Combined treatment with GH and IGF-I: additive effect on cortical bone mass but not on linear bone growth in female rats

Both epilepsy and anti-seizure medications affect bone metabolism in children with self-limited epilepsy with centrotemporal spikes

OBJECTIVE

Bone metabolism can be influenced by a range of factors. We selected children with self-limited epilepsy with centrotemporal spikes (SeLECTS) and lifestyles similar to those of healthy children to control for the confounding factors that may influence bone metabolism. We aimed to identify the specific effects of epilepsy and/or anti-seizure medications (ASMs) on bone metabolism.

METHODS

Patients with SeLECTS were divided into an untreated group and a monotherapy group, and the third group was a healthy control group. We determined the levels of various biochemical markers of bone metabolism, including procollagen type I nitrogenous propeptide (PINP), alkaline phosphatase (ALP), osteocalcin (OC), collagen type I cross-linked C-telopeptide (CTX), calcium, magnesium, phosphorus, parathyroid hormone (PTH), and vitamin D3 (VD3 ).

RESULTS

A total of 1487 patients (from 19 centers) were diagnosed with SeLECTS; 1032 were analyzed, including 117 patients who did not receive any ASMs (untreated group), 643 patients who received only one ASM (monotherapy group), and 272 children in the healthy control group. Except for VD3 , other bone metabolism of the three groups were different (p < .001). Bone metabolism was significantly lower in the untreated group than the healthy control group (p < .05). There were significant differences between the monotherapy and healthy control group in the level of many markers. However, when comparing the monotherapy and untreated groups, the results were different; oxcarbazepine, levetiracetam, and topiramate had no significant effect on bone metabolism. Phosphorus and magnesium were significantly lower in the valproic acid group than the untreated group (adjusted p < .05, Cliff's delta .282-.768). CTX was significantly higher in the lamotrigine group than in the untreated group (adjusted p = .012, Cliff's delta = .316).

SIGNIFICANCE

Epilepsy can affect many aspects of bone metabolism. After controlling epilepsy and other confounders that affect bone metabolism, we found that the effects of ASMs on bone metabolism differed. Oxcarbazepine, levetiracetam, and topiramate did not affect bone metabolism, and lamotrigine corrected some of the abnormal markers of bone metabolism in patients with epilepsy.

Orally administered zingerone does not mitigate alcohol-induced hepatic oxidative stress in growing Sprague Dawley rat pups

Neonatal alcohol exposure (NAE) can induce oxidative stress. We determined whether zingerone (ZO), a phytochemical with anti-oxidant activity, can mitigate the negative impact of neonatal alcohol-induced oxidative stress. Seventy ten-day-old Sprague-Dawley rat pups (35 male, 35 female) were randomly assigned and administered the following treatment regimens daily from postnatal day (PND) 12-21: group 1 - nutritive milk (NM), group 2 - NM +1 g/kg ethanol (Eth), group 3 - NM + 40 mg/kg ZO, group 4 - NM + Eth + ZO. Growth performance, blood glucose and plasma triglycerides (TGs), total cholesterol, HDL-cholesterol, leptin and insulin concentration were determined. Cytochrome p450E21(CYP2E1) and thiobarbituric acid (TBARS); markers of hepatic oxidative stress and catalase, superoxide dismutase (SOD) and total glutathione (GSH), anti-oxidant markers of the pups were determined. Oral administration of ethanol (NM + Eth), zingerone (NM + ZO) and combined ethanol and zingerone (NM + Eth + ZO) did not affect the growth performance and insulin and leptin concentration of the rats (p > 0.05). Ethanol significantly reduced plasma TGs concentration of female rats (p = 0.04 vs control). However, ethanol and/or its combination with zingerone decreased hepatic GSH (p = 0.02 vs control) and increased CYP2E1 (p = 0.0002 vs control) activity in male rat pups. Zingerone had no effect (p > 0.05 vs control) on the rats' CYP2E1, GSH, SOD and catalase activities. Neonatal alcohol administration elicited hepatic oxidative stress in male rat pups only, showing sexual dimorphism. Zingerone (NM + ZO) prevented an increase in CYP2E1 activity and a decrease in GSH concentration but did not prevent the alcohol-induced hepatic oxidative stress in the male rat pups.

Exosomal hsa-miR-21-5p derived from growth hormone-secreting pituitary adenoma promotes abnormal bone formation in acromegaly

Growth hormone-secreting pituitary adenoma (GHPA), a benign endocrine tumor located in the base of the skull, results in acromegaly. In addition to the mass effect of the tumor itself in the sellar region, GHPA can lead to the overgrowth of almost every organ. Previous findings indicated that the processes underlying acromegaly were partly attributable to hyperactivity of the growth hormone/insulin-like growth factor-1 (GH/IGF-1) axis. However, the mechanisms driving this syndrome remains largely unknown. Additionally, the roles of GHPA-derived exosomes, which contain functional microRNAs and proteins that manipulate target cell proliferation and differentiation in distal extremities, are also unknown. In this study, we demonstrated that GHPA exosomes promote bone formation in vitro and trabecula number in vivo. The mechanism of increased trabecula formation may be attributable to GHPA exosome-induced osteoblast proliferation via increased cell viability and DNA replication. We further discovered that exosomal hsa-miR-21-5p plays a distinct role from the GH/IGF-1 axis in these processes. Accordingly, the results of this study provide a novel mechanism whereby GHPA influences distal extremities and a new perspective for treating GHPA.

Effects of muscular strength training and growth hormone (GH) supplementation on femoral bone tissue: analysis by Raman spectroscopy, dual-energy X-ray absorptiometry, and mechanical resistance

The aim of the present study was to verify the effects of muscular strength training and growth hormone (GH) supplementation on femoral bone tissue by Raman spectroscopy (Raman), dual-energy X-ray absorptiometry (DXA), and mechanical resistance (F-max) analysis. A total of 40 male Wistar animals, 60 days old, were used. The animals were distributed into four groups: control (C), control with GH (GHC), muscular strength training (T), and muscular strength training with GH (GHT). Blood samples were collected for the quantification of creatine kinase (CK-MB) and the femurs were removed for analysis by Raman, DXA, and F-max. A more pronounced increase in the bone mineral components was verified in the T group, for all the variables obtained by the Raman (calcium, phosphate, amide, and collagen). In addition, for animals submitted to GH supplementation, there was a reduction in the variable bone mineral density (BMD) obtained by the DXA (p < 0.05). Finally, the animals that received GH supplementation presented a higher F-max, but without statistical significance (p > 0.05). It was concluded that animals that received GH supplementation demonstrated a decrease in BMD. In addition, T alone was able to promote increased calcium, phosphate, amide, and collagen compounds in bone tissue.

Short-Term Neonatal Oral Administration of Oleanolic Acid Protects against Fructose-Induced Oxidative Stress in the Skeletal Muscles of Suckling Rats

Nutritional manipulations in the neonatal period are associated with the development of negative or positive health outcomes later in life. Excessive fructose consumption has been attributed to the increase in the global prevalence of metabolic syndrome (MetS) and the development of oxidative stress. Oleanolic acid (OA) has anti-diabetic and anti-obesity effects. We investigated the protective potential of orally administering OA in the neonatal period, to prevent fructose-induced oxidative stress, adverse health outcomes and maturation of the gastrointestinal tract (GIT) in suckling rats. Seven-day old Sprague-Dawley rats (N = 30) were gavaged daily with 10 mL/kg of: distilled water (DW), oleanolic acid (OA; 60 mg/kg), high fructose solution (HF; 20% w/v), or OAHF for 7 days. On day 14, tissue samples were collected to determine clinical health profiles, hepatic lipid content, and activity of anti-oxidant enzymes. Furthermore, biomarkers of oxidative stress and anti-oxidant capacity in the skeletal muscles were assessed. The gastrointestinal tract (GIT) morphometry was measured. Rats in all groups grew over the 7-day treatment period. There were no significant differences in the terminal body masses, GIT morphometry, surrogate markers of general health, liver lipid content across all treatment groups (p < 0.05). Neonatal fructose administration decreased the activity of catalase, depleted GSH and increased lipid peroxidation. However, the level of GSH and catalase activity were improved by neonatal OA treatment. Short-term oral OA administration during the critical developmental period protects against fructose-induced oxidative stress without adverse effects on health outcomes associated with MetS or precocious development of the GIT in suckling male and female rats.

Astragalus Extract Mixture HT042 Improves Bone Growth, Mass, and Microarchitecture in Prepubertal Female Rats: A Microcomputed Tomographic Study

Astragalus extract mixture HT042 is a standardized multiherbal mixture comprising Astragalus membranaceus, Eleutherococcus senticosus, and Phlomis umbrosa, which has proven to promote children's height growth. The aim of this study was to investigate the effects of HT042 on longitudinal bone growth, bone mass, and bone microstructure in growing rats using a high-resolution microcomputed tomography system. Four-week-old female rats were fed an HT042-containing diet for 2 weeks. Tibial length was measured at baseline and weekly in vivo. At the end of the study, volumetric bone mineral density (vBMD) and microarchitectural parameters were estimated in the trabecular and cortical bone of the tibia. Tibial length gain was significantly increased by HT042 compared to that reported with the control diet. In the proximal tibial metaphysis, HT042-treated rats had significantly higher trabecular vBMD, bone volume fraction, and trabecular number and lower trabecular separation, trabecular pattern factor, and structure model index values than control rats did. Total cross-sectional area and bone area of the cortical bone in the tibial diaphysis also increased. These findings suggest that HT042 increases longitudinal bone growth rate, improves trabecular bone mass, and enhances the microarchitecture of trabecular and cortical bone during growth.

Mice with infectious colitis exhibit linear growth failure and subsequent catch-up growth related to systemic inflammation and IGF-1

In developing communities, intestinal infection is associated with poor weight gain and linear-growth failure. Prior translational animal models have focused on weight gain investigations into key contributors to linear growth failure have been lacking. We hypothesized that murine intestinal infection with Citrobacter rodentium would induce linear-growth failure associated with systemic inflammation and suppressed serum levels of insulin-like growth factor-1 (IGF-1). We evaluated 4 groups of mice infected or sham-infected on day-of-life 28: uninfected-controls, wild-type C rodentium-infected, partially-attenuated C rodentium-infected (with deletion of 3 serine protease genes involved in colonization), and pair-fed (given the amount of daily food consumed by the wild-type C rodentium group). Relative to the uninfected group, mice infected with wild-type C rodentium exhibited temporal associations of lower food intake, weight loss, linear-growth failure, higher IL-6 and TNF-α and lower IGF-1. However, relative to the pair-fed group, the C rodentium-infected group only differed significantly by linear growth and systemic inflammatory cytokines. Between post-infection days 15-20, the infected group exhibited resolution of systemic inflammation. Between days 16-20, both wild-type C rodentium and pair-fed groups exhibited rapid linear-growth velocities exceeding the uninfected and mutant C rodentium groups; during this time levels of IGF-1 increased to match the uninfected group. We submit this as a model providing important opportunities to study mechanisms of catch-up growth related to intestinal inflammation. We conclude that in addition to known effects of weight loss, infection with C rodentium induces linear-growth failure potentially related to systemic inflammation and low levels of IGF-1, with catch-up of linear growth following resolution of inflammation.

Bone Status in a Patient with Insulin-Like Growth Factor-1 Receptor Deletion Syndrome: Bone Quality and Structure Evaluation Using Dual-Energy X-Ray Absorptiometry, Peripheral Quantitative Computed Tomography, and Quantitative Ultrasonography

Haploinsufficiency of the insulin-like growth factor (IGF)-1 receptor (IGF1R) gene is a rare, probably under-diagnosed, cause of short stature. However, the effects of IGF1R haploinsufficiency on glucose metabolism, bone status, and metabolism have rarely been investigated. We report the case of a patient referred to our center at the age of 18 months for short stature, failure to thrive, and Silver-Russell-like phenotype. Genetic analysis did not show hypomethylation of the 11p15.5 region or uniparental disomy of chromosome 7. Growth hormone (GH) stimulation tests revealed GH deficiency, whereas IGF-1 was 248 ng/mL. r-hGH treatment showed only a slight improvement (from -4.4 to -3.5 SDS). At 10 years of age, the child was re-evaluated: CGH-array identified a heterozygous de novo 4.92 Mb deletion in 15q26.2, including the IGF1R gene. Dual-energy X-ray absorptiometry showed a normal bone mineral density z-score, while peripheral quantitative computed tomography revealed reduced cortical and increased trabecular elements. A phalangeal bone quantitative ultrasonography showed significantly reduced amplitude-dependent speed of sound and bone transmission time values. The changes in bone architecture, quality, and metabolism in heterozygous IGF1R deletion patients, support the hypothesis that IGF-1 can be a key factor in bone modeling and accrual.

Growth and the Growth Hormone-Insulin Like Growth Factor 1 Axis in Children With Chronic Inflammation: Current Evidence, Gaps in Knowledge, and Future Directions

Growth failure is frequently encountered in children with chronic inflammatory conditions like juvenile idiopathic arthritis, inflammatory bowel disease, and cystic fibrosis. Delayed puberty and attenuated pubertal growth spurt are often seen during adolescence. The underlying inflammatory state mediated by proinflammatory cytokines, prolonged use of glucocorticoid, and suboptimal nutrition contribute to growth failure and pubertal abnormalities. These factors can impair growth by their effects on the GH-IGF axis and also directly at the level of the growth plate via alterations in chondrogenesis and local growth factor signaling. Recent studies on the impact of cytokines and glucocorticoid on the growth plate further advanced our understanding of growth failure in chronic disease and provided a biological rationale of growth promotion. Targeting cytokines using biological therapy may lead to improvement of growth in some of these children, but approximately one-third continue to grow slowly. There is increasing evidence that the use of relatively high-dose recombinant human GH may lead to partial catch-up growth in chronic inflammatory conditions, although long-term follow-up data are currently limited. In this review, we comprehensively review the growth abnormalities in children with juvenile idiopathic arthritis, inflammatory bowel disease, and cystic fibrosis, systemic abnormalities of the GH-IGF axis, and growth plate perturbations. We also systematically reviewed all the current published studies of recombinant human GH in these conditions and discussed the role of recombinant human IGF-1.

Markers of bone turnover in patients with epilepsy and their relationship to management of bone diseases induced by antiepileptic drugs

Data from cross-sectional and prospective studies revealed that patients with epilepsy and on long-term treatment with antiepileptic drugs (AEDs) are at increased risk for metabolic bone diseases. Bone diseases were reported in about 50% of patients on AEDs. Low bone mineral density, osteopenia/osteoporosis, osteomalacia, rickets, altered concentration of bone turnover markers and fractures were reported with phenobarbital, phenytoin, carbamazepine, valproate, oxcarbazepine and lamotrigine. The mechanisms for AEDs-induced bone diseases are heterogeneous and include hypovitaminosis D, hypocalcemia and direct acceleration of bone loss and/or reduction of bone formation. This article reviews the evidence, predictors and mechanisms of AEDs-induced bone abnormalities and its clinical implications. For patients on AEDs, regular monitoring of bone health is recommended. Prophylactic administration of calcium and vitamin D is recommended for all patients. Treatment doses of calcium and vitamin D and even anti-resorptive drug therapy are reserved for patients at high risk of pathological fracture.

Endurance exercise and growth hormone improve bone formation in young and growth-retarded chronic kidney disease rats

BACKGROUND

Childhood chronic kidney disease (CKD) is associated with both short stature and abnormal bone mineralization. Normal longitudinal growth depends on proper maturation of epiphyseal growth plate (EGP) chondrocytes, leading to the formation of trabecular bone in the primary ossification centre. We have recently shown that linear growth impairment in CKD is associated with impaired EGP growth hormone (GH) receptor signalling and that exercise improved insulin-like growth factor I (IGF-I) signalling in CKD-related muscle atrophy.

METHODS

In this study, 20-day-old rats underwent 5/6 nephrectomy (CKD) or sham surgery (C) and were exercised with treadmill, with or without GH supplementation.

RESULTS

CKD-related growth retardation was associated with a widened EGP hypertrophic zone. This was not fully corrected by exercise (except for tibial length). Exercise in CKD improved the expression of EGP key factors of endochondral ossification such as IGF-I, vascular endothelial growth factor (VEGF), receptor activator of nuclear factor kappa-B ligand (RANKL) and osteocalcin. Combining GH treatment with treadmill exercise for 2 weeks improved the decreased trabecular bone volume in CKD, as well as the expression of growth plate runt-related transcription factor 2, RANKL, metalloproteinase 13 and VEGF, while GH treatment alone could not do that.

CONCLUSIONS

Treadmill exercise improves tibial bone linear growth, as well as growth plate local IGF-I. When combined with GH treatment, running exercise shows beneficial effects on trabecular bone formation, suggesting the potential benefit of this combination for CKD-related short stature and bone disease.