Short-term induced hyperinsulinaemia and dexamethasone challenge do not affect circulating total adiponectin concentrations in insulin-sensitive ponies.

BACKGROUND: Hypoadiponectinaemia is a risk factor for endocrinopathic laminitis, but the directionality and nature of its association with insulin dysregulation is unclear. OBJECTIVES: To investigate the effects of short-term induced hyperinsulinaemia and dexamethasone challenge on circulating [total adiponectin] and whole blood expression of adiponectin (AdipoR1 and AdipoR2), insulin, and insulin-like growth factor 1 (IGF-1) receptors in insulin-sensitive ponies. STUDY DESIGN: In vivo experiment. METHODS: Six never-laminitic, insulin-sensitive, native-breed UK ponies first underwent a dexamethasone challenge (0.08 mg/kg i.v.) with blood samples collected every 15 min over 3 h. After a 14-day washout period, hyperinsulinaemia was induced for 9 h via a euglycaemic-hyperinsulinaemic clamp (EHC), with blood samples collected every 30 min. Serum [insulin], plasma [total adiponectin], and plasma [IGF-1] were measured using validated assays and receptor gene expression was assessed via quantitative polymerase chain reaction (qPCR). Finally, whole blood was incubated with 10-1000 ng/mL dexamethasone for 3 h at 37°C to investigate its direct effects on gene expression. RESULTS: There were no adverse effects observed during either protocol. Dexamethasone challenge did not alter circulating [insulin] or [total adiponectin] at any time-point, but significantly upregulated AdipoR1 and IGF-1R expression at 150 and 180 min. Ex vivo incubation of whole blood with dexamethasone did not alter expression of the genes examined. There was no change in [total adiponectin] or expression of the genes examined associated with EHC-induced hyperinsulinemia. MAIN LIMITATIONS: This was a small sample size that included only native-breed ponies; total adiponectin was measured rather than high-molecular-weight adiponectin. CONCLUSIONS: Short-term induced hyperinsulinaemia and dexamethasone challenge did not affect circulating [total adiponectin] in insulin-sensitive ponies. However, dexamethasone administration was associated with upregulation of two receptors linked to adiponectin signalling, suggesting that a physiological response occurred possibly to counteract dexamethasone-associated changes in tissue insulin sensitivity.

SIRT2 inhibition attenuates the vasculopathy and vision impairment via Akt signaling in retinopathy of prematurity.

Despite decades of researches, the underlying mechanism of retinopathy of prematurity (ROP) remains unclear. The role of Sirt2, which is involved in both angiogenesis and inflammation, both pivotal in ROP, was investigated in an animal model of ROP known as oxygen-induced retinopathy (OIR). Our study found that Sirt2 was overexpressed and colocalized with microglia in OIR. Furthermore, it demonstrated that the level of Sirt2 was upregulated in hypoxia microglia BV-2 in vitro. Subsequently, our results elucidated that administration of the Sirt2 antagonist AGK2 attenuated the avascular and neovascular area and downregulated the expression of IGF-1. The phosphorylation of Akt and the expression of IGF-1 were upregulated in hypoxia BV-2 and conditional media collected from BV-2 under hypoxia promoted the migration and tube formation of retinal capillary endothelial cells, which were suppressed with AGK2. Notably, our findings are the first to demonstrate the deleterious role of Sirt2 in ROP, as Sirt2 inhibition led to the downregulation of Akt/IGF-1 and ameliorated vasculopathy, ultimately improving visual function. These results suggest that Sirt2 may be a promising therapeutic target for ROP.

Doping and sports endocrinology: growth hormone, IGF-1, insulin, and erythropoietin.

Among the substances prohibited by the World Anti-Doping Agency, "peptide hormones, growth factors, related substances, and mimetics" are classified as prohibited both in- and out-of-competition in section S2. This work reviews growth hormone and its releasing peptides, insulin-like growth factor 1 as the main growth factor, insulin, and erythropoietin and other agents that affect erythropoiesis. This review analyzes the prevalence of use among professional athletes and gym clients, the forms of use, dosing, ergogenic effects and effects on physical performance, as well as side effects and anti-doping detection methods.

Effects of Rosa damascena on reproductive improvement, metabolic parameters, liver function and insulin-like growth factor-1 gene expression in estradiol valerate induced polycystic ovarian syndrome in Wistar rats.

BACKGROUND: Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders in reproductive-age women. The present study aimed to evaluate the effects of Rosa damascena (RD) extract in estradiol valerate (EV) induced polycystic ovary syndrome rats. METHODS: Adult female Wistar rats were divided into control (n = 12) and PCOS groups (n = 36). The PCOS model was induced using EV (4 mg/kg/day), which was confirmed in 6 rats in each control and PCOS group by observation of irregular estrous cycles in vaginal smears and ovarian multiple cystic. Then, the rest of the control group (n = 6) and PCOS rats (n = 30 in 5 divided groups) were treated orally for 28 days with metformin (MET) as a positive control (200 mg/kg/day) and RD extract (400, 800, and 1200 mg/kg/day, respectively). Body and ovary weights, biochemical and histological parameters, and expression of the IGF-1 gene were measured. RESULTS: Compared to the PCOS group, metformin and higher doses of RD extract (800 and 1200 mg/kg/day) significantly reduced BW, HOMA-IR, FBS, FINS, TG, LDL, TT, E2, LH, TC, and liver enzymes, and increased HDL and FSH levels. In addition, ovarian weight and CFs decreased, and the findings showed an increment in PFs, CLs, PAFs, AFs, and GFs. IGF-1 gene expression levels were significantly decreased (p < 0.001). CONCLUSION: RD extract seems to have the potential therapeutic effect of alleviating PCOS complications, and IGF-1 signaling may be involved in the beneficial effects of RD on PCOS.

Enfermedad nodular tiroidea en personas con diagnóstico de acromegalia / Nodular thyroid disease in people diagnosed with acromegaly

La aparición de nódulos tiroideos en las personas con acromegalia es una consecuencia de la elevación crónica de la hormona de crecimiento y el factor de crecimiento similar a la insulina tipo 1. Su naturaleza varía según la zona geográfica, suficiencia de yodo y antecedentes patológicos familiares, entre otros factores. No se han publicado estudios cubanos sobre la enfermedad nodular tiroidea en estas personas. Objetivos: Describir las características clínicas, bioquímicas y ultrasonográficas de la glándula tiroidea, según la presencia o no de la enfermedad nodular tiroidea. Métodos: Estudio observacional descriptivo, transversal, que incluyó 73 pacientes con acromegalia entre enero de 2003 y diciembre de 2017. Se estudiaron las variables: edad, sexo, color de la piel, antecedentes familiares de la enfermedad nodular tiroidea, niveles de la hormona de crecimiento, hormona estimulante del tiroides, T4 libre, anticuerpos contra la peroxidasa tiroidea y contra la tiroglobulina, volumen tiroideo, patrón ecográfico nodular y estudio citológico. Resultados: La enfermedad nodular tiroidea se presentó en el 75,3 por ciento de los casos, con predominio del bocio multinodular. La edad al diagnóstico fue menor en los pacientes con la enfermedad (43,53 ± 9,67), que en los que no la tenían (49,33 ± 6,96 años) (p = 0,02). La hormona de crecimiento al diagnóstico de acromegalia, resultó menor en los pacientes con este padecimiento (18,73 ± 11,33 µg/L vs. 35,91 ± 21,68 µg/L; (p = 0,00). El volumen tiroideo mostró diferencias significativas entre ambos grupos (14,2 ± 4,5 mL en los casos positivos de la enfermedad nodular tiroidea y 10,5 ± 2,8 mL en los casos negativos; p = 0,002), siendo el nódulo de baja sospecha de malignidad el más frecuente. El resto de las variables resultaron similares entre los pacientes con y sin la enfermedad. La citología se informó como benigna en el 75 por ciento en los nódulos únicos, el 80 por ciento de los bocios nodulares y el 90 por ciento de los bocios multinodulares (p = 0,51). Conclusiones: La enfermedad nodular tiroidea fue frecuente en los casos de acromegalia, y se asoció a la menor edad y los niveles inferiores de la hormona de crecimiento al diagnóstico. El bocio multinodular constituyó la forma clínica más frecuente y los parámetros hormonales y de autoinmunidad no se asociaron al tipo de la enfermedad nodular tiroidea(AU)

The appearance of thyroid nodules in people with acromegaly is a consequence of chronic elevation of growth hormone (GH) and insulin-like growth factor type 1 (IGF-1). Its nature varies according to the geographical area, the iodine sufficiency and family pathological history, among other factors. No Cuban studies on thyroid nodular disease (TND) in these people have been published. Objectives: Describe some clinical characteristics, as well as biochemical and ultrasonographic ones related to the thyroid gland, according to the presence or not of TND, and to identify the possible association of clinical, biochemical, ultrasonographic and cytological factors with the different types of TND in patients with acromegaly. Methods: A descriptive, cross-sectional observational study that included 73 patients with acromegaly between January 2003 and December 2017. The following variables were studied: age, sex, skin color, family history of TND, GH levels, thyroid stimulating hormone, free T4, antibodies against thyroid peroxidase and thyroglobulin, thyroid volume, nodular ultrasound pattern and cytological study. Results: TND occurred in 75.3 percent of cases, with a predominance of multinodular goiter. The age at diagnosis time was lower in patients with TND (43.53 ± 9.67) than in those who did not have it (49.33 ± 6.96 years) (p=0.02). GH at diagnosis time of acromegaly was lower in patients with TND (18.73±11.33µg/L vs 35.91±21.68µg/L; (p=0.00). The thyroid volume showed significant differences between both groups (14.2±4.5mL in positive cases of TND and 10.5±2.8mL in negative cases; p=0.002), being the most frequent the nodule with low suspicion of malignancy. The rest of the variables were similar between patients with and without TNDs. Cytology was reported as benign in 75 percent in single nodules, 80 percent of nodular goiters and 90 percent of multinodular goiters (p=0.51). Conclusions: TND was frequent in cases of acromegaly, and was associated with lower age and lower GH levels at diagnosis time. Multinodular goiter was the most frequent clinical form and hormonal and autoimmunity parameters were not associated with the type of TND(AU)

Use of hormones in doping and cancer risk.

Hormones with anabolic properties such as growth hormone (GH) and insulin-like growth factor-1 (IGF-1) are commonly abused among professional and recreational athletes to enhance physical ability. Despite their adverse effects are well-documented, the use of GH and IGF-1 has recently grown. This article highlights the anabolic activity related to mechanisms of cancer development and progression. GH/IGF-1 axis is able to activate cellular mechanisms that modulate every key stage of cancer formation and progression, such as inhibition of apoptosis, resistance to treatments, and induction of angiogenesis, metastatic process and cell proliferation. Results from pre-clinical studies and epidemiological observations in patients with an excess of GH and IGF-1 production or treated with these hormones showed a positive association with the risk to develop several types of cancer. In conclusion, athletes should be made aware that long-term treatment with doping agents might increase the risk of developing cancer, especially if associated with other licit or illicit drugs and/or high-protein diet.

The in vitro functional analysis of single-nucleotide polymorphisms associated with growth hormone (GH) response in children with GH deficiency.

Response to recombinant human growth hormone (r-hGH) in the first year of therapy has been associated with single-nucleotide polymorphisms (SNPs) in children with GH deficiency (GHD). Associated SNPs were screened for regulatory function using a combination of in silico techniques. Four SNPs in regulatory sequences were selected for the analysis of in vitro transcriptional activity (TA). There was an additive effect of the alleles in the four genes associated with good growth response. For rs3110697 within IGFBP3, rs1045992 in CYP19A1 and rs2888586 in SOS1, the variant associated with better growth response showed higher TA with r-hGH treatment. For rs1024531 in GRB10, a negative regulator of IGF-I signalling and growth, the variant associated with better growth response had a significantly lower TA on r-hGH stimulation. These results indicate that specific SNP variants have effects on TA that provide a rationale for their clinical impact on growth response to r-hGH therapy.

Peripheral pain is enhanced by insulin-like growth factor 1 and its receptors in a mouse model of type 2 diabetes mellitus.

BACKGROUND: Insulin-like growth factor 1 (IGF1) is a neurotrophic factor with many actions, including a possible hyperalgesic effect. This study investigated the effects of IGF1 on the overall behavior of diabetic mice and explored the possible mechanisms underlying IGF1-induced pain. METHODS: Mice were divided into five groups (db/m, db/db, vehicle-treated db/db, IGF1-treated db/db, and IGF1 + JB1-treated db/db mice). Behavioral studies were conducted using the hot plate and Von Frey tests after intraplantar injection of recombinant (r) IGF1 (50 µg/kg) and the IGF1 receptor (IGF1R) antagonist JB1 (6 µg/mouse). Morphological changes in dorsal root ganglia (DRG) were evaluated using electron microscopy. Immunofluorescence was used to detect IGF1R expression and colocalisation with pain mediators in the DRG. Changes in the expression of IGF1R, extracellular signal-regulated kinase (ERK), and ras-associated factor-1 (c-raf) in the DRG were evaluated using western blotting. RESULTS: Intraplantar injection of rIGF1 resulted in a hyperalgesic effect after 2 hours. This IGF1-induced hypersensitivity was attenuated by prior intraplantar injection of the IGF1R antagonist. There was no significant change in neuronal structure in the db/m group, whereas neuronal structure was impaired in the other four groups. Moreover, IGF1R was colocalised with pain mediators in the DRG of mice. Intraplantar injection of rIGF1 resulted in increased IGF1R, phosphorylated (p-) ERK, and c-raf expression in the DRG; prior intraplantar injection of the IGF1R antagonist attenuated rIGF1-induced increases in p-ERK and c-raf. CONCLUSIONS: The results indicate that IGF1-induced acute hyperalgesia may be associated with the IGF1R/c-raf/ERK pathway. The IGF1-induced hypersensitivity was attenuated by an IGF1R antagonist.

Treatment of severe primary IGF-1 deficiency using rhIGF-1 preparation - first three years of Polish experience.

INTRODUCTION: The objective of this study was to analyse the effects of the first three years of treatment with recombinant human insulinlike growth factor 1 (rhIGF-1) in patients from the Polish population. MATERIAL AND METHODS: Twenty-seven children (22 boys and five girls) aged 2.8 to 16.0 years old were qualified for treatment with rhIGF-1 (mecasermin) in different treatment centres, according to Polish criteria: body height below -3.0 SD and IGF-1 concentration below percentile 2.5 with normal growth hormone (GH) levels. Mecasermin initial dose was 40 µg/kg bw twice a day and was subsequently increased to an average of 100 µg/kg bw twice a day. Body height, height velocity, weight, body mass index (BMI), and adverse events were measured. RESULTS: Mecasermin treatment resulted in a statistically significant increase in body height (1.45 ± 1.06 SD; p < 0.01) and height velocity in comparison with pre-treatment values. The biggest change in height velocity happened during the first year and diminished during subsequent years. Body weight and BMI also increased significantly after treatment (1.16 ± 0.76 SD and 0.86 ± 0.75 SD, respectively; p < 0.01). Eight patients reported adverse events. These were mild and temporary and did not require treatment modification except in two patients. CONCLUSIONS: Treatment with rhIGF-1 was effective and safe in Polish patients with primary IGF-1 deficiency. It had a clear beneficial effect on the height of the patients and significantly accelerated the height velocity, particularly in the first year of treatment.

Increased placental IGF-1/mTOR activity in macrosomia born to women with gestational diabetes.

AIMS: Newborns of women with gestational diabetes mellitus (GDM) are susceptible to be macrosomic, even if the blood glucose levels are in normal ranges. The underlying mechanisms are largely unknown. We tested the hypothesis that placental insulin like growth factor(IGF)-I and mammalian target of rapamycin (mTOR) signaling is activated and amino acid transporter expression is increased in women with GDM who give birth to macrosomic babies. METHODS: 50 Chinese pregnant women with GDM whose blood glucose levels were controlled within normal range were recruited and their placental tissues were collected. 23 women gave birth to macrosomia and 27 women gave birth to babies with normal birth weight. We determined the phosphorylation of key signaling molecules (including Akt, IRS-1, S6K1, 4E-BP-1, and AMPKα) in the placental IGF-I and mTOR signaling pathways. We also measured the protein expression of the amino acid transporter systems A in placenta. RESULTS: Birth weights (range 2500-4400 g) were positively correlated to maternal IGF-1 (P < 0.05). The activity of placental IGF-I and mTOR signaling was positively correlated (P < 0.05), whereas AMPKα phosphorylation was inversely (P < 0.05) correlated to birth weight. Protein expression of the system A isoform sodium-dependent neutral amino acid transporter (SNAT) 1 were positively correlated to birth weight (P < 0.05). CONCLUSIONS: Up-regulation of placental amino acid transporters may contribute to more macrosomic babies in women with GDM. Activation of IGF-I and mTOR signaling pathways might involve in this effect.

Can Plasma Rich in Growth Factors Be Safe for Parental Use? A Safety Study in the Canine Model.

Low invasiveness is the main goal of modern surgery. The use of platelet-rich plasma (PRP) is known to be effective in a variety of applications, such as oral, maxillofacial, orthopedic, dermatologic and cosmetic surgeries. However, a potential ergogenic and carcinogenic effect of PRP derivatives by means of the insulin-like growth factor-1 (IGF-1) pathway has been suggested. Because of this notion, the purpose of this study is to assess the effect of a commercially available PRP-derivative intramuscular injection in the lumbar muscular tissue (local effect) and to determine the IGF-1 blood concentration (systemic effect) on healthy beagle dogs. Local effect was evaluated by computed tomography (CT) scan and echography, and systemic effect was calculated by blood testing on days 0, 14, 28, 42 and 56. No statistically significant changes were observed; thus, PRGF could be considered safe when using therapeutic doses.

Guía de recomendaciones para el diagnóstico clínico, bioquímico y por imágenes de la acromegalia. Federación Argentina de Sociedades de Endocrinología (FASEN) - 2017 / Guidelines for the clinical, biochemical and imaging diagnosis of acromegaly. Federación Argentina de Sociedades de Endocrinología (FASEN) - 2017

RESUMEN Objetivo El objetivo de esta guía es formular pautas para el diagnóstico de acromegalia adecuadas a los parámetros internacionales y a los recursos disponibles en Argentina. Participantes El grupo de trabajo propuesto por la Federación Argentina de Sociedades de Endocrinología (FASEN) incluyó un equipo multidisciplinario compuesto por 5 médicos endocrinólogos (4 especialistas y una profesional joven), un neurocirujano y una bioquímica, expertos en el tema. Evidencia Esta guía basada en la evidencia se desarrolló utilizando la metodología AGREE para describir tanto las recomendaciones como la calidad de las pruebas. Los borradores de esta guía fueron revisados por un grupo multidisciplinario de especialistas reconocidos en acromegalia. Conclusiones Utilizando un enfoque basado en la evidencia, esta guía aborda la evaluación diagnóstica de la acromegalia en Argentina.

ABSTRACT Objective The aim is to formulate guidelines for the clinical, biochemical and imaging diagnosis of acromegaly in accordance with international criteria and resources available in Argentina. Participants The task force selected by FASEN included a multidisciplinary team of 5 endocrinologists (4 senior and 1 junior), a neurosurgeon and a biochemist, experts in the field. Evidence This evidence-based guidelines were developed using the AGREE methodology to describe both the recommendations and the quality of evidence. The draft of these guidelines was reviewed by endocrinologists, biochemists and neurosurgeons experts in the field. Conclusions Using an approach based on evidence, these guidelines address the diagnosis of acromegaly in Argentina.

Use of growth hormone, IGF-I, and insulin for anabolic purpose: Pharmacological basis, methods of detection, and adverse effects.

Hormones with anabolic properties such as growth hormone (GH), insulin-like growth factor-1 (IGF-I), and insulin are commonly abused among professional and recreational athletes to enhance physical ability. Performance enhancing drugs (PEDs) such as these are also commonly used by recreational athletes to improve body aesthetics. The perception of increased muscle mass due to supraphysiologic hormone supplementation, or doping, is widespread among PED users despite a paucity of evidence-based data in humans. Even still, athletes will continue to abuse PEDs in hopes of replicating anecdotal results. It is important to educate the general public and potential treating physicians of the risks of PED use, including the dangers of polypharmacy and substance dependence. It will also be important for the research community to address the common challenges associated with studying PED use such as the ethical considerations of PED administration, the general reticence of the PED-using community to volunteer information, and the constant need to improve or create new detection methods as athletes continually attempt to circumvent current methods. This review highlights the anabolic mechanisms and suggestive data implicating GH, IGF-I, and insulin for use as PEDs, the specific detection methods with cutoff ranges that may be utilized to diagnose abuse of each substance, and their respective side effects.

Impact of intramuscular administration of lipid-soluble and water-soluble vehicles into regenerating muscle at the distinct phases of skeletal muscle regeneration.

Interpretation on the effectiveness of potential substances to enhance skeletal muscle regeneration is difficult if an inappropriate vehicle is administered, since vehicle administration can directly enhance or suppress regenerative capacity. In the current study, intramuscular administration of lipid-soluble and water-soluble vehicles into regenerating muscle at the distinct phases of skeletal muscle regeneration (regenerative vs. remodeling) were investigated. Tested vehicles included lipid-soluble [olive oil, (0.1, 1, 5, and 40%) dimethyl sulfoxide (DMSO), and 40% propylene glycol (PG)] and water-soluble [0.9% NaCl, PBS, 0.1% ethanol, and distilled water]. Skeletal muscle regeneration was induced by 1.2% BaCl2 injection to the tibialis anterior muscle of 10-week-old C57BL/6 male mice. Histological features, skeletal muscle stem cell activity, regenerating muscle fiber formation, angiogenesis, extracellular matrix remodeling, and macrophage infiltration were examined. The results revealed repeated administration of 40% DMSO and 40% PG causes significant recurrent muscle injury, which is pronounced during the remodeling phase compared to the regenerative phase. These findings were supported by (1) massive infiltration of F4/80+ macrophages; (2) significant increase of skeletal muscle stem cell re-activation and nascent regenerating muscle fiber formation; (3) excess fibrous formation; and (4) decreased regenerating muscle fiber cross-sectional area. These deleterious effects were comparable to 2% trypsin (degenerative substance) administration and less pronounced with a single administration. Nevertheless, recurrent muscle injury was still presented with 5% DMSO administration but it can be alleviated when 0.1% DMSO was administered during the remodeling phase. In contrast, none of the tested vehicles enhanced regenerative capacity compared with IGF-1 administration. Altogether, intramuscular administration of vehicle containing high concentration of DMSO or PG could impair skeletal muscle regenerative capacity and potentially affect validation of the investigational substance.

IGF1 potentiates the pro-inflammatory response in human peripheral blood mononuclear cells via MAPK.

Acromegaly is characterized by growth hormone (GH) and insulin-like growth factor 1 (IGF1) excess and is accompanied by an increased cardiovascular diseases (CVD) risk. As innate immune responses are crucial in CVD development, and IGF1 is linked to subclinical inflammation, we hypothesized that GH/IGF1 excess contributes to CVD development by potentiating systemic inflammation. We aimed to assess the effects of GH/IGF1 on inflammatory cytokine production. Whole blood from acromegaly patients and healthy volunteers and peripheral blood mononuclear cells (PBMCs) from healthy volunteers were stimulated with Toll-like receptor (TLR) ligands, with or without adding GH or IGF1 (in PBMC). Cytokine concentrations were measured by ELISA. The underlying signalling pathways were investigated by the inhibition of downstream targets of the IGF1 receptor. The following results were obtained. GH or IGF1 alone did not influence cytokine production in PBMCs. GH did not affect TLR-induced cytokine production, but co-stimulation with IGF1 dose dependently increased the TLR ligand-induced production of IL6 (P < 0.01), TNF alpha (P = 0.02) and IFNg (P < 0.01), as well as the production of the anti-inflammatory cytokine IL10 (P = 0.01). IGF1 had no effect on IL1B, IL17 and IL22 production. Inhibition of the MAPK pathway, but not mTOR, completely abrogated the synergistic effect of IGF1 on the LPS-induced IL6 and TNF alpha production. In whole blood of acromegaly patients, ex vivo IL6 production was increased (P < 0.01). In conclusion, IGF1, but not GH, has pro-inflammatory effects, probably via the MAPK signalling pathway and might be involved in the pathogenesis of atherosclerosis in acromegaly. The increased IL10 production possibly counteracts the pro-inflammatory effects.

Treatment With Recombinant Human Insulin-Like Growth Factor-1 Improves Growth in Patients With PAPP-A2 Deficiency.

CONTEXT: Pregnancy-associated plasma protein-A2 (PAPP-A2) is a metalloproteinase that specifically cleaves IGFBP-3 and IGFBP-5. Mutations in the PAPP-A2 gene have recently been shown to cause postnatal growth failure in humans, with specific skeletal features, due to the resulting decrease in IGF-1 bioavailability. However, a pharmacological treatment of this entity is yet to be established. CASE DESCRIPTION: A 10.5-year-old girl and a 6-year-old boy, siblings from a Spanish family, with short stature due to a homozygous loss-of-function mutation in the PAPP-A2 gene (p.D643fs25*) and undetectable PAPP-A2 activity, were treated with progressive doses (40, 80, 100, and 120 µg/kg) of recombinant human IGF-1 (rhIGF-1) twice daily for 1 year. There was a clear increase in growth velocity and height in both siblings. Bioactive IGF-1 was increased, and spontaneous GH secretion was diminished after acute administration of rhIGF-1, whereas serum total IGF-1 and IGFBP-3 levels remained elevated. No episodes of hypoglycemia or any other secondary effects were observed during treatment. CONCLUSION: Short-term treatment with rhIGF-1 improves growth in patients with PAPP-A2 deficiency.

Drug delivery of Insulin-like growth factor I.

This review starts off outlining the control of Insulin-like growth factor I (IGF-I) kinetics in Nature and by virtue of a complex system of 6 binding proteins controlling half-life and tissue distribution of this strong anabolic peptide. In addition, alternative splicing is known to result in IGF-I variants with modulated properties in vivo and this insight is currently translated into advanced IGF-I variants for therapeutic use. Insights into these natural processes resulted in biomimetic strategies with the ultimate goal to control pharmacokinetics and have recently propelled new developments leading to optimized pharmaceutical performance of this protein in vivo. Aside from parenteral administration routes, IGF-I was successfully delivered across various epithelial barriers from liquid as well as from solid pharmaceutical forms opening novel and more convenient delivery modalities. IGF-I decoration yielded effective targeting upon systemic administration expanding the options for optimally deploying the growth factor for therapy. This review summarizes the exciting biotechnological and pharmaceutical progress seen for IGF-I delivery in recent years and critically discusses outcome in light of translational application for future IGF-I therapeutics.

Effectiveness and Safety of rhIGF-1 Therapy in Children: The European Increlex® Growth Forum Database Experience.

BACKGROUND/AIMS: We report data from the EU Increlex® Growth Forum Database (IGFD) Registry, an ongoing, open-label, observational study monitoring clinical practice use of recombinant human insulin-like growth factor-1 (rhIGF-1) therapy in children. METHODS: Safety and effectiveness data on rhIGF-1 treatment of 195 enrolled children with growth failure were collected from December 2008 to September 2013. RESULTS: Mean ± SD (95% CI) height velocity during first year of rhIGF-1 treatment was 6.9 ± 2.2 cm/year (6.5; 7.2) (n = 144); in prepubertal patients naïve to treatment, this was 7.3 ± 2.0 cm/year (6.8; 7.7) (n = 81). Female sex, younger age at start of rhIGF-1 therapy, and lower baseline height SDS predicted first-year change in height SDS. The most frequent targeted treatment-emergent adverse events (% patients) were hypoglycemia (17.6%, predictors: young age, diagnosis of Laron syndrome, but not rhIGF-1 dose), lipohypertrophy (10.6%), tonsillar hypertrophy (7.4%), injection site reactions (6.4%), and headache (5.9%). Sixty-one serious adverse events (37 related to rhIGF-1 therapy) were reported in 31 patients (16.5%). CONCLUSION: Safety and effectiveness data on use of rhIGF-1 in a 'real-world' setting were similar to those from controlled randomized trials. Severe growth phenotype and early start of rhIGF-1 improved height response and predicted risk of hypoglycemia.

A case of central serous chorioretinopathy associated with use of deer antler spray supplement.

This case report describes central serous chorioretinopathy (CSC) in a healthy man associated with the use of deer antler spray, an athletic supplement purported to contain insulin-like growth factor-1 (IGF-1). The CSC resolved after cessation of the supplement. Currently, there are no reports in the literature linking IGF-1 and CSC. We conclude that agents containing IGF-1, such as deer antler supplements, may be correlated with the development of CSC.

Insulin-like growth factor 1 receptor signaling induced by supraphysiological doses of IGF-1 in human peripheral blood lymphocytes.

Insulin-like growth factor-1 (IGF-1) mediates some of growth hormone anabolic functions through its receptor, IGF-1R. Following ligand binding, intracellular signaling pathways are activated favouring proliferation, cell survival, tissue growth, development, and differentiation. IGF-1 is included in the World Anti-Doping Agency Prohibited List. While the evidence for IGF-1 as performance-enhancing substrate in healthy humans is still weak, clinical studies demonstrated that the endogenous growth hormone/IGF-1 excess is associated with cardiovascular implications. Previously, we demonstrated that human peripheral blood lymphocytes represent a suitable system to identify a gene signature, related to dihydrotestosterone or IGF-1 abuse, independent from the type of sport. In addition, in a proteomic study, we demonstrated that dihydrotestosterone hyperdosage affects cell motility and apoptosis. Here, we investigate the doping action of IGF-1 by means of a differential proteomic approach and specific protein arrays, revealing an active cytoskeletal reorganization mediated by Stat-1; moreover, IGF-1 stimulation produces a sustained activation of different signaling pathways as well as an overproduction of cytokines positively related to immune response and inflammation. In conclusion, these data indicate that, following IGF-1 hyperdosage, circulating peripheral blood lymphocytes could be more prone to transendothelial migration.