Omeprazole improves the anti‐obesity and antidiabetic effects of exendin‐4 in db/db mice (奥美拉唑改善唾液素‐4 对db/db小鼠的减肥与降糖作用)*

Background: In addition to its glucoregulatory actions, exendin‐4, a stable glucagon‐like peptide‐1 receptor agonist, exhibits protective effects in the pancreas and anti‐obesity effects. Suitable combination treatment with other anti‐obesity or pancreas protective agents would be an effective approach to optimize these additional effects. In the present study, we investigated the effects of the addition of omeprazole, a proton pump inhibitor, to exendin‐4 in db/db mice, an experimental model of obesity and type 2 diabetes. Methods: The effects repeated dose treatment for 14 days with exendin‐4 (8 μg/kg, s.c.) and omeprazole (30 mg/kg, s.c.) on glycemic control, food intake, and body weight were determined in obese and hyperglycemic db/db mice. The effects of these treatments on plasma gastrin, ghrelin, and leptin levels were determined, along with effects on nausea‐like symptoms. The pancreatic effects of the repeated dose treatment were assessed by measuring %HbA1c in the circulation as well as pancreatic insulin and glucagon content and glucokinase activity. Results: Combination treatment resulted in significant decreases in plasma leptin and ghrelin levels after repeated dosing. Omeprazole improved the anorectic and body weight‐lowering effects and reversed the inhibitory effect of exendin‐4 on gastrin levels after repeated dose treatment. The 14‐day combination treatment significantly reduced glucose excursion and improved insulin levels, with a concomitant decrease in %HbA1c levels. It also improved glucokinase activity and pancreatic insulin content, with a significant decrease in glucagon content. Conclusions: Combined treatment with omeprazole with exendin‐4 reduces food intake and body weight gain, most likely through changes in plasma ghrelin and leptin levels, and improves pancreatic insulin and glucagon content by improving glucokinase activity.     

Anti–interleukin‐6 receptor antibody therapy favors adrenal androgen secretion in patients with rheumatoid arthritis: A randomized,double‐blind,placebo‐controlled study

Objective

Proinflammatory cytokines such as tumor necrosis factor (TNF) were demonstrated to inhibit adrenal steroidogenesis in patients with rheumatoid arthritis (RA), and this was particularly evident in the increase in adrenal androgen levels during anti‐TNF therapy. This study investigated the influence on steroidogenesis of an interleukin‐6 (IL‐6)–neutralizing strategy using IL‐6 receptor monoclonal antibodies (referred to as MRA).

Methods

In a placebo‐controlled, double‐blind, randomized study over 12 weeks in 29 patients with RA being treated with prednisolone, 13 of whom received placebo and 16 of whom received 8 mg MRA/kg body weight, the effects of MRA on serum levels of adrenocorticotropic hormone (ACTH), cortisol, 17‐hydroxyprogesterone (17OHP), dehydroepiandrosterone (DHEA), DHEA sulfate (DHEAS), androstenedione (ASD), estrone, and 17β‐estradiol, as well as their respective molar ratios, were determined.

Results

MRA therapy markedly improved clinical signs of inflammation (the erythrocyte sedimentation rate, swollen joint score, and Disease Activity Score in 28 joints). Serum levels of ACTH and cortisol and the molar ratio of cortisol to ACTH did not change. Although serum levels of DHEA and DHEAS remained stable during therapy, the DHEAS:DHEA molar ratio significantly decreased in treated patients (P = 0.048). Serum levels of ASD as well as the ASD:cortisol and ASD:17OHP molar ratios increased in MRA‐treated patients (minimum P < 0.004). Serum levels of estrone and 17β‐estradiol did not change. but the estrone:ASD molar ratio (an indicator of aromatization) decreased during 12 weeks of MRA treatment (P = 0.001).

Conclusion

Neutralization of IL‐6 increases secretion of biologically active adrenal androgens in relation to that of precursor hormones and estrogens. This is another important indication that proinflammatory cytokines interfere with adrenal androgen steroidogenesis in patients with RA.

     

Anti‐cancer activity of anti‐p185HER‐2 ricin A chain immunotoxin on gastric cancer cells

Background and Aim: Overexpression of the human epidermal growth factor receptor 2 (HER‐2) protein has been detected in gastric cancer and has been associated with an unfavorable prognosis. We investigated the anti‐cancer effects of anti‐p185^HER‐2 ricin A chain (RTA) immunotoxin, alone or in combination with 5‐flurouracil on SGC7901‐HER‐2+ cells. Methods: SGC7901‐HER‐2+ cells were obtained by transfecting SGC7901 cells with HER‐2‐pcDNA3.1. Anti‐p185^HER‐2‐RTA was prepared by chemical conjugation of anti‐HER‐2 monoclonal antibody (mAb) and RTA. The SGC7901‐HER‐2+ cells were incubated with RTA, anti‐p185^HER‐2‐RTA, and/or 5‐flurouracil. The effects of drugs on cells were evaluated by MTT assay and Annexin V‐fluorescein isothiocyanate and propidium iodide double staining flow cytometry. The expression of caspase‐3, caspase‐9, cyclooxygenase‐2, and nuclear factor‐κB/p65 were assayed by western blot. SGC7901‐HER‐2+ cells were transplanted into BALB/c nude mice to produce solid tumors in an attempt to study the immunotoxin activity in vivo. Results: In vitro, anti‐p185^HER‐2‐RTA inhibited cell growth and induced apoptosis in SGC7901‐HER‐2+ cells. Anti‐p185^HER‐2‐RTA enhanced caspase‐3 and caspase‐9 activity, while downregulating the expression of cyclooxygenase‐2 and nuclear factor‐κB/p65. Its combination with 5‐flurouracil further inhibited the growth of SGC7901‐HER‐2+ cells. In vivo, our data showed that anti‐p185^HER‐2‐RTA significantly inhibited the growth of SGC7901‐HER‐2+ cells‐transplanted tumors. Conclusions: Anti‐p185^HER‐2‐RTA inhibits the growth of SGC7901‐HER‐2+ cells. The effect may be related to the activation of caspase‐3 and caspase‐9 and inhibition of cyclooxygenase‐2 and nuclear factor‐κB/p65. Anti‐p185^HER‐2‐RTA plus 5‐FU enhance anti‐cancer activity, suggesting useful clues for further study for the treatment of HER‐2 positive gastric cancers.     

Oral anti‐CD3 immunotherapy for HCV‐nonresponders is safe,promotes regulatory T cells and decreases viral load and liver enzyme levels: results of a phase‐2a placebo‐controlled trial

Orally administered anti‐CD3 antibodies are biologically active in the gut through induction of regulatory T cells, exert an immune‐modulatory effect, and alleviate insulin resistance and liver damage in patients with NASH. Aims: To determine the safety of oral anti‐CD3 monoclonal antibody (MAb) immunotherapy in chronic HCV patients with associated immune dysfunction. Methods: Four groups (n = 9) of chronic HCV patients who were nonresponders to interferon plus ribavirin therapy received oral placebo (group A) or anti‐CD3 MAb at one of three dosage levels for 30 days. Patients were followed for safety parameters and serum levels of liver enzymes, virus, cytokines and regulatory T cells. Results: Oral anti‐CD3 immunotherapy was safe and well tolerated; no treatment‐related adverse events were noted. The following improvements were noted relative to pretreatment levels: HCV viral load and AST and ALT levels decreased in the low‐ and high‐dose groups following 30 days of therapy. In two of the treated groups, an increase in regulatory T cells (CD4⁺ CD25⁺) was noted. The positive effects were somewhat more apparent in subjects with initially elevated liver enzyme levels. Conclusions: Oral anti‐CD3 MAb immunotherapy for nonresponder HCV patients was safe and well tolerated. Trends and statistically significant improvements were observed as reductions in viral load and liver enzyme levels, along with an increase in regulatory T‐cell levels. These data support a role for the immune system in the pathogenesis of HCV infection and suggest that this immunotherapy is worthy of evaluation in combination with HCV antiviral drugs.     

Anti–N‐methyl‐D‐aspartate receptor antibodies,cognitive dysfunction,and depression in systemic lupus erythematosus

Objective

To assess the association of cognitive dysfunction and depression with serum antibodies to N‐methyl‐D ‐aspartate (NMDA) receptor (anti‐NR2) and analyze clinical and neuroimaging correlates in patients with systemic lupus erythematosus (SLE).

Methods

Sixty patients underwent neurocognitive assessment, evaluation for depression with the Beck Depression Inventory II (BDI‐II) and psychiatric interview (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition [DSM‐IV] criteria), brain magnetic resonance imaging, and proton magnetic resonance spectroscopy imaging (¹H‐MRSI). Cognition was assessed in 5 domains: memory, attention/executive, visuospatial, motor, and psychomotor, and adjusted to each individual's best level of prior cognitive functioning estimated from the reading subtest of the Wide Range Achievement Test–3 (WRAT‐3). Serum anti‐NR2 antibodies were measured by enzyme‐linked immunosorbent assay using a pentapeptide from the human NMDA receptor.

Results

Cognitive dysfunction was found in 28 of 60 patients (mild in 8, moderate in 20) before adjustment for WRAT‐3 and in 35 of 60 patients (mild in 15, moderate in 11, and severe in 9) after adjustment for WRAT‐3. The changes were most pronounced in the memory and visuospatial domains. There was no significant association between anti‐NR2 antibody levels and cognition. On ¹H‐MRSI, patients with moderate or severe cognitive dysfunction had significantly higher choline:creatine ratios in the dorsolateral prefrontal cortex and the white matter, compared with patients with mild or absent cognitive dysfunction. Anti‐NR2 antibodies were significantly correlated with BDI scores; patients with BDI‐II scores of ≥14 had higher serum levels of anti‐NR2 antibodies (P = 0.005, 95% confidence interval 0.83, 4.31), and there was a trend toward higher anti‐NR2 antibody levels among patients who fulfilled the DSM‐IV criteria for major depression.

Conclusion

Serum anti‐NR2 antibodies are associated with depressive mood but not with cognitive dysfunction in SLE at a given time point. Larger longitudinal studies are needed to address the possible association between anti‐NR2 antibodies and depression in SLE.

     

Anti-androgens increase N-terminal pro-BNP levels in men with prostate cancer

Objective The aim of this study was to determine the effects of anti‐androgens on left ventricular (LV) function and levels of N‐terminal proB‐type natriuretic peptide (NT‐proBNP), a sensitive cardiac risk marker, in men with prostate cancer as these are widely used drugs in this condition, and evidence suggests that endogenous androgens are cardioprotective in men. Design and patients Forty‐three men (mean age 70·7 ± 6·2 years) with prostate cancer were randomized to goserelin (an LH‐releasing hormone analogue) or bicalutamide (an androgen‐receptor blocker) for 6 months; 20 men with a history of prostate cancer on no treatment were studied in parallel. Results Mean changes in testosterone and oestradiol, respectively, from baseline to 6 months were –88% and –46% with goserelin, +50% and +44% with bicalutamide, and –1% and –9% for the ‘no‐treatment’ group. Bicalutamide significantly increased NT‐proBNP from baseline to 3 and 6 months (median value at baseline, 3 and 6 months: 55, 101 and 118 ng/l, respectively). Goserelin caused a significant increase from baseline to 3 months but not to 6 months (median value at baseline, 3 and 6 months: 66, 87 and 72 ng/l, respectively). No significant changes occurred in the ‘no‐treatment’ cohort (median value at baseline 3 and 6 months: 60, 53 and 60 ng/l, respectively). No significant changes in LV function, blood pressure (BP), body mass index or waist–hip ratio occurred to account for the changes in NT‐proBNP. Conclusion Androgen receptor blockade and, to a lesser extent, androgen suppression cause an increase in NT‐pro‐BNP in men with prostate cancer. The significance is not clear but could imply an adverse effect on cardiovascular risk following hormonal manipulation.     

Therapeutic effect of photodynamic therapy using PAD‐S31 and diode laser on human liver cancer cells

Abstract: Background/aims: Photodynamic therapy (PDT) is an effective local cancer treatment which a photosensitizer is administered and the tumor is irradiated with light. We examined the effect of PDT using PAD‐S31 as the photosensitizer, and the 670 nm diode laser on human hepatocellular carcinomas (HCCs). Methods: Huh‐7, HepG2 and Hep3B cell lines were used in the all experiments. Cell viability was determined by a modified MTT assay. Two methods were used for the determination of apoptosis: terminal deoxynucleotidyl transferase (TdT)‐mediated dUTP nick‐end labeling assay and detection of fragmented mono‐ and oligo‐nucleosomes by enzyme‐linked immunosorbent assay. The caspase activity was measured by fluorometric assay. Cytochrome c in cytosolic fraction was determined using a human cytochrome c immunoassay. Xenografts of human oral HCC cells were generated in KSN S1c nude mice. Results: In vitro PDT showed excellent cytotoxicity that was a function of laser energy, drug concentration and time to the hepatoma cell lines. The combined use of PAD‐S31 and laser irradiation showed excellent anti‐tumor activity without severe side‐effect against human hepatoma xenografts in nude mice. PDT‐mediated cell death occurred predominantly by apoptosis in vitro and in vivo. Furthermore, this treatment initiates early cytochrome c release, followed by late caspase‐3 and ‐9 activation. Conclusion: Our study demonstrates that PDT using PAD‐S31 and the diode laser induces apoptosis that is mediated by cytochrome c release and caspase activation in human liver cancer cell lines. It is expected that this therapy will be clinically useful for the treatment of patients with HCC.     

Growth inhibition of liver metastases by the anti‐angiogenic drug TNP‐470

Abstract: Objective: This study was undertaken in order to assess the efficacy of a potent angiogenesis inhibitor, TNP‐470, on tumor growth in a syngeneic rodent model of liver metastases from colorectal cancer. Background: New blood vessel formation is a prerequisite for primary and metastatic tumor growth. TNP‐470, a synthetic derivative of fumagillin when subcutaneously transplanted into nude mice, inhibits endothelial cell proliferation and migration, as well as the growth of various human cancers. However, the antitumor effect of this drug has not been studied in models reproducing a natural metastatic environment. Since the liver provides an extensive vascular bed for secondary tumor growth, an anti‐angiogenic strategy may therefore be less efficient for treating hepatic metastases than primary tumors. Methods: 10⁷ DHD K12 colon carcinoma cells were injected intrasplenically into syngeneic BD IX rats to produce diffuse liver metastases. TNP‐470 (30 mg/kg/day) was administered on alternate days starting 4 days after tumor implantation. The animals were sacrificed after 4 weeks and their livers were processed for histologic examination. In both the treatment and control groups (n=7), tumor volume was determined using a computerized analytical system, and tumor microvessel density was measured by immunostaining with anti‐von Willebrand Factor monoclonal antibody. Results:In vitro, TNP‐470 demonstrated a direct toxicity towards the DHD K12 cell line with an IC₅₀ of 0.1 μg/ml. Metastases were present in all animals from both groups. Liver weight (15.2 g vs 11.7 g, p=0.01), and tumor volume (1218 mm³ vs 406 mm³, p=0.03) were significantly reduced in the TNP‐470 group compared to the control group. Tumor microvessel density was not statistically different between the two groups (67 vs 63 microvessels/×200 field, p=0.41). Conclusion: TNP‐470 inhibits the growth of liver metastases in a syngeneic rat model of colorectal cancer. The mechanism responsible for this effect remains unclear, but may involve a combination of anti‐angiogenic and direct cytotoxic effects.     

Eukaryotic expression of extracellular ligand binding domains of murine Tie‐2 and its anti‐angiogenesis effect in SGC‐7901 cell lines

Background and Aims: Researches about blocking angiogenesis to treat tumor have become one of the most promising and active fields in anticancer research. This study aimed to investigate the eukaryotic expression of extracellular ligand binding domains of murine Tie‐2 and its anti‐angiogenesis effect. Methods: A eukaryotic expression vector pcDNA3.1⁺ integrating with a DNA fragment which encode extracellular ligand binding domains of murine Tie‐2 was transfected into SGC‐7901 gastric cancer cell line. The protein expression was detected by western blot analysis and immunocytochemistry staining. Following the construction of nude mouse tumor xenograft model with and without transfected cells, tumor microvessel density was determined by counting per high power field in the sections stained with an antibody to CD31 to test its inhibition of angiogenesis. Results: The extracellular ligand binding domains of murine Tie‐2 receptor was highly expressed in SGC‐7901 gastric cancer cells with plasmid transfection. The mean tumor sizes of groups with and without transfection were 1.27 ± 0.35 and 1.75 ± 0.17 cm³, respectively (P = 0.025). The mean inhibitory rate of tumor was 27.18 ± 19.93%. The comparison between highest microvessel density of group with transfection (14.00 ± 3.80) and that of group without transfection (22.30 ± 5.91) was statistically significant at P = 0.030. Conclusion: The protein of extracellular ligand binding domains of murine Tie‐2 can be expressed at high level in the eukaryotic expression system, and the expressed protein may have the anti‐angiogenesis effect.     

IGFBP3 and MAPK/ERK signaling mediates melatonin‐induced antitumor activity in prostate cancer

Treatment of prostate cancer (PCa), a leading cause of cancer among males, lacks successful strategies especially in advanced, hormone‐refractory stages. Some clinical studies have shown an increase in neuroendocrine‐like cells parallel to the tumor progression but their exact role is a matter of debate. The prostate is a well‐known target for melatonin, which reduces PCa cells proliferation and induces neuroendocrine differentiation. To evaluate the mechanisms underlying the indole effects on neuroendocrine differentiation and its impact on PCa progression, we used a cell culture model (LNCaP) and a murine model (TRAMP). Persistent ERK1/2 activation was found in both, melatonin and androgen‐deprived cells. Melatonin blocked nuclear translocation of androgen receptor (AR), thus confirming anti‐androgenic actions of the indole. However, using a comparative genome microarray to check the differentially expressed genes in control, melatonin, or androgen‐deprived cells, some differences were found, suggesting a more complex role of the indole. By comparing control cells with those treated with melatonin or depleted of androgen, a cluster of 26 differentially expressed genes (±2.5‐fold) was found. Kallikreins (KLK)2 and KLK3 (PSA) were dramatically downregulated by both treatments whereas IGFBP3 and IGF1R were up‐ and downregulated, respectively, in both experimental groups, thus showing a role for IGF in both scenarios. Finally, melatonin prolonged the survival of TRAMP mice by 33% when given at the beginning or at advances stages of the tumor. Serum IGFBP3 was significantly elevated by the indole in early stages of the tumor, confirming in vivo the role of the IGF signaling in the oncostatic action of the indole.     

Oral delivery of mouse [d‐Leu‐4]‐OB3, a synthetic peptide amide with leptin‐like activity,in male C57BL/6J wild‐type and ob/ob mice: effects on energy balance,glycaemic control and serum osteocalcin levels

Background: We have recently shown that intranasal administration of mouse [d ‐Leu‐4]‐OB3 reconstituted in Intravail^® to male Swiss Webster mice resulted in significantly higher bioavailability than commonly used injections methods of delivery. The absorption profile associated with intranasal delivery of mouse [d ‐Leu‐4]‐OB3 showed an early peak representing absorption across the nasal mucosa, and a later peak suggesting a gastrointestinal site of uptake. Aim and Methods: In the present study, we examined the effects of orally administered (by gavage) mouse [d ‐Leu‐4]‐OB3 on energy balance, glycaemic control and serum osteocalcin levels in male C57BL/6J wild‐type and ob/ob mice allowed food and water ad libitum or calorie restricted by 40% of normal intake. Results: In wild‐type mice fed ad libitum, oral delivery of mouse [d ‐Leu‐4]‐OB3 reduced body weight gain, food intake and serum glucose, by 4.4, 6.8 and 28.2% respectively. Serum osteocalcin levels and water intake were essentially the same in control and treated wild‐type mice. In ob/ob mice fed ad libitum, mouse [d ‐Leu‐4]‐OB3 reduced body weight gain, food intake, water intake and serum glucose by 11.6, 16.5, 22.4 and 24.4% respectively. Serum osteocalcin in ob/ob mice treated with mouse [d ‐Leu‐4]‐OB3 was elevated by 62% over controls. Calorie restriction alone caused significant weight loss in both wild‐type (9.0%) and ob/ob (4.8%) mice, and mouse [d ‐Leu‐4]‐OB3 did not further enhance this weight loss. As expected, serum glucose levels in wild‐type and ob/ob mice were significantly reduced by calorie restriction alone. Mouse [d ‐Leu‐4]‐OB3 further reduced serum glucose in wild‐type mice and normalized levels in ob/ob mice. Calorie restriction alone reduced serum osteocalcin levels by 44.2% in wild‐type mice and by 19.1% in ob/ob mice. Mouse [d ‐Leu‐4]‐OB3 prevented this decrease in groups of mice. Conclusions: The results of this study suggest that oral delivery of mouse [d ‐Leu‐4]‐OB3 in Intravail^® is possible and may have potential not only as an alternative therapy in the treatment of human obesity and some of its associated metabolic dysfunctions, but also may help to prevent and/or reverse at least some of the bone loss which accompanies osteoporosis, anorexia nervosa and other wasting diseases.     

Anti–N‐methyl‐D‐aspartate receptor encephalitis: A newly recognized inflammatory brain disease in children

Objective

Anti–N‐methyl‐D ‐aspartate receptor (anti‐NMDAR) encephalitis is a newly recognized antineuronal antibody–mediated inflammatory brain disease that causes severe psychiatric and neurologic deficits in previously healthy children. The present study was undertaken to describe characteristic clinical features and outcomes in children diagnosed as having anti‐NMDAR encephalitis.

Methods

Consecutive children presenting over a 12‐month period with newly acquired psychiatric and/or neurologic deficits consistent with anti‐NMDAR encephalitis and evidence of central nervous system (CNS) inflammation were screened. Children were included in the study if they had confirmatory evidence of anti‐NMDAR antibodies in the serum and/or cerebrospinal fluid. Features at clinical presentation and results of investigations were recorded. Type and duration of treatment and outcomes at last followup were documented.

Results

Seven children were screened, and 3 children with anti‐NMDAR encephalitis were identified. All patients presented with neurologic and/or psychiatric abnormalities, seizures, speech disorder, sleep disturbance, and fluctuating level of consciousness. The 2 older patients had more prominent psychiatric features, while the younger child had significant autonomic instability and prominent involuntary movement disorder. None had an underlying tumor. Immunosuppressive therapy resulted in near or complete recovery; however, 2 of the patients had early relapse necessitating re‐treatment.

Conclusion

Anti‐NMDAR encephalitis is an important cause of neuropsychiatric deficits in children, which must be included in the differential diagnosis of CNS vasculitis and other inflammatory brain diseases. Early diagnosis and treatment are essential for neurologic recovery.

     

Dexamethasone administration inhibits skeletal muscle expression of the androgen receptor and IGF‐1 – implications for steroid‐induced myopathy

Context Glucocorticoids are a well‐recognized cause of muscle weakness. The early effects of glucocorticoids on skeletal muscle (SkM) androgen and IGF‐1 pathways have not been previously investigated in human subjects. Objective To determine if administration of the potent glucocorticoid dexamethasone down‐regulates SkM androgen receptor and the IGF‐1 signalling pathway. Methods and subjects Twenty‐four subjects (12 men and 12 women), including 12 with type 2 diabetes and 12 nondiabetics were enrolled. Venous blood sampling and biopsy of vastus lateralis were performed before and after administration of oral dexamethasone 4 mg/day for 4 days. Main outcome measures Changes in plasma testosterone and IGF‐1, SkM androgen receptor mRNA, SkM IGF‐1mRNA and SkM IGF‐1 receptor mRNA by quantitative RT‐PCR after dexamethasone. Results Relative expression of SkM androgen receptor was similar in male (1·63 ± 0·37) vs. female (1·57 ± 0·30) subjects, despite the significant difference in plasma testosterone levels. Plasma IGF‐1 and SkM expression of IGF‐1 and IGF‐1 receptor were also similar between males and females. Following dexamethasone, there was a significant down‐regulation of SkM androgen receptor (1·60 ± 0·23 vs. 1·11 ± 0·16, P < 0·05) and IGF‐1 (1·72 ± 0·29 vs. 1·06 ± 0·14, P < 0·05) mRNA, but no change in expression of the IGF‐1 receptor. Plasma testosterone fell significantly in both sexes (male: 15·0 ± 1·3 vs. 11·3 ± 1·2 nmol/l, P < 0·01, female: 1·8 ± 0·5 vs. 0·5 ± 0·1 nmol/l, P < 0·05). Conclusions Exogenous steroid excess results in relative androgen deficiency at two levels, reduced circulating testosterone and SkM androgen receptor mRNA, along with reduced SkM IGF‐1 mRNA. These defects may contribute to the development of steroid‐induced myopathy.     

Anti‐PDGF‐B monoclonal antibody reduces liver fibrosis development

Aim: To evaluate the usefulness of a platelet‐derived growth factor (PDGF)‐B specific monoclonal antibody (mAb) as a therapeutic agent to treat chronic liver fibrosis. Methods: Liver fibrosis was induced in ICR mice by bile duct ligation (BDL) or BALB/c mice by weekly injection of concanavalin A (ConA) for 4 or 8 weeks. A mAb specific for mouse and human PDGF‐B chain, AbyD3263, was generated, tested in vitro and administered twice a week throughout the experimental period. Results: AbyD3263 showed neutralizing activity against mouse and human PDGF‐B chain in cell‐based assays, as measured in vitro by inhibition of phosphorylation of PDGF receptor β and proliferation of hepatic stellate cells induced by PDGF‐BB. The half life of AbyD3263 in mice exceeded 7 days and dosing of animals twice a week resulted in constant plasma levels of the mAb. Induction of liver fibrosis by BDL and ConA resulted in elevated levels of alanine aminotransferase (ALT) in plasma and hydroxyproline in the liver. Treatment with AbyD3263 did not modify ALT levels, but significantly reduced hydroxyproline content in the liver with a maximum reduction of 39% and 54% in the BDL and ConA models, respectively, compared to controls. Conclusios: Consistent with the notion that PDGF‐BB plays an important role in the progression of liver fibrosis, AbyD3263 exhibits efficacy in pre‐clinical disease models suggesting that pharmacological inhibition of PDGF‐B chain may be a therapeutic approach to treat liver fibrosis.     

Long‐term anti–tumor necrosis factor antibody therapy in rheumatoid arthritis patients sensitizes the pituitary gland and favors adrenal androgen secretion

Objective

New insights into the role of tumor necrosis factor (TNF) in the pathogenesis of rheumatoid arthritis (RA) have expanded our understanding about the possible mechanisms by which anti‐TNF antibody therapy reduces local synovial inflammation. Beyond local effects, anti‐TNF treatment may modulate systemic antiinflammatory pathways such as the hypothalamic–pituitary–adrenal (HPA) axis. This longitudinal anti‐TNF therapy study was designed to assess these effects in RA patients.

Methods

RA patients were given 5 infusions of anti‐TNF at weeks 0, 2, 6, 10, and 14, with followup observation until week 16. We measured serum levels of interleukin‐6 (IL‐6), adrenocorticotropic hormone (ACTH), 17‐hydroxyprogesterone (17[OH]progesterone), cortisol, cortisone, androstenedione (ASD), dehydroepiandrosterone (DHEA), and DHEA sulfate in 19 RA patients.

Results

Upon treatment with anti‐TNF, we observed a fast decrease in the levels of serum IL‐6, particularly in RA patients who did not receive parallel prednisolone treatment (P = 0.043). In these RA patients who had not received prednisolone, the mean serum ACTH levels sharply increased after every injection of anti‐TNF, which indicates a sensitization of the pituitary gland (not observed for the adrenal gland). During treatment, the ratio of serum cortisol to serum ACTH decreased, which also indicates a sensitization of the pituitary gland (P < 0.001), and which was paralleled by constant cortisol secretion. The adrenal androgen ASD significantly increased relative to its precursor 17(OH)progesterone (P = 0.013) and relative to cortisol (P = 0.009), which indicates a normalization of adrenal androgen production. The comparison of patients previously treated with prednisolone and those without previous prednisolone revealed marked differences in the central and adrenal level of this endocrine axis during long‐term anti‐TNF therapy.

Conclusion

Long‐term therapy with anti‐TNF sensitizes the pituitary gland and improves adrenal androgen secretion in patients who have not previously received prednisolone treatment. These changes are indicative of normalization of the HPA axis and must therefore be considered as evidence of an additional antiinflammatory influence of anti‐TNF treatment in patients with RA.

     

Targeting SYK kinase‐dependent anti‐apoptotic resistance pathway in B‐lineage acute lymphoblastic leukaemia (ALL) cells with a potent SYK inhibitory pentapeptide mimic

The present study found that the pentapeptide mimic C‐61, targeting the substrate binding P‐site of SYK tyrosine kinase acted as a potent inducer of apoptosis in chemotherapy‐resistant SYK‐expressing primary leukemic B‐cell precursors taken directly from relapsed B‐precursor leukaemia (BPL) patients (but not SYK‐deficient infant pro‐B leukaemia cells), exhibited favourable pharmacokinetics in mice and non‐human primates, and eradicated in vivo clonogenic leukaemia cells in severe combined immunodeficient mouse xenograft models of chemotherapy‐resistant human BPL at dose levels non‐toxic to mice and non‐human primates. These in vitro and in vivo findings provide proof of principle for effective treatment of chemotherapy‐resistant BPL by targeting SYK‐dependent anti‐apoptotic blast cell survival machinery with a SYK P‐Site inhibitor. Further development of C‐61 may provide the foundation for therapeutic innovation against chemotherapy‐resistant BPL.     

Metabolic Syndrome Enhances Prostate Contractility and In Vitro Phenylephrine‐induced α1‐Adrenoceptor Protein Expression in the Fructose‐fed Rat

Objectives: To study the effects of metabolic syndrome on prostate α‐adrenergic contractile function using fructose‐fed rats (FR). Methods: Age‐matched male Wistar rats were divided into two groups: group I, normal control rats; and group II, 9‐week FR. Animal body weight, blood pressure and serum metabolic parameters were monitored. The prostate was removed 9 weeks after induction of metabolic syndrome in the FR. The contractile responses of prostatic strips to phenylephrine (10^?7 to 10^?6 M) and KCl (50 mM) were tested. Prostate α₁‐adrenoceptor (α₁‐AR) protein expression was studied by Western blotting analysis with a polyclonal antiserum. Results: At week 9, the FR showed significant increases in body weight, blood pressure, plasma glucose, insulin and triglyceride levels. The FR prostate weight was significantly higher than that of the controls (610.5 ± 13.2 vs 422.3 ± 7.7 mg, P < 0.05 for n = 8). FR prostate contractile responses to phenylephrine and KCl were both significantly increased. Interestingly, prostate α₁‐AR protein expression level was lower in the FR. However, after in vitro 10^?6 M phenylephrine stimulation, FR prostate α₁‐AR protein expression was significantly increased. Conclusion: Metabolic syndrome in FR significantly increases prostate contractile responses to KCl and α‐adrenergic stimulation. Paradoxically, FR prostate α₁‐AR protein expression is decreased, but significantly enhanced after in vitro phenylephrine stimulation.     

Anti–interleukin‐6 receptor antibody therapy reduces vascular endothelial growth factor production in rheumatoid arthritis

Objective

To investigate whether interleukin‐6 (IL‐6) is a regulator of vascular endothelial growth factor (VEGF) in rheumatoid arthritis (RA).

Methods

Serum VEGF levels in RA patients were assayed before and after 8 weeks or 24 weeks of maintenance therapy with humanized anti–IL‐6 receptor monoclonal antibody (anti–IL‐6R mAb). VEGF secreted by RA synovial fibroblasts cultured in the presence of IL‐6, IL‐1β, and/or tumor necrosis factor α (TNFα) was measured. The inhibitory effect of anti–IL‐6R mAb, recombinant IL‐1 receptor antagonist (IL‐1Ra), and anti‐TNFα mAb on VEGF production was also examined.

Results

Serum VEGF levels in RA patients before anti–IL‐6R mAb therapy were significantly higher than those in healthy controls (P < 0.0005). Treatment of RA patients with anti–IL‐6R mAb normalized serum VEGF levels. In the in vitro study, IL‐6 and IL‐1β each induced a slight amount of VEGF production in synovial cells, but TNFα did not. Although VEGF‐inducing activity of these cytokines was not remarkable when they were added alone, IL‐6 acted synergistically with IL‐1β or TNFα to induce VEGF production. There was no synergistic effect between IL‐1β and TNFα. In the presence of all of these cytokines, anti–IL‐6R mAb eliminated the synergistic effect of IL‐6, IL‐1β, and TNFα, while IL‐1Ra or anti‐TNFα mAb did not.

Conclusion

Anti–IL‐6R mAb therapy reduced VEGF production in RA. IL‐6 is the pivotal cytokine that induces VEGF production in synergy with IL‐1β or TNFα, and this may be the mechanism by which IL‐6 blockade effectively suppresses VEGF production in synovial fibroblasts.