Experimental approach to IGF-1 therapy in CCl4-induced acute liver damage in healthy controls and mice with partial IGF-1 deficiency.

BACKGROUND: Cell necrosis, oxidative damage, and fibrogenesis are involved in cirrhosis development, a condition in which insulin-like growth factor 1 (IGF-1) levels are diminished. This study evaluates whether the exogenous administration of low doses of IGF-1 can induce hepatoprotection in acute carbon tetrachloride (CCl4)-induced liver damage compared to healthy controls (Wt Igf +/+). Additionally, the impact of IGF-1 deficiency on a damaged liver was investigated in mice with a partial deficit of this hormone (Hz Igf1 +/-). METHODS: Three groups of 25 ± 5-week-old healthy male mice (Wt Igf +/+) were included in the protocol: untreated controls (Wt). Controls that received CCl4 (Wt + CCl4) and Wt + CCl4 were treated subcutaneously with IGF-1 (2 µg/100 g body weight/day) for 10 days (Wt + CCl4 + IGF1). In parallel, three IGF-1-deficient mice (Hz Igf1 +/-) groups were studied: untreated Hz, Hz + CCl4, and Hz + CCl4 + IGF-1. Microarray and real-time quantitative polymerase chain reaction (RT-qPCR) analyses, serum aminotransferases levels, liver histology, and malondialdehyde (MDA) levels were assessed at the end of the treatment in all groups. All data represent mean ± SEM. RESULTS: An altered gene coding expression pattern for proteins of the extracellular matrix, fibrosis, and cellular protection were found, as compared to healthy controls, in which IGF-1 therapy normalized in the series including healthy mice. Liver histology showed that Wt + CCl4 + IGF1 mice had less oxidative damage, fibrosis, lymphocytic infiltrate, and cellular changes when compared to the Wt + CCl4. Moreover, there was a correlation between MDA levels and the histological damage score (Pearson's r = 0.858). In the IGF-1-deficient mice series, similar findings were identified, denoting a much more vulnerable hepatic parenchyma. CONCLUSIONS: IGF1 treatment improved the biochemistry, histology, and genetic expression of pro-regenerative and cytoprotective factors in both series (healthy and IGF-1-deficient mice) with acute liver damage, suggesting that low doses of IGF-1, in acute liver damage, could be a feasible therapeutic option.

miRNA signature associated with R-CHOP refractoriness in patients diagnosed with diffuse large B cell lymphoma.

Refractoriness remains as one of the challenges in patients with lymphoma under chemotherapy, and among biological regulators in cells driving this type of response are microRNAs (miRNAs). Different genes are constantly turned on or off according to the miRNAs expression profiles affecting the drug response in patients and their stability in serum and plasma makes them potential prognostic biomarkers in several diseases. Here we described a profile of miRNAs in plasma of diffuse large B cell lymphoma (DLBCL) patients. miRNA expression arrays were carried using pre-treatment plasma samples of sixteen patients, followed by a comparison between the responder and the non-responders. After six cycles of R-CHOP treatment, twelve out of sixteen patients were clinically diagnosed with complete response while in four patients no clinical response was observed. Between these groups, a signature of fifteen differential expressed miRNAs was found. The circulating miRNAs in plasma of patients with no response were related to the drug resistance in other types of cancer, by targeting genes involved in cell proliferation and apoptosis, among other cell processes.

Neurotrophic Factors and Their Receptors Are Altered by the Mere Partial IGF-1 Deficiency.

Neurotrophic factors (NTFs) are a relevant group of secreted proteins that modulate growth, differentiation, repair, and survival of neurons, playing a role in the maintenance of the synaptic unions, dendrites, and axons and also being crucial for peripheral nervous system development and regulating plasticity in the adult central nervous system. On the other hand, insulin-like growth factor 1 (IGF-1) has been ascertained multiple beneficial actions in the brain: neuro-development, -protection, -genesis and plasticity. To further investigate the possible mechanisms underlying IGF-1 deficiency in the establishment of neurological disease, microarray and reverse transcription polymerase chain reaction gene expression analyses coupled with in silico processing were performed in an experimental model of partial IGF-1 deficiency. Results show that the mere IGF-1 deficiency seems to be responsible for an altered expression of genes coding for neurotrophic factors (particularly ciliary neurotrophic factor and mesencephalic astrocyte-derived neurotrophic factor), their receptors and signaling pathways (specially RET). The presented findings support that IGF-1 deficiency might be involved in the establishment and progression of neurodegenerative disorders.

A 42-Year-Old Woman with Untreated Growth Hormone Insensitivity, Diabetic Retinopathy, and Gene Sequencing Identifies a Variant of Laron Syndrome.

BACKGROUND Growth hormone insensitivity and reduced levels of insulin-like growth factor-1 (IGF-1) are associated with metabolic syndrome that includes obesity, hyperglycemia, type 2 diabetes mellitus, and dyslipidemia. Laron syndrome is a rare autosomal recessive condition associated with insensitivity to growth hormone that results in short stature and metabolic syndrome and is usually diagnosed in childhood. This report is of a 42-year-old Mexican woman with untreated growth hormone insensitivity and diabetic retinopathy, in whom gene sequencing supported the identification of a variant of Laron syndrome. CASE REPORT A 42-year-old Mexican woman with untreated growth hormone insensitivity, metabolic syndrome, and type 2 diabetes mellitus was diagnosed with cataracts, severe retinopathy and hearing loss. She was investigated for genetic causes of reduction in IGF-1. Next-generation sequencing (NGS) showed genetic changes in the growth hormone and IGF-1 axis. The patient's phenotype and genetic changes were consistent with Laron syndrome. CONCLUSIONS The early detection of reduced IGF-1 and identification of the cause of growth hormone insensitivity require international consensus on the approach to diagnosis and treatment methods, including effective IGF-1 replacement therapy. Early diagnosis may reduce the clinical consequences of complications that include short stature the development of metabolic syndrome, type 2 diabetes mellitus, and retinopathy.

Primary growth hormone insensitivity and psychomotor delay.

We report a case of short stature irresponsive to growth hormone (GH) replacement therapy. Low GH response to provocative tests and undetectable IGF-1 levels had suggested GH deficiency, while response to therapy indicated GH insensitivity. Molecular evaluation of the GH/IGF-1 axis should be performed in these cases to improve diagnosis and therapy.

Mexican case report of a never-treated Laron syndrome patient evolving to metabolic syndrome, type 2 diabetes, and stroke.

Glucose and lipid profile together with blood pressure should always be considered for low sera-IGF-1 patients. Even when adulthood is reached, IGF-1 therapy in these patients should be pursued as metabolic and protective cellular effects could be triggered. Real incidence of growth hormone insensitivity is still to be uncovered.

Fanconi Anemia and Laron Syndrome.

BACKGROUND: Fanconi anemia (FA) is a condition characterized by genetic instability and short stature, which is due to growth hormone (GH) deficiency in most cases. However, no apparent relationships have been identified between FA complementation group genes and GH. In this study, we thereby considered an association between FA and Laron syndrome (LS) (insulin-like growth factor 1 [IGF-1] deficiency). METHODS: A 21-year-old female Mexican patient with a genetic diagnosis of FA was referred to our research department for an evaluation of her short stature. Upon admission to our facility, her phenotype led to a suspicion of LS; accordingly, serum levels of IGF-1 and IGF binding protein 3 were analyzed and a GH stimulation test was performed. In addition, we used a next-generation sequencing approach for a molecular evaluation of FA disease-causing mutations and genes involved in the GH-IGF signaling pathway. RESULTS: Tests revealed low levels of IGF-1 and IGF binding protein 3 that remained within normal ranges, as well as a lack of response to GH stimulation. Sequencing confirmed a defect in the GH receptor signaling pathway. CONCLUSIONS: To the best of our knowledge, this study is the first to suggest an association between FA and LS. We propose that IGF-1 administration might improve some FA complications and functions based upon IGF-1 beneficial actions observed in animal, cell and indirect clinical models: erythropoiesis modulation, immune function improvement and metabolic regulation.

Partial IGF-1 deficiency induces brain oxidative damage and edema, which are ameliorated by replacement therapy.

Insulin-like growth factor 1 (IGF-1) induces multiple cytoprotective effects on every tissue, including the brain. Since the mechanisms by which IGF-1 produces neuroprotection are not fully understood, the aim of this work was to delve into the underlying mechanisms. IGF-1 deficient mice (Hz) were compared with wild type (WT) and Hz mice treated with low doses of IGF-1 (2 µg/100 g body weight/day) for 10 days (Hz + IGF). Gene expression, quantitative PCR, histology, and magnetic resonance imaging were performed in the three groups. IGF-1 deficiency induced increased oxidative damage determined by markers of lipid peroxidation and hypoxia, as well as gene expression of heat shock proteins, antioxidant enzymes, and molecules involved in inflammation, apoptosis, and mitochondrial protection. These changes correlated with edema and learning impairment in Hz mice. IGF-1 therapy improved all these alterations. In conclusion, IGF-1 deficiency is responsible for increased brain oxidative damage, edema, and impaired learning and memory capabilities which are rescued by IGF-1 replacement therapy.

Mechanisms Underlying Testicular Damage and Dysfunction in Mice With Partial IGF-1 Deficiency and the Effectiveness of IGF-1 Replacement Therapy.

OBJECTIVE: To determine whether insulin-like growth factor (IGF-1) deficiency can cause testicular damage and to examine changes of the testicular morphology and testicular function-related gene expression caused by IGF-1 deficiency. Therefore, this study aims to determine the benefits of low doses of IGF-1 and to explore the mechanisms underlying the IGF-1 replacement therapy. MATERIALS AND METHODS: A murine model of IGF-1 deficiency was used to avoid any factor that could contribute to testicular damage. Testicular weight, score of histopathological damage, and gene expressions were studied in 3 experimental groups of mice: controls (wild-type Igf1(+/+)), heterozygous Igf1(+/-) with partial IGF-1 deficiency, and heterozygous Igf1(+/-) treated with IGF-1. RESULTS: Results show that the partial IGF-1 deficiency induced testicular damage and altered expression of genes involved in IGF-1 and growth hormone signaling and regulation, testicular hormonal function, extracellular matrix establishment and its regulation, angiogenesis, fibrogenesis, inflammation, and cytoprotection. In addition, proteins involved in tight junction expression were found to be reduced. However, low doses of IGF-1 restored the testicular damage and most of these parameters. CONCLUSION: IGF-1 deficiency caused the damage of the blood-testis barrier and testicular structure and induced the abnormal testicular function-related gene expressions. However, low doses of IGF-1 constitute an effective replacement therapy that restores the described testicular damage. Data herein show that (1) cytoprotective activities of IGF-1 seem to be mediated by heat shock proteins and that (2) connective tissue growth factor could play a relevant role together with IGF-1 in the extracellular matrix establishment.