerization dynamics of HSPCs were assessed. In vivo homing assays were carried out in NOD/SCID mice to corroborate these observations. We observed that the presence of zVADfmk or zLLYfmk (inhibitors) caused the functional up regulation of CXCR4, integrins, and adhesion molecules, reflecting in a higher migration and adhesive interactions in vitro. The enhanced actin polymerization and the RhoGTPase protein expression complemented these observations. Furthermore, in vivo experiments showed a significantly enhanced homing to the bone marrow of NOD/SCID mice

    Panax ginseng Modulates Cytokines in Bone Marrow Toxicity and Myelopoiesis: Ginsenoside Rg1 Partially Supports Myelopoiesis

    Get PDF
    In this study, we have demonstrated that Korean Panax ginseng (KG) significantly enhances myelopoiesis in vitro and reconstitutes bone marrow after 5-flurouracil-induced (5FU) myelosuppression in mice. KG promoted total white blood cell, lymphocyte, neutrophil and platelet counts and improved body weight, spleen weight, and thymus weight. The number of CFU-GM in bone marrow cells of mice and serum levels of IL-3 and GM-CSF were significantly improved after KG treatment. KG induced significant c-Kit, SCF and IL-1 mRNA expression in spleen. Moreover, treatment with KG led to marked improvements in 5FU-induced histopathological changes in bone marrow and spleen, and partial suppression of thymus damage. The levels of IL-3 and GM-CSF in cultured bone marrow cells after 24 h stimulation with KG were considerably increased. The mechanism underlying promotion of myelopoiesis by KG was assessed by monitoring gene expression at two time-points of 4 and 8 h. Treatment with Rg1 (0.5, 1 and 1.5 µmol) specifically enhanced c-Kit, IL-6 and TNF-α mRNA expression in cultured bone marrow cells. Our results collectively suggest that the anti-myelotoxicity activity and promotion of myelopoiesis by KG are mediated through cytokines. Moreover, the ginsenoside, Rg1, supports the role of KG in myelopoiesis to some extent

    Inhibitor of caspase-activated DNase expression enhances caspase-activated DNase expression and inhibits oxidative stress-induced chromosome breaks at the mixed lineage leukaemia gene in nasopharyngeal carcinoma cells

    Get PDF
    BACKGROUND: Nasopharyngeal carcinoma (NPC) is commonly found in Asia, especially among the Chinese ethnic group. Chromosome rearrangements are common among NPC patients. Although the mechanism underlying the chromosome rearrangements in NPC is unclear, various mechanisms including activation of caspase-activated DNase (CAD) were proposed to contribute to chromosome rearrangements in leukaemia. Activation of CAD can be initiated by multiple agents, including oxidative stress, which is well implicated in carcinogenesis. CAD is the main enzyme that causes DNA fragmentation during apoptosis, and CAD is also implicated in promoting cell differentiation. In view of the role of oxidative stress in carcinogenesis and CAD activation, and since CAD was suggested to contribute to chromosome rearrangement in leukaemia, we hypothesise that oxidative stress-induced CAD activation could be one of the mechanisms that leads to chromosome rearrangements in NPC. METHODS: SUNEI cells were treated with various concentrations of H(2)O(2) for different period of time to ensure that cells undergo H(2)O(2)-induced MLL gene cleavage. Transfections with hCAD, mCAD, mutant hCAD, or cotransfection with hCAD and mICAD, and cotransfection with mutant hCAD and mICAD were performed. Gene expression was confirmed by Western blotting and MLL gene cleavage was assessed by inverse polymerase chain reaction (IPCR). RESULTS: Treatment with H(2)O(2) clearly induces cleavages within the MLL gene which locates at 11q23, a common deletion site in NPC. In order to investigate the role of CAD, CAD was overexpressed in SUNE1 cells, but that did not result in significant changes in H(2)O(2)-induced MLL gene cleavage. This could be because CAD requires ICAD for proper folding. Indeed, by overexpressing ICAD alone or co-expressing ICAD with CAD, Western blotting showed that CAD was expressed. In addition, ICAD overexpression also suppressed H(2)O(2)-induced MLL gene cleavage, suggesting a possible role of CAD in initiating chromosome cleavage during oxidative stress. CONCLUSIONS: Oxidative stress mediated by H(2)O(2) induces cleavage of the MLL gene, most likely via the caspase-activated DNase, CAD, and CAD expression requires ICAD. Since the MLL gene is located at 11q23, a common deletion site in NPC, thus stress-induced CAD activation may represent one of the mechanisms leading to chromosome rearrangement in NPC

    Anti-neutrophil cytoplasmic antibody associated vasculitis following rituximab: Outcomes of 50 patients in a tertiary single centre

    No full text
    Introduction: Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is an uncommon condition with heterogeneous multisystem organ involvement and significant morbidity and mortality. This study aimed to characterize the clinical features and laboratory characteristics, including B cell depletion, the ability to reduce corticosteroid dosage, and outcomes, of patients with AAV following rituximab treatment. Methods: Retrospective clinical and laboratory data were collected from patients with AAV who visited our lupus unit, including 50 treated with rituximab. Numeric response variables (median and range) were collected, including age, follow-up duration, disease duration, and Birmingham Vasculitis Activity Score (version 3). Statistical analyses were conducted using the SPSS 25.0 software. Statistical significance was considered a p -value <.05. Results: Of the 50 patients, 40 (80%) had granulomatosis with polyangiitis, 30 (75%) achieved remission, and 10 (25%) had active disease. Fifteen patients (30%) had positive ANCA levels at their last ANCA level assessment follow-up. Thirty-seven patients (74%) had B cell depletion, and 30 (81.1%) were in remission. Their median immunoglobulin levels were 7.6 (2.7–21.2) g/L for IgG, 0.5 (0.07–1.71) g/L for IgM, and 1.83 (0.14–4.87) g/L for IgA. Forty-two patients (84%) were able to lower their steroid dose to <7.5 mg, with 36 (85.7%) in remission and six (14.3%) having active disease ( p = .003). Conclusion: Our data suggests that most patients experience clinical remission after rituximab maintenance treatment. Half the patients were in remission, with normal creatinine levels and inflammatory markers. In addition, our patients could reduce steroid use

    Thermal efficiency analysis of a nanofluid-based micro combined heat and power system using CNG and biogas

    Full text link
    In the present study, a micro combined heat and power (micro-CHP) system using compressed natural gas (CNG) and biogas fuels, was developed. The objective of this research study was to investigate the utilization of nanofluids as a working fluid to improve thermal performance of the micro-CHP system. Three different nanofluids based on the CNT, Al2O3, and SiO2 have been investigated. The nanofluids was used as the circulating fluid to recover the heating power from the micro-CHP system. Three different concentration of nanoparticles (25, 50 and 100 ppm) have been used. The efficiency of separated heat and power (SHP) system was 27.6% while using combined heat and power, the total efficiency increased up to 65.3%. The results showed that by using CNG gas thermal efficiency of micro-CHP improve compared to the biogas. The result of the present study showed that nanofluids enhances the thermal efficiency of the micro-CHP system. By using the Al2O3 nanofluid the efficiency of micro-CHP efficiency is 73%. While by using the SiO2 and CNTs nanofluids the efficiency of micro-CHP efficiency is 70% and 66.3% respectively. So, we can coclude that by using the Al2O3 nanofluid thermal performance of micro-CHP systems improves

    Electrodeposition of Lithium-Based Upconversion Nanoparticle Thin Films for Efficient Perovskite Solar Cells

    No full text
    In this work, high-quality lithium-based, LiYF4=Yb3+,Er3+ upconversion (UC) thin film was electrodeposited on fluorene-doped tin oxide (FTO) glass for solar cell applications. A complete perovskite solar cell (PSC) was fabricated on top of the FTO glass coated with UC thin film and named (UC-PSC device). The fabricated UC-PSC device demonstrated a higher power conversion efficiency (PCE) of 19.1%, an additional photocurrent, and a better fill factor (FF) of 76% in comparison to the pristine PSC device (PCE = ~16.57%; FF = 71%). Furthermore, the photovoltaic performance of the UC-PSC device was then tested under concentrated sunlight with a power conversion efficiency (PCE) of 24% without cooling system complexity. The reported results open the door toward efficient PSCs for renewable and green energy applications

    Lupus Nephritis Outcomes after Stopping Immunosuppression

    No full text
    Background/Objectives: Immunosuppression (IS) is a standard therapy for lupus nephritis (LN). Data on the outcomes of patients with LN after the discontinuation of immunosuppression remain uncertain. This study aimed to evaluate the outcomes and results of patients with lupus nephritis (LN) who ceased immunosuppressive (IS) therapy. Methods: Records were obtained on the clinical and laboratory features of LN patients who were treated at our Lupus Unit. They included median values and ranges for various numerical variables such as patient age, disease duration, and treatment duration. Categorical variables such as gender, LN class, IS treatment type, and patient outcomes, which were categorized as either “stable” or “flare experienced”, were presented as percentages and frequencies. A flare in LN was characterized by a two-fold increase in serum creatinine levels and a rise in proteinuria following the cessation of IS medication. Results: Outcomes were assessed for 45 patients with LN who ceased IS therapy after achieving remission. The patients’ median age was 55 years (29–78). The median duration of treatment was 4 years (0.5–14). The LN histology distribution was class V = 24.4%, class IV = 17.8 %, class III = 17.8%, class III + IV = 15.6%, class III + V = 6.7%, class IV + V = 2.2%, and class II + IV and II = 2.2%. At the discontinuation of IS treatment, creatinine levels were elevated in 9/45 (20%) patients. Furthermore, 28.9% of patients relapsed after IS treatment discontinuation. Patients with anti-Smith antibodies (anti-Sm) were observed to have a higher occurrence of relapses, with six patients experiencing flare compared to four patients who remained stable (p = 0.03). Five (38.5%) of the patients with flares had high creatinine levels after IS discontinuation. Conclusions: Most of our patients maintained clinical remission and stable levels of LN parameters after IS treatment discontinuation. Those with a high serum creatinine level, ongoing proteinuria, depleted complement levels, and the presence of anti-Sm antibodies were more likely to experience flares after the discontinuation of IS therapy
    corecore