Laron Syndrome Research Articles

Epigenetic dysregulation of metabolic programs mediates liposarcoma cell plasticity.

Sarcomas are rare connective tissue cancers thought to arise from aberrant mesenchymal stem cell (MSC) differentiation. Liposarcoma (LPS) holds valuable insights into dysfunctional differentiation given its well- and dedifferentiated histologic subtypes (WDLPS, DDLPS). Despite well-established differences in histology and clinical behavior, the molecular pathways underlying each subtype are poorly understood. Here, we performed single-nucleus multiome sequencing and spatial profiling on carefully curated human LPS samples and found defects in adipocyte-specific differentiation within LPS. Loss of insulin-like growth factor 1 (IGF1) and gain of cellular programs related to early mesenchymal development and glucagon-like peptide-1 (GLP-1)-induced insulin secretion are primary features of DDLPS. IGF1 loss was associated with worse overall survival in LPS patients. Through in vitro stimulation of the IGF1 pathway, we identified that DDLPS cells are deficient in the adipose-specific PPARG isoform 2 (PPARG2). Defects in IGF1/PPARG2 signaling in DDLPS led to a block in differentiation that could not be fully overcome with the addition of exogenous IGF1 or the pro-adipogenic agonists to PPARG and GLP-1. However, we noted upregulation of the IGF1 receptor (IGF1R) in the setting of IGF1 deficiency, which promoted sensitivity to an IGF1R-targeted antibody-drug conjugate that may serve as a novel therapeutic strategy in LPS. In summary, lineage-specific defects in adipogenesis drive dedifferentiation in LPS and may translate into selective therapeutic targeting in this disease.

IGF-1 impacts neocortical interneuron connectivity in epileptic spasm generation and resolution

Little is known about the mechanisms that generate epileptic spasms following perinatal brain injury. Recent studies have implicated reduced levels of Insulin-like Growth Factor 1 (IGF-1) in these patients' brains. Other studies have reported low levels of the inhibitory neurotransmitter, GABA. In the TTX brain injury model of epileptic spasms, we undertook experiments to evaluate the impact of IGF-1 deficiencies on neocortical interneurons and their role in spasms. Quantitative immunohistochemical analyses revealed that neocortical interneurons that express glutamic acid decarboxylase, parvalbumin, or synaptotagmin 2 co-express IGF-1. In epileptic rats, expression of these three interneuron markers were reduced in the neocortex. IGF-1 expression was also reduced, but surprisingly this loss was confined to interneurons. Interneuron connectivity was reduced in tandem with IGF-1 deficiencies. Similar changes were observed in surgically resected neocortex from infantile epileptic spasms syndrome (IESS) patients. To evaluate the impact of IGF-1 deficiencies on interneuron development, IGF-1R levels were reduced in the neocortex of neonatal conditional IGF-1R knock out mice by viral injections. Four weeks later, this experimental maneuver resulted in similar reductions in interneuron connectivity. Treatment with the IGF-1 derived tripeptide, (1-3)IGF-1, abolished epileptic spasms in most animals, rescued interneuron connectivity, and restored neocortical levels of IGF-1. Our results implicate interneuron IGF-1 deficiencies, possibly impaired autocrine IGF-1 signaling and a resultant interneuron dysmaturation in epileptic spasm generation. By restoring IGF-1 levels, (1-3)IGF-1 likely suppresses spasms by rescuing interneuron connectivity. Results point to (1-3)IGF-1 and its analogues as potential novel disease-modifying therapies for this neurodevelopmental disorder.

Long-Term Treatment for Laron Syndrome with IGF-1 Injection over 22 Years in Saudi Arabia: A Cohort Study

Introduction: Laron syndrome (LS) is a rare autosomal recessive disorder caused by mutations in the growth hormone (GH) receptor gene, resulting in GH resistance and reduced levels of insulin-like growth factor 1 (IGF-1). Patients with LS exhibit severe growth retardation, low IGF-1 levels, elevated basal GH, and poor response to GH stimulation. Recombinant IGF-1 is the only approved treatment and has been shown to improve linear growth. This study evaluates the long-term efficacy and safety of IGF-1 therapy in a large cohort of LS patients treated at King Faisal Specialist Hospital and Research Center (KFSH & RC), Riyadh, Saudi Arabia over 22 years. Methods: We conducted a retrospective review of medical records for 28 patients with growth hormone insensitivity syndrome, including 12 males and 16 females, treated with IGF-1 from 1998 to 2020. Patients were selected based on criteria including age over 2 years, height standard deviation score (SDS) ≤−2.8, normal or elevated GH secretion (>2.5 ng/mL), IGF-1 levels <50 ng/mL, and insensitivity to exogenous GH. IGF-1 was administered initially at 40 μg/kg/dose subcutaneously twice daily, escalating to a maximum of 120 μg/kg/dose as tolerated. Dosage was adjusted to minimize hypoglycemia risk, with blood glucose monitored frequently during hospitalization. In addition, molecular genetic results were reviewed for each patient in the cohort. Results: IGF-1 treatment significantly increased height velocity (HV) from a baseline of 3.4 cm/year to 6.5 cm/year in the first year (mean difference of 3.1 cm/year, p < 0.0001). In the second year, HV remained elevated at 5 cm/year (mean difference of 1.6 cm/year, p = 0.0015). Long-term follow-up over 10 years demonstrated sustained improvements in HV compared to baseline, with the most substantial gains occurring within the initial 5 years. Weight SDSs also showed significant improvement. Age at the start of therapy did not notably affect growth outcomes, though longer treatment durations were associated with greater growth. Ten disease-causing variants in the GHR gene were identified in 24 of the 28 LS patients. Conclusion: IGF-1 therapy significantly enhanced linear growth in children with Laron syndrome and was generally well tolerated. Although many patients did not reach normal adult height, the growth achieved with IGF-1 treatment was markedly better than expected without therapy. This study underscores the effectiveness of IGF-1 in improving growth outcomes and highlights the need for continued longitudinal studies to optimize treatment strategies and manage potential complications.

Ethanol consumption during gestation promotes placental alterations in IGF-1 deficient mouse placentas

Background During pregnancy, the placenta is an extremely important organ as it secretes its own hormones, e.g. insulin-like growth factor 1 (IGF-1), to ensure proper intrauterine fetal growth and development. Ethanol, an addictive and widely used drug, has numerous adverse effects during pregnancy, including fetal growth restriction (FGR). To date, the molecular mechanisms by which ethanol triggers its toxic effects during pregnancy, particularly in the placenta, are not entirely known. For this reason, a murine model of partial IGF-1 deficiency was used to determine ethanol alterations in placental morphology and aspartyl/asparaginyl β-hydroxylase (AAH) expression. Methods Wild type (WT, Igf1 +/+) and heterozygous (HZ, Igf1 +/-) female mice were given 10% ethanol in water during 14 days as an acclimation period and throughout pregnancy. WT and HZ female mice given water were used as controls. At gestational day 19, pregnant dams were sacrificed, placentas were collected and genotyped for subsequent studies. Results IGF-1 deficiency and ethanol consumption during pregnancy altered placental morphology, and decreased placental efficiency and AAH expression in placentas from all genotypes. No differences were found in Igf1, Igf2, Igf1r and Igf2r mRNA expression in placentas from all groups. Conclusions IGF-1 deficiency and ethanol consumption throughout gestation altered placental development, suggesting the crucial role of IGF-1 in the establishment of an adequate intrauterine environment that allows fetal growth. However, more studies are needed to study the precise mechanism to stablish the relation between both insults.

GHRH and its analogues in central nervous system diseases.

Growth hormone-releasing hormone (GHRH) is primarily produced by the hypothalamus and stimulates the release of growth hormone (GH) in the anterior pituitary gland, which subsequently regulates the production of hepatic insulin-like growth factor-1 (IGF-1). GH and IGF-1 have potent effects on promoting cell proliferation, inhibiting cell apoptosis, as well as regulating cell metabolism. In central nerve system (CNS), GHRH/GH/IGF-1 promote brain development and growth, stimulate neuronal proliferation, and regulate neurotransmitter release, thereby participating in the regulation of various CNS physiological activities. In addition to hypothalamus-pituitary gland, GHRH and GHRH receptor (GHRH-R) are also expressed in other brain cells or tissues, such as endogenous neural stem cells (NSCs) and tumor cells. Alternations in GHRH/GH/IGF-1 axis are associated with various CNS diseases, for example, Alzheimer's disease, amyotrophic lateral sclerosis and emotional disorders manifest GHRH, GH or IGF-1 deficiency, and GH or IGF-1 supplementation exerts beneficial therapeutic effects on these diseases. CNS tumors, such as glioma, can express GHRH and GHRH-R, and activating this signaling pathway promotes tumor cell growth. The synthesized GHRH antagonists have shown to inhibit glioma cell growth and may hold promising as an adjuvant therapy for treating glioma. In addition, we have shown that GHRH agonist MR-409 can improve neurological sequelae after ischemic stroke by activating extrapituitary GHRH-R signaling and promoting endogenous NSCs-derived neuronal regeneration. This article reviews the involvement of GHRH/GH/IGF-1 in CNS diseases, and potential roles of GHRH agonists and antagonists in treating CNS diseases.

Clinical characteristics and treatment efficacy in patients with primary severe IGF-1 deficiency treated with recombinant IGF-1.

To evaluate the clinical characteristics and treatment efficacy of patients with severe primary IGF-1 deficiency (PSIGFD) using a recombinant IGF-1 (rhIGF-1). To examine the clinical characteristics of patients with PSIGFD before starting treatment with a rIGF-1. To assess the height changes in patients with PSIGFD, before and after treatment with a rhIGF-1. To analyze the clinical characteristics, side effect frequency, and treatment efficacy with a rhIGF-1 analog in patients with PSIGFD. A retrospective analysis was conducted on patients with PSIGFD treated with the rhIGF-1 (mecasermin). Data were collected from patients' medical records, focusing on the impact of treatment on their growth and monitoring any side effects. The study showed that treatment with rhIGF-1 positively affects growth rate, especially in the first years of treatment. However, the growth rate decreases over time. The change in height from the beginning to the end of the treatment was 0.76 ± 0.64 SD, with the first quartile at 0.29 SD and the third quartile at 1.14 SD. During the treatment period, patients' average body mass increased by 0.37 ± 1.35 SD, with the first quartile at -0.33 SD and the third quartile at 0.92 SD. Side effects occurred in 50% of patients, with 40% of patients treated with rhIGF-1 experiencing hypoglycemia during treatment. Treatment with rhIGF-1 is effective in treating patients with PSIGFD, causing significant improvement in growth, but requires continuous monitoring and treatment adjustment.

IGF1 drives Wnt-induced joint damage and is a potential therapeutic target for osteoarthritis

Osteoarthritis is the most common joint disease and a global leading cause of pain and disability. Current treatment is limited to symptom relief, yet there is no disease-modifying therapy. Its multifactorial etiology includes excessive activation of Wnt signaling, but how Wnt causes joint destruction remains poorly understood. Here, we identify that Wnt signaling promotes the transcription of insulin-like growth factor 1 (IGF1) in articular chondrocytes and that IGF1 is a major driver of Wnt-induced joint damage. Male mice with cartilage-specific Igf1 deficiency are protected from Wnt-triggered joint disease. Mechanistically, Wnt-induced IGF1 transcription depends on β-catenin and binding of Wnt transcription factor TCF4 to the IGF1 gene promoter. In a clinically relevant mouse model of post-traumatic osteoarthritis, cartilage-specific deletion of Igf1 protects against the disease in male mice. IGF1 silencing in chondrocytes from patients with osteoarthritis restores a healthy molecular profile. Our findings reveal that reducing Wnt-induced IGF1 is a potential therapeutic strategy for osteoarthritis.

In Vivo Effects of a GHR Synthesis Inhibitor during Prolonged Treatment in Dogs

Background: The activation of the growth hormone receptor (GHR) is a major determinant of body growth. Defective GHR signaling, as seen in human Laron dwarfism, resulted in low plasma IGF-1 concentrations and limited growth, but also marked absence in the development of breast cancer and type 2 diabetes. In vitro, we identified a small molecule (C#1) that inhibits the translation of GHR mRNA to receptor protein. Methods: Before its application in humans as a potential anticancer drug, C#1 was tested in animals to evaluate whether it could be administered to achieve a plasma concentration in vivo that inhibits cell proliferation in vitro without causing unwanted toxicity. To evaluate the efficacy and toxicity of C#1, a group of six intact female Beagle dogs was treated daily each morning for 90 days with an oral solution of C#1 in Soiae oleum emulgatum at a dose of 0.1 mg/kg body weight. During treatment, dogs were closely monitored clinically, and blood samples were taken to measure plasma C#1 concentrations, complete blood counts (CBC), clinical chemistry, and endocrinology. At the end of the treatment, dogs were euthanized for gross and histopathological analysis. An additional group of six female Beagle dogs was included for statistical reasons and only evaluated for efficacy during treatment for 30 days. Results: Daily administration of C#1 resulted in a constant mean plasma concentration of approximately 50 nmol/L. In both groups, two out of six dogs developed decreased appetite and food refusal after 4–5 weeks, and occasionally diarrhea. No significant effects in CBC or routine clinical chemistry were seen. Plasma IGF-1 concentrations, used as biomarkers for defective GHR signaling, significantly decreased by 31% over time. As plasma growth hormone (GH) concentrations decreased by 51% as well, no proof of GHR dysfunction could be established. The measured 43% decrease in plasma acylated/non-acylated ghrelin ratios will also lower plasma GH concentrations by reducing activation of the GH secretagogue receptor (GHSR). C#1 did not directly inhibit the GHSR in vivo, as shown in vitro. There were no significant effects on glucose, lipid, or folate/homocysteine metabolism. Conclusions: It is concluded that with daily dosing of 0.1 mg C#1/kg body weight, the induction of toxic effects prevented further increases in dosage. Due to the concomitant decrease in both IGF-1 and GH, in vivo inhibition of GHR could not be confirmed. Since the concept of specific inhibition of GHR synthesis by small molecules remains a promising strategy, searching for compounds similar to C#1 with lower toxicity should be worthwhile.

6367 Growth gone Awry: A Rare Case of Acromegaly in a 16-Year-Old Female with Panhypopituitarism Secondary to Craniopharyngioma on Low Doses of Growth Hormone with Low IGF-1 levels

Abstract Disclosure: L.M. Ayala Castro: None. J. Ye Tay: None. A. Diaz: None. This report highlights a rare case of a 16-year-old female with panhypopituitarism due to craniopharyngioma, where GH replacement therapy triggered acromegaly features despite having low IGF-1 levels. Background: Craniopharyngiomas are the most common tumors causing acquired pituitary deficiencies in children. Various mechanisms contribute to acromegaly, and hypersensitivity to hormonal treatment in this benign tumor emerges as a plausible avenue for investigation. Case Presentation: A 16-year-old female diagnosed with craniopharyngioma at age 5 developed secondary panhypopituitarism. Baseline hormonal profiles indicated markedly reduced levels of IGF-1 and insulin growth factor–binding protein 3 (IGF-BP3). Despite the established condition, GH treatment was initiated at age 8 for potential growth and development benefits. Before commencing GH therapy, a bone age assessment revealed normal skeletal development. However, GH replacement therapy led to an unexpectedly robust response, resulting in physical changes consistent with acromegaly. Paradoxically, laboratory evaluations showed low IGF-1 levels. Imaging studies, including pituitary MRI, ruled out new abnormalities or tumors. As the patient approached peak adult height at 16, having been on adult GH therapy since age 13, a decision was made to discontinue GH replacement therapy and address acromegaly symptoms. Frequent follow-up visits were planned to assess growth velocity, monitor hormonal levels, and evaluate potential adverse effects. Discussion: This case demonstrates an unusual sensitivity to exogenous GH, resulting in an exaggerated response contrary to expected IGF-1 elevation. Atypical IGF-1 levels may suggest alterations in liver physiology, GH receptor signaling pathways (e.g., Laron Syndrome), or downstream defects in IGF-1 synthesis. Further research is crucial to elucidate the underlying mechanisms. Conclusion: Only 3 cases of acromegaly as a side effect of GH replacement therapy have been reported in the literature. We report a further case that underscores the complexity of managing hormonal imbalances, especially in unique patient populations with panhypopituitarism secondary to craniopharyngioma. The unexpected response to GH treatment emphasizes the need for individualized approaches and vigilant monitoring.

8186 Hypoglycemia as an Unusual Presentation of Panhypopituitarism

Abstract Disclosure: P. Chalasani: None. M. Asfaw: None. M. Mansour: None. M. Hammoud: None. T. Altaweel: None. H. Ilyas: None. L. Lawrence: None. Introduction: Hypopituitarism refers to the diminished or complete absence of anterior pituitary function, which may arise from acquired or congenital factors. The symptoms depend on the patient’s age and the hormones affected. We report a case where hypoglycemia led to a new diagnosis of panhypopituitarism in an adult patient. Clinical Case:A 53-year-old female with a past medical history of hypertension was brought to the emergency department after syncope. Patient experienced diaphoresis and loss of consciousness associated with urinary incontinence. She did not have confusion, tongue biting, or muscular weakness after the episode. On presentation, the patient was hypoglycemic with blood glucose of 39 mg/dl and received IV dextrose. No focal neurologic deficits were noted on physical examination. She was mildly hypotensive with blood pressure 98/66 mmHg, and received hydrocortisone 100 mg IV once, and started on IV dextrose infusion. Hypoglycemia workup revealed elevated insulin 16.6 uIU/mL and C-peptide 4.8 ng/mL (1.1-4.4) levels for a blood glucose level of 132 mg/dl, with normal beta-hydroxybutyrate of 0.14 mmol/L (0.02-0.27). Sulfonylurea screen was negative. CT abdomen revealed no pancreatic lesions or abnormalities. Hyperinsulinemia was attributed to insulin resistance in this patient with a BMI of 34 kg/m2. CT head revealed a heterogeneous low-density expansile mass in the sella/suprasellar region measuring approximately 2.5 x 2.3 x 2 cm. MRI brain confirmed a heterogeneous sellar mass with suprasellar extension measuring 3.4 x 2.3 x 2.1 cm abuting the optic chiasm without displacement. Biochemical workup revealed panhypopituitarism with secondary adrenal insufficiency ACTH &amp;lt; 1.5 pg/mL (7.2-63.3) and cortisol 3.63 ug/dL (3.70-19.40); secondary hypothyroidism TSH 0.84 mIU/mL (0.27-4.20) and FT4 &amp;lt; 0.50 ng/dL (0.70-14.8); growth hormone deficiency with low IGF-1 23 ng/mL (65-216); secondary hypogonadism FSH &amp;lt; 1 mIU/mL (46-177), LH &amp;lt; 1 mIU/mL (7.7-59) and estrone &amp;lt; 6 pg/mL (0-125); with normal prolactin 14.1 ng/mL (4.8-23.3). Patient revealed she had been amenorrheic since 23 years old and conceived one child prior. Patient was transitioned to oral hydrocortisone 20 mg AM and 10 mg PM, and started on levothyroxine 50 mcg PO daily. No neurosurgical intervention was recommended. Subsequently, patient requested a second opinion and was transferred to a tertiary center. Conclusion: The link between hypoglycemia and hypopituitarism, may be attributed to hypocortisolism and growth hormone / IGF-1 deficiency. Intriguingly, this patient's initial clinical presentation centered around hypoglycemia, and further evaluation led to the identification of a sellar mass and new diagnosis of panhypopituitarism. This case demonstrates the need to include hypopituitarism in the differential when evaluating hypoglycemic patients. Presentation: 6/2/2024

The vasoprotective role of IGF-1 signaling in the cerebral microcirculation: prevention of cerebral microhemorrhages in aging.

Aging is closely associated with various cerebrovascular pathologies that significantly impact brain function, with cerebral small vessel disease (CSVD) being a major contributor to cognitive decline in the elderly. Consequences of CSVD include cerebral microhemorrhages (CMH), which are small intracerebral bleeds resulting from the rupture of microvessels. CMHs are prevalent in aging populations, affecting approximately 50% of individuals over 80, and are linked to increased risks of vascular cognitive impairment and dementia (VCID). Hypertension is a primary risk factor for CMHs. Vascular smooth muscle cells (VSMCs) adapt to hypertension by undergoing hypertrophy and producing extracellular matrix (ECM) components, which reinforce vessel walls. Myogenic autoregulation, which involves pressure-induced constriction, helps prevent excessive pressure from damaging the vulnerable microvasculature. However, aging impairs these adaptive mechanisms, weakening vessel walls and increasing susceptibility to damage. Insulin-like Growth Factor 1 (IGF-1) is crucial for vascular health, promoting VSMC hypertrophy, ECM production, and maintaining normal myogenic protection. IGF-1 also prevents microvascular senescence, reduces reactive oxygen species (ROS) production, and regulates matrix metalloproteinase (MMP) activity, which is vital for ECM remodeling and stabilization. IGF-1 deficiency, common in aging, compromises these protective mechanisms, increasing the risk of CMHs. This review explores the vasoprotective role of IGF-1 signaling in the cerebral microcirculation and its implications for preventing hypertension-induced CMHs in aging. Understanding and addressing the decline in IGF-1 signaling with age are crucial for maintaining cerebrovascular health and preventing hypertension-related vascular injuries in the aging population.

Insulin-like growth factor-1 deficiency caused by hepatocellular adenoma leads to growth arrest, primary amenorrhea and metabolic syndrome: a case report and 4 years follow up

BackgroundHepatocellular adenoma (HCA) is a rare benign neoplasm, seldom ascribed as the cause of endocrine and metabolic derangement. We herein report a case of primary amenorrhea, growth arrest and metabolic syndrome. En bloc resection of the tumor normalized all the disturbances.Case presentationA 16-year-old girl complained of primary amenorrhea and growth arrest for the past 2 years. Her height and weight were at the 3rd percentile, whereas waist circumference was at the 90th percentile for chronological age. She was hypertensive on admission. Plasma cholesterol, triglyceride and uric acid were elevated. Evaluation of GH/IGF-1 axis showed extremely low IGF-1 concentration, which was unresponsive to hGH stimulation. Computer tomography identified a huge liver mass (18.2 cm×13.7 cm×21 cm). The patient underwent an uneventful open right hepatic lobectomy. The tumor was en bloc resected. Immunohistochemistry indicated an unclassified HCA, which was confirmed by genetic screening. IGF-1 concentration, blood pressure, lipid profile and ovarian function were all normalized after surgery, and the girl had reduction in waist circumference and gain in height during the follow up.ConclusionWe provide evidence that liver-derived IGF-1 has a direct effect on skeletal and pubertal development, blood pressure, visceral adiposity and dyslipidemia independent of insulin resistance and obesity in the circumstance of undernutrition. Though rare, we propose the need to look into HCA cases for the existence of IGF-1 deficiency and its impact on metabolic derangement.

Adult patients with Laron syndrome tend to develop the metabolic syndrome

The metabolic Syndrome is the name of a cluster of abnormal clinical and metabolic states, which constitute a risk factor for diabetes and cardiovascular disease. To determine whether adult patients with Laron Syndrome with excessive obesity develop the characteristics of the Metabolic Syndrome. Out of a cohort of adult patients with Laron Syndrome followed in our clinic, records of 23 patients (12 females, 11 males) were found to have sufficient data for analysis. The degree of obesity was determined by the measurement of subscapular skinfold thickness (SSFT), BMI and total body DEXA. NAFLD was determined by liver ultrasonography, serum lipids including adiponectin leptin, insulin and glucose were assessed by radioimmunoassay. Both female and male patients were markedly obese with 59% and 39% fat of the total body mass respectively, as were total and LDL cholesterol, triglycerides and adiponectin. Some had developed NAFLD. They also suffered from insulin resistance and glucose intolerance. Eleven patients (3 females, 8 males) developed diabetes. All had varying degrees of hypertension. Eight subjects (3 females, 5 males) suffered from cardiovascular disease. One female died at aged 53years, and two males died at ages 75 and 78years. With advancing age and increasing obesity, adult patients with Laron Syndrome developed the characteristics of Metabolic Syndrome including diabetes and cardiovascular disease.

Insights into Laron Syndrome: Unraveling the Molecular Basis, Clinical Manifestations, and Therapeutic Prospects

Laron Syndrome, a rare and intriguing genetic disorder, stands as a testament to the intricate interplay between genetics and endocrinology. This article delves into the comprehensive exploration of Laron Syndrome, elucidating its molecular underpinnings, intricate clinical presentations, and the evolving landscape of therapeutic interventions. By synthesizing current research and clinical observations, we aim to enhance the understanding of this syndrome, shedding light on the challenges posed by its unique pathophysiology. The exploration of growth hormone receptor insensitivity, molecular signaling cascades, and associated comorbidities will be discussed in detail, providing a foundation for future advancements in both diagnostic approaches and therapeutic strategies.

Challenges of Access to Treatments: The Case Of Laron Syndrome and the Fight For Social Inclusion

Objective: To identify and disseminate the challenges faced by patients with Laron syndrome in accessing Mecasermin treatment in Ecuador. Theoretical Framework: Laron syndrome is a rare genetic disease characterised by metabolic disorders such as hypoglycemia and severe growth retardation. Treatment with Mecasermin improves growth and thus quality of life for those affected. Ecuador has the largest Laron syndrome population in the world, extensively studied contributing to understanding the peculiarities and needs of these patients. Method: Official documents, letters, news articles from national and international press, and legal and medical databases were reviewed. Legal and medical advice was sought for this study. Results and Discussion: Over approximately ten years, a group of parents pursued national and international legal action to provide their children with the only scientifically validated treatment for this syndrome. However, authorities denied these requests without justification. It was only after the Inter-American Commission on Human Rights report the admissibility of this case that Ecuador began administering medication to children with Laron syndrome. Research Implications: Increase public awareness of this rare disease and barriers faced by those affected, fostering empathy, and understanding of patients' needs. Originality/Value: Identification of specific barriers to accessing treatment, while the quality of life of patients and their families is affected.

Normal or improved cardiovascular risk factors in IGF-I-deficient adults with growth hormone receptor deficiency

Human subjects with generalized growth hormone (GH) insensitivity due to GH receptor deficiency (GHRD)/Laron syndrome display a very low incidence of insulin resistance, diabetes, and cancer, as well as delayed age-related cognitive decline. However, the risk of cardiovascular disease (CVD) in these subjects is poorly understood. Here, we have assessed cardiovascular function, damage, and risk factors in GHRD subjects and their relatives. We measured markers of CVD in two phases: one in a cohort of 30 individuals (GHRD= 16, control relatives= 14) brought to USC (in Los Angeles, CA) and one in a cohort including additional individuals examined in Ecuador (where the subjects live) for a total of 44 individuals (GHRD= 21, control relatives= 23). Data were collected on GHRD and control groups living in similar geographical locations and sharing comparable environmental and socio-economic circumstances. Compared to controls, GHRD subjects displayed lower serum glucose, insulin, blood pressure, smaller cardiac dimensions, similar pulse wave velocity, lower carotid artery intima-media thickness, lower creatinine, and a non-significant but major reduction in the portion of subjects with carotid atherosclerotic plaques (7% GHRDs vs. 36%, Controls p= 0.1333) despite elevated low-density lipoprotein cholesterol levels. The current study indicates that individuals with GHRD have normal or improved levels of cardiovascular disease risk factors as compared to their relatives. This study was funded in part by NIH/NIA grant P01 AG034906 to V.D.L.

Ethanol consumption during gestation promotes placental alterations in IGF-1 deficient placentas

Background During pregnancy, the placenta is an extremely important organ as it secretes its own hormones, e.g. insulin-like growth factor 1 (IGF-1), to ensure proper intrauterine fetal growth and development. Ethanol, an addictive and widely used drug, has numerous adverse effects during pregnancy, including fetal growth restriction (FGR). To date, the molecular mechanisms by which ethanol triggers its toxic effects during pregnancy, particularly in the placenta, are not entirely known. For this reason, a murine model of partial IGF-1 deficiency was used to determine ethanol alterations in placental morphology and AAH expression. Methods Heterozygous (HZ, Igf1+/- ) female mice were given 10% ethanol during 14 days as an acclimation period and throughout pregnancy. HZ female mice given water were used as controls. At gestational day 19, pregnant dams were sacrificed, placentas were collected and genotyped for subsequent studies. Results IGF-1 deficiency and ethanol consumption during pregnancy altered placental morphology, and decreased placental efficiency and aspartyl/asparaginyl β-hydroxylase (AAH) expression in placentas from all genotypes. No differences were found in Igf1, Igf2, Igf1r and Igf2r mRNA expression in placentas from all groups. Conclusions IGF-1 deficiency and ethanol consumption throughout gestation altered placental development, suggesting the crucial role of IGF-1 in the establishment of an adequate intrauterine environment that allows fetal growth. However, more studies are needed to study the precise mechanism to stablish the relation between both insults.

Early IGF-1 receptor inhibition in mice mimics preterm human brain disorders and reveals a therapeutic target.

Besides recent advances in neonatal care, preterm newborns still develop sex-biased behavioral alterations. Preterms fail to receive placental insulin-like growth factor-1 (IGF-1), a major fetal growth hormone in utero, and low IGF-1 serum levels correlate with preterm poor neurodevelopmental outcomes. Here, we mimicked IGF-1 deficiency of preterm newborns in mice by perinatal administration of an IGF-1 receptor antagonist. This resulted in sex-biased brain microstructural, functional, and behavioral alterations, resembling those of ex-preterm children, which we characterized performing parallel mouse/human behavioral tests. Pharmacological enhancement of GABAergic tonic inhibition by the U.S. Food and Drug Administration-approved drug ganaxolone rescued functional/behavioral alterations in mice. Establishing an unprecedented mouse model of prematurity, our work dissects the mechanisms at the core of abnormal behaviors and identifies a readily translatable therapeutic strategy for preterm brain disorders.

Vascular smooth muscle cell-specific Igf1r deficiency exacerbates the development of hypertension-induced cerebral microhemorrhages and gait defects.

Cerebrovascular fragility and cerebral microhemorrhages (CMH) contribute to age-related cognitive impairment, mobility defects, and vascular cognitive impairment and dementia, impairing healthspan and reducing quality of life in the elderly. Insulin-like growth factor 1 (IGF-1) is a key vasoprotective growth factor that is reduced during aging. Circulating IGF-1 deficiency leads to the development of CMH and other signs of cerebrovascular dysfunction. Here our goal was to understand the contribution of IGF-1 signaling on vascular smooth muscle cells (VSMCs) to the development of CMH and associated gait defects. We used an inducible VSMC-specific promoter and an IGF-1 receptor (Igf1r) floxed mouse line (Myh11-CreERT2 Igf1rf/f) to knockdown Igf1r. Angiotensin II in combination with L-NAME-induced hypertension was used to elicit CMH. We observed that VSMC-specific Igf1r knockdown mice had accelerated development of CMH, and subsequent associated gait irregularities. These phenotypes were accompanied by upregulation of a cluster of pro-inflammatory genes associated with VSMC maladaptation. Collectively our findings support an essential role for VSMCs as a target for the vasoprotective effects of IGF-1, and suggest that VSMC dysfunction in aging may contribute to the development of CMH.

The Treatment of Growth Disorders in Childhood and Adolescence.

3% of all children are unusually short, and 3% are unusually tall. New approaches have broadened the range of therapeutic options in treating growth disorders. This review is based on publications retrieved by a selective review of the literature and on the authors' clinical experience. Pituitary growth hormone deficiency is treated with recombinant growth hormone. Long-acting preparations of this type became available recently, but their long-term safety and efficacy are still unknown. Vosoritide, a CNP analogue, has also been approved for the treatment of achondroplasia, and severe primary deficiency of insulin-like growth factor 1 (IGF-1) can be treated with recombinant IGF-1. In the treatment of excessively tall stature, new information on the safety of growth-attenuating treatment and an altered perception of above-average height in society have led to a change in management. There are new options for the treatment of rare causes of short stature, while new information on the safety of treatment strategies for excessive tallness have led to a reconsideration of surgical intervention. There is insufficient evidence on the benefits and risks of supraphysiological GH therapy and of newer treatment options for which there are as yet no robust data on adult height. Therefore, before any treatment is provided, physicians should give patients and their families detailed information and discuss their expectations from treatment and the goals that treatment can be expected to achieve.