Functional Characteristics and Application of Mesenchymal Stem Cells in Systemic Lupus Erythematosus.

Systemic lupus erythematosus (SLE) is a rare, heterogeneous autoimmune and autoinflammatory disease that affects both sexes and all races, although this disease exhibits its highest incidence/prevalence among the black population and shows a predilection for women of reproductive age. Although SLE has no cure, treatment can help decrease its signs and symptoms. Thus, we should focus primarily on personalized treatment. Mesenchymal stem/stromal cells (MSCs), which are multipotent cells capable of differentiating into osteoblasts, chondrocytes, adipocytes, and myoblasts, among other cell types, are potential candidates for use in a promising strategy to treat severe and refractory SLE. MSCs have an immunomodulatory function that can suppress the proliferation and activities of many immune cells, such as T lymphocytes, B lymphocytes, natural killer cells, macrophages and dendritic cells. Substantial progress has recently been made in MSC therapy, and experimental and clinical data suggest that such a therapy is a promising strategy for the treatment of severe and refractory SLE. In this review, we highlight the effects of MSCs on different immune cell types, describe the mechanisms underlying MSC-mediated immunoregulation, and discuss the treatment of SLE with MSCs from different sources in various animal models and clinical applications.

Metabolic engineering of Yarrowia lipolytica for improving squalene production.

The aim of this present research is to enhance the squalene production in Yarrowia lipolytica using pathway engineering and bioprocess engineering. Firstly, to improve the production of squalene, the endogenous HMG-CoA reductase (HMG1) was overexpressed in Y. lipolytica to yield 208.88 mg/L squalene. Secondly, the HMG1 and diacylglycerol acyltranferase (DGA1) were co-overexpressed, the derived recombinant Y. lipolytica SQ-1 strain produced 439.14 mg/L of squalene. Thirdly, by optimizing the fermentation medium, the improved titer of squalene with 514.34 mg/L was obtained by the engineered strain SQ-1 grown on YPD-80 medium. Finally, by optimizing the addition concentrations of acetate, citrate and terbinafine, the 731.18 mg/L squalene was produced in the engineered strain SQ-1 with the addition of 0.5 mg/L terbinafine. This work describes the highest reported squalene titer in Y. lipolytica to date. This study will provide the foundation for further engineering Y. lipolytica capable of cost-efficiently producing squalene.

Abnormal thymic B cell activation and impaired T cell differentiation in pristane-induced lupus mice.

Changes in the thymus and potential mechanisms underlying the pathogenesis in pristane-induced lupus (PIL) mice are poorly understood. This study aimed to systematically and specifically examine changes in the thymus and the potential mechanisms responsible for immunological abnormalities in PIL mice. The results showed that PIL mice exhibit serious thymic hyperplasia, an elevated thymus index, a damaged histopathological structure and increased thymocyte apoptosis. We found that thymic T cell differentiation was impaired as the CD4+ CD8+ double-positive (DP) thymocyte frequency significantly decreased, becoming almost absent at 28 weeks after induction, while CD4 CD8- double-negative (DN) thymocytes and CD4+ CD8- single-positive (CD4+ SP) and CD4 CD8+ single-positive (CD8+ SP) cells were increased. This phenomenon might be explained by an inhibition of the DN-to-DP-cell transition and stimulation of DP cell conversion into CD4+ /CD8+ SP thymocytes. Moreover, we discovered a dramatic and abnormal increase in thymic B cells, that was associated with CD19, Irf8, Ebf1, Pax5, Irf4, Blk, CXCL13, CXCR5, CD79a, CD79b, Lyn, Syk, Btk, and BLNK gene accumulation, which exhibited positive interactions. We further verified that the mRNA expression of these genes was significantly upregulated and consistent with the RNA-seq results. These results suggest a role of these genes in the increase of B cells in the thymus of PIL mice. In summary, our results showed the changes in the thymus in PIL and elucidated the immunologic abnormalities of increased B cells, potentially providing insight into the associated molecular mechanisms and facilitating further research.

Up-regulated miR-155 is associated with poor prognosis in childhood acute lymphoblastic leukemia and promotes cell proliferation targeting ZNF238.

OBJECTIVES: Acute lymphoblastic leukemia (ALL) is one of the most common malignancies in children. Our aim was to identify a novel miRNA that can predict prognosis of childhood ALL patients and explore its potential mechanism. METHODS: The miRNA expression profiles of childhood ALL were analyzed using GEO database and HiSeq instruments. The expression of miR-155 was examined by RT-PCR in 42 ALL patients. To investigate the role of miR-155 in ALL, four ALL cell lines (CEM-C1, Jurkat, MOLT-3 and MOLT-4) were transfected with miR-155 mimics, miR-155 inhibitors or corresponding controls. Dual-luciferase reporter system was applied to confirm the miR-155 target ZNF238. Moreover, proliferation and apoptosis were evaluated by MTT and flow cytometry. RESULTS: Dataset GSE56489 and GSE23024 demonstrated that miR-155 was up-regulated and ZNF238 was down-regulated at diagnosis status of ALL. High miR-155 expression was associated with poor outcome. Overexpressed miR-155 promoted ALL cell proliferation and inhibited apoptosis. Dual-luciferase reporter result showed that miR-155 directly regulated ZNF238. Silencing ZNF238 promoted cell proliferation in ALL cells. DISCUSSION: Our research indicating that miR-155 might possess potential value as a biomarker for predicting the prognosis of individuals. However, the role of ZNF238 in childhood ALL remain unknown. In the present study, we found the possible role of ZNF238 as a new tumor suppressor in ALL, which might be necessary for the antiproliferative functions of normal cells to counteract ALL formation. CONCLUSION: Our results propose that miR-155 is in association with poor prognosis of childhood ALL. Furthermore, miR-155 could promote cell proliferation targeting ZNF238.

Encephalopathy and brain atrophy during induction chemotherapy in acute lymphoblastic leukemia.

The MRI showed encephalopathy and brain atrophy of the left parietal lobe, occipital lobe and temporal lobe and decreased infiltration of the dura mater on T2-weighted imaging. But encephalopathy and brain atrophy could be improved with neurotrophic drugs and additional intelligence teaching.

Arsenic trioxide and all-trans retinoic acid suppress the expression of FLT3-ITD.

The prognosis of patients with acute myeloid leukemia (AML) caused by the FLT3-ITD mutation is poor. Arsenic trioxide (ATO) and all-trans retinoic acid (ATRA) can down-regulate FLT3-ITD level and selectively kill leukemia cells carrying the FLT3-ITD mutation. However, the mechanisms of action of these two compounds are unknown. Here, we found that ATO could bind FLT3-ITD at Lys91 and Asp225, whereas ATRA could bind FLT3-ITD at Lys5 and Gln6. Both compounds could not bind wild-type FLT3. Further studies revealed that ATO/ATRA may suppress the Expression of FLT3-ITD by promoting the UBE2L6-mediated ubiquitination pathway and decreasing the expression of C-MYC. However, further studies are needed to define the mechanisms of these compounds on AML. Our research provides an experimental basis for the use of ATO/ATRA in FLT3-ITD AML in clinical practice.

Melatonin inhibits MLL-rearranged leukemia via RBFOX3/hTERT and NF-κB/COX-2 signaling pathways.

MLL-rearranged leukemia is an aggressive malignancy associated with poor outcome, which is refractory to conventional treatment. Melatonin has been proven to exert anti-tumor activity, but the effect of melatonin on MLL-r leukemia and the underlying mechanism remain poorly understood. In this study, melatonin inhibited cell proliferation and induced apoptosis by activating the caspase-dependent apoptotic pathway in MLL-r leukemia cells. Mechanistic investigations revealed that melatonin suppressed the expression of hTERT by abrogating the binding activity of RBFOX3 to the hTERT promoter. Melatonin also blocked NF-κB nuclear translocation and suppressed NF-κB binding to the COX-2 promoter, thereby suppressing the expression of COX-2. In addition, clinical samples revealed that melatonin exerts anti-leukemic activity in primary MLL-r leukemia blasts ex vivo. In vivo, the mice treated with melatonin experienced a larger reduction in leukemic burden than the control group in a MLL-r leukemia xenograft mouse model. Collectively, these results suggest that melatonin inhibits MLL-rearranged leukemia through suppressing the RBFOX3/hTERT and NF-κB/COX-2 signaling pathways. Our findings provide new insights into the role of melatonin for MLL-r leukemia treatment.

[Bioequivalence of tiopronin enteric capsules in healthy volunteers].

OBJECTIVE: To evaluate the bioequivalence of tiopronin enteric capsules (testing preparation, T) versus tablets (reference preparation, R). METHODS: A single oral dose of tiopronin enteric capsules or tablets at 200 mg was administered in 2 groups of Chinese healthy volunteers (n=9) in a randomized crossover design at the interval of 2 weeks. The plasma concentrations of tiopronin were measured by HPLC-MS/MS, and the pharmacokinetic parameters were calculated by DAS 2.0 program. The bioequivalence between the two preparations was evaluated. RESULTS: The main pharmacokinetic parameters were as follows: C(max)(microg.ml(-1)) 3.612-/+1.2393 (R), 3.644-/+1.540 (T); t(max) 4.333-/+1.0853 (R), 3.611-/+1.420 (T); t((1/2))(h) 18.245-/+11.270 (R), 23.403-/+10.500 (T); AUC0-t (microg.h.ml(-1)) 18.732-/+6.92318 (R), 18.713-/+6.585 (T); AUC0-infinity (microg.h.ml(-1)) 21.900-/+7.31220 (R), 20.780-/+7.965 (T). The relative bioavailability of tiopronin enteric capsule was 103.712-/+23.956%, with 90% confidential intervals of ln(AUC0-->72), ln(AUC0-infinity) and ln(C(max)) of 91.1%-111.8%, 96.8%-118.3%, and 85.1%-113.0%, respectively. CONCLUSION: The tiopronin enteric capsules were bioequivalent to the tablets.

[Determination of plasma escitalopram with liquid chromatography-mass spectrometry].

OBJECTIVE: To establish an liquid chromatography-mass spectrometry (HPLC-MS/MS)-based method for determining escitalopram in human plasma. METHODS: A liquid-liquid ether extraction approach was adopted using dextromethorphan as the internal standard. The Agilent ZORBAX SB-C18 (3.5 microm,2.1 x 150 mm) was used as the analytical column with acetonitrile-NH4AC buffer (70:30, V/V) as the mobile phase at the flow rate of 0.3 ml/min. The sample was ionized by electrospray ionization source in the triple quadruple tandem mass spectrometer, and the plasma escitalopram determined with a multiple reaction monitoring mode of m/z325.4-->109.4. RESULTS: The linear range was 0.0866-64.13 microg/L (r=0.9965) for escitalopram in human plasma, with the absolute recovery between 64.98% and 78.72% and the within-day and between-day deviations less than 10%. CONCLUSION: The method is sensitive, accurate, rapid, specific and well applicable for clinical pharmacokinetics study of escitalopram.