Quantitative Intracerebral Iodine Extravasation in Risk Stratification for Intracranial Hemorrhage in Patients with Acute Ischemic Stroke

BACKGROUND AND PURPOSE

Intracerebral hemorrhage poses a severe threat to the outcomes in patients with postthrombectomy acute stroke. We aimed to compare the absolute intracerebral iodine concentration and normalized iodine concentration ratio in predicting intracerebral hemorrhage in patients postthrombectomy.

MATERIALS AND METHODS

Patients with acute anterior circulation large-vessel occlusion who underwent mechanical thrombectomy and had successful recanalization were retrospectively included in the study. Dual-energy CT was performed within 1 hour after mechanical thrombectomy. Postprocessing was performed to measure the absolute intracerebral iodine concentration and the normalized iodine concentration ratio. The correlation between the absolute intracerebral iodine concentration and the normalized iodine concentration ratio was analyzed using the Spearman rank correlation coefficient. We compared the area under the receiver operating characteristic curve of the absolute intracerebral iodine concentration and the normalized iodine concentration ratio using the DeLong test.

RESULTS

We included 138 patients with successful recanalization. Of 43 patients who did not have parenchymal contrast staining on postthrombectomy dual-energy CT, 5 (11.6%) developed intracerebral hemorrhage. Among patients (95/138, 68.8%) with parenchymal contrast staining, 37 (38.9%, 37/95) developed intracerebral hemorrhage. The absolute intracerebral iodine concentration was significantly correlated with the normalized iodine concentration ratio (ρ = 0.807; 95% CI, 0.718-0.867; P < .001). The cutoffs of the normalized iodine concentration ratio and absolute intracerebral iodine concentration for identifying patients with intracerebral hemorrhage development were 222.8%, with a sensitivity of 67.6% and specificity of 76.4%, and 2.7 mg I/mL, with a sensitivity of 75.7% and specificity of 65.5%, respectively. No significant difference was found between the areas under the receiver operating characteristic curve for the absolute intracerebral iodine concentration and the normalized iodine concentration ratio (0.753 versus 0.738) (P = .694).

CONCLUSIONS

The hemorrhagic transformation predictive power of the normalized iodine concentration ratio is similar to that of the absolute intracerebral iodine concentration in patients with successful recanalization.

The role of mitochondrial apoptotic pathway in islet amyloid-induced β-cell death

Islet amyloid, formed by aggregation of human islet amyloid polypeptide (hIAPP), contributes to β-cell death in type 2 diabetes. We previously showed that extracellular hIAPP aggregates promote Fas-mediated β-cell apoptosis. Here, we tested if hIAPP aggregates can trigger the mitochondrial apoptotic pathway (MAP). hIAPP aggregation in Ad-hIAPP transduced INS-1 and human islet β-cells promoted cytochrome c release, caspase-9 activation and apoptosis, which were reduced by Bax inhibitor. Amyloid formation in hIAPP-expressing mouse islets during culture increased caspase-9 activation in β-cells. Ad-hIAPP transduced islets from CytcKA/KA and BaxBak βDKO mice (models of blocked MAP), had lower caspase-9-positive and apoptotic β-cells than transduced wild-type islets, despite comparable amyloid formation. Blocking Fas (markedly) and Bax or caspase-9 (modestly) reduced β-cell death induced by extracellular hIAPP aggregates. These findings suggest a role for MAP in amyloid-induced β-cell death and a potential strategy to reduce intracellular amyloid β-cell toxicity by blocking cytochrome c apoptotic function.

Early overnutrition in male mice negates metabolic benefits of a diet high in monounsaturated and omega-3 fats

Overconsumption of saturated fats promotes obesity and type 2 diabetes. Excess weight gain in early life may be particularly detrimental by promoting earlier diabetes onset and potentially by adversely affecting normal development. In the present study we investigated the effects of dietary fat composition on early overnutrition-induced body weight and glucose regulation in Swiss Webster mice, which show susceptibility to high-fat diet-induced diabetes. We compared glucose homeostasis between a high-fat lard-based (HFL) diet, high in saturated fats, and a high-fat olive oil/fish oil-based (HFO) diet, high in monounsaturated and omega-3 fats. We hypothesized that the healthier fat profile of the latter diet would improve early overnutrition-induced glucose dysregulation. However, early overnutrition HFO pups gained more weight and adiposity and had higher diabetes incidence compared to HFL. In contrast, control pups had less weight gain, adiposity, and lower diabetes incidence. Plasma metabolomics revealed reductions in various phosphatidylcholine species in early overnutrition HFO mice as well as with diabetes. These findings suggest that early overnutrition may negate any beneficial effects of a high-fat diet that favours monounsaturated and omega-3 fats over saturated fats. Thus, quantity, quality, and timing of fat intake throughout life should be considered with respect to metabolic health outcomes.

[Untargeted metabolomic analysis of serum samples from children with mycoplasma pneumonia in a hospital in Beijing]

Objective: This study was aimed to analyze the untargeted metabolomics of serum samples from children with mycoplasma pneumonia in a hospital in Beijing. Methods: A total of 50 children with mycoplasma pneumonia as the case group were recruited from Department of Pediatrics, China-Japan Friendship Hospital in Beijing from January 2019 to February 2020, and meanwhile 50 age-and gender-matched heathy children were selected and formed the control group. 2 ml venous fasting blood samples was collected from all children. Serum metabolites were quantified by using the untargeted ultra-high performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) technique. Unsupervised principle component analysis and (orthogonal) partial least-squares-discriminant analysis were employed to identify differential metabolites between cases and controls. MBRole software was used for pathway enrichment analysis. Results: There were 27 boys and 23 girls in the case group with an average age of (6.0±3.65) years, and the control group consisted of 28 boys and 22 girls with an average age of (6.62±2.64) years. A total of 392 different metabolites were detected. Compared with the control group, 306 metabolites were decreased and 86 increased in case group. Forty-one differential metabolites with variable important in projection (VIP) values larger than 5 and P values less than 0.05 were teased out, and they mainly concentrated on phospholipid. The levels of 38 metabolites were significantly lower in the case group, yet 4 metabolites were significantly higher than that of the control group. Metabolic enrichment analysis showed that different metabolites were related to the biosynthesis of phenylalanine, tyrosine, tryptophan, unsaturated fatty acid, ammonia acyl tRNA and insulin signaling pathway, as well as the metabolism of ABC transporters. Conclusion: The serum untargeted metabolomics differed remarkably between children with mycoplasma pneumonia and healthy children.

[Expression and effect of microRNA-627 in human hypertrophic scar]

Objective: To investigate the expression and effect of microRNA-627 (miR-627) in human hypertrophic scar. Methods: The experimental research method was used. From October 2019 to January 2020, hypertrophic scar tissue from 6 patients with hypertrophic scar (2 males and 4 females, aged (34±11) years) and the remaining normal skin tissue from 6 trauma patients (3 males and 3 females, aged (35±13) years) after flap transplantation were collected. The above-mentioned 12 patients were admitted to the General Hospital of Northern Theater Command and met the inclusion criteria. The mRNA expression of miR-627 was detected by real-time fluorescent quantitative reverse transcription polymerase chain reaction. The 3rd to 5th passages of fibroblasts (Fbs) were isolated from hypertrophic scar tissue and cultured for subsequent experiments after identification. Fbs from hypertrophic scar were divided into miR-627 negative control group, miR-627 mimic group, and miR-627 inhibitor group. The corresponding sequences were transfected respectively. At 0 (immediately), 12, 24, 36, and 48 h after transfection, the cell viability was detected by thiazolyl blue method; at 24 h after transfection, the apoptosis was detected by flow cytometry; at 24 h after transfection, the protein expression levels of insulin-like growth factor Ⅰ (IGF-Ⅰ), type Ⅰ collagen, and α smooth muscle actin (α-SMA) were detected by Western blotting. Two batches of Fbs from hypertrophic scar were used, one batch was divided into IGF-Ⅰ wild type+miR-627 negative control group and IGF-Ⅰ wild type+miR-627 mimic group, and the other batch was divided into IGF-Ⅰ mutant+miR-627 negative control group and IGF-Ⅰ mutant+miR-627 mimic group. The corresponding sequences were transfected respectively. At 48 h after transfection, the expressions of luciferase and renal luciferase were detected by luciferase reporter gene detection kit, and the ratio of the two was calculated to reflect the activity of IGF-Ⅰ. Fbs from hypertrophic scar were divided into miR-627 negative control group, miR-627 mimic alone group, and miR-627 mimic+IGF-Ⅰ group, and were transfected with the corresponding sequences respectively. At 24 h after transfection, the protein expression levels of IGF-Ⅰ, type Ⅰ collagen, and α-SMA were detected by Western blotting. The number of samples in cell experiment was 3. Data were statistically analyzed with analysis of variance for factorial design, one-way analysis of variance, independent sample t test, and chi-square test. Results: The expression of miR-627 mRNA in hypertrophic scar tissue was 0.47±0.06, which was significantly lower than 1.12±0.23 in normal skin tissue (t=15.090, P<0.01). At 12, 24, 36, and 48 hours after transfection, the cell viability of miR-627 mimic group was significantly lower than that of miR-627 negative control group (t=9.918, 34.370, 13.580, 61.550, P<0.05 or P<0.01); the cell viability of miR-627 inhibitor group was significantly higher than that of miR-627 negative control group (t=4.722, 8.616, 13.330, 14.000, P<0.05 or P<0.01). At 24 h after transfection, compared with the apoptosis rate (8.42±0.47)% in miR-627 negative control group, (10.89±0.35)% in miR-627 mimic group was significantly higher (t=7.301, P<0.01), and (5.00±0.22)% in miR-627 inhibitor group was significantly lower (t=11.510, P<0.01). At 24 h after transfection, compared with the cell protein expressions of IGF-Ⅰ, type Ⅰ collagen, and α-SMA in miR-627 negative control group, those in miR-627 mimic group were significantly lower (t=25.470, 5.282, 7.415, P<0.01), and those in miR-627 inhibitor group were significantly higher (t=15.930, 8.857, 9.763, P<0.01). At 48 h after transfection, the luciferase/renal luciferase ratio of IGF-Ⅰ of cells in IGF-Ⅰ wild type+miR-627 mimic group was 0.463±0.061, which was significantly lower than 0.999±0.011 in IGF-Ⅰ wild type+miR-627 negative control group (t=16.852, P<0.01); the luciferase/renal luciferase ratio of IGF-Ⅰ of cells in IGF-Ⅰ mutant+miR-627 mimic group was 0.934±0.021, which was similar to 0.930±0.023 in IGF-Ⅰ mutant+miR-627 negative control group (t=1.959, P>0.05). At 24 h after transfection, the protein expressions of IGF-Ⅰ, type Ⅰ collagen, and α-SMA of cells in miR-627 mimic alone group were 1.623±0.070, 1.363±0.042, and 1.617±0.025, which were significantly lower than 2.723±0.045, 2.147±0.067, and 2.533±0.055 in miR-627 negative control group (t=22.831, 7.280, 26.220, P<0.01); the protein expressions of IGF-Ⅰ, type Ⅰ collagen, and α-SMA of cells in mimic+IGF-Ⅰ group were 2.477±0.102, 1.760±0.046, and 2.387±0.049, which were significantly higher than those of miR-627 mimic alone group (t=3.830, 8.286, 3.436, P<0.05 or P<0.01). Conclusions: miR-627 expression in human hypertrophic scars is down-regulated; miR-627 can inhibit the proliferation and promote the apoptosis of Fbs in human hypertrophic scar by targeted inhibition of IGF-Ⅰ expression.

[Effects and mechanism of eleutheroside E on the growth of human hypertrophic scar fibroblasts]

Objective: To investigate the effects and mechanism of eleutheroside E on the growth of human hypertrophic scar fibroblasts (Fbs). Methods: The experimental research method was used. The hypertrophic scar tissue was collected from 6 patients with hypertrophic scar (1 male and 5 females, aged 20 to 51 (37±8) years) admitted to General Hospital of Northern Theater Command, from October 2018 to March 2019. The third to seventh passages of human hypertrophic scar Fbs were cultured for later experiments. Cells were divided into normal saline group, 100 μmol/L eleutheroside E group, 200 μmol/L eleutheroside E group, and 400 μmol/L eleutheroside E group, and normal saline, eleutheroside E at the final molarity of 100, 200, and 400 μmol/L were added to cells in the corresponding groups. Cells were collected and divided into small interfering RNA (siRNA)-negative control alone group, siRNA-thrombospondin 1 (THBS1) alone group, siRNA-negative control+400 μmol/L eleutheroside E group, and siRNA-THBS1+400 μmol/L eleutheroside E group. Cells in siRNA-negative control alone group and siRNA-negative control+400 μmol/L eleutheroside E group were transfected with siRNA-negative control, cells in siRNA-THBS1 alone group and siRNA-THBS1+400 μmol/L eleutheroside E group were transfected with siRNA-THBS1. At 24 h after transfection, cells in siRNA-negative control alone group and siRNA-THBS1 alone group were added with normal saline, and cells in siRNA-negative control+400 μmol/L eleutheroside E group and siRNA-THBS1+400 μmol/L eleutheroside E group were added with eleutheroside E at the final molarity of 400 μmol/L. At 0 (immediately), 12, 24, 36, and 48 h after treatment, the cell proliferation activity (expressed as absorbance value) was detected by thiazolyl blue assay. Cells were divided into normal saline group, 200 μmol/L eleutheroside E group, 400 μmol/L eleutheroside E group, siRNA-negative control alone group, siRNA-THBS1 alone group, siRNA-negative control+400 μmol/L eleutheroside E group, and siRNA-THBS1+400 μmol/L eleutheroside E group. The corresponding treatments in each group were the same as before. At 24 h after treatment, the apoptosis was observed by Hoechst 33258 staining. Cells were collected and divided into normal saline group, 100 μmol/L eleutheroside E group, 200 μmol/L eleutheroside E group, 400 μmol/L eleutheroside E group, siRNA-negative control alone group, siRNA-THBS1 alone group, siRNA-negative control+400 μmol/L eleutheroside E group, and siRNA-THBS1+400 μmol/L eleutheroside E group. The corresponding treatments in each group were the same as before. At 24 h after treatment, the THBS1 protein level of cells was detected by Western blotting. The number of sample in each group was all 3 at each time point. Data were statistically analyzed with analysis of variance for factorial design, one-way analysis of variance, independent sample t test, and Bonferroni correction. Results: At 0 h after treatment, the absorbance values of cells in normal saline group, 100 μmol/L eleutheroside E group, 200 μmol/L eleutheroside E group, and 400 μmol/L eleutheroside E group were similar (P>0.05). At 12, 24, 36, and 48 h after treatment, the absorbance values of cells in 100 μmol/L eleutheroside E group, 200 μmol/L eleutheroside E group, and 400 μmol/L eleutheroside E group were significantly lower than those of normal saline group (t=7.64, 28.94, 13.69, 5.87, 6.96, 22.83, 14.75, 11.52, 21.09, 20.15, 29.52, 23.12, P<0.05 or P<0.01). At 0 h after treatment, the absorbance values of cells in siRNA-negative control alone group, siRNA-THBS1 alone group, siRNA-negative control+400 μmol/L eleutheroside E group, and siRNA-THBS1+400 μmol/L eleutheroside E group were similar (P>0.05). At 12, 24, 36, and 48 h after treatment, the absorbance values of cells in siRNA-THBS1 alone group and siRNA-negative control+400 μmol/L eleutheroside E group were significantly lower than those in siRNA-negative control alone group (t=7.14, 44.87, 20.67, 40.98, 9.26, 11.08, 15.33, 20.56, P<0.05 or P<0.01); the absorbance values of cells in siRNA-THBS1 alone group, siRNA-negative control+400 μmol/L eleutheroside E group, and siRNA-THBS1+400 μmol/L eleutheroside E group were similar (P>0.05). Compared with that in normal saline group, the numbers of apoptotic cells in 200 μmol/L eleutheroside E group and 400 μmol/L eleutheroside E group were increased at 24 h after treatment. At 24 h after treatment, compared with that in siRNA-negative control alone group, the numbers of apoptotic cells in siRNA-THBS1 alone group and siRNA-negative control+400 μmol/L eleutheroside E group were increased, while the numbers of apoptotic cells in siRNA-THBS1 alone group, siRNA-negative control+400 μmol/L eleutheroside E group, and siRNA-THBS1+400 μmol/L eleutheroside E group were similar. At 24 h after treatment, the protein levels of THBS1 of cells in 100 μmol/L eleutheroside E group, 200 μmol/L eleutheroside E group, and 400 μmol/L eleutheroside E group (0.87±0.12, 0.38±0.07, 0.20±0.09) were significantly lower than 1.83±0.17 in normal saline group (t=16.61, 16.17, 17.29, P<0.01). At 24 h after treatment, the protein levels of THBS1 of cells in siRNA-THBS1 alone group and siRNA-negative control+400 μmol/L eleutheroside E group (0.61±0.07, 0.58±0.07) were significantly lower than 1.86±0.07 in siRNA-negative control alone group (t=71.06, 83.80, P<0.01), and the protein levels of THBS1 of cells siRNA-THBS1 alone group, siRNA-negative control+400 μmol/L eleutheroside E group, and siRNA-THBS1+400 μmol/L eleutheroside E group (0.63±0.11) were similar (P>0.05). Conclusions: Eleutheroside E can inhibit the growth of human hypertrophic scar Fbs by down-regulating the expression of THBS1.

[Proliferation of hypertrophic scar fibroblasts inhibited by microRNA-627 targeting IGF-Ⅰin hypertrophic scar]

Objective: To investigate the mechanism of microRNA-627(miR-627) inhibiting the proliferation of hypertrophic scar fibroblasts (Fbs) by targeting IGF-I. Methods: The experimental method was used. From October 2019 to January 2020, hypertrophic scar tissues from 6 patients with hypertrophic scar (2 males and 4 females, aged (34±11) years) and the remaining normal skin tissues from 6 patients with trauma (3 males and 3 females, aged (35±13) years) after skin flap transplantation were collected. the above-mentioned 12 patients were admitted to the General Hospital of Northern Theater Command and met inclusion criteria. The mRNA expression of miR-627 was detected by real-time fluorescent quantitative reverse transcription polymerase chain reaction. The 3rd to 5th generations of Fbs were cultured from hypertrophic scar tissue for subsequent experiments. Fbs from hypertrophic scar were divided into miR-627 control group, miR-627 mimic group and miR-627 inhibitor group. The corresponding sequences were transfected respectively. At 0 (immediate), 12, 24, 36 and 48 h after transfection, the cell viability was detected by thiazolyl blue reagent; at 24 h after transfection, the apoptosis was detected by Annexin V-fluorescein-5-isothiocyanate/propidium iodide kit; at 24 h after transfection, the expression levels of IGF-Ⅰ, collagen I and a-SMA were detected by Western blot. The hypertrophic scar Fbs were divided into IGF-Ⅰ wild type + miR-627 control group, IGF- wild type + miR-627 mimics group, IGF-Ⅰ mutant + miR-627 control group. At 48 hours after transfection, the expression of luciferase and renal luciferase were detected by luciferase reporter gene detection kit, and the ratio of the two was calculated to reflect the activity of IGF-Ⅰ. Fbs from hypertrophic scar were divided into miR-627 control group, miR-627 mimic group and miR-627 mimic + IGF-I group, and were transfected with corresponding sequences respectively. At 24 h after transfection, the expression levels of IGF-Ⅰ, type I collagen and a-SMA were detected by Western blot. The number of samples in cell experiment was 3. Analysis of variance, one-way analysis of variance, t test and chi-square test were used to statistic the data. Results: The expression of miR-627 mRNA in hypertrophic scar tissue was 0.47±0.06, which was significantly lower than that in normal tissue 1.12±0.23 (t=15.090, P<0.01). At 12, 24, 36 and 48 hours after transfection, the cell viability of miR-627 mimic group was significantly lower than that of miR-627 control group (t=9.918, 34.370, 13.580, 61.550, P<0.05 or P<0.01); the cell viability of miR-627 inhibitor group was significantly higher than that of miR-627 control group (t=4.722, 8.616, 13.330, 14.000, P<0.05 or P<0.01). At 24 h after transfection, the apoptosis rate of miR-627 mimic group was (10.89±0.35)% significantly higher than that of miR-627 control group (8.42±0.47)% (t=7.301, P<0.01), and that of miR-627 inhibitor group was (5.00±0.22)% significantly lower significantly (t=11.510, P<0.01). At 24 h after transfection, compared with miR-627 control group, miR-627 mimics could significantly down regulate the expression of IGF-Ⅰ, type I collagen and a-SMA (t=25.470, 5.282, 7.415, P<0.05); miR-627 inhibitor could up regulate the expression of IGF-Ⅰ, type I collagen and a-SMA (t=15.930, 8.857, 9.763, P<0.05). At 48 h after transfection, the luciferase/renal luciferase ratio of IGF-Ⅰ in IGF-Ⅰ wild type + miR-627 mimic group was 0.463±0.061, which was significantly lower than that of IGF-Ⅰ wild type + miR-627 control group 0.999±0.011 (t=16.852, P<0.01), The luciferase/renal luciferase ratio of IGF-mutant + miR-627 mimic group was 0.934±0.021, which was similar to that of IGF-Ⅰ mutant+miR-627 control group 0.930±0.023 (t=1.959, P>0.05). After 24 hours of transfection, the protein expressions of IGF-Ⅰ, collagen I and a-SMA in miR-627 mimic group were 1.623±0.070, 1.363±0.042 and 1.617±0.025, which were significantly lower than those in miR-627 control group 2.723±0.045, 2.147±0.067 and 2.533±0.055 (t=22.831, 7.280 and 26.220, P<0.05); The protein expression of miR-627 mimic+IGF-Ⅰ group was 2.477±0.102, 1.760±0.046, 2.387±0.049, which was significantly higher than that of miR-627 mimic group (t=3.83, 8.286, 3.436, P<0.05). Conclusion: miR-627 can inhibit the proliferation of Fbs in hypertrophic scar by targeting IGF-Ⅰ.

The feasibility of dual-energy CT to predict the probability of symptomatic intracerebral haemorrhage after successful mechanical thrombectomy

AIM

To study the ability of dual-energy computed tomography (DECT) after successful mechanical thrombectomy (MT) to predict symptomatic intracerebral haemorrhage (sICH) in anterior circulation acute ischaemic stroke (AIS).

MATERIALS AND METHODS

From June 2018 to February 2020, 102 AIS patients with DECT performed immediately after successful MT were enrolled prospectively. According to the presence of iodine contrast media extravasation (ICME) on DECT and subsequent sICH development, patients were classified into four groups. The neurological outcome was compared among groups. Imaging parameters, together with clinical factors, were investigated for sICH prediction based on a linear logistic regression model after class-imbalance resolved by Synthetic Minority Sampling Technique (SMOTE) method.

RESULTS

Among 102 patients, patients (14.7%, 15/102) with the presence of sICH experienced worse outcomes than others without sICH (p<0.001). No case without ICME was observed with sICH development (0/102). The parameters derived from DECT have excellent performance for sICH prediction after successful MT, which is better than clinical predictive model boosted data (area under the curve [AUC]: DECT 0.87 versus clinical prediction 0.65), cross-validation results (AUC: DECT 0.87 versus clinical prediction 0.65), and original data (AUC: DECT 0.85 versus clinical prediction 0.68). By combining clinical and radiological parameters, the predictive performance for sICH could be further improved with an AUC of 0.90 (95% CI: 0.85-0.96).

CONCLUSIONS

Based on DECT parameters acquired immediately after successful MT, the present model was more efficient than the clinical model for accurate prediction of sICH. Rho and ICME volume appeared to be the best parameters for predicting sICH using DECT.

[Expression and effect of microRNA-205 in hypertrophic scar]

Objective: To investigate the expression and effect of microRNA-205 (miR-205) in hypertrophic scar. Methods: The experimental research method were applied. From October 2019 to January 2020, hypertrophic scar tissue from 6 patients with hypertrophic scar [1 male and 5 females, aged (36±7) years], and remaining normal skin tissue from 6 trauma patients [2 males and 4 females, aged (38±9) years] after flap transplantation operation were collected. The above-mentioned 12 patients were admitted to the General Hospital of Northern Theater Command and met the inclusion criteria. Real time fluorescent quantitative polymerase chain reaction was used to detect the mRNA expressions of miR-205 and thrombospondin-1 (TSP-1). The hypertrophic scar tissue was taken to culture the 3rd to 5th passage of fibroblasts (Fbs) for the follow-up experiments. Fbs of hypertrophic scar was divided into TSP-1+miR-205 control group, TSP-1+miR-205 mimic group, TSP-1 mutant+miR-205 control group, TSP-1 mutant +miR-205 mimic group, which were transfected with the corresponding sequences. At 48 h after transfection, the expressions of luciferase and renal luciferase were detected by luciferase reporter gene detection kit, and the luciferase/renal luciferase ratio was calculated to indicate the activity of TSP-1. Two batches of hypertrophic scar Fbs were collected and divided into miR-205 control group, miR-205 mimic group, and miR-205 inhibitor group and miR-205 control group, miR-205 mimic group, and miR-205 mimic+TSP-1 group, respectively, which were transfected with the corresponding sequences. At 0 (immediately), 12, 24, 36, and 48 h after transfection, the cell viability was detected by microplate reader. Two batches of hypertrophic scar Fbs were collected, grouped, and treated as the cell viability detecting experiment. At 24 h after transfection, Hoechst 33258 staining was performed to observe the nuclear shrinkage, so as to reflect the apoptosis of Fbs. The number of samples in cell experiment was 3. Data were statistically analyzed with analysis of variance for factorial design, one-way analysis of variance, and t test. Results: The mRNA expression of miR-205 in hypertrophic scar tissue was 0.54±0.05, which was significantly lower than 1.26±0.07 in normal skin tissue (t=8.213, P<0.01). The expression of TSP-1 mRNA in hypertrophic scar tissue was 1.46±0.07, which was significantly higher than 0.68±0.11 in normal skin tissue (t=6.031, P<0.01). At 48 h after transfection, the luciferase/renal luciferase ratio reflecting the TSP-1 activity of cells in TSP-1+miR-205 mimic group was 0.532±0.028, which was significantly lower than 0.998±0.012 in TSP-1+miR-205 control group (t=26.500, P<0.01), and the luciferase/renal luciferase ratio of cells in TSP-1 mutant+miR-205 mimic group was 0.963±0.012, which was close to 0.976±0.010 in TSP-1 mutant+miR-205 control group (t=0.816, P>0.05). At 12, 24, 36, and 48 h after transfection, the cell viability in miR-205 mimic group was significantly lower than that in miR-205 control group (t=6.169, 12.670, 27.130, 12.670, P<0.05 or P<0.01). At 0, 12, 24, 36, and 48 h after transfection, the cell viability in miR-205 inhibitor group was significantly higher than that in miR-205 control group (t=6.169, 7.221, 7.787, 7.835, 13.030, P<0.05 or P<0.01). At 12, 24, 36, and 48 h after transfection, the cell viability in miR-205 mimic group was significantly lower than that in miR-205 control group and miR-205 mimic+TSP-1 group (t=8.118, 26.970, 39.550, 42.490, 14.570, 12.240, 36.830, 45.220, P<0.05 or P<0.01). At 24 h after transfection, compared with miR-205 control group, the cell apoptosis in miR-205 mimic group was increased, and the cell apoptosis in miR-205 inhibitor group was decreased. At 24 h after transfection, compared with miR-205 mimic group, the cell apoptosis in miR-205 control group miR-205 mimic+TSP-1 group were decreased. Conclusions: miR-205 can inhibit the proliferation and promote the apoptosis of Fbs in hypertrophic scar by inhibiting the expression of TSP-1, which has the potential to be the therapeutic target for hypertrophic scar.

Early overnutrition reduces Pdx1 expression and induces β cell failure in Swiss Webster mice

Childhood obesity and early rapid growth increase the risk for type 2 diabetes. Such early overnutrition can be modeled in mice by reducing litter size. We investigated the effects of early overnutrition and increased dietary fat intake on β cell function in Swiss Webster mice. On a moderate-fat diet, early overnutrition accelerated weight gain and induced hyperinsulinemia in pups. Early overnutrition males exhibited higher β cell mass but reduced islet insulin content and Pdx1 expression. Males had a high diabetes incidence that was increased by early overnutrition, characterized by a progressive increase in insulin secretion as well as β cell death, indicated by histological analysis and increased circulating miR-375 levels. Females maintained normoglycemia throughout life. High-fat diet (HFD) increased diabetes incidence in males, whereas low-fat diet was completely protective. This protective effect was abolished in early overnutrition males transiently exposed to HFD in early life. Although Swiss Webster mice are not known to be diabetes-prone, the high diabetes incidence suggests an underlying genetic susceptibility that can be induced by overnutrition and increased dietary fat intake in early life. Thus, the nutritional environment in early life may impact long-term β cell function and increase diabetes risk, particularly in genetically susceptible individuals.

Amyloid formation disrupts the balance between interleukin-1β and interleukin-1 receptor antagonist in human islets

Objectives

β-cell dysfunction and apoptosis associated with islet inflammation play a key role in the pathogenesis of type 2 diabetes (T2D). Growing evidence suggests that islet amyloid, formed by aggregation of human islet amyloid polypeptide (hIAPP), contributes to islet inflammation and β-cell death in T2D. We recently showed the role of interleukin-1β (IL-1β)/Fas/caspase-8 apoptotic pathway in amyloid-induced β-cell death. In this study, we used human islets in culture as an ex vivo model of amyloid formation to: (1) investigate the effects of amyloid on islet levels of the natural IL-1 receptor antagonist (IL-1Ra); (2) examine if modulating the IL-1β/IL-1Ra balance can prevent amyloid-induced β-cell Fas upregulation and apoptosis.

Methods

Isolated human islets (n = 10 donors) were cultured in elevated glucose (to form amyloid) with or without a neutralizing human IL-1β antibody for up to 7 days. Parallel studies were performed with human islets in which amyloid formation was prevented by adeno-siRNA-mediated suppression of hIAPP expression (as control). β-cell levels of IL-1Ra, Fas, apoptosis as well as islet function, insulin- and amyloid-positive areas, and IL-1Ra release were assessed.

Results

Progressive amyloid formation in human islets during culture was associated with alterations in IL-1Ra. Islet IL-1Ra levels were higher at early stages but were markedly reduced at later stages of amyloid formation. Furthermore, IL-1Ra release from human islets was reduced during 7-day culture in a time-dependent manner. These changes in IL-1Ra production and release from human islets during amyloid formation adversely correlated with islet IL-1β levels, β-cell Fas expression and apoptosis. Treatment with IL-1β neutralizing antibody markedly reduced amyloid-induced β-cell Fas expression and apoptosis, thereby improving islet β-cell survival and function during culture.

Conclusions

These data suggest that amyloid formation impairs the balance between IL-1β and IL-1Ra in islets by increasing IL-1β production and reducing IL-1Ra levels thereby promoting β-cell dysfunction and death. Restoring the IL-1β/IL-1Ra ratio may provide an effective strategy to protect islet β-cells from amyloid toxicity in T2D.

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Endogenous amyloid formation alters IL-1Ra levels in human islet β-cells.

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Amyloid impairs islet IL-1β/IL-1Ra balance by promoting IL-1β and reducing IL-1Ra.

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Restoring IL-1β/IL-1Ra ratio by blocking IL-1β protects human islets against amyloid.

Identification of potential therapeutic targets for melanoma using gene expression analysis

Metastatic melanoma represents a significant cause of death in patients with melanoma and the frequency is increasing. The aim of this study was to identify potential therapeutic targets for metastatic melanoma. Gene expression profile GSE44660 was downloaded from Gene Expression Omnibus database. A total of 22 samples were analyzed in our study, including 3 specimens of normal melanocytes, 12 specimens of melanoma LNM (lymph node metastasis) and 7 specimens of MBM (melanoma brain metastasis). DEGs (differentially expressed genes) in LNM and MBM were identified respectively using Limma package. GO (Gene Ontology) and KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways analyses of common DEGs between two comparison groups were performed using DAVID, followed by cancer-related genes and transcription factor analysis. PPI (protein-protein interaction) network was constructed by STRING, and significant key genes were selected. Totally, 401 common DEGs were identified. Disease analysis showed that ICAM1 (intercellular adhesion molecule 1) and NBN (nibrin) were related to melanoma. In the PPI network, BIRC5 (baculoviral IAP repeat containing 5), BUB1 (BUB1 mitotic checkpoint serine/threonine kinase), GMNN (geminin, DNA replication inhibitor), AURKA (aurora kinase A), TOP2A (topoisomerase (DNA) II alpha) and BUB1B (BUB1 mitotic checkpoint serine/threonine kinase B) were with higher degree more than 50. ICAM1, NBN, BIRC5, BUB1, BUB1B, GMNN, AURKA and TOP2A may play key roles in the progression and development of melanoma. They may be used as specific therapeutic targets in the treatment of metastatic melanoma. However, further experiments are still needed to confirm our results.

In vitro and in vivo studies of antitumor effects of the recombinant immunotoxin MSH-PE38KDEL on melanoma

MSH-PE38KDEL is a chimeric molecule composed of MSH, and fused to a truncated mutant form of Pseudomonas exotoxin (PE38KDEL). Our study aims to evaluate the specific cytotoxicity of recombinant immunotoxin MSH-PE38KDEL on melanoma cells A875 and B16 in vitro, as well as its inhibition of metastatic melanoma in vivo. MSH-PE38KDEL was expressed in Escherichia coli, and greater than 90% purity was obtained. The purified MSH-PE38KDEL was found to be selectively cytotoxic to MSH receptor-positive melanoma cells in vitro. The specific cytotoxicity of recombinant MSH-PE38KDEL to A875 and B16 was over 85% by cell viability assay; however, MSH-PE38KDEL had no cytotoxicity to the human 2BS cells. The anti-tumor activity of MSH-PE38KDEL was evaluated in mice with induced melanoma through intra-tumor or intravenous administration. The results showed that 90% melanoma growths were inhibited, and 40% of the tumors were disappeared completely. Histopathology results showed MSH-PE38KDEL can effectively inhibit intrahepatic metastasis. In conclusion, MSH-PE38KDEL had cytotoxic effects on MSH receptor-positive melanoma cells, and causes significant tumor growth inhibition. These results support a possible new approach for the treatment of melanoma.

[Simultaneous determination of tryptophan and tyrosine by second order derivative fluorimetry]

A new method of second order derivative fluorimetry for the simultaneous determination of tryptophan and tyrosine is described. The measurement of emission spectra is carried out with excitation at 221 nm in a KH2PO4-NaOH buffer solution (pH = 7.4). The second-derivative peak is at 318 nm and 283 nm for tryptophan and tyrosine respectively. The two amino acids can be determined directly from corresponding second order derivative signals. Linear regression equation of the calibration graph is c = 0.000 7H-0.004, with a correlation coefficient of linear regression of 0.9964 for tryptophan and c = 0.001 2H-0.0040, with a correlation coefficient of linear regressin of 0.9971 for tyrosine. The linear ranges of determination of tryptophan and tyrosine are from 0.004 to 0.200 microgram.mL-1 and from 0.002 to 0.025 microgram.mL-1, respectively. Effects of pH, temperature and foreign ions on the determination of tryptophan and tyrosine have been examined. Recovery is from 92.0% to 104% for tryptophan and 98.7% to 102.0% for tyrosine, and relative standard deviation of 3.5% and 2.8%, respectively.