Insulin receptor substrate 2 plays important roles in 17beta-estradiol-induced bone formation

BACKGROUND

Discovering the mechanisms of the estrogen effects on the osteoblasts is very important for the development of new agents which have the clear-cut beneficial effects of estrogen while free of adverse effect.

AIM

The aim of this study was to investigate the differential gene expression of 17beta-estradiol (E2)-treated osteoblast-like cells, and the effect of E2 on the insulin receptor substrate 2 (IRS- 2) expression in human cultured osteoblast-like cells and the osteoblasts of ovariectomized (OVX) rats.

MATERIAL AND METHODS

The differential gene expression of E2-treated osteoblast- like cells was analyzed by cytokine expression array and validated by RT-PCR and Western blot analysis. The protein expression and phosphorylation of one of the differentially expressed gene, IRS-2, treated at different times with E2 were analyzed. The Sprague-Dawley rats were ovariectomized and then treated with E2, the IRS-2 expression was analyzed by immunohistochemistry analysis.

RESULTS

E2 upregulated the mRNA expression of IRS-2, bone morphogenetic protein 9, and connective tissue growth factor expression, down-regulated the mRNA expression of matrix metalloproteinase 15 and some tumor suppressor genes. Peak expression of IRS-2 was observed at 12-24 h of treatment by 10-8M E2. E2 can also increase the phosphorylation of IRS-2. The IRS-2 expression was down-regulated in the osteoblasts and bone marrow cells of the OVX rats, which had lower bone mineral density (BMD) than the normal rats. However, both BMD and IRS-2 expression can be rescued by 10-8M E2 in the OVX rats.

CONCLUSION

IRS-2 in osteoblast is up-regulated by E2 and plays important roles in the estrogen- induced bone formation.

Detection and analysis of Borna disease virus in Chinese patients with neurological disorders

BACKGROUND AND PURPOSE

Borna disease virus (BDV) is a neurotropic RNA virus that is known to cause neurological disturbances in various animal species, potentially even humans. However, the association between BDV infection and human neurological disorders remains unclear.

METHODS

Between August 2005 and March 2006, 65 patients with neurological disorders were enrolled into our study. The presence of BDV p24 RNA from peripheral blood mononuclear cells (PBMCs) was investigated by using nested reverse transcriptase PCR (RT-PCR) assay.

RESULTS

Borna disease virus p24 RNA was detected from PBMCs in six patients with viral encephalitis by using nested RT-PCR assay. However, BDV p24 RNA was not detected in patients with multiple sclerosis or peripheral nerve diseases.

CONCLUSION

There might be possible associations between BDV infection and human viral encephalitis.

Elaboration of an electroporation protocol for large plasmids and wild-type strains of Bacillus thuringiensis

AIMS

To elaborate an effective electroporation protocol for large plasmids and wild type strains of Bacillus thuringiensis.

METHODS AND RESULTS

The effect of DNA desalting, wall-weakening agency, cell growth conditions, electroporation solutions, and electric fields on electroporation efficiency was evaluated to optimize electroporation conditions for B. thuringiensis. By using this improved method, the greatest efficiency was reached 2 x 10(10 )CFU microg(-1) with pHT304, which is 10(4) times higher than previously reported. Four large plasmids (29.1, 44.9, 58 and 60 kb) were successfully transferred into the acrystalliferous B. thuringiensis strain BMB171; these results have not been achieved with previous protocols. Three wild type B. thuringiensis strains which could not be transformed previously were also transferred successfully.

CONCLUSIONS

This improved method is more efficient for small plasmids; it is also appropriate for large plasmids and wild type B. thuringiensis strains which were not transformed by previous procedures.

SIGNIFICANCE AND IMPACT OF THE STUDY

The present study established an effective electroporation protocol for large plasmids and wild type strains of B. thuringiensis. This method is well suited for the cloning and expression of huge DNA fragments such as gene clusters in B. thuringiensis. It also can be used as a reference method for other Bacillus strains that are refractory to electroporate.

Callus distraction for humeral nonunion with bone loss and limb shortening caused by chronic osteomyelitis

Nonunion of the humerus with bone loss and shortening due to osteomyelitis is rare but difficult to treat. We describe our experience with a callus distraction technique using a monolateral external fixator for the treatment of this condition. Between October 1994 and January 2004, 11 patients were treated. There were seven males and four females, with a mean age of 14 years (10 to 17). The mean bone loss was 1.9 cm (1 to 2.7) and the mean length discrepancy in the upper limb was 5.6 cm (3.5 to 8.0). The mean follow-up was for 106 months (54 to 166). The mean external fixation index was 34.8 days/cm (29.8 to 40.5). The mean lengthening was 9.5 cm (5.5 to 13.4). There were seven excellent results, three good and one poor. There were nine excellent functional results and two good. The treatment of humeral nonunion with bone loss and shortening due to osteomyelitis by callus distraction is a safe and effective means of improving function and cosmesis.

Vegetative insecticidal protein enhancing the toxicity of Bacillus thuringiensis subsp kurstaki against Spodoptera exigua

AIMS

The objective of this work was to enhance the insecticidal activity or widen the pesticidal spectrum of a commercial Bacillus thuringiensis strain YBT1520.

METHODS AND RESULTS

A vegetative insecticidal protein gene vip3Aa7, under the control of its native promoter and cry3A promoter, was subcloned into B. thuringiensis acrystalliferous BMB171 to generate BMB8901 and BMBvip respectively. It was found that the amount of Vip3Aa7 protein produced by BMBvip was 3.2-fold more than that produced by BMB8901. Therefore, the vip3Aa7 gene under the control of cry3A promoter was transformed into strain YBT1520. The toxicity of the resulting strain BMB218V against Spodoptera exigua was 10-fold more than that of YBT1520, and that the toxicity of BMB218V against Helicoverpa armigera retained the same level as that of strain YBT1520.

CONCLUSIONS

Strain YBT1520 obtained high toxicity against S. exigua after it was transformed and expressed the foreign vip3Aa7 gene.

SIGNIFICANCE AND IMPACT OF THE STUDY

Commercial B. thuringiensis strain YBT1520 has high toxicity against H. armigera and Plutella xylostella, but almost no activity against S. exigua, which is a major crop pest in China. This work provides a new strategy for widening the activity spectrum of B. thuringiensis against agriculture pests.

[Apoptosis of chondrocytes in experimental osteoarthritis]

The right knees of rabbits were immobilized in full extension for up to eight weeks using plaster cast. Specimens of the articular cartilage obtained from tibial plateau were studied by histopathologic and TDT-mediated fluorescein-dUTP nick-end labelling(TUNEL) techniques. The results showed that TUNEL-positive chondrocytes with apoptosis specific morphology were detected on superficial and middle layer of the articular cartilage from one to two weeks after immobilization, and these changes progressed until 4 weeks after immobilization. Six weeks after immobilization, TUNEL-positive chondrocytes were seen through the entire thickness of the articular cartilage. Our findings indicate that apoptosis of chondrocytes could be induced by immobilization and might be responsible for articular cartilage degeneration, and which is one of the pathways involved in the pathophysiological mechanism of osteoarthritis.

Treatment of diffuse alveolar hemorrhage after allogeneic bone marrow transplant with recombinant factor VIIa

Diffuse alveolar hemorrhage (DAH) is a potentially life-threatening pulmonary toxicity that occurs in 1-21% of patients following bone marrow transplantation. The syndrome is associated with a high mortality rate; and current treatment options are limited. Recombinant factor VIIa (rFVIIa, Novoseven) has recently been approved for the treatment of bleeding in patients with hemophilia A/B with inhibitors. A greater understanding of the mechanism by which rFVIIa restores hemostasis has recently become available; with in vitro evidence supporting that the thrombin burst achieved by rFVIIa is independent of the presence or binding to tissue factor. This insight has suggested a range of other potential clinical uses for the drug; including the setting of pulmonary hemorrhage. We review our experience with using rFVIIa for treatment of DAH in a patient with acute myelogenous leukemia following a matched unrelated donor bone marrow transplant. Boluses of 90 microg/kg rFVIIa were given every 3 h x 4 doses/day, concurrently with high-dose corticosteroids and maintenance of a platelet count >50 000/mm(3). Rapid clinical and radiological improvement was noted within several doses of rFVIIa, with discontinuation of the drug after eight doses. However, the patient's clinical condition began to rapidly deteriorate following cessation of rVIIa, resulting in reinstitution of therapy 24 h later. The patient again exhibited rapid clinical improvement; and rFVIIa was continued for an additional 16 doses with no further evidence of pulmonary hemorrhage noted. No toxicity or adverse events were observed with rFVIIa treatment. Our experience indicates that rFVIIa may be an effective treatment option for DAH post bone marrow transplant; although further clinical studies are needed before recommendations can be made regarding off label use of rFVIIa in this clinical setting.

A novel strategy for the generation of angiostatic kringle regions from a precursor derived from plasminogen

In this study we have explored the feasibility of generating angiostatin by incorporating an endoproteolytic furin cleavage site into plasminogen to allow conversion of the precursor molecule into an angiostatic active K1-3 fragment. We show that secretable angiostatin can be successfully generated from cells infected with adenovirus carrying the furin-mutated plasminogen (AdmuthPlgK3). Supernatant from cells transduced with AdmuthPlagK3 inhibits tube formation and proliferation and migration of human umbilical vein endothelial cells with an efficiency similar to that of supernatant from cells infected with adenovirus expressing kringle 1-3 of plasminogen (AdK1-3). Administration of AdmuthPlgK3 and AdK1-3 in mice results in significantly decreased endothelial cell infiltration in VEGF-embedded Matrigel plugs. Treatment with AdmuthPlgK3 and AdK1-3 exerts strong antitumoral effect in models of hepatocellular carcinoma and Lewis lung cancer. This antitumor effect was associated with decreased microvessel density in the tumors. Taken together, our data demonstrate that angiostatin endowed with strong antiangiogenic and antitumor effects can be released from a furin-mutated plasminogen acting as a precursor. This strategy may have potential to develop angiostatic anti-cancer therapies.

[Serum lipids, lipoprotein and stroke]

The serum levels of lipids and lipoproteins were measured in 180 consecutive patients with acute stroke(90 hemorrhagic stroke, 90 ischemic stroke) and 107 age- and sex-matched controls. As compared with the control group, hemorrhagic group had lower levels of total cholesterol(TC) (P < 0.05), low density lipoprotein-cholesterol(LDL-C) (P < 0.01) and Lp(a) (P < 0.05) while the ischemic group had higher serum TC(P < 0.05), LDL-C(P < 0.01), Lp(a) (P < 0.01) and lower high density lipoprotein-cholesterol(HDL-C) (P < 0.05) and ApoAI(P < 0.01). Multiple factor logistic regression showed that cigarette smoking, hypertension and family history of stroke were the common risk factors for both hemorrhagic and ischemic stroke, and that lowered TC and elevated LP(a) levels were independent risk factors for hemorrhagic stroke and ischemic stroke respectively.

[Muscarinic receptor subtype-3 expression in trabecular meshwork of normal human eye and primary open-angle glaucoma]

OBJECTIVE

To identify the muscarinic receptor subtype-3 (M3-receptor) expression in trabecular meshworks (TM) of normal human eyes and eyes with primary open-angle glaucoma (POAG) and discuss the pathological changes of TM in POAG.

METHOD

TM specimens were taken from 5 normal persons and 10 patients with POAG at late stage. Then LSAB immunohistochemical technique was used to identify M3-receptors. The results were observed under microscope and compared with computer-image-analysis system.

RESULTS

(1) The trabecular meshwork cells in all the 5 normal persons expressed M3-receptors. The positive cells mainly existed in the uveal part of TM, from Schwalbe's line to scleral spur. (2) In TM from eyes with POAG, the amount of both TM cells and M3-receptor positive cells were reduced obviously, even some specimens had no such positive expression. The positive cells were correspondingly decreased in number and scattered in distribution.

CONCLUSION

The TM cells in normal human eyes express M3-receptors. The TM cells and M3-positive cells in eyes with late POAG are reduced in number and their distribution is irregular.

[Apolipoprotein E 4 gene is a risk factor for Alzheimer's disease]

OBJECTIVE

To study the association of Alzheimer disease (AD) with apolipoprotein E (ApoE) epsilon 4 allele and to find the biological peripheral markers for the laboratory diagnosis of AD.

METHODS

107 patients with AD, 68 patients with vascular dementia (VD) and 74 sex- and age-matched non-demented healthy individuals (NDC) were collected. DNA from patients and healthy individuals was extracted from peripheral blood samples with the phenol-chloroform procedure and ApoE was investigated with the methods of polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP).

RESULTS

The frequency of epsilon 4 was significantly higher in AD than that in VD and NDC and there was no difference in the frequency of epsilon 4 between VD and NDC. The age at onset of the disease in the group carrying two epsilon 4 alleles was significantly younger than that in the group with one epsilon 4 allele in AD. Moreover, in comparison with AD patients without epsilon 4 allele, the age at onset in the group with one epsilon 4 allele was younger. Patients with epsilon 4 or without epsilon 4 allele in VD patients did not differ significantly in age at onset. Meanwhile, 3 familial AD cases were found, all carrying epsilon 4 allele.

CONCLUSION

AD and ApoE4 were closely related. ApoE epsilon 4 was a dangerous factor of AD and ApoE 4 allele made contribution to the heterogenicity of AD.

Adenovirus-mediated CD40 ligand gene therapy in a rat model of orthotopic hepatocellular carcinoma

Unresectable hepatocellular carcinoma (HCC) lacks effective therapy and entails very poor prognosis. In this study, we have explored a gene-therapeutic approach to stimulate antitumor immunity by adenoviral-mediated transfer of CD40 ligand to treat HCC in rats. In vitro infection of a rat HCC cell line (McA-RH7777) with adenoviral vector expressing CD40 ligand (AdCMVmCD40L) induced CD40L expression in a dose-dependent manner. Expression of CD40L in McA-RH7777 cells did not alter their growth rate in vitro, but it abrogated their tumorigenicity when CD40L-expressing cells were implanted into the liver of syngenic Buffalo rats. In vivo gene therapy of established orthotopic HCC nodules (6.5 mm in diameter) in Buffalo rats by intratumor injection of AdCMVmCD40L vector led to complete tumor eradication and long-term survival in 69.5% of treated animals. Therapy with AdCMVmCD40L induced strong lymphocytic infiltration of the tumoral tissue and increased apoptosis of malignant cells. The observed antitumoral effect was mediated by CD8(+) T cells and was associated with increased interleukin (IL)-12 serum levels and enhanced natural killer (NK) activity. Animals that eliminated the tumor after in vivo gene therapy developed protective antitumor immunity being resistant to rechallenge with neoplastic cells. Toxicity of the therapy with AdCMVmCD40L was slight, with only a transient increase in the level of serum transaminases and minor lymphocyte infiltration of normal liver tissue. These data demonstrate that intratumoral administration of AdCMVmCD40L may provide an efficient and safe treatment for HCC.

[The expression of growth factors in filtering area following sclerectomy and the interaction between growth factors and interferon]

OBJECTIVE

To study the expression of beta-Fibroblastic Growth Factor (bFGF) and Transforming Growth Factor beta 1 (TGF beta 1) in filtering area following sclerectomy and the interaction between growth factors and interferon alpha-2b (IFN alpha-2b).

METHODS

Immunohistochemical technique were applied to test the expression bFGF and TGF beta 1 in frozen sections of filtration area following sclerectomy on postoperative day three, five, seven and 14 in white rabbits, respectively. 16 eyes of eight rabbits in all were randomly and equally divided into two groups. The experimental eyes had subconjunctivally been administered IFN alpha-2b 5 x 10(5) IU 0.2 ml each time at filtering bleb following operation whereas the control eyes hadn't taken.

RESULTS

In control group, positive cell and substance expressing bFGF and TGF beta 1 on postoperative day three were revealed in the filtration area, on postoperative day five and seven, they were gradually increased. On the postoperative day 14, all significant cells and substance markly decreased. In experimental group only small amount of positive cell and bFGF or TGF beta 1-expressing substance were sparely distributed in the filtration area.

CONCLUSION

The filtration area after glaucoma filtering surgery was "bathed" in growth factors such as bFGF and TGF beta 1 which well-known play an important role in stimulating wound healing response, IFN alpha-2b had an inhibitory effect on bFGF or TGF beta 1 expression in wound environment.

Effects of APF gel on the physical structure of compomers and glass ionomer cements

This study assessed the effect of an acidulated phosphate fluoride (APF) gel on the surfaces of eight modern esthetic restorative materials. Five specimens each of three high powder: liquid ratio conventional glass ionomer cements (ChemFlex, Fuji IX GP, Ionofil Molar), four polyacid-modified resin composites (compomers) (Compoglass F, Dyract AP, Freedom, F2000) and an alkaline glass filled resin composite (Ariston pHc) were prepared and immersed at 37 degrees C in 2 mL of artificial saliva for six weeks. The aged specimens were then coated with 1.23% APF gel for four minutes, rinsed and again immersed in artificial saliva for another six weeks. The immersed, fresh specimens for each material were then examined with SEM and surface profilometry. After APF gel application, mean surface roughness (Ra) measurements and SEMs showed that roughness increased significantly, generally from the resin composite and compomers to the conventional glass ionomer cements (p < 0.05).

Effect of long-term treatment with vanadate in drinking water on KK mice with genetic non-insulin-dependent diabetes mellitus

The glucose-lowering effect of vanadate, ammonium metavanadate (AMV), on diabetic KK mice was examined. Five-week-old male KK mice were administrated with a solution of AMV via drinking water at concentrations of vanadium (V) with 0.1, 1.0, 10 and 100 microg/mL for a period of 10 wk, respectively. Body weight, consumption of food and water, and blood glucose levels was measured every week for 10 wk. The results showed that food consumption and body weight in the experimental groups were similar to those in the control group. A statistically significant decrease of drinking water consumption and blood glucose levels in the group treated with 100 microg V/mL was observed. The glucose tolerance in the vanadate-treated mice with 10 and 100 microg V/mL was remarkably improved compared with the control group. Biochemical analyses at the end of experiments demonstrated that a distinct tendency for the glucose and hemoglobin A1c (HbA1c) levels to decrease with vanadate treatment in the blood was also observed. The glutamic pyruvic transaminase, glutamic oxaloacetate transaminase, blood urea nitrogen, triglyceride, high-density lipoprotein, and total cholesterol levels in plasma were lower in the higher vanadium groups than those in the control group. These results indicate that vanadium effectively produced the glucose-lowering effect at a higher dose than that at a low dose of vanadium in drinking water, without any overt signs of toxicity.

[The muscarinic receptor subtype study of the action on lowering IOP of cholinomimetic drugs]

PURPOSE

Clarify the relationship between lowering intraocular pressure (IOP) action of cholinomimetic drugs and muscarinic receptor subtypes.

METHODS

Measuring rabbit IOP with gas driving ophthalmotonometer, measuring size of pupil with pupil rule and measuring contraction of rabbit iris by iris experiment in vitro. Figuring out pD2 of cholinomimetic drugs and pA2 of the antagonists of muscarinic receptor subtypes.

RESULTS

The order of effect on lowering IOP and miosis of cholinomimetic drugs is Erycibele Alkaloid > Aceclidine > Pilocarpine and the order of effect on constracting iris is Erycibele Alkaloid > Pilocarpine > Aceclidine. The sequence of antagonistic effect of subtype antagonists is 4-DAMP(M3) > Pirenzepine(M1) > Gallamine(M2).

CONCLUSION

Effect cholinomimetics on lowing IOP and miosis is primary mediated by M3 receptor, next by M1 receptor and has little relation with M2 receptor.

[The postburn change in splenic T lymphocyte transmembrane signal transduction and its relationship with the secretion of IL-2 and IL-10 in severely scalded mice]

OBJECTIVE

To explore the postburn functional change in splenic T lymphocytes and the secretory rules of IL-2 and IL-10 in severely scalded mice, and to look for the explanation of the change by means of T lymphocyte transmembrane signal transdunction study.

METHODS

The changes in the antigen receptors on T cells (TCRalpha/beta), assisting stimulating molecule (CD28) and the activities of GTPase, protein tyrosine kinase (PTK) and protein kinase C (PKC) that participated in the transmembrane signal transduction were detected, so as to observe the proliferation and transformation function of T cells at different post-burn periods and the secretion of IL-2 and IL-10. Furthermore, the changes in every signal transduction molecules were analyzed with the consideration of their relationship with the change in T cell function activities.

RESULTS

The postburn positive rates of the expressions of TCRalpha/beta and CD28 on T cell membrane decreased. The postburn GTPase activity and membrane PTK activity were all suppressed but recovered at 168 postburn hours. Membrane PKC activity exhibited a dual-phase change (increase following decrease), which was closely related to IL-10 level.

CONCLUSION

The postburn changes in TCRalpha/beta, CD28 on T cell membrane molecules and transmembrane signal transduction enzymes were important factors contributing to the decrease in IL-2 secretion, suppressed T cell function and the dual-directional changes in IL-10 secretion.

[The protein expression of insulin receptor substrate-1 and protein tyrosine phosphatase with two src-homology II in the adipose tissue from type II diabetic patients]

OBJECTIVE

To investigate the protein expression of insulin receptor substrate-1 (IRS-1), protein tyrosine phosphatase with two src-homology 2 (SH-PTP(2)) in adipose tissues of type II diabetic patients, and explore molecular mechanisms of insulin resistance from adipose tissues of type II diabetic individuals.

METHODS

The levels of protein expression of IRS-1 and SH-PTP(2) in adipose tissues from type II diabetic individuals were measured by Western blot analysis; meanwhile compared the level of protein expression of one's own abdominal subcutaneous and omentum majus adipose tissue from patients with type II diabetes mellitus.

RESULTS

The expression of IRS-1 protein in abdominal subcutaneous (A) 2.14 +/- 0.67 and omentum majus 3.25 +/- 0.70 adipose tissues from patients with type II diabetes mellitus was significantly lower than that of control group [subcutaneous: 4.33 +/- 0.57 (P < 0.001), omentum majus: 8.65 +/- 2.85 (P < 0.05)]. The expression of SH-PTP(2) protein had no difference compared with control group (P > 0.05). The protein expression of IRS-1 was significantly lower in abdominal subcutaneous adipose tissue (1.09 +/- 0.13) than that in omentum majus adipose tissue (2.10 +/- 0.22) from the type II diabetic patients (P < 0.05), but the protein expression of SH-PTP(2) was significantly higher in subcutaneous adipose tissue (70.75 +/- 2.18) than that in omentum majus (43.69 +/- 11.07, P < 0.05).

CONCLUSION

The abnormal changes in expression of IRS-1 and SH-PTP(2) protein in adipose tissues of the patients with type II diabetic mellitus may be one of the mechanisms of leading to insulin resistance. The abdominal subcutaneous adipose tissue of type II diabetic patients, as visceral adipose tissues, contributes to their insulin resistance.

In vivo gene transfer of CD40 ligand into colon cancer cells induces local production of cytokines and chemokines, tumor eradication and protective antitumor immunity

The interaction between CD40 ligand (CD40L, CD154) and its receptor CD40 on antigen-presenting cells, is essential for the initiation of cell-mediated and humoral immune responses. In this study, we investigated the antitumor effect of in vivo gene transfer of CD40L to tumor cells using an adenoviral vector (AdCMVmCD40L) in a murine CT-26 colon cancer model. We found that injection of AdCMVmCD40L caused tumor regression in a dose-dependent manner. A complete regression of tumor was observed in 81% of mice treated with 10(9) p.f.u. of AdCMVmCD40L. The antitumor effect induced by CD40L was mediated by CD8+ T cells and was associated with the generation of tumor-specific cytolytic T lymphocytes (CTL). Animals that eradicated the tumor were protected against tumor cell rechallenge, and both CD4+ and CD8+ T cells were involved in specific protective immunity. Treatment with AdCMVmCD40L in one tumor nodule also caused complete regression of established tumors at distant sites. The antitumor effect elicited by AdCMVmCD40L was associated with the intratumoral production of IL-12 and IFN-gamma and with an increased intratumoral expression of chemokines such as MIP- 1alpha, MIP-1beta, MIP-2, RANTES, and eotaxin. These data demonstrate that intratumoral injection of AdCMVmCD40L induces a powerful cascade of chemokines and cytokines in the tumor mass and stimulates an efficient antitumor immunity leading to regression of established colon cancer and protection against tumor cell rechallenge.