Could recombinant insulin compounds contribute to adenocarcinoma progression by stimulating local angiogenesis?

Aims/hypothesis  

Negative effects on the progression of adenocarcinomas by hyperinsulinaemia and the insulin analogue glargine (A21Gly,B31Arg,B32Arg human insulin) have recently been suggested. Most actions of this insulin analogue have hitherto been explained by direct stimulation of growth potential of neoplastic cells and by its IGF-1 related properties. However, insulin-stimulated angiogenesis could be an additional factor involved in tumour progression and clinical outcomes associated with cancer.     

Does granulocyte-colony stimulating factor administration induce damage or repair response in schistosomiasis?

AIM: To introduce Granulocyte-colony stimulating factor (G-CSF) as a new therapeutic modality for schistosomiasis through stem cell mobilization, immunomodulation or fibrosis remodeling.METHODS: In this study, a 5 d course of human recombinant G-CSF (100 μg/kg sc) was applied to Schistosoma mansoni-infected mice at different stages of disease (5 d before infection as well as 3, 5 and 7 wk post-infection). The animals were sacrificed at 10 d as well as 4, 6 and 8 wk post infection. Mice were examined for: (1) Total leukocyte count which is an accepted surrogate marker for the stem cell mobilization into the circulation; (2) Egg count in intestine and liver tissue to assess the parasitic load; and (3) Histopathological changes in Hx/E and Masson trichrome stained sections as well as collagen content in Sirius red-stained liver sections to determine the severity of liver fibrosis.RESULTS: Mice developed leukocytosis. The egg load and the number of granulomas were not affected by the G-CSF treatment but there was an obvious change in the composition of granulomas towards an increased cellularity. Moreover, fibrosis was significantly decreased in treated groups compared to untreated animals (collagen content either preinfection or at 3 and 5 wk post infection: 5.8 ± 0.5, 4.7 ± 0.5, 4.0 ± 0.7 vs 8.2 ± 0.9; P ≤ 0.01).CONCLUSION: Although G-CSF did not cause direct elimination of the parasite, it enhanced granulomatous reaction and reduced the fibrosis. Further investigation of the underlying mechanisms of these two actions is warranted.     

Antigen loading on dendritic cells affects the lell function in stimulating T cells.

Objective: To study the effect of antigen loading on dendritic cells (DC). Methods: DCs collected from peripheral blood monocytes were loaded with a tumor antigen from XG-7 cell line. These DCs were then co-cultured with allogeneic T cells and were compared with those DCs without antigen exposure.     

Initial versus confirmatory thyroid stimulating hormone (TSH) levels: is there a correlation?

Newborn screening for congenital hypothyroidism (CH) in the Philippines began in 1996. The screening method used is the fluoroimmunometric assay of thyroid stimulating hormone (TSH) from dried blood spot. In the past five years (June 1996--Sept 2001), 176,548 newborns have been screened. Of these, 237 had elevated TSH levels and 51 (22%) were confirmed to have CH. One hundred forty-six (61%) had normal TSH levels on confirmatory testing; five (2%) expired; 25 (11%) were lost to follow-up, while 10 (4%) were being recalled at the time of this study. Thirty-three out of 51(65%) CH patients are female. Only 38 of 51 patient charts were available for data analysis. Thirteen of 51 CH patients were lost to follow-up after confirmation of the disorder. The mean age at which levo-thyroxine was initiated is 1 1/2 months at a modal dosage of 25 microg OD. The initial TSH levels as determined by the Philippine Newborn Screening Laboratory directly correlates with the confirmatory TSH levels done in other endocrine laboratories (Spearman's rho=0.57, p value=0.0002, at a=0.05). However, the time of heel prick on the newborn was independent of the TSH levels, (Spearman's rho=-0.16, p value=0.377 at a=0.05) hence there was no significant difference with respect to the initial TSH level of blood samples taken at 48 hours, less than one week, one to two weeks; or even more than two weeks after birth (Kruskall Wallis test, p value=0.064 at a=0.05). Using Fisher's exact test, there is no sufficient evidence to say that there is an association between gender and the incidence of CH among screened newborns whose TSH levels were initially elevated (p 2-tailed=0.183, p 1-tailed=0.113 at a=0.05).     

Is nonalcoholic steatohepatitis associated with a high-though-normal thyroid stimulating hormone level and lower cholesterol levels?

Hypothyroidism is associated with the risk of development of the metabolic syndrome (MS) and hypercholesterolemia. Direct evidence that hypothyroidism might be associated with advanced chronic liver disease via nonalcoholic steatohepatitis (NASH) is limited. We studied the relationship between thyroid hormones, thyroid stimulating hormone (TSH), cholesterol, and NASH. In consecutive euthyroid patients with biopsy-proven nonalcoholic fatty liver disease, TSH and thyroid hormone (FT3 and FT4) concentrations were compared in 25 patients with steatosis and 44 non-cirrhotic NASH patients featuring concurrent ballooning, lobular inflammation and steatosis. The MS was diagnosed according to ATP III criteria. A meta-analysis of previously published studies was performed to evaluate whether NASH, compared to simple steatosis, is associated with lower cholesterol levels. At univariate analysis, compared to those with steatosis, patients with NASH have a wider waist, elevated levels of BMI, ALT, AST, fasting insulin, HOMA-IR, ferritin, TSH and a lower serum cholesterol. At stepwise multivariable logistic regression analysis, the independent predictors of NASH are high HOMA and TSH and lower total cholesterol (Model 1); MS and high TSH (Model 2). At meta-analysis, serum total cholesterol levels are significantly lower in predominantly non-cirrhotic NASH than in simple steatosis. This study provides cross-sectional and meta-analytic evidence that, in euthyroid patients, high-though-normal TSH values are independently associated with NASH. Further work is needed to ascertain the role, if any, of lower cholesterol serum levels in assisting in the diagnosis of NASH.     

Human chorionic gonadotrophin (hCG) enhances immunity against L. tropica by stimulating human macrophage functions

During pregnancy, there are important changes in hormone levels such as the huge production of human chorionic gonadotropin (hCG), which is supposed to influence the immune system. The aim of this study was to investigate the effect of hCG on immune response against Leishmania, through the evaluation of the functions of human macrophages infected with L. tropica. This study demonstrated that hCG significantly increased the NO production by rHu‐IFNγ‐primed macrophages then infected with L. tropica, which was correlated with decrease in the number of infected macrophages as well as the number of amastigotes per macrophage in a dose‐dependent manner; however, the greatest effect was shown with the 250 U/mL concentration. The addition of the same concentration of hCG to rHu‐IFNγ‐primed macrophages caused also a major increase in both IL‐6 and IL‐12p40 production. In conclusion, hCG enhances different macrophage functions involved in immunity against L. tropica.     

Granulocyte colony–stimulating factor–induced blood stem cell mobilisation in patients with chronic heart failure

Bone marrow-derived stem cells may contribute to the regeneration of non-haematopoietic organs. In order to test whether an increase in circulating stem cell numbers improves impaired myocardial function we treated 16 male patients with chronic heart failure due to dilated (DCM; n = 7) or ischaemic cardiomyopathy (ICM; n = 9) with the stem cell mobilising cytokine granulocyte colony-stimulating factor (G-CSF; four 10-day treatment periods interrupted by treatment-free intervals of equal length). Safety and efficacy analyses were performed at regular intervals. Peak CD34+ cell counts remained constant from cycle to cycle. Cardiac side effects in ICM patients included occasional episodes of dyspnea or angina and one episode of fatal ventricular fibrillation. Nine (4 DCM, 5 ICM) of 12 patients receiving four full G-CSF cycles experienced an improvement by one New York Heart Association (NYHA) class and a statistically significant increase in six-minute walking distance. By contrast, none of 8 ICM historical controls had a change in NYHA class during a similar time period. Statistically significant changes in echocardiographic parameters were not recorded. Sequential administration of G-CSF is feasible and possibly effective in improving physical performance in patients with chronic heart failure. Patients with ICM may be at risk of increased angina and arrhythmias.     

Effects of thyroid status on bone metabolism: a primary role for thyroid stimulating hormone or thyroid hormone?

Thyroid hormones are essential for normal skeletal growth and the maintenance of bone mass in adulthood, although their mechanism of action in bone is poorly understood. Hypothyroidism causes impaired bone formation and growth retardation whereas thyrotoxicosis results in accelerated growth, advanced bone age and decreased bone mass. Adults with thyrotoxicosis or a suppressed thyroid stimulating hormone (TSH) from any cause have an increased risk of osteoporotic fracture. Conventionally, bone loss in thyrotoxicosis has been regarded as a direct consequence of thyroid hormone excess acting locally on bone. Recently, however, it has been proposed that TSH may be a direct negative regulator of bone turnover acting via the TSH receptor on both osteoblasts and osteoclasts. Thus, TSH deficiency could be partly responsible for the skeletal loss seen in thyrotoxicosis. Here we provide an overview of the molecular actions of thyroid hormone in bone and discuss in detail the current evidence relating to a possible role for TSH in bone metabolism.     

Blocking antibody to the β-subunit of FSH prevents bone loss by inhibiting bone resorption and stimulating bone synthesis

Low estrogen levels undoubtedly underlie menopausal bone thinning. However, rapid and profuse bone loss begins 3 y before the last menstrual period, when serum estrogen is relatively normal. We have shown that the pituitary hormone FSH, the levels of which are high during late perimenopause, directly stimulates bone resorption by osteoclasts. Here, we generated and characterized a polyclonal antibody to a 13-amino-acid-long peptide sequence within the receptor-binding domain of the FSH β-subunit. We show that the FSH antibody binds FSH specifically and blocks its action on osteoclast formation in vitro. When injected into ovariectomized mice, the FSH antibody attenuates bone loss significantly not only by inhibiting bone resorption, but also by stimulating bone formation, a yet uncharacterized action of FSH that we report herein. Mesenchymal cells isolated from mice treated with the FSH antibody show greater osteoblast precursor colony counts, similarly to mesenchymal cells isolated from FSH receptor (FSHR)(-/-) mice. This suggests that FSH negatively regulates osteoblast number. We confirm that this action is mediated by signaling-efficient FSHRs present on mesenchymal stem cells. Overall, the data prompt the future development of an FSH-blocking agent as a means of uncoupling bone formation and bone resorption to a therapeutic advantage in humans.     

The five “Ws” for bone pain due to the administration of granulocyte-colony stimulating factors (G-CSFs)

Granulocyte-colony stimulating factors (G-CSFs) are commonly employed in clinical practice. The most relevant adverse event of G-CSF administration is bone pain. Approximately 20% of cancer patients experienced bone pain with the administration of prophylactic daily G-CSFs (lenograstim and filgrastim). The reported incidence of bone pain in cancer patients undergoing pegfilgrastim prophylaxis ranged from 25% to 38%. In healthy donors the incidence of bone pain was higher than in cancer patients, ranging from 52% to 84%. There are four main causes of G-CSF related bone pain: bone marrow quantitative and qualitative expansion, peripheral nociceptor sensitization to nociceptive stimuli, modulation of immune function and direct effect on bone metabolism. For the prevention and treatment of bone pain occurring after or during GCSFs administration, acetaminophen and nonsteroidal anti-inflammatory agents are commonly used as first-line treatment; antihistamines, opioids and dose reduction of G-CSFs are considered as second line therapy. The only randomized clinical trial conducted for the prevention and treatment of G-CSF induced bone pain showed the efficacy of naproxen in reducing the incidence, the severity and the duration of bone pain induced by the administration of pegfilgrastim.     

Interferon-α suppressed granulocyte colony stimulating factor production is reversed by CL097, a TLR7/8 agonist

Background and Aim: Neutropenia, a major side‐effect of interferon‐α (IFN‐α) therapy can be effectively treated by the recombinant form of granulocyte colony stimulating factor (G‐CSF), an important growth factor for neutrophils. We hypothesized that IFN‐α might suppress G‐CSF production by peripheral blood mononuclear cells (PBMCs), contributing to the development of neutropenia, and that a toll‐like receptor (TLR) agonist might overcome this suppression. Methods: Fifty‐five patients who were receiving IFN‐α/ribavirin combination therapy for chronic hepatitis C virus (HCV) infection were recruited. Absolute neutrophil counts (ANC), monocyte counts and treatment outcome data were recorded. G‐CSF levels in the supernatants of PBMCs isolated from the patients and healthy controls were assessed by enzyme‐linked immunosorbent assay following 18 h of culture in the absence or presence of IFN‐ α or the TLR7/8 agonist, CL097. Results: Therapeutic IFN‐α caused a significant reduction in neutrophil counts in all patients, with 15 patients requiring therapeutic G‐CSF. The reduction in ANC over the course of IFN‐α treatment was paralleled by a decrease in the ability of PBMCs to produce G‐CSF. In vitro G‐CSF production by PBMCs was suppressed in the presence of IFN‐α; however, co‐incubation with a TLR7/8 agonist significantly enhanced G‐CSF secretion by cells obtained both from HCV patients and healthy controls. Conclusions: Suppressed G‐CSF production in the presence of IFN‐α may contribute to IFN‐α‐induced neutropenia. However, a TLR7/8 agonist elicits G‐CSF secretion even in the presence of IFN‐α, suggesting a possible therapeutic role for TLR agonists in treatment of IFN‐α‐induced neutropenia.     

Passive anaphylaxis and IgE antibody production are compromised in tumor necrosis factor- and in granulocyte–macrophage colony stimulating factor-deficient mice

BackgroundA number of recent studies has demonstrated a critical role for mast cells and mast cell-derived cytokines, especially tumour necrosis factor (TNF), in the control of host defense mechanisms during inflammation. In the presesnt study, we investigated whether TNF-deficient (TNF^−/−) and granulocyte-macrophage colony stimulating factor (GM-CSF)-deficient (GM-CSF^−/−) mice expressed defects in normal mast cell function.MethodsBecause the first step in the passive cutaneous anaphylactic (PCA) reaction is fixation of the antibody to mast cells, we tried to obtain a PCA in TNF^−/− and GM-CSF^−/−mice.ResultsWhile an anti-dinitrophenyl IgE monoclonal antibody induced a strong PCA reaction in wild-type mice, it was not possible to obtain a PCA reaction in either TNF^−/− or GM-CSF^−/− mice. We next examined whether mast cells were present in these mice and if so, did they have functional FcεRI receptors on their surface. The number of mast cells in smears from the peritoneal fluid of the TNF^−/− and GM-CSF^−/− mice was similar to that seen in wild-type mice. However, the expression of FcεRI on mast cells from the peritoneal fluid of TNF^−/− and GM-CSF^−/− mice, measured by either rosetting assay or FACScan analysis, was compromised compared with wild-type mice. Previous studies have established that defects in FCεRI expression often have found that IgE production was compromised in both TNF^−/− and GM-CSF^−/− mice.ConclusionsThe observed defects may partially explain the immunodeficiency of these cytokine-deficient animals during infection.     

Acute stress increases the synthesis of 7α-hydroxypregnenolone, a new key neurosteroid stimulating locomotor activity, through corticosterone action in newts

7α-Hydroxypregnenolone (7α-OH PREG) is a newly identified bioactive neurosteroid stimulating locomotor activity in the brain of newt, a wild animal, which serves as an excellent model to investigate the biosynthesis and biological action of neurosteroids. Here, we show that acute stress increases 7α-OH PREG synthesis in the dorsomedial hypothalamus (DMH) through corticosterone (CORT) action in newts. A 30-min restraint stress increased 7α-OH PREG synthesis in the brain tissue concomitant with the increase in plasma CORT concentrations. A 30-min restraint stress also increased the expression of cytochrome P450(7α) (CYP7B), the steroidogenic enzyme of 7α-OH PREG formation, in the DMH. Decreasing plasma CORT concentrations by hypophysectomy or trilostane administration decreased 7α-OH PREG synthesis in the diencephalon, whereas administration of CORT to these animals increased 7α-OH PREG synthesis. Glucocorticoid receptor was present in DMH neurons expressing CYP7B. Thus, CORT appears to act directly on DMH neurons to increase 7α-OH PREG synthesis. We further investigated the biological action of 7α-OH PREG in the brain under stress. A 30-min restraint stress or central administration of 7α-OH PREG increased serotonin concentrations in the diencephalon. Double immunolabeling further showed colocalization of CYP7B and serotonin in the DMH. These results indicate that acute stress increases the synthesis of 7α-OH PREG via CORT action in the DMH, and 7α-OH PREG activates serotonergic neurons in the DMH that may coordinate behavioral responses to stress. This is the first demonstration of neurosteroid biosynthesis regulated by peripheral steroid hormone and of neurosteroid action in the brain under stress in any vertebrate class.