Mesenchymal Stem Cell-Derived Extracellular Vesicle: A Promising Alternative Therapy for Osteoporosis.

Osteoporosis is the chronic metabolic bone disease caused by the disturbance of bone remodeling due to the imbalance of osteogenesis and osteoclastogenesis. A large population suffers from osteoporosis, and most of them are postmenopausal women or older people. To date, bisphosphonates are the main therapeutic agents in the treatment of osteoporosis. However, limited therapeutic effects with diverse side effects caused by bisphosphonates hindered the therapeutic applications and decreased the quality of life. Therefore, an alternative therapy for osteoporosis is still needed. Stem cells, especially mesenchymal stem cells, have been shown as a promising medication for numerous human diseases including many refractory diseases. Recently, researchers found that the extracellular vesicles derived from these stem cells possessed the similar therapeutic potential to that of parental cells. To date, a number of studies demonstrated the therapeutic applications of exogenous MSC-EVs for the treatment of osteoporosis. In this article, we reviewed the basic back ground of EVs, the cargo and therapeutic potential of MSC-EVs, and strategies of engineering of MSC-EVs for osteoporosis treatment.

Investigation of biodistribution and tissue penetration of PEGylated gold nanostars and their application for photothermal cancer treatment in tumor-bearing mice.

Gold nanostars (AuNSs), with unique physicochemical properties, are thought to be a promising agent for photothermal therapy (PTT). In this study, we prepared PEGylated gold nanostars (pAuNSs) using the HEPES-reduction method. The high photothermal conversion efficiency (∼80%) and photothermal stability of pAuNSs were demonstrated in vitro and in vivo. 111In-DTPA-pAuNSs were prepared as a radioactive surrogate for the biodistribution studies of pAuNSs. In both microSPECT/CT images and the biodistribution study, the tumor-to-muscle (T/M) ratio reached a maximum at 24 h post intravenous injection of 111In-DTPA-pAuNSs. The high linear correlation between the 111In radioactivity and the gold content in the tumors (R2 0.86-0.99) indicated that 111In-DTPA-pAuNSs were appropriate for noninvasively tracking pAuNSs in vivo after systemic administration. Histological examination after silver enhancement staining clearly illustrated that the accumulated pAuNSs in the tumors were mainly located on the luminal surface of vessels. The mice bearing a SKOV-3 xenograft exhibited remarkable therapeutic efficacy with negligible organ damage after receiving pAuNS-mediated photothermal therapy. Our findings suggested that pAuNSs, together with their radioactive surrogate 111In-DTPA-pAuNSs, are promising for applications in image-guided photothermal therapy.

Evaluation of the In Vivo Therapeutic Effects of Radix Paeoniae Rubra Ethanol Extract with the Hypoglycemic Activities Measured from Multiple Cell-Based Assays.

Background. Radix Paeoniae Rubra (Chi Shao) contains several phytochemicals with hypoglycemic actions. Current research aims to explore potential insulinotropic effects and long-term therapeutic efficacy of such herb against type 2 diabetes. Methods. Composition analysis for the ethanol extract (PRExt) was executed by high performance liquid chromatography. Polyphenol-enriched fraction was characterized by high pressure size exclusion chromatography. Multiple cell platforms were employed to evaluate hypoglycemic bioactivities. In animal experiments, blood glucose, the homeostasis model assessment (HOMA)-index assessment, glucose tolerance test, and in vivo glucose uptake were all measured. Additional effects of PRExt on obesity and hepatic steatosis were evaluated by serum and histological analysis. Results. PRExt provides multiple hypoglycemic effects including the enhancement of glucose-mediated insulin secretion. Pentagalloylglucose and polyphenol-enriched fraction are two insulinotropic constituents. Moreover, PRExt intraperitoneal injection causes acute hypoglycemic effects on fasted db/db mice. Oral administration of PRExt (200 mg/kg b.w.) gradually reduces blood glucose in db/db mice to the level similar to that in C57J/B6 mice after 30 days. The improvement of glucose intolerance, HOMA-index, and in vivo glucose uptake is evident in addition to the weight loss effect and attenuation of hepatic steatosis. Conclusion. PRExt is an effective antidiabetic herbal extract with multiple hypoglycemic bioactivities.

Serial low doses of sorafenib enhance therapeutic efficacy of adoptive T cell therapy in a murine model by improving tumor microenvironment.

Requirements of large numbers of transferred T cells and various immunosuppressive factors and cells in the tumor microenvironment limit the applications of adoptive T cells therapy (ACT) in clinic. Accumulating evidences show that chemotherapeutic drugs could act as immune supportive instead of immunosuppressive agents when proper dosage is used, and combined with immunotherapy often results in better treatment outcomes than monotherapy. Controversial immunomodulation effects of sorafenib, a multi-kinases inhibitor, at high and low doses have been reported in several types of cancer. However, what is the range of the low-dose sorafenib will influence the host immunity and responses of ACT is still ambiguous. Here we used a well-established E.G7/OT-1 murine model to understand the effects of serial low doses of sorafenib on both tumor microenvironment and transferred CD8+ T cells and the underlying mechanisms. Sorafenib lowered the expressions of immunosuppressive factors, and enhanced functions and migrations of transferred CD8+ T cells through inhibition of STAT3 and other immunosuppressive factors. CD8+ T cells were transduced with granzyme B promoter for driving imaging reporters to visualize the activation and distribution of transferred CD8+ T cells prior to adoptive transfer. Better activations of CD8+ T cells and tumor inhibitions were found in the combinational group compared with CD8+ T cells or sorafenib alone groups. Not only immunosuppressive factors but myeloid derived suppressive cells (MDSCs) and regulatory T cells (Tregs) were decreased in sorafenib-treated group, indicating that augmentation of tumor inhibition and function of CD8+ T cells by serial low doses of sorafenib were via reversing the immunosuppressive microenvironment. These results revealed that the tumor inhibitions of sorafenib not only through eradicating tumor cells but modifying tumor microenvironment, which helps outcomes of ACT significantly.

Sorafenib increases efficacy of vorinostat against human hepatocellular carcinoma through transduction inhibition of vorinostat-induced ERK/NF-κB signaling.

Sorafenib is effective for patients with advanced hepatocellular carcinoma (HCC) and particularly for those who are unsuitable to receive life-prolonging transarterial chemo-embolization. The survival benefit of sorafenib, however, is unsatisfactory. Vorinostat also known as suberoylanilide hydroxamic acid (SAHA) is a histone deacetylase (HDAC) inhibitor with anti-HCC efficacy in preclinical studies. SAHA induces nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) activity in vitro, which may lead to cancer cell progression and jeopardize cytotoxic effect of SAHA in HCC. The goal of this study was to investigate whether sorafenib enhances SAHA cytotoxicity against HCC through inhibition of SAHA-induced NF-κB activity. The human HCC cell line Huh7 transfected with dual reporter genes, luciferase (luc) and thymidine kinase (tk) with NF-κB response elements, was co-transfected with red fluorescent protein (rfp) gene for non-invasive molecular imaging to assess NF-κB activity and living cells simultaneously. Cell viability assay, DNA fragmentation, western blotting, electrophoretic mobility shift assay (EMSA) and multiple modalities of molecular imaging were used to assess the combination efficacy and mechanism of sorafenib and SAHA. The administration of high-dose SAHA (10 µM) with long treatment time (48 h) in vitro, and 25 mg/kg/day by gavage in HCC-bearing nude mice to induce NF-κB activity were performed. Sorafenib inhibited SAHA-induced NF-κB activity and the expression of NF-κB-regulated effector proteins while it increased the efficacy of SAHA against HCC both in vitro and in vivo. The mechanism of sorafenib to enhance SAHA efficacy on HCC is through the suppression of ERK/NF-κB pathway, which induces extrinsic and intrinsic apoptosis. Combination of sorafenib and SAHA may have the potential as new strategy against HCC.

Immunomodulation of curcumin on adoptive therapy with T cell functional imaging in mice.

Adoptive T-cell therapy involves the ex vivo expansion and subsequent transfusion of tumor-specific T lymphocytes to eliminate tumors. Using immune modulators to block immunosuppressive factors in the tumor microenvironment has emerged as a promising strategy to enhance T-cell-mediated tumor regression. Curcumin, a major component of turmeric, has been shown to possess antitumor and immunomodulatory effects by regulating a diverse range of molecular targets. Thus, we hypothesize that these beneficial effects of curcumin may improve the therapeutic efficacy of adoptive therapy. Here, we have shown that curcumin enhances cytotoxicity of CD8(+) T cells toward tumors via alteration of the tumor microenvironment when combined with adoptive therapy. We found that T-cell accumulation and function were increased in combined treatment due to the blockade of different immunosuppressors, including TGF-ß, indoleamine 2,3-dioxygenase, and regulatory T cells. Furthermore, bioluminescent imaging with a granzyme B promoter-conjugated optical reporter also reflected improved cytotoxicity of antigen-specific CD8(+) T cells in tumor-bearing mice during treatment. These findings suggest that combination of multitargeting drugs, such as curcumin, with adoptive therapy may have potential for clinical application. In addition, using a granzyme B-specific imaging reporter to assess T-cell function may also be applied for the development and therapeutic evaluation of new immunotherapy in preclinical studies.

Unilateral thalamic hypometabolism in patients with temporal lobe epilepsy.

BACKGROUND/PURPOSE: Interictal brain 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) is useful for localizing the focus of a seizure, and thalamic hypometabolism has been observed in temporal lobe epilepsy (TLE). In this study, we aimed to investigate the prevalence of thalamic hypometabolism and to assess the usefulness of this supplementary finding for lateralizing epileptic foci on FDGPET scans in patients with TLE. METHODS: This was a retrospective study of 47 patients who underwent anterior temporal lobectomy to treat medically intractable TLE. Other inclusion criteria were age older than 18 years, preoperative interictal FDG-PET, no structural abnormality (except for mesial temporal sclerosis) on preoperative magnetic resonance imaging, and seizure-free status (Engel class I) for at least 2 years after the operation. The presence and location of hypometabolism on FDG-PET scans were recorded. RESULTS: Of the 47 patients examined, 12 were subsequently excluded. Concomitant hypometabolism in both the temporal lobe and the ipsilateral thalamus was observed on FDG-PET scans in seven (20%) of the remaining 35 patients. One patient had thalamic hypometabolism contralateral to the hypometabolic temporal lobe. CONCLUSION: Ipsilateral thalamic hypometabolism is a supplementary finding on FDG-PET scans in patients with TLE and can aid in lateralizing epileptic foci during FDG-PET. However, in rare cases, hypometabolism of the contralateral thalamus can occur and cause false lateralization.

Topographic brain mapping of the international cooperative ataxia rating scale. A positron emission tomography study.

The International Cooperative Ataxia Rating Scale (ICARS) is a 100-point semiquantitative scale designed primarily to assess cerebellar dysfunction. However, little is known of the metric properties of this scale. We assessed the ICARS by rating the severity of cerebellar dysfunction in 27 patients with spinocerebellar ataxias (SCA), three patients with sporadic olivopontocerebellar ataxia and 24 healthy control subjects. [(18)F]-fluorodeoxyglucose (FDG) positron emission tomography (PET) study was also performed on each subject. The statistical parametric mapping analyses revealed a significant correlation between the ICARS scores and functional impairment of the frontal regions within SCA patients. The glucose metabolism in the cerebellum, thalamus and caudate nucleus had significant differences between SCA patients and healthy control subjects. The results suggested that the clinical severity of SCA patients correlated with the functional impairment in the frontal regions, the targets of cerebellar efferent projections.

Early prediction of response to intravenous iron supplementation by reticulocyte haemoglobin content and high-fluorescence reticulocyte count in haemodialysis patients.

BACKGROUND: Optimal response to recombinant human erythropoietin (rHuEpo) in haemodialysis (HD) patients requires provision of sufficient available iron. However, a balance between iron requirements and supplements remains a challenge in clinical practice. Reticulocyte parameters, i.e. reticulocyte haemoglobin content (CHr) and reticulocytes in a high-fluorescence intensity region (HFR), have been shown to be accurate predictors of iron-deficient erythropoiesis as compared with traditional markers. Therefore, the aim of this study was to appraise the diagnostic power of these two parameters in the early prediction of response to intravenous iron (IVFE) medications in HD patients receiving rHuEpo. METHODS: Sixty-five HD patients with a serum ferritin level of <500 microg/l and on rHuEpo therapy for >6 months were enrolled for IVFE supplementation (100 mg iron saccharate three times a week for 4 weeks, then 100 mg every 2 weeks for 5 months). Haemoglobin, haematocrit, serum ferritin, transferrin saturation, reticulocyte count, percentage of hypochromic red cells, CHr and HFR were measured before and following iron supplementation. Response was defined as a rise in haematocrit of >3% and/or a reduction in rHuEpo dose of >30% over the baseline values at the end of the study. RESULTS: Forty-two patients had a dramatic response to IVFE therapy with a 13.5% increase in mean haematocrit and a 38% reduction in rHuEpo dose at the end of the study (P<0.001). This paralleled a statistically significant rise in CHr and HFR (P<0.001). Univariate analyses showed that ferritin (P<0.010) and CHr (P<0.001) at baseline, changes in CHr (DeltaCHr(2W), P<0.001) and HFR (DeltaHFR(2W), P<0.010) at 2 weeks, as well as changes in CHr (DeltaCHr(4W), P<0.001) and HFR (DeltaHFR(4W), P<0.001) at 4 weeks, strongly correlated with response to IVFE supplementation. Stepwise discriminant analysis disclosed that DeltaCHr(4W) in conjunction with DeltaHFR(4W) exhibited an r(2) value of 0.531 (P<0.001) to predict response to IVFE therapy. Analyses by receiver operating characteristic curves and logistic regression further revealed that DeltaCHr(4W) at a cut-off value of >1.2 pg and DeltaHFR(4W) of >500/microl were more specific to the status of iron-deficient erythropoiesis following IVFE medications. Combined use of the two cut-off values allowed for the highest accuracy in the early prediction of the response to IVFE therapy, with a sensitivity of 96% and a specificity of 100%. CONCLUSIONS: Our study shows that changes in CHr and HFR at either 2 or 4 weeks are superior to the conventional erythrocyte and iron metabolism indices and may serve as reliable parameters to detect iron-deficient erythropoiesis in HD patients undergoing rHuEpo therapy. During aggressive IVFE treatment, early identification of non-responsiveness and subsequent discontinuation of treatment can avoid the inadvertent iron-related toxicity due to over-treatment.

Complementary role of 18F-fluorodeoxyglucose positron emission tomography and 131I scan in the follow-up of post-therapy differentiated thyroid cancer.

BACKGROUND AND PURPOSE: 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) is a relatively new modality in the follow-up of patients with differentiated thyroid cancer (DTC) who have undergone total thyroidectomy and postoperative radioiodine therapy. The aim of this study was to assess the diagnostic value of FDG-PET, comparing it with 131I whole-body scan (WBS) and 201Tl WBS. METHODS: Fifteen selected patients with local invasive and/or aggressive DTC were included in this study. The follow-up period ranged from 1 to 12 years, with a mean +/- standard error of 6 +/- 3 years. FDG-PET was performed when patients were still receiving thyroxin therapy. RESULTS: In the cervical region, residual cancer in two patients was demonstrated by FDG-PET, but could not be detected using 131I WBS or 201Tl WBS. Pathology of the surgical specimen showed dedifferentiation of thyroid cancer in one of these patients. Metastatic cervical lymph nodes were detected using FDG-PET in three patients, but in only one patient using 131I WBS and in another one patient using 201Tl WBS. Mediastinal metastases were detected using FDG-PET in three patients, 131I WBS in two patients, and 201Tl WBS in one patient. Diffuse lung metastasis was detected only by 131I WBS in two patients. The use of FDG-PET in conjunction with computerized tomography provided useful diagnostic information about small nodular lesions of the lung which could not be localized by 131I WBS or 201Tl WBS in three patients. In skeletal metastases, 131I WBS detected more metastatic lesions than FDG-PET or 201Tl WBS, especially when the lesions were located in the pelvis. CONCLUSIONS: In the follow-up evaluation of patients with post-therapy DTC, FDG-PET was useful for detecting dedifferentiated lesions and was superior to 131I WBS in detecting residual cervical or mediastinal lesions and suspected small metastatic foci in the lung. FDG-PET was inferior to 131I WBS in detecting diffuse lung metastases and distant bone metastases.