Overcoming chemoresistance in non-angiogenic colorectal cancer by metformin via inhibiting endothelial apoptosis and vascular immaturity.

The development of chemoresistance which results in a poor prognosis often renders current treatments for colorectal cancer (CRC). In this study, we identified reduced microvessel density (MVD) and vascular immaturity resulting from endothelial apoptosis as therapeutic targets for overcoming chemoresistance. We focused on the effect of metformin on MVD, vascular maturity, and endothelial apoptosis of CRCs with a non-angiogenic phenotype, and further investigated its effect in overcoming chemoresistance. In situ transplanted cancer models were established to compare MVD, endothelial apoptosis and vascular maturity, and function in tumors from metformin- and vehicle-treated mice. An in vitro co-culture system was used to observe the effects of metformin on tumor cell-induced endothelial apoptosis. Transcriptome sequencing was performed for genetic screening. Non-angiogenic CRC developed independently of angiogenesis and was characterized by vascular leakage, immaturity, reduced MVD, and non-hypoxia. This phenomenon had also been observed in human CRC. Furthermore, non-angiogenic CRCs showed a worse response to chemotherapeutic drugs in vivo than in vitro. By suppressing endothelial apoptosis, metformin sensitized non-angiogenic CRCs to chemo-drugs via elevation of MVD and improvement of vascular maturity. Further results showed that endothelial apoptosis was induced by tumor cells via activation of caspase signaling, which was abrogated by metformin administration. These findings provide pre-clinical evidence for the involvement of endothelial apoptosis and subsequent vascular immaturity in the chemoresistance of non-angiogenic CRC. By suppressing endothelial apoptosis, metformin restores vascular maturity and function and sensitizes CRC to chemotherapeutic drugs via a vascular mechanism.

Metformin enhances T lymphocyte anti-tumor immunity by increasing the infiltration via vessel normalization.

Abnormal tumor vasculature blocks the extravasation of T lymphocytes into the tumor, thereby suppressing anti-tumor immunity. Recently, metformin has been shown to affect tumor vasculature and enhance T lymphocyte anti-tumor immunity. However, whether or how metformin affects T lymphocyte anti-tumor immunity via a vascular mechanism remains poorly understood. Herein, we show that a large number of CD8+ lymphocytes gathered in the peri-tumoral region, while very few infiltrated the tumor. Metformin administration increased the expression of anti-tumor immunity-associated genes and the number of tumor-infiltrating CD8+ lymphocytes. Injection of CD8 but not CD4 neutralization antibody into tumor-bearing mice significantly abrogated the anti-tumor effect of metformin. Critically, CD8+ lymphocytes were found to pass through the wall of perfused vessel. Further results of immunofluorescent staining showed that metformin greatly elevated tumor perfusion, which was accompanied by increased vascular maturity in the intratumoral region (ITR) but not peritumoral region (PTR). These findings provide evidence for the vascular mechanism involved in metformin-induced enhancement of T lymphocyte anti-tumor immunity. By remodeling the abnormal tumor vasculature, also called vessel normalization metformin increases vascular maturity and tumor perfusion, thus allowing more CD8+ lymphocytes to infiltrate the tumor.

HIF-1α inhibitor YC-1 suppresses triple-negative breast cancer growth and angiogenesis by targeting PlGF/VEGFR1-induced macrophage polarization.

Triple negative breast cancer (TNBC) is an invasive and metastatic phenotype of breast cancer with limited treatment options. Published studies have demonstrated an inhibitory effect of HIF-α inhibition by its inhibitor YC-1 (lificiguat) on growth and angiogenesis of TNBC. However, the underlying mechanism remains poorly understood. In the current paper, our results show that HIF-1α inhibitor significantly inhibited TNBC growth by increasing cellular apoptosis and decreasing MVD, independent of a cell-autonomous mechanism in both endothelial and tumor cells. Genetic screening and in vivo experiments showed that a large number of M2-polarized TAMs accumulated in the hypoxic peri-necrotic region (PNR), where placental growth factor (PlGF) and its ligand, vascular endothelial growth factor receptor-1 (VEGFR-1) were upregulated. Furthermore, YC-1 skewed the polarization of TAMs away from M2 to M1 phenotype, therefore inhibiting TNBC angiogenesis and growth. This effect was further abrogated by VEGFR-1 neutralization and TAM depletion following clodronate liposome injection. These findings provide preclinical evidence for an indirect mechanism underlying YC-1-induced suppression of TNBC growth and angiogenesis, thereby offering a treatment option for TNBC.

Elastic-inertial separation of microparticle in a gradually contracted microchannel.

Separation of microparticle in viscoelastic fluid is highly required in the field of biology and clinical medicine. For instance, the separation of the target cell from blood is an important prerequisite step for the drug screening and design. The microfluidic device is an efficient way to achieve the separation of the microparticle in the viscoelastic fluid. However, the existing microfluidic methods often have some limitations, including the requirement of the long channel length, the labeling process, and the low throughput. In this work, based on the elastic-inertial effect in the viscoelastic fluid, a new separation method is proposed where a gradually contracted microchannel is designed to efficiently adjust the forces exerted on the particle, eventually achieving the high-efficiency separation of different sized particles in a short channel length and at a high throughput. In addition, the separation of WBCs and RBCs is also validated in the present device. The effect of the flow rate, the fluid property, and the channel geometry on the particle separation is systematically investigated by the experiment. With the advantage of small footprint, simple structure, high throughput, and high efficiency, the present microfluidic device could be utilized in the biological and clinical fields, such as the cell analysis and disease diagnosis.

Transforming growth factor-ß1 and inducible nitric oxide synthase signaling were involved in effects of prostaglandin E2 on progression of lower limb varicose veins.

OBJECTIVE: The vital pathogenesis of varicose veins includes remodeling of the extracellular matrix and decreased vascular tone. Prostaglandin E2 (PGE2), a small molecule substance and inflammatory medium that belongs to the arachidonic acid derivatives, has the capacity to influence the expression of metalloproteinase and the vascular tone of the venous wall. The purpose of the present study was to investigate the role of PGE2 in the development of varicose veins in lower limbs. METHODS: The collected venous specimens were analyzed using hematoxylin and eosin, Masson's trichrome, and immunohistochemical staining. Transforming growth factor (TGF)-ß1, PGE2, CD31, and α-smooth muscle actin antibody were used to detect the expression and distribution of these proteins. The effect of PGE2 on the proliferation, migration, and tube formation capacity of human umbilical vein endothelial cells (HUVECs) was detected in vitro. The effect of TGF-ß1 on the expression of PGE2 and matrix metalloproteinases (MMPs) was assessed using Western blotting. Quantitative reverse transcription polymerase chain reaction was used to evaluate the effect of PGE2 on the expression of nitric oxide synthase (NOS) and other genes. RESULTS: The expression of PGE2 and TGF-ß1 in varicose veins was upregulated in the media tunica and intima tunica, and a strong positive correlation was found between PGE2 and TGF-ß1 expression in both varicose veins (95% confidence interval, 0.5207-0.9582; R = 0.848; P = .0005) and normal veins (95% confidence interval, 0.2530-0.8532; R = 0.643; P = .003). PGE2 promoted the migration and tube formation ability of HUVECs. Moreover, PGE2 also upregulated the expression of MMP-1 and TGF-ß1 in HUVECs and increased the mRNA level of inducible NOS. CONCLUSIONS: PGE2 can affect the remodeling of the extracellular matrix and reduce the elasticity of the vascular walls by promoting the synthesis of TGF-ß1 and MMP-1. PGE2 can also reduce the tension of the great saphenous vein by promoting the expression of inducible NOS, thus aggravating the blood stasis.

Stem signatures associated antibodies yield early diagnosis and precise prognosis predication of patients with non-small cell lung cancer.

BACKGROUND: This study was designed to detect patients with early NSCLC with tentatively using the stem signatures associated autoantibodies (AAbs), and to evaluate its latent values in the early diagnosis and precise prognosis prediction. METHODS: The serum concentrations of selective antibodies were quantitated by enzyme-linked immunosorbent assay (ELISA), and a total of 458 cases were enrolled (training set = 401; validation set = 57). TCGA databases were used to analyze the distinct expressions and prognostic values of related genes. The optimal cut-off values were 11.60 U/ml for P53, 4.90 U/ml for MAGEA1, 3.85 U/ml for SOX2, and 7.05U/ml for PGP9.5. RESULTS: We found that the stem signatures associated antibodies of MAGEA1, PGP9.5, SOX2, and TP53 exhibited high expressions in NSCLC, negatively correlating with the overall survival (OS) (P < 0.05). In the test groups, the diagnosis sensitivity of P53, PGP9.5, SOX2, and MAGEA1 reached to 21.5%, 39.0%, 50.3%, and 35.0%, respectively, and the specificity reached to 98.7%, 99.4%, 92.2%, and 97.4%. The four candidates' panel gave a sensitivity of 71.8% with a specificity of 89%. In the validation group, the detection of the four antibodies in early diagnosis of NSCLC also exhibited high specificity and sensitivity, further consolidating their potential application. CONCLUSIONS: The detection regarding stem signatures associated antibodies could be used as effective tools in early NSCLC diagnosis, but not for localized screening of cancers, and their abnormal expression was in accordance with poorer survival.

Matrine Inhibitory Effect on Self-renewal and Re-sensitization of 5-FU Resistant NSCLC Stem Cells were through Let-7b dependent Downregulation of CCND1.

Matrine is one of the major alkaloids extracted from Sophora flavescens Ait of the traditional Chinese medicine, was the main chemical ingredient of compounds of Kushen injection. The Matrine is considered as a promising therapeutic agent for curing nonsmall cell lung cancer (NSCLC), used either alone or combined with chemotherapeutic agents. In the present study, we focused on the possible roles of Matrine exerted on the self-renewal ability of stem-like cells of the NSCLC group, as well as the cytotoxicity of chemotherapeutic agents, in vitro and in vivo. Here we reported that Matrine inhibits cancer stem-like cell (CSC) properties through upregulation of Let-7b and suppression of the Wnt pathway. Overexpression of Let-7b suppressed the ability of tumorsphere formation, decreased Wnt pathway activation through inhibiting its transcriptional activity in lung CSCs. Further studies revealed that Let-7b directly targeted CCND1 and decreased its expression, whereas Matrine increased Let-7b levels and followed by inactivation of the CCND1/Wnt signaling pathway and inhibition of EMT, which was characterized by loss of epithelial markers and acquisition of a mesenchymal phenotype in lung CSCs. What is more, we found that Matrine increased Let-7b level in an endoribonuclease DICER1-dependent manner. And xenografts in nude mice evidenced that Matrine increased the sensitivity of lung CSCs to 5-FU and inhibited the accumulation of CCND1 in tumor tissues induced by 5-FU. Taken together, these data illustrate the role of Let-7b in regulating lung CSCs traits and DICER1/let-7/CCND1 axis in Matrine or in combination with 5-FU intervention of lung CSCs' expansion, helping to fulfill the anti-cancer action of Matrine.

Matrine suppression of self-renewal was dependent on regulation of LIN28A/Let-7 pathway in breast cancer stem cells.

Matrine, a natural product extracted from the root of Sophora flavescens Ait, was the main chemical ingredient of compounds of Kushen injection, which has been widely used for its remarkable anticancer effects for years. The underlying mechanisms for Matrine regulations of human breast cancer stem cells (BrCSCs) are barely known. LIN28, a well-characterized suppressor of Let-7 microRNA biogenesis, playing vital roles in regulations of stem cells' renewal and tumorigenesis. Here we show that the compounds of Kushen injection derived Matrine could suppress the BrCSCs differentiation and self-renewal through downregulating the expression of Lin28A, resulting in the inactivation of Wnt pathway through a Let-7b-dependent way. In opposite to Matrine, Cisplatin treatment increases the ability of tumorsphere formation and the expression of BrCSCs markers, which was partially blocked by either Let-7b overexpression or CCND1 inhibition. Furthermore, Matrine sensitized BrCSCs to cisplatin's suppression of cancer expansion in vitro and in vivo. Our study uncovers the role of the LIN28A/Let-7 in BrCSCs renewal, and more importantly, elucidated a novel mechanism by which Matrine induces breast cancer involution.

PlGF signaling and macrophage repolarization contribute to the anti-neoplastic effect of metformin.

Placental growth factor (PlGF) related signaling pathway has been shown to have close relationship with the progression of cancers. Metformin has been reported to have an inhibitory effect on PlGF expression in a breast cancer model. However, little is known about whether the anti-neoplastic activity of metformin is contributed by its inhibitory effect on PlGF expression. Protein, mRNA and secretion levels of PlGF were tested and the proliferation of cancer cells was determined. After treatment of metformin, BALB/c mice bearing 4T1 tumors were sacrificed and immunohistochemistry staining of the tumor sections was obtained. Baseline expression of autocrine PlGF varied between different breast cancer cell lines, while the expression of vascular endothelial growth factor receptor-1 (VEGFR-1) was comparable between cell lines. Other clinical data showed that the expression of PlGF other than VEGFR-1 had a prognostic value for patients with breast cancers. Metformin significantly decreased the secretion and mRNA levels of PlGF, which greatly contributed to its inhibitory effect on the proliferation of breast cancer cells with high P1GF expression. The unresponsiveness of tumor cells with low PlGF expression to genetic silencing was reversed by the supplementation of exogenous PlGF. Systemic metformin administration apparently inhibited the in vivo growth of 4T1 carcinoma, which was accompanied by the repolarization of macrophages from M2 to M1. These findings indicated that both autocrine and paracrine PlGF signaling and macrophage repolarization are involved in the progression of breast cancer, which could be targeted by metformin.

Metformin inhibits metastatic breast cancer progression and improves chemosensitivity by inducing vessel normalization via PDGF-B downregulation.

BACKGROUND: Vascular maturity and functionality are closely associated with tumor progression and chemosensitivity. The antidiabetic agent metformin has shown its ability to inhibit tumor angiogenesis in metastatic breast cancer models. However, it remains unclear if or how metformin remodels the abnormal vasculature of metastatic breast cancer, while inhibiting angiogenesis. METHODS: Metastatic breast cancer models were constructed to compare microvessel density (MVD), vascular maturity and function, lung metastasis and chemosensitivity in metformin-treated or untreated mice. Protein array assay and transcriptome sequencing were performed for genetic screening. Lentiviral shRNA-PDGF-B transfection was used for observing the contribution of PDGF-B knockdown to metformin's vascular effects. RESULTS: Metastatic breast cancers were characterized by an excessively angiogenic, immature and morphologically abnormal vasculature. Compared to control, metformin significantly reduced MVD, leakage and hypoxia, and increased vascular mural cells coverage and perfusion, namely, "vessel normalization". Metformin at human blood concentrations had no direct effect on the migration and proliferation of cancer cells. Based on that, reduced lung metastasis of the primary tumor and improved chemosensitization by metformin were assumed to be mediated via metformin's vascular effects. Further results of genetic screening and in vivo experiments showed that the downregulation of platelet-derived growth factor B (PDGF-B) greatly contributed to the metformin-induced vessel normalization. CONCLUSIONS: These findings provide pre-clinical evidences for the vascular mechanism of metformin-induced metastasis inhibition and the chemosensitization of metastatic breast cancers.

Nutlin-3-Induced Sensitization of Non-Small Cell Lung Cancer Stem Cells to Axitinib-Induced Apoptosis Through Repression of Akt1/Wnt Signaling.

The aim of this study was to investigate the potential biological activities of nutlin-3 in the regulation of growth and proliferation of non-small cell lung cancer (NSCLC) stem cells (CSCs), which may help in sensitizing to axitinib-induced apoptosis. Nutlin-3 induction of p53 expression was used to test its role in controlling the cell division pattern and apoptosis of NSCLC cells. A549 cells and H460 cells were pretreated with nutlin-3 and then treated with either an Akt1 activator or shRNA-GSK3ß, to investigate the potential role of p53 sensitization in the biological effects of axitinib. We also determined the expression levels of GSK3ß and p-Akt1 in patients with NSCLC and determined their potential association with survival data using Kaplan-Meier plots and CBIOTAL. Increased p53 expression stimulated the induction of apoptosis by axitinib and promoted asymmetric cell division (ACD) of NSCLC CSCs. The repression of Akt phosphorylation induced by nutlin-3 promoted the ACD of lung CSCs, decreasing the proportion of the stem cell population. In addition to the induction of apoptosis by axitinib through inhibition of Wnt signaling, nutlin-3 treatment further enhanced axitinib-induced apoptosis by inhibiting Akt1/GSK3ß/Wnt signaling. The low expression of GSK3ß and increased expression of p-Akt in patients with NSCLC were closely associated with the development of NSCLC. TP53 stimulates the induction of apoptosis in NSCLC by axitinib and the ACD of lung CSCs through its regulatory effects on the p53/Akt/GSK3ß pathways.

H19 regulation of oestrogen induction of symmetric division is achieved by antagonizing Let-7c in breast cancer stem-like cells.

OBJECTIVES: Breast cancer stem-like cells (BrCSCs) are the major reason for tumour generation, resistance and recurrence. The turbulence of their self-renewal ability could help to constrain the stem cell expansion. The way BrCSCs divided was related to their self-renewal capacity, and the symmetric division contributed to a higher ability. Non-coding long RNA of H19 was involved in multiple malignant procedures; the role and mechanistic proof of non-coding long RNA of H19 in controlling the divisions of BrCSCs were barely known. MATERIALS AND METHODS: Indicative functions of H19 in preclinical study were analysed by using the TCGA data base. Division manners were defined by using fluorescence staining. RESULTS: We identified the stimulation of H19 on symmetric division of BrCSCs, which subsequently resulted in self-renewing increasing. H19 inhibited the Let-7c availability by acting as its specific molecular sponge, and with Let-7c inhibition, oestrogen receptor activated Wnt signalling was unconstrained. Similarly, restoring Let-7c constrained oestrogen receptor activated Wnt factors, which sequentially inhibited the H19 decreasing of Let-7 bioavailability. Let-7c is reactivated in vitro where H19 was knockdown, and later inhibited the symmetric division of BrCSCs. Reciprocally, Wnt pathway activation leads to H19 increasing, which in turn decreased Let-7c bioavailability. CONCLUSIONS: Our results revealed a previously undescribed double negative feedback loop between sponge H19 and targeted Let-7c through oestrogen activated Wnt signalling that dominated in stem cells' division.

Metformin's antitumour and anti-angiogenic activities are mediated by skewing macrophage polarization.

Beneficial effects of metformin on cancer risk and mortality have been proved by epidemiological and clinical studies, thus attracting research interest in elucidating the underlying mechanisms. Recently, tumour-associated macrophages (TAMs) appeared to be implicated in metformin-induced antitumour activities. However, how metformin inhibits TAMs-induced tumour progression remains ill-defined. Here, we report that metformin-induced antitumour and anti-angiogenic activities were not or only partially contributed by its direct inhibition of functions of tumour and endothelial cells. By skewing TAM polarization from M2- to M1-like phenotype, metformin inhibited both tumour growth and angiogenesis. Depletion of TAMs by clodronate liposomes eliminated M2-TAMs-induced angiogenic promotion, while also abrogating M1-TAMs-mediated anti-angiogenesis, thus promoting angiogenesis in tumours from metformin treatment mice. Further in vitro experiments using TAMs-conditioned medium and a coculture system were performed, which demonstrated an inhibitory effect of metformin on endothelial sprouting and tumour cell proliferation promoted by M2-polarized RAW264.7 macrophages. Based on these results, metformin-induced inhibition of tumour growth and angiogenesis is greatly contributed by skewing of TAMs polarization in microenvironment, thus offering therapeutic opportunities for metformin in cancer treatment.

A Comparison of Concomitant Tributary Laser Ablation and Foam Sclerotherapy in Patients Undergoing Truncal Endovenous Laser Ablation for Lower Limb Varicose Veins.

PURPOSE: To compare outcomes of patients who received simultaneous tributary endovenous laser ablation (EVLA) or foam sclerotherapy (FS) with EVLA of the great saphenous vein (GSV) trunk. METHODS AND MATERIALS: This study recruited 418 patients (542 legs) with diagnosed varicose veins. Patients in the EVLA/FS group (255 patients, 327 legs) received concomitant FS for the tributaries with truncal lasering. For the EVLA-alone group (163 patients, 215 legs), tributaries (8W) were ablated with EVLA in addition to the GSV trunk (14W). Complications, Aberdeen Varicose Vein Questionnaire (AVVQ), EuroQol Group 5-Dimension Self-Report Questionnaire (EQ-5D), numerical rating scale (NRS) scores, and condition of residual varicosities were assessed at 3 days, 4 weeks, and 6 months after procedure. All residual varicosities were identified and treated with a staged FS at 6 months. RESULTS: Except for ecchymosis, incidence of other complications was not significantly different between both groups at 6 months. Pain NRS scores of the EVLA/FS group were remarkably elevated at 4 weeks and then, at 6 months, declined to a level similar to the EVLA-alone group. The EVLA/FS group exhibited more significant improvement in both AVVQ and EQ-5D scales than the EVLA group at 6 months, while exhibiting poor improvement at 4 weeks. The EVLA/FS group had a significantly lower rate of residual varicosities than the EVLA group, thus reducing the need for the staged FS. CONCLUSIONS: These results confirm the feasibility and safety of simultaneous tributary EVLA and FS. In addition, they indicate better early quality-of-life improvement and a reduced reoperation rate of simultaneously combined truncal EVLA and tributary FS.

Activation of AMPK by simvastatin inhibited breast tumor angiogenesis via impeding HIF-1α-induced pro-angiogenic factor.

Substantial data from preclinical studies have revealed the biphasic effects of statins on cardiovascular angiogenesis. Although some have reported the anti-angiogenic potential of statins in malignant tumors, the underlying mechanism remains poorly understood. The aim of this study is to elucidate the mechanism by which simvastatin, a member of the statin family, inhibits tumor angiogenesis. Simvastatin significantly suppressed tumor cell-conditioned medium-induced angiogenic promotion in vitro, and resulted in dose-dependent anti-angiogenesis in vivo. Further genetic silencing of hypoxia-inducible factor-1α (HIF-1α) reduced vascular endothelial growth factor and fibroblast growth factor-2 expressions in 4T1 cells and correspondingly ameliorated HUVEC proliferation facilitated by tumor cell-conditioned medium. Additionally, simvastatin induced angiogenic inhibition through a mechanism of post-transcriptional downregulation of HIF-1α by increasing the phosphorylation level of AMP kinase. These results were further validated by the fact that 5-aminoimidazole-4-carboxamide ribonucleotide reduced HIF-1α protein levels and ameliorated the angiogenic ability of endothelial cells in vitro and in vivo. Critically, inhibition of AMPK phosphorylation by compound C almost completely abrogated simvastatin-induced anti-angiogenesis, which was accompanied by the reduction of protein levels of HIF-1α and its downstream pro-angiogenic factors. These findings reveal the mechanism by which simvastatin induces tumor anti-angiogenesis, and therefore identifies the target that explains the beneficial effects of statins on malignant tumors.

Suppression of hypoxia-induced excessive angiogenesis by metformin via elevating tumor blood perfusion.

The anti-diabetic metformin has been demonstrated to be effective in suppression of tumor progression via multiple mechanisms, in which angiogenic inhibition is involved. Hypoxia is a common feather of malignant tumor and promotes angiogenesis via induction of pro-angiogenic factors. However, the effect of metformin on tumor hypoxia and the association with angiogenic inhibition are still unclear. In the current study, we investigated the effects of metformin on both tumor blood perfusion and hypoxia-induced excessive angiogenesis. In the tumor region adjacent to necrosis, aberrantly excessive angiogenesis resulted from hypoperfusion-induced intense hypoxia and greatly contributed to the high average levels of both microvessel density and vascular branch density. Metformin administration increased the percentage of lectin-perfused vessels and reduced hypoxyprobe-positive area. This metformin-induced amelioration of hypoxia was accompanied by a significant reduction in expressions of both HIF-1α and angiogenesis-associated factors (AAFs). Consequently, inhibited excessive angiogenesis in hypoxic peri-necrotic region was observed in metformin-treated tumor. Further stable knockdown of HIF-1α abrogated hypoxia-induced AAFs in vitro and reduced both microvessel density and area of fitc-conjugated dextran that leaked outside the vascular lumen. Taken together, metformin ameliorated tumor hypoxia and restrained HIF-1α-induced expressions of AAFs through elevating tumor blood perfusion, thus suppressing the excessive tumor angiogenesis.

The mitochondrial genome sequence of a diabetes disease Rattus norvegicus Wistar strain.

We sequenced a diabetic Rattus norvegicus Wistar strain mitochondrial genome for the first time (GenBank Accession No. KM114608). Its mitogenome was 16,311 bp and coding 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes. This mitogenome sequence will provide definite genetic information for diabetes disease.

Complete mitochondrial genome sequence and mutations of the insulin resistance model inbred C57BL/6 mice strain.

In the present work we undertook the complete mitochondrial genome sequencing of an important insulin resistance model inbred rat strain for the first time. The total length of the mitogenome was 16,308 bp. It harbored 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes and 1 non-coding control region (D-loop region). The mutation events were also reported.

Transplantation of hypoxia preconditioned bone marrow mesenchymal stem cells improves survival of ultra-long random skin flap.

BACKGROUND: Random flap is one kind of the most widely used skin flaps in reconstructive surgery; however, partial necrosis of its distal end remains a significant problem now. The aim of this study was to evaluate the effect of hypoxia preconditioned bone marrow mesenchymal stem cells (HpBMSCs) transplantation on ultra-long random skin flap survival in rats. METHODS: Normoxic bone marrow mesenchymal stem cells (nBMSCs) were cultured under normoxia (20% O2) and HpBMSCs under hypoxia (1% O2) for 48 hours before transplantation. Thirty Sprague-Dawley rats were randomly divided into control group, nBMSCs group and HpBMSCs group with each consisting of 10 rats. Survival area of ultra-long random skin flap on the dorsal of rats was measured seven days after flap surgery and cell transplantation. Cell survival in vivo, microvessel density and vascular endothelial growth factor (VEGF) were evaluated by histological examination and enzyme-linked immunosorbent assay. RESULTS: Compared with other two groups, flap survival area in HpBMSCs group was significantly larger (P < 0.05). Microvessel density in HpBMSCs group (36.20 ± 8.19) was higher than that in nBMSCs group (30.01 ± 5.68) and control group (17.60 ± 4.19) (P < 0.05). VEGF in HpBMSCs group ((300.05 ± 50.41) pg/g) was higher than those in nBMSCs group ((240.55 ± 33.64) pg/g) and control group ((191.65 ± 32.58) pg/g) (P < 0.05). CONCLUSION: HpBMSCs transplantation improves ultra-long random skin flap survival via promoting angiogenesis of more survival cells.

Transforming growth factor-ß1 phage model peptides isolated from a phage display 7-mer peptide library can inhibit.

BACKGROUND: Transforming growth factor-ß1 (TGF-ß1) is known to have a role in keloid formation through the activation of fibroblasts and the acceleration of collagen deposition. The objective of this current study was to isolate TGF-ß1 phage model peptides from a phage display 7-mer peptide library to evaluate their therapeutic effect on inhibiting the activity of keloid fibroblasts. METHODS: A phage display 7-mer peptide library was screened using monoclonal anti-human TGF-ß1 as the target to obtain specific phages containing ectogenous model peptides similar to TGF-ß1. Enzyme-linked immunosorbent assay (ELISA) was performed to select monoclonal phages with good binding activity, which underwent DNA sequencing. MTT assay and apoptosis assessment were used to evaluate the biological effects of the phage model peptides on keloid fibroblasts. Immunofluorescence assay was employed to show the binding affinity of the model peptides on phages causing keloid fibroblasts. Quantitative real-time PCR analysis was carried out to detect the expressions of nuclear factor κB (NF-κB) mRNA, connective tissue growth factor (CTGF) mRNA and TGF-ß receptor II (TßRII) mRNA in keloid fibroblasts. RESULTS: Specific phages with good results of ELISA were beneficiated. Four phage model peptides were obtained. The data of MTT showed that TGF-ß1 and one phage model peptide (No. 4) could promote keloid fibroblasts proliferation, however, three phage model peptides (No. 1 - 3) could inhibit keloid fibroblasts proliferation. The results of apoptosis assessment showed that the three phage model peptides could slightly induce the apoptosis in keloid fibroblasts. The data of immunofluorescence assay revealed that the model peptides on phages rather than phages could bind to keloid fibroblasts. The findings of quantitative real-time PCR analysis suggested that the expressions of NF-κB mRNA and CTGF mRNA in the three phage model peptide groups decreased, while the expression of TßRII mRNA slightly increased. CONCLUSIONS: Three phage model peptides isolated from a phage display 7-mer peptide library can inhibit keloid fibroblasts proliferation and induce the apoptosis in keloid fibroblasts. They can inhibit the activity of keloid fibroblasts by blocking TGF-ß1 binding to its receptor and then regulating the expressions of NF-κB, CTGF and TßRII.