Effects of vitamin family members on insulin resistance and diabetes complications

The following letter to the editor highlights the article "Effects of vitamin D supplementation on glucose and lipid metabolism in patients with type 2 diabetes mellitus and risk factors for insulin resistance" in World J Diabetes 2023 Oct 15; 14 (10): 1514-1523. It is necessary to explore the role of vitamin family members in insulin resistance and diabetes complications.

Insulin reduces pyroptosis-induced inflammation by PDHA1 dephosphorylation-mediated NLRP3 activation during myocardial ischemia-reperfusion injury

BACKGROUND

Previous studies proved that pyrin domain-containing protein 3 (NLRP3)-induced pyroptosis plays an important role in Myocardial ischemia-reperfusion injury (MIRI). Insulin can inhibit the activation of NLRP3 inflammasome, although the exact mechanism remains unclear. The aim of this study was to determine whether insulin reduces NLRP3-induced pyroptosis by regulating pyruvate dehydrogenase E1alpha subunit (PDHA1) dephosphorylation during MIRI.

METHODS

Rat hearts were subject to 30 min global ischemia followed by 60 min reperfusion, with or without 0.5 IU/L insulin. Myocardial ischemia-reperfusion injury was evaluated by measuring myocardial enzymes release, Cardiac hemodynamics, pathological changes, infarct size, and apoptosis rate. Cardiac aerobic glycolysis was evaluated by measuring ATP, lactic acid content, and pyruvate dehydrogenase complex (PDHc) activity in myocardial tissue. Recombinant adenoviral vectors for PDHA1 knockdown were constructed. Pyroptosis-related proteins were measured by Western blotting analysis, immunohistochemistry staining, and ELISA assay, respectively.

RESULTS

It was found that insulin significantly reduced the area of myocardial infarction, apoptosis rate, and improved cardiac hemodynamics, pathological changes, energy metabolism. Insulin inhibits pyroptosis-induced inflammation during MIRI. Subsequently, Adeno-associated virus was used to knock down cardiac PDHA1 expression. Knockdown PDHA1 not only promoted the expression of NLRP3 but also blocked the inhibitory effect of insulin on NLRP3-mediated pyroptosis in MIRI.

CONCLUSIONS

Results suggest that insulin protects against MIRI by regulating PDHA1 dephosphorylation, its mechanism is not only to improve myocardial energy metabolism but also to reduce the NLRP3-induced pyroptosis.

PDHA1 Alleviates Myocardial Ischemia-Reperfusion Injury by Improving Myocardial Insulin Resistance During Cardiopulmonary Bypass Surgery in Rats

OBJECTIVE

Cardiopulmonary bypass (CPB) is a requisite technique for thoracotomy in advanced cardiovascular surgery. However, the consequent myocardial ischemia-reperfusion injury (MIRI) is the primary culprit behind cardiac dysfunction and fatal consequences post-operation. Prior research has posited that myocardial insulin resistance (IR) plays a vital role in exacerbating the progression of MIRI. Nonetheless, the exact mechanisms underlying this phenomenon remain obscure.

METHODS

We constructed pyruvate dehydrogenase E1 α subunit (PDHA1) interference and overexpression rats and used ascending aorta occlusion in an in vivo model of CPB-MIRI. We devised an in vivo model of CPB-MIRI by constructing rat models with both pyruvate dehydrogenase E1α subunit (PDHA1) interference and overexpression through ascending aorta occlusion. We analyzed myocardial glucose metabolism and the degree of myocardial injury using functional monitoring, biochemical assays, and histological analysis.

RESULTS

We discovered a clear downregulation of glucose transporter 4 (GLUT4) protein content expression in the CPB I/R model. In particular, cardiac-specific PDHA1 interference resulted in exacerbated cardiac dysfunction, significantly increased myocardial infarction area, more pronounced myocardial edema, and markedly increased cardiomyocyte apoptosis. Notably, the opposite effect was observed with PDHA1 overexpression, leading to a mitigated cardiac dysfunction and decreased incidence of myocardial infarction post-global ischemia. Mechanistically, PDHA1 plays a crucial role in regulating the protein content expression of GLUT4 on cardiomyocytes, thereby controlling the uptake and utilization of myocardial glucose, influencing the development of myocardial insulin resistance, and ultimately modulating MIRI.

CONCLUSION

Overall, our study sheds new light on the pivotal role of PDHA1 in glucose metabolism and the development of myocardial insulin resistance. Our findings hold promising therapeutic potential for addressing the deleterious effects of MIRI in patients.

Integrated Proteomics and Metabolomics Analysis to Explore the Amelioration Mechanisms of Rosa roxburghii Tratt Fruit Polyphenols on Lipopolysaccharide-Induced Acute Lung Injury Mice

Acute lung injury (ALI) is the main cause of death for the elderly and children due to its high morbidity and mortality rates. Plant-derived functional foods are becoming increasingly important to the healthcare and food industries for adjunctive and alternative treatments of ALI. Polyphenols have been regarded to be beneficial to the prevention and amelioration of ALI. Rosa roxburghii Tratt fruit polyphenols (RRTP) has potential to prevent ALI, but mechanism remains unclear. This study was set up to systematically analyze the RRTP extract active ingredients, comprehensively evaluate its protective effects via lung histopathological examination, protein concentration, and cytokines production in ALI mice induced by lipopolysaccharide (LPS), and finally revealed alleviation mechanisms of the regulatory effects of RRTP by proteomics and metabolomics approach. The results demonstrated RRTP could synergistically exert significant preventive effects against ALI by notably ameliorating lung histopathological damage and pulmonary capillary permeability in ALI mice, inhibiting lung tissue inflammatory response and acute phase proteins and S-100 calcium binding proteins, suppressing excessive activation of complement and coagulation cascades, and regulating disordered lipids metabolism and amino acid metabolism. This study illustrated that RRTP has obvious advantages in ALI adjunctive therapy and revealed the complicated amelioration mechanisms, which provides a breakthrough for the development and demonstration of RRTP as a nutritional compound additive for complementary therapy of ALI.

[Characteristics and risk factors of spinal epidural hematoma after unilateral biportal endoscopic lumbar interbody fusion]

Objective: To investigate the incidence, characteristics and risk factors of spinal epidural hematoma after unilateral biportal endoscopic (UBE) lumbar spine surgery. Methods: The clinical data of 105 patients who underwent lumbar spine surgery under UBE in Guangdong Provincial People's Hospital from February 2020 to March 2021 were retrospectively reviewed. Of the patients, 48(45.7%) were male and 57(54.3%) were female, the mean age was (60.1±11.4) years (ranged 26 to 85 years). The MRI images at the third day post-surgery were observed, and the occurrence of hematoma was counted. Patients were assigned to normal group and hematoma group based on the presence of hematoma or not. The related clinical indicators of each patients were collected and used for comparison between two different groups. Logistic stepwise regression model was used to analyze whether each index was a risk factor for hematoma after the UBE lumbar fusion. Results: The total hematoma incidence rate was 28.6%(30/105), the symptomatic hematoma rate was 6.7%(7/105), and the hematoma reoperation rate was 0.9%(1/105). Univariate logistic regression analysis showed that hypertension (OR=3.368, 95%CI: 1.389-8.171), diabetes (OR=3.589, 95%CI: 1.230-10.476), admission systolic blood pressure>140 mmHg (1 mmHg=0.133 kPa,OR=3.687, 95%CI: 1.493-9.017), platelets<200×10⁹/L (OR=0.300, 95%CI: 0.119-0.785), preoperative blood calcium<2.25 mmol/L (OR=0.340, 95%CI: 0.142-0.818), spinal stenosis grade D (OR=4.462, 95%CI: 1.810-10.996) were possible risk factors for spinal hematoma after UBE lumbar fusion. Multivariate logistic regression analysis showed that admission blood pressure systolic blood pressure>140 mmHg (OR=3.788, 95%CI:1.055-13.606), preoperative blood calcium<2.25 mmol/L (OR=78.544, 95%CI:3.895-1 584.058) and spinal stenosis grade D (OR=3.698, 95%CI:1.110-12.325) were risk factors for spinal hematoma after UBE lumbar fusion (all P<0.05). Conclusion: The types of spinal canal hematoma after UBE lumbar fusion include localized and extended type. The risk factors for hematoma include high systolic blood pressure on admission, low preoperative blood calcium and severe spinal stenosis.

Acute or chronic inflammation role in gastrointestinal oncology

The following letter to the editor highlights the review titled “Inflammatory bowel disease-related colorectal cancer: Past, present and future perspectives” in World J Gastrointest Oncol 2022 March 15; 14(3): 547-567. It is necessary to explore the role of inflammation in promoting tumorigenesis and development of gastrointestinal cancers.

Bioinformatics prediction of potential mechanisms and biomarkers underlying dilated cardiomyopathy

BACKGROUND

Heart failure is a health burden responsible for high morbidity and mortality worldwide, and dilated cardiomyopathy (DCM) is one of the most common causes of heart failure. DCM is a disease of the heart muscle and is characterized by enlargement and dilation of at least one ventricle alongside impaired contractility with left ventricular ejection fraction < 40%. It is also associated with abnormalities in cytoskeletal proteins, mitochondrial ATP transporter, microvasculature, and fibrosis. However, the pathogenesis and potential biomarkers of DCM remain to be investigated.

AIM

To investigate the candidate genes and pathways involved in DCM patients.

METHODS

Two expression datasets (GSE3585 and GSE5406) were downloaded from the Gene Expression Omnibus database. The differentially expressed genes (DEGs) between the DCM patients and healthy individuals were identified using the R package "linear models for microarray data." The pathways with common DEGs were analyzed via Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and gene set enrichment analyses. Moreover, a protein-protein interaction network (PPI) was constructed to identify the hub genes and modules. The MicroRNA Database was applied to predict the microRNAs (miRNAs) targeting the hub genes. Additionally, immune cell infiltration in DCM was analyzed using CIBERSORT.

RESULTS

In total, 97 DEGs (47 upregulated and 50 downregulated) were identified. GO analysis showed that the DEGs were mainly enriched in "response to growth factor," "extracellular matrix," and "extracellular matrix structural constituent." KEGG pathway analysis indicated that the DEGs were mainly enriched in "protein digestion and absorption" and "interleukin 17 (IL-17) signaling pathway." The PPI network suggested that collagen type III alpha 1 chain (COL3A1) and COL1A2 contribute to the pathogenesis of DCM. Additionally, visualization of the interactions between miRNAs and the hub genes revealed that hsa-miR-5682 and hsa-miR-4500 interacted with both COL3A1 and COL1A2, and thus these miRNAs might play roles in DCM. Immune cell infiltration analysis revealed that DCM patients had more infiltrated plasma cells and fewer infiltrated B memory cells, T follicular helper cells, and resting dendritic cells.

CONCLUSION

COL1A2 and COL3A1 and their targeting miRNAs, hsa-miR-5682 and hsa-miR-4500, may play critical roles in the pathogenesis of DCM, which are closely related to the IL-17 signaling pathway and acute inflammatory response. These results may provide useful clues for the diagnosis and treatment of DCM.

[Effect of Dendrobium nobile Lindl. alkaloids on myocardial lipid metabolism during cardiopulmonary bypass ischemia-reperfusion in dogs]

Objective: To explore the effects and mechanisms of Dendrobium nobile Lindl. alkaloids (DNLA) on myocardial lipid metabolism during ischemia-reperfusion in dogs undergoing cardiopulmonary bypass (CPB). Methods: Twenty-four healthy hybrid dogs, half male and half female, were randomly divided into sham group, model group, solvent control group and treatment group (DNLA, 6 mg/kg) (n=6), all of which were established with CPB. Except for the sham group, the aorta of the other groups was occluded for 60 min and then reopened. The uptake rate of free fatty acids, the concentration of long-chain acyl coenzyme A (LCACoA), mRNA and protein expression of fatty acid translocase enzyme/CD36 (FAT/CD36) in myocardial tissue and the cardiac function indexes were measured at 4 time points: before cardiopulmonary bypass (T1), 15 min (T2), 60 min (T3), and 90 min (T4) after reperfusion in each group. Results: Before CPB, there were no statistically significant differences in the uptake rate of free fatty acids, the concentration of LCACoA and mRNA expression of FAT/CD36 in myocardial tissue in each group (P>0.05). After the opening of the aorta, the above indexes in model group [(35.8±4.7)%, (8.55±1.51) nmol/g, 3.23±0.68] and treatment group [(27.4±2.7)%, (6.10±1.38) nmol/g, 2.20±0.56] were higher than those in sham group [(19.6±3.9)%, (4.16±0.81)nmol/g, 1.19±0.52], which were the highest at T2, and then gradually decreased (all P<0.05). Compared with the model group, the increase of above indicators in the treatment group was significantly lower at T2 (all P<0.05). Before CPB, there was no statistically significant differences in cardiac function indexes [left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP) and±dp/dtmax] among the groups (P>0.05). After the aorta was opened, the above indexes in model group [(76.5±9.1) mmHg, (31.1±2.9) mmHg, (1.2±0.4) mmHg/ms, (-0.9±0.1) mmHg/ms] and treatment group [(92.9±8.7) mmHg, (25.3±3.6) mmHg, (1.8±0.4) mmHg/ms, (-1.3±0.1) mmHg/ms] were lower than those in sham group [(165.5±12.9) mmHg, (6.5±0.5) mmHg, (3.3±0.6) mmHg/ms, (-2.9±0.3) mmHg/ms] (all P<0.05), but the impairment degree of cardiac function indicators in treatment group was significantly lower than that those in model group (all P<0.05). Conclusion: During CPB in dogs, DNLA can inhibit the abnormal expression of FAT/CD36, decrease the uptake of free fatty acids, and reduce the abnormal accumulation of LCACoA in myocardium,thereby alleviating the myocardial injury after ischemia-reperfusion.

Expression pattern of estrogen receptor β and its correlation with multidrug resistance in non-small cell lung cancer

The aim of this work was to determine the expression of the ERβ (estrogen receptor β) and multidrug resistance, namely MDR1 (P-glycoprotein, P-gp), in 152 samples of non-small cell lung cancer. The expression pattern of ERβ and MDR1 were assessed by the quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) and immunohistochemistry. We also analyzed the correlation between ERβ and MDR1 with clinical and pathological data. The co-expression pattern of ERβ and individual MDR1 proteins was assessed by correspondence analysis and chi-squared tests. In the present study, we found that patients with tumor stage I-II showed higher ERβ mRNA expression levels and decreased expression of ERβ protein with increasing tumor grade, which is opposite to MDR1 expression. In addition, an opposite co-expression pattern of ERβ and individual MDR1 proteins was also observed. In conclusion, the results can be used to better understand the expression control of MDR1 and may allow for the establishment of new cancer chemistry strategies that will control P-gp expression in NSCLC.

Role of Phosphorylated AMP-Activated Protein Kinase (AMPK) in Myocardial Insulin Resistance After Myocardial Ischemia-Reperfusion During Cardiopulmonary Bypass Surgery in Dogs

Background

The aim of this study was to determine the role of AMP-activated protein kinase (AMPK) in myocardial insulin resistance after myocardial ischemia-reperfusion during cardiopulmonary bypass surgery in dogs.

Material/Methods

Twenty-four mongrel dogs were randomly assigned to 4 groups. The control group did not undergo aortic cross-clamping; the model group underwent 60 mins of aortic cross-clamping with 150 ml cardioplegic solution. The treatment group, the inhibition group respectively with 0.11mg/kg AICAR (AMPK agonist) in 150 ml cardioplegic solution and 0.11 mg/kg Compound C (AMPK inhibitor) in 150 ml cardioplegic solution. The blood flow was determined and left ventricular myocardial tissue were taken at pre-bypass, 15, 60, and 90 min after aorta declamping, respectively. Expression of AMPK mRNA, p-AMPK and GLUT-4 proteins was determined by RT-PCR, IHC and WB.

Results

Compared with the control group, receiving 60 min ischemia at 15 min after reperfusion, Myocardial Glucose Extraction Ratio were significantly decreased in the other 3 groups, it was significantly decreased from 20.0% to 1.2% at 60 min of reperfusion, and recovered to 6.1% after 90 min reperfusion in model group, while recovered to 4.1%, 12.0% after 90 min reperfusion respectively exposed to Compound C and AICAR. The expressions of p-AMPK, GLUT-4 protein and AMPK mRNA in myocardium were decreased in different experiment groups, but these changes occurred to a lesser extent in the treatment group.

Conclusions

The inability of GLUT-4 expression induced by the decreases in p-AMPK protein expression that may be one of the reasons for myocardial insulin resistance.

CCR7 enhances the angiogenic capacity of esophageal squamous carcinoma cells in vitro via activation of the NF-κB/VEGF signaling pathway

High levels of angiogenesis are associated with poor prognosis and a highly invasive phenotype in esophageal squamous carcinoma. C-C chemokine receptor type 7 (CCR7) is overexpressed in multiple tumor types and has been suggested to act as an oncogene and pro-angiogenic factor. This study aimed to elucidate the effect of CCR7 on the angiogenic capacity of esophageal squamous carcinoma cells in vitro. Expression of CCR7 in esophageal squamous carcinoma cell lines and normal human esophageal epithelial cell line was examined by western blotting and quantitative real-time PCR. CCR7 was stably overexpressed or transiently knocked down in esophageal squamous carcinoma cell lines. Overexpressing CCR7 enhanced the capacity of esophageal squamous carcinoma cell conditioned media to induce human umbilical vein endothelial cells (HUVEC) proliferation and migration and neovascularization in the chicken chorioallantoic membrane (CAM) assay. While silencing CCR7 caused an opposite outcome. Moreover, we demonstrated that CCR7 activated nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling and regulated its targets, including vascular endothelial growth factor A (VEGF-A), VEGF-C, tumor necrosis factor-α (TNFα), interleukin (IL)-6, IL-8 and transforming growth factor-β (TGF-β) expression. Additionally, CCR7 down-regulation reduced tumor volume and weight in xenograft mouse model, and significantly decreased NF-κB signaling pathway. This study suggests that CCR7 plays an important pro-angiogenic role in esophageal squamous carcinoma via a mechanism linked to activation of the NF-κB pathway; CCR7 may represent a potential target for anti-angiogenic therapy in esophageal squamous carcinoma.

[The multicenter study on the registration and follow-up of low anticoagulation therapy for the heart valve operation in China]

OBJECTIVE

To investigate the optimal anticoagulation methods and monitoring strategy for Chinese patients undergoing heart valve replacement, which is potentially quite different from western populations.

METHODS

In this multicenter prospective cohort study, the anticoagulation and monitoring strategy data was acquired from 25 773 in-hospital patients in 35 medical centers and 20 519 patients in outpatient clinic in 11 medical centers from January 1st, 2011 to December 31th, 2015.

RESULTS

As for in-hospital patients, mean age of study population was (48.6±11.2) years old; main etiology of valve pathology was rheumatic (87.5%) origin among study cohort; 94.8% of study population received mechanical valve implantation; international normalized ratio (INR) monitoring (in all the study centers) and low-intensity anticoagulation strategy (31 hospitals chose target INR range of 1.5-2.5, and actual values of INR among 89.2% of 100 069 in-hospital monitoring samples were 1.5-2.5), with mean actual INR values of 1.84±0.53, and warfarin dosage of (2.82±0.93) mg/d were widely adopted among the study centers; strategies of in-hospital warfarin administration were similar in all the study centers; complication rates of low-intensity anticoagulation strategy were low in severe hemorrhage (0.02%), thrombosis (0.05%), and thromboembolism (0.05%) events, without anticoagulation-related death.As for 18 974 outpatient clinic patients, the follow-up rate was 92.47%, with a total of 30 012 patient-years (Pty). Anticoagulation-related morbidity and mortality rates were 0.67% and 0.15% Pty; major hemorrhage morbidity and mortality rates were 0.25% and 0.13% Pty; thromboembolism morbidity and mortality rates were 0.45% and 0.03% Pty.The mean dosage of warfarin daily dosage was (2.85±1.23) mg/d and INR value was 1.82±0.57.No significant regional difference in the intensity of anticoagulation therapy was noted during the study.

CONCLUSIONS

INR can be used as a normalized indicator for intensity of anticoagulation therapy in China.The optimal anticoagulation intensity with INR range from 1.5 to 2.5 is safe and effective for Chinese patients with heart valve replacement, and there is no significant regional difference in the intensity of anticoagulation therapy.

Effects of RNA silencing of matrix metalloproteinase-2 on the growth of esophageal carcinoma cells in vivo

Esophageal carcinoma is one of the most common malignancies in China. Previous studies reported that matrix metalloproteinases (MMPs) have important roles in the progression and invasion of numerous types of solid tumors. Among the MMPs, MMP-2 has been closely associated with tumor growth and invasion. In the present study, a short hairpin RNA (shRNA) lentiviral expression vector targeting the MMP-2 gene was constructed in order to observe the inhibitory effect of MMP-2 gene silencing on the growth of the KYSE150 esophageal carcinoma cell line in vivo. Three small hairpin RNA sequences targeting MMP-2 were designed and cloned into lentiviral vectors. Following transfection of the lentiviral vectors into KTSE150 cells, MMP-2 mRNA and protein expression levels were examined by reverse transcription-quantitative polymerase chain reaction and western blotting, and the growth rate of cells was analyzed by MTT assays. Subsequently, tumor growth was assessed in nude mice. Lentivirus-mediated RNA interference effectively inhibited the expression of MMP-2 mRNA and protein in KYSE150 esophageal carcinoma cells, and suppressed the growth of esophageal carcinoma cells in vivo. The results of the present study suggested that lentivirus-mediated gene therapy targeting MMP-2 may be an attractive strategy for the treatment of esophageal carcinoma and justifies the performance of further studies on the application of lentivirus vectors to cancer gene therapy.

Video-assisted thoracoscopic surgery for adult Bochdalek hernia: a case report

Background

Bochdalek hernia is a type of congenital diaphragmatic hernia that typically presents in childhood, while this diseases is extremely rare in adults.

Case presentation

We review a case of a 63-year-old man with a left-sided Bochdalek hernia who was experiencing occasional pain at the left side of his chest for 8 months. The diagnosis of Bochdalek hernia was made by chest computed tomography. A part of the retroperitoneal adipose tissue was herniated into the left thoracic cavity through the diaphragmatic defect. The hernia was treated via video-assisted thoracoscopic surgery and he made an uneventful recovery.

Conclusions

We report a rare case of a left-sided Bochdalek hernia for which our patient was treated successfully via video-assisted thoracoscopic surgery. Even though rare, this disorder should be recognised, examined and treated appropriately to avoid complications.

Synergistic antitumor efficacy of antibacterial helvolic acid from Cordyceps taii and cyclophosphamide in a tumor mouse model

The antibacterial agent helvolic acid, which was isolated from the active antitumor fraction of Cordyceps taii, showed potent cytotoxicity against different human cancer cells. In the present study, the in vivo antitumor effect of helvolic acid was investigated in murine sarcoma S180 tumor-bearing mice. Doses of 10 and 20 mg/kg/day helvolic acid did not exert significant antitumor activity. Interestingly, co-administration of 10 mg/kg/day helvolic acid and 20 mg/kg/day cyclophosphamide (CTX) - a well-known chemotherapy drug - showed promising antitumor activity with a growth inhibitory rate of 70.90%, which was much higher than that of CTX alone (19.5%). Furthermore, the combination markedly prolonged the survival of tumor-bearing mice. In addition, helvolic acid enhanced the immune organ index. The protein expression levels of β-catenin, cyclin D1, and proliferating cell nuclear antigen were significantly suppressed in mice treated with 20 mg/kg/day helvolic acid and in those receiving combination therapy. Taken together, these results indicated that helvolic acid in combination with CTX showed potent in vivo synergistic antitumor efficacy, and its mechanism of action may involve the Wnt/ β-catenin signaling pathway.

miR-96 inhibits cardiac hypertrophy by targeting growth factor receptor-bound 2

Increasing evidence has indicated that microRNAs are involved in the pathogenesis of cardiac hypertrophy. However, whether miR-96 is involved in heart diseases, particularly cardiac hypertrophy, remains unclear. In this study, we found that miR-96 is a negative regulator of cardiac hypertrophy. In primary cardiomyocytes, overexpression of miR-96 inhibited phenylephrine-induced cardiomyocyte hypertrophy and decreased the mRNA expression of cardiac hypertrophy markers such as atrial natriuretic factor and β-myosin heavy chain. Interestingly, we found that growth factor receptor-bound 2 is a direct target of miR-96, which is a negative regulator of cardiac hypertrophy. Overexpression of miR-96 in cardiomyocytes led to reduced growth factor receptor-bound 2 expression. More importantly, miR-96 repressed the extracellular-regulated protein kinase signaling pathway by targeting growth factor receptor-bound 2 in cardiomyocytes. Our data demonstrate that miR-96 is a negative regulator of cardiac hypertrophy and extracellular-regulated protein kinase signaling, thus offering a new therapeutic strategy for cardiac hypertrophy.

Effect of Si-RNA-silenced HIF-1α gene on myocardial ischemia-reperfusion-induced insulin resistance

OBJECTIVE

To explore the effect (expression and implication) of hypoxia-inducible factor-1α (HIF-1α) silence induced by siRNA on the myocardial ischemia-reperfusion-induced insulin resistance in adult rats.

METHODS

One-step enzymolysis method was used to isolate adult rat cardiomyocytes; adult rat cardiomyocytes were cultured; HIF-1α gene-specific Si-RNA was constructed and transfected into rat cardiomyocytes using liposome method. Myocardial IRI model was prepared. HIF-1α and glucose transporter 4 (GLUT-4) mRNA expression was detected by RT-PCR; distribution of GLUT-4 protein expression in adult rat cardiomyocytes was detected by immunofluorescence; Western blot was used for the detection of HIF-1α protein expression; isotope tracer assay was used to detect the changes in cell glucose (Glu) uptake rate.

RESULTS

This method can stably get 85% to 90% active calcium tolerant adult rat cardiac myocytes, and the cultured cells were proved to be cardiomyocytes. After experiencing ischemia-reperfusion injury, HIF-1α mRNA expression levels in adult rat hypoxia cardiomyocytes had different degrees of increase compared with the control group (compared with the control group, P < 0.05). Compared with the model group, HIF-1α mRNA expression levels after ischemia and reperfusion in HIF-1αsi-RNA group and empty-vector group were lower than that in the control group and the model group; the expression reached the peak after 60 min of reperfusion, which did not change significantly in the control group. Expression of HIF-1α protein in myocardial cells was quite low in the control group; in the model group and intervention group, only after hypoxia-ischemia for 60 min, expression bands could be detected; especially in the model group, the expression had been increased until 60 min after reperfusion and began to decline from the time point of 180 min after reperfusion, but was still higher than that in the control group; in the intervention and empty-vector groups, it also increased rapidly at 60 min, but the expression was significantly lower than that in the model group; at 180 min after reperfusion, its protein expression peaked; while at 8 h after reperfusion, all the expression was extremely low. Compared with the control group, Glut4 mRNA expression in model group, transfected group and empty-vector group was reduced at the time points of T1-T4 (P < 0.05); the decline was the most significant at the time points of T1 and T2, followed by slightly increase at T3 and gradual recovery at T4; Compared with model group, Glut4 mRNA expression in transfection group was significantly reduced (P < 0.05); the decline was the most obvious at T1-T2, and then there was an increasing trend and it was recovered at T5 point. After experiencing ischemia, GLUT-4 protein expression changing trend was as follows: it was significantly reduced on the cell membrane, which was the most obvious from T1 to T3 and began to improve at T3, but still had not reached the level in the control group; it had been reached the levels of the control group at T5. After HIF-1αsi-RNA transfection and ischemia, GLUT-4 protein expression was increased in plasma and reduced on cell membrane; the decline was slightly improved at T3 and recovered to control distribution level at T5. After cardiac ischemia-reperfusion, glucose uptake rate decreased to varying degrees in myocardial cells and reached the lowest value after 60 min of ischemia, then gradually increased. After 8 h of reperfusion, the level in model group returned to the control level; compared with the model group, glucose concentration increased more serious in transfection group and empty-vector group after reperfusion.

CONCLUSION

HIF-1α played a central regulatory role in this mechanism; HIF-1α may be one of the molecular mechanisms triggering myocardial IR.

Antitumor and antimetastatic activities of chloroform extract of medicinal mushroom Cordyceps taii in mouse models

BACKGROUND

Cordyceps taii, an entomogenous fungus native to south China, is a folk medicine with varieties of pharmacological activities including anticancer effect. To validate the ethnopharmacological claim against cancer, the antitumor and antimetastatic activities of chloroform extract of C. taii (CFCT) were investigated in vivo.

METHODS

The in vitro cytotoxic activities of CFCT against human lung cancer (A549) and gastric cancer (SGC-7901) cells were evaluated using the Sulforhodamine B (SRB) assay. In vivo anti tumor and antimetastatic activities, Kunming mice bearing sarcoma 180 and C57BL/6 mice bearing melanoma B16F10 were employed, respectively. The antitumor effects of CFCT were completely evaluated on the basis of the tumor weight, survival time, histologic analysis, and immune organ indices. The histopathological change, metastatic foci and malignant melanoma specific marker HMB45 in the lung tissue were detected for the evaluation of the antimetastatic activity of CFCT.

RESULTS

CFCT exhibited dose- and time-dependent cytotoxicities against A549 and SGC-7901 cells with the IC50 values of 30.2 and 65.7 μg/mL, respectively. Furthermore, CFCT at a dose of 50 or 100 mg/kg could significantly inhibit the tumor growth in vivo and prolonged the survival time in two different models as compared with the model group, especially when combined with the CTX at a low dose rate. And it also increased spleen index of Kunming mice and thymus index of C57BL/6 mice. Meanwhile, histologic analysis illustrated that CFCT alone or in combination with CTX could induce tumor tissue necrosis of both models. In addition, CFCT at a dose of 50 or 100 mg/kg inhibited the lung metastasis of melanoma B16F10 in tumor-bearing C57BL/6 mice. The antimetastatic effect was also observed when CFCT was used in combination with CTX. In comparison to any other groups, CFCT at a dose of 100 mg/kg could effectively enhance the GSH-Px activities of various tissues in tumor-bearing C57BL/6 mice.

CONCLUSIONS

These findings demonstrate that CFCT has potent in vivo antitumor and antimetastatic activities, and may be helpful to the development of anticancer chemopreventive agents from C. taii.

[Influence of siRNA-mediated PPARgamma gene knockdown on insulin resistance induced by myocardial ischemia-reperfusion in rats]

OBJECTIVE

To observe the influenece of siRNA-mediated PPARgamma gene knockdown on insulin resistance induced by myocardial ischemia-reperfusion in adult rats.

METHOD

The targeting PPARgamma siRNA was synthesized. The myocardial cells of adult rats were isolated and cultured. They were divided into four groups: IRI group, siRNA-PPARgamma group, empty group and blank control group. Two groups of rat cardiac cells were transfected with PPARgamma-targeting siRNA (siRNA-PPARgamma group), or empty small interfering RNA (NC group), respectively. Real-time quantitive PCR was performed to detect the mRNA levels of PPARgamma and GLUT-4. PPARgamma protein expression level was determined with Western blot test. The uptake rate of glucose was determined by the isotope tracer method.

RESULT

The PPARgamma mRNA and protein expression of IRI group were significantly higher than those in blank control group (P < 0.05). The PPARgamma mRNA and protein expression of siRNA-PPARgamma group were significantly less than those in blank control and IRI group (P < 0.01). There was no significant difference in the PPARgamma mRNA and protein expression between the blank group and IRI group. The mRNA expression of GLUT-4 in blank control was no significant difference at each time point. The mRNA expression of GLUT-4 in IRI group was significantly less at 0 min, but increased gradually over the following time point. Finally, The mRNA expression of GLUT-4 in IRI group restored the same level as blank control. There was no significant difference in the GLUT-4 mRNA expression between the empty group and IRI group. The GLUT-4 mRNA expression in siRNA-PPARgamma group was significantly less than that in IRI group or NC group (P < 0.05), and recovered more slowly than IRI group. After given insulin, The uptake rate of glucose in siRNA-PPARgamma group was significantly less at each time point compared with those in IRI group (P < 0.05), declined by 49.78%, 38.94%, 18.61%, 11.54% at 0 min, 15 min, 1 h, 2 h, respectively. At 6 h time point, the uptake rate of glucose in siRNA-PPARgamma group reached the same level as IRI group. There was no significant difference was observed in the uptake rate of glucose between the empty group and IRI group.

CONCLUSION

The siRNA-mediated PPARgamma gene knockdown may enhance the myocardial insulin resistance. The molecular mechanisms that trigger myocardial cell insulin resistance might because the silence of PPARgamma expression decreasing the expression of GLUT-4 and decline its transportation from cytoplasm to membrane.

Expression of metallothionein and Nrf2 pathway genes in lung cancer and cancer-surrounding tissues

Background

Nuclear factor (erythroid-derived 2)-like (Nrf)2 and metallothionein have been implicated in carcinogenesis. This study investigated the expression of Nrf2 and of Nrf2-targeted genes (NQO1 and GCLC) and the genes for the metallothionein (MT) isoforms (MT-1A and MT-2A) in human lung cancer and cancer-surrounding tissues.

Methods

Surgically removed lung cancer samples (n = 80) and cancer-surrounding tissues (n = 38) were collected from Zunyi Medical College Hospital, China. Total RNA was extracted, purified, and used for real-time reverse transcription-PCR analysis of interested genes.

Results

Expression of the Nrf2-targed genes NQO1 and GCLC tended to be higher (30 to 60%) in lung cancers, but was not significantly different from that in peri-cancer tissues. By contrast, expression of the genes for M)-1A, MT-2A, and the metal transcription factor MTF-1 were three-fold to four-fold lower in lung cancers.

Conclusion

In surgical samples of lung cancer, MT expression was generally downregulated, whereas Nrf2 expression tended to be upregulated. These changes could play an integral role in lung carcinogenesis.

Role of insulin receptors in myocardial ischaemia-reperfusion injury during cardiopulmonary bypass

BACKGROUND

Ischaemia-reperfusion injury after cardiac bypass causes cardiac dysfunction and tissue damage. Insulin resistance during reperfusion contributes to the dysfunction, but the role of changes in myocardial insulin receptors during this period has not been determined yet.

METHODS

Twelve mongrel dogs underwent cardiac bypass, 6 for 30 min and 6 for 120 min. Blood samples were taken from the coronary artery and coronary sinus and tissue samples from the apex of the left ventricle before bypass and 15, 45, and 75 min after termination of bypass surgery and initiation of reperfusion. Plasma glucose and insulin, the Insulin Resistance Index, myocardial glycogen, insulin receptor alpha and beta subunits, and total insulin mRNA were measured in these samples.

RESULTS

Plasma glucose and insulin and the insulin resistance index all increased significantly during the reperfusion period. A significant decrease in myocardial glycogen occurred at the same time. The alpha subunits of the insulin receptor were seen on the myocyte surface and the beta subunits mostly in the cytoplasm.The expression of both subunits and total insulin mRNA decreased in a similar manner after termination of bypass surgery. All parameters gradually returned toward pre-bypass values as the post-bypass period progressed. And at all post-bypass time points, the 120-min bypass group showed a significantly greater effect from ischaemia than the 30-min bypass group.

CONCLUSION

A decrease in insulin receptor expression is a cause of post-bypass insulin resistance, and this decrease is initiated at the mRNA level. Increased insulin resistance leads to excessive reliance on myocardial glycogen as an energy source and a deficit in energy substrates that contributes to cardiac dysfunction.

[The effect of SenQi FuZheng injection on lung cell apoptosis following cardiopulmonary bypass in dogs]

OBJECTIVE

To study the effect and possible mechanism of SenQi FuZheng injection on lung cell apoptosis in dogs with ischemia reperfusion (I/R) following cardiopulmonary bypass (CPB).

METHODS

CPB dog models were established. The 12 mongrel dogs were randomly divided into two groups: CPB I/R group (control) and SenQi FuZheng injection group (therapy). The lung tissue samples of 1.0 cm3 from the same lobes of lung were obtained at 10 min before CPB (T1) and 60 (T2), 120 min (T3) after reperfusion. These samples were fixed and then embedded in paraffin imbedding, and cut into thin slices (5 microm). Streptavidin/peroxidase (SP) immunohistochemical method was employed to detect Caspase -3, Bcl-2, and Bax protein expressions.

RESULTS

The expressions of Caspase-3 and Bax protein in the tissues with SenQi FuZheng therapy were significantly lower at 60 and 120 min after reperfusion than the controls (P < 0.05). The expression of Bcl-2 protein and the Bcl-2/Bax ratio in the tissues with SenQi FuZheng therapy were significantly higher at 60 and 120 min after reperfusion than the controls (P < 0.05).

CONCLUSION

Administration of SenQi FuZheng injection in CPB dogs can inhibit apoptosis of alveolar cells by reducing the expressions of Caspase-3 and Bax protein and increasing the expression of Bcl-2 protein.

Cardiac glucose uptake and suppressed expression/translocation of myocardium glucose transport-4 in dogs undergoing ischemia-reperfusion

Impaired glucose metabolism is implicated in cardiac failure during ischemia-reperfusion. This study examined cardiac glucose uptake and expression of glucose transport-4 (GLUT-4) in dogs undergoing ischemia-reperfusion. Cardiac ischemia was induced by cardiopulmonary bypass for 30 min or 120 min in dogs. Plasma insulin and glucose concentrations were measured at pre-bypass (control), and aortic cross-clamp off (ischemia-reperfusion) at 15, 45, and 75 min. At the same time, the left ventricle biopsies were taken for GLUT-4 immunohistochemistry and glycogen content analysis. In dogs receiving 120-min ischemia, coronary arterial and venous glucose concentrations were increased, but the net glucose uptake in ischemia-reperfusion heart were significantly decreased from 25% (control) to zero at 15 and 45 min of reperfusion, and recovered to only 7% after 75 min reperfusion. Myocardium glycogen contents were decreased by 65%. Plasma insulin levels and Insulin Resistant Index were markedly increased in dogs undergoing 120-min ischemia and reperfusion. These changes were relatively mild and reversible in dogs receiving only 30-min ischemia followed by reperfusion. Expression of total GLUT-4 in myocardium was decreased 40% and translocation of GLUT-4 from cytoplasm to surface membrane was decreased 90% in dogs receiving 120-min ischemia followed by 15-min reperfusion. Suppressed translocation of GLUT-4 was also evident in dogs receiving 30-min ischemia, but to a lesser extent. Reduced myocardium glucose uptake, utilization, and glycogen content are clearly associated with ischemia-reperfusion heart injury. This appears to be due, at least in part, to suppressed expression and translocation of myocardium GLUT-4.

Accurate optical frequency-interval measurement by use of nonresonant frequency comb generation

A novel technique for measuring the separation of widely spaced optical frequencies is demonstrated. It relies on frequency comb generation by use of a laser that incorporates a frequency-shifting element. A Nd:YLF laser is used to produce a frequency comb that has a bandwidth of 140 GHz and that contains in excess of 875 discrete frequencies, accurately spaced by 160 MHz. The longitudinal mode spacing of a dual-frequency laser was measured to an accuracy of +/-5 kHz in 3,733,440.0 kHz by use of the technique described here.

Chemistry of the Burseraceae. XI. X-Ray-Diffraction Studies on Some Tirucall-7-ene Triterpenes From Aucoumea klaineana (Burseraceae)

In a recent study of the resin of Aucoumea klaineana several triterpenes with a tirucall-7-ene skeleton were isolated. X-ray diffraction analysis of flindissol lactone and flindissone lactone have confirmed the stereochemistry of the lactone ring formed through C21 and C23 to be (20S,23R), derived from a tirucallane precursor. A third triterpene was characterized as (225)-hydroxytirucalla-7,24-diene-3,23-dione.