Since its discovery in 1921, insulin has been considered to be the most important hormone in the regulation of glucose and fat metabolism. In recent years, studies have revealed that besides metabolism regulation, insulin can also act as a growth factor like hormone in regulating multiple processes and various cellular activities in the process of wound healing. This review summarizes the role of insulin in wound healing and its underlying mechanism.
Glucose ; metabolism ; Growth Hormone ; metabolism ; physiology ; Humans ; Insulin ; physiology ; Insulin-Like Growth Factor I ; physiology ; Insulin-Like Growth Factor II ; physiology ; Wound Healing ; physiology

Mechano growth factor (MGF) is an autocrine/paracrine factor and sensitive to mechanical stimulation. MGF can be highly expressed in various soft tissues under physical stimuli, biochemistry stimuli or in damaged situation. MGF may "compensate" the stress for tissue in the processing of tissue repair. MGF can effectively accelerate the repair of the soft tissue by promoting the proliferation, migration and differentiation of cells. This paper summarizes the MGF expressions in different soft tissues and their functions in soft tissue repair. The paper also discusses current problems and challenges in using MGF to repair the soft tissue.
Cell Differentiation ; Cell Proliferation ; Humans ; Insulin-Like Growth Factor I ; physiology ; Soft Tissue Injuries ; Wound Healing

Animals ; Benzodiazepines ; pharmacology ; Ducks ; physiology ; Growth Hormone ; blood ; Insulin-Like Growth Factor I ; metabolism ; Serum ; metabolism ; Weight Gain ; drug effects

Cows with different Insulin-like Growth Factor-I (IGF-I) concentrations showed comparable expression levels of hepatic growth hormone receptor (GHR). Suppressor of cytokine signaling 2 (SOCS2), could be responsible for additional inhibition of the GHR signal cascade. The aims were to monitor cows with high or low antepartal IGF-I concentrations (IGF-I(high) or IGF-I(low)), evaluate the interrelationships of endocrine endpoints, and measure hepatic SOCS2 expression. Dairy cows (n = 20) were selected (240 to 254 days after artificial insemination (AI)). Blood samples were drawn daily (day -17 until calving) and IGF-I, GH, insulin, thyroid hormones, estradiol, and progesterone concentrations were measured. Liver biopsies were taken (day 264 +/- 1 after AI and postpartum) to measure mRNA expression (IGF-I, IGFBP-2, IGFBP-3, IGFBP-4, acid labile subunit (ALS), SOCS2, deiodinase1, GHR1A). IGF-I concentrations in the two groups were different (p < 0.0001). However, GH concentrations and GHR1A mRNA expression were comparable (p > 0.05). Thyroxine levels and ALS expression were higher in the IGF-I(high) cows compared to IGF-I(low) cows. Estradiol concentration tended to be greater in the IGF-I(low) group (p = 0.06). It was hypothesized that low IGF-I levels are associated with enhanced SOCS2 expression although this could not be decisively confirmed by the present study.
Animals ; Cattle ; Estradiol/blood ; Female ; Growth Hormone/blood ; Insulin/blood ; Insulin-Like Growth Factor Binding Protein 2/analysis ; Insulin-Like Growth Factor Binding Protein 3/analysis ; Insulin-Like Growth Factor Binding Protein 4/analysis ; Insulin-Like Growth Factor I/*analysis/physiology ; Liver/chemistry ; Pregnancy/metabolism/physiology ; Pregnancy, Animal/*metabolism/physiology ; Progesterone/blood ; Suppressor of Cytokine Signaling Proteins/analysis ; Thyroid Hormones/blood

OBJECTIVE: To investigate the influence of activin and follistatin on the expression of IGF (insulin-like growth factor)-I, II, IGFBP (insulin-like growth factor binding protein)-1, 2, and 3 mRNA in cultured mouse granulosa cells MATERIALS AND METHODS: The granulosa cells were obtained from the mouse and cultured for 6 days with 10 ng/ml of activin, 10 ng/ml of follistatin, and 10 ng/ml of activin with 10 ng/m of follistatin, respectively. The cells not treated with activin or follistatin served as control. Reverse transcription-polymerase chain reaction (RT-PCR) has been used to examine the expression of IGF-I, II, IGFBP-1, 2, and 3 mRNA. Results were analyzed with Kolmogorov-Smirnov test and analysis of variance (ANOVA) and statistical significance was defined as p<0.05. RESULTS: The expression of IGF-I and II mRNA were not different significantly. However, the expression of IGFBP-3 mRNA was significantly increased in the follistatin group compared to the control group (p<0.05) and significantly decreased in the activin with follistatin group compared to the control group (p<0.05). The expression of IGFBP-1 mRNA was seemed to be increased in the activin group and decreased in the follistatin group compared to the control group, respectively (p=0.07, p=0.07). The expression of IGFBP-2 and 3 mRNA were seemed to be decreased in the activin group compared to the control group (p=0.06, p=0.07, respectively). CONCLUSION: Activin and follistatin might play a role as regulators of mouse ovarian physiology by modulating the IGF system, especially IGFBPs.
Activins* ; Animals ; Carrier Proteins* ; Female ; Follistatin* ; Granulosa Cells* ; Insulin-Like Growth Factor Binding Protein 1 ; Insulin-Like Growth Factor Binding Protein 2 ; Insulin-Like Growth Factor Binding Protein 3 ; Insulin-Like Growth Factor Binding Proteins ; Insulin-Like Growth Factor I ; Mice* ; Physiology ; RNA, Messenger*

Body Height ; Child ; Female ; Ghrelin ; pharmacology ; Growth Disorders ; physiopathology ; Growth Hormone-Releasing Hormone ; pharmacology ; Human Growth Hormone ; blood ; physiology ; urine ; Humans ; Insulin-Like Growth Factor Binding Protein 3 ; blood ; Insulin-Like Growth Factor I ; physiology ; Male

BACKGROUNDThis study transferred a recombinant gene encoding human insulin like growth factor-1 (hIGF-1) into modified primary skeletal myoblasts with a retroviral vector (pLgXSN) and determined whether the hIGF-1 promoted growth of skeletal muscle in rat.

METHODShIGF-1cDNA was amplified in vitro from normal human liver cells by using RT-PCR and cloned into plasmid vector pLgXSN. The recombinant vector pLghIGF-1SN and control vector pLgGFPSN were transfected into packaging cell PT67 and G418 was used to select positive colony. Myoblasts were infected with a high titre viral supernatant and transduction efficiency was evaluated as GFP expression. The expression of hIGF-1 mRNA in myoblasts was investigated by immunocytochemistry and RT-PCR. MTT assays detected the growth of myoblasts in vitro. Myoblasts transduced with pLghIGF-1SN were injected into hind limb muscles of 10 - 12 week male SD rats. Formed tissues were harvested 4 weeks later. Myocyte diameter, mean weight of hind limb and body were measured to evaluate the skeletal muscle growth.

RESULTSRecombinant retroviral plasmid vector pLghIGF-1SN was constructed successfully. The titre of the packaged recombinant retrovirus was 1 x 10(6) cfu/ml. The transfection rate of PT67 cells reached 100% after G418 screening. hIGF-1 expression was positive in myoblast-IGF-1. The proliferation rate of myoblast-IGF-1 in vitro was higher than GFP-myoblast or myoblast (P < 0.05). The mean weights of hind limb and body of rats injected myoblast-IGF-1 were higher than those of the rats injected with myoblast-GFP or myoblast (P < 0.05). Myocyte diameter had a significant increase in IGF-1 group compared to GFP group and myoblast group (P < 0.05).

CONCLUSIONSThe transfection of the human IGF-1 gene mediated by a retroviral vector can promote the growth of skeletal muscle in rats. Genetically modified primary skeletal myoblasts provide a possibly effective approach to treat some skeletal muscle diseases.

Animals ; Cells, Cultured ; DNA, Recombinant ; genetics ; Genetic Vectors ; Insulin-Like Growth Factor I ; genetics ; physiology ; Muscle, Skeletal ; growth & development ; Myoblasts ; physiology ; Rats ; Rats, Sprague-Dawley ; Retroviridae ; genetics ; Transfection

OBJECTIVETo explore the etiology, incidence and methods to prevent and treat severe retinopathy of prematurity (ROP), which is rapidly becoming a threat to the vision of babies in areas of the world where increasing numbers of premature babies are surviving.

DATA SOURCESThe data used in this review were mainly from Medline and PubMed published in English. The search term was "retinopathy of prematurity and premature birth".

STUDY SELECTIONWe discuss the historical perspectives, prevalence and incidence, classification and treatment methods of ROP in premature babies.

RESULTSPeripheral retinal ablation for eyes with severe ROP can help prevent progression to blindness and several large clinical trials have shown the effectiveness of this treatment in high risk eyes. As a greater proportion of VLBW and ELBW babies survive, the population of babies at risk increases. In various regions of the world, different identification criteria are used to determine which babies are at risk of blindness in order to provide timely diagnostic examinations and treatment as needed. Methods for preventing ROP include better ante-natal and obstetric care leading to a reduction in the rate of prematurity, the use of ante-natal corticosteroids, and better neonatal care practices. Recent developments have indicated that management of oxygen supplementation is important for the prevention of severe ROP; however, there is not yet known what oxygen saturation target should be adopted. Sepsis increases severe ROP in very preterm infants. Genetic associations and a telemedicine approach may be explored to detect ROP. Treatment of anti-VEGF therapy are potentially useful in eyes with severe ROP, but long term effects are not yet known and such treatment should be used with great caution.

CONCLUSIONSROP is a potentially binding disease for premature babies which is becoming more prevalent with the development improving neonatal services in many countries in recent years. High priority should be placed on developing approaches to prevent ROP blindness by reducing preterm birth, improving care of premature babies in neonatal care units, and providing adequate ophthalmological services in those regions.

Humans ; Incidence ; Infant, Newborn ; Insulin-Like Growth Factor I ; physiology ; Prevalence ; Retinopathy of Prematurity ; classification ; epidemiology ; prevention & control ; Sepsis ; complications ; Vascular Endothelial Growth Factor A ; antagonists & inhibitors

PURPOSE: The serum concentrations of insulin-like growth factors-I (IGF-I), insulin-like growth factor binding protein-3 (IGFBP-3) and growth hormone (GH) are related to body composition, function and metabolism, and are influenced by the aging process. This study was to investigate the influence of gender on serum concentrations of IGF-I, IGFBP-3 and GH in middle and old age subjects. MATERIALS AND METHODS: Sixty healthy volunteers (male 35, female 25, 36-70 years) were divided into < or = 50 and > 50 years groups, based on gender. Women > 50 years were post-menopause. IGF-I, IGFBP-3, and GH were determined by immunoradiometric assay. RESULTS: IGF-I was shown to be negatively correlated with age (women r = -0.62, p < 0.001; men r = -0.38, p < 0.05), whereas there was no correlation between IGF-I and GH values. Women > 50 years showed a significant reduction in IGF-I values than women < or = 50 years (p < 0.01). Women > 50 years showed smaller IGF-I/IGFBP-3 molar ratios (0.177998 +/- 0.039404) than men of same age group (0.228326 +/- 0.050979, p < 0.01) and women < or = 50 years (0.247667 +/- 0.069411, p < 0.01). Age was shown to positively correlate with GH/IGF-I (r = 0.49, p < 0.05) and GH/IGFBP-3 ratios (r = 0.40, p < 0.05) in women. CONCLUSIONS: The influence of aging on serum concentrations of IGF-I is more remarkable in women than in men. Menopause causes reduction of IGF-I/IGFBP-3 molar ratio. Women have the trend of progressive hypoactivity of GH to stimulate IGF-I and IGFBP-3 secretions with age.
Adult ; Age Factors ; Aged ; Aging/*physiology ; Female ; Gene Expression Regulation, Developmental ; Human Growth Hormone/*blood ; Humans ; Immunoradiometric Assay ; Insulin-Like Growth Factor Binding Protein 3/*blood ; Insulin-Like Growth Factor I/*metabolism ; Male ; Middle Aged ; Sex Factors

PURPOSE: MicroRNAs are small non-coding RNAs that play important roles in vascular smooth muscle cell (VSMC) function. This study investigated the role of miR-379 on proliferation, invasion, and migration of VSMCs and explored underlying mechanisms thereof. MATERIALS AND METHODS: MicroRNA, mRNA, and protein levels were determined by quantitative real-time PCR and western blot. The proliferative, invasive, and migratory abilities of VSMCs were measured by CCK-8, invasion, and wound healing assay, respectively. Luciferase reporter assay was used to confirm the target of miR-379. RESULTS: Platelet-derived growth factor-bb was found to promote cell proliferation and suppress miR-379 expression in VSMCs. Functional assays demonstrated that miR-379 inhibited cell proliferation, cell invasion, and migration. Flow cytometry results further showed that miR-379 induced apoptosis in VSMCs. TargetScan analysis and luciferase report assay confirmed that insulin-like growth factor-1 (IGF-1) 3'UTR is a direct target of miR-379, and mRNA and protein levels of miR-379 and IGF-1 were inversely correlated. Rescue experiments showed that enforced expression of IGF-1 sufficiently overcomes the inhibitory effect of miR-379 on cell proliferation, invasion, and migration in VSMCs. CONCLUSION: Our results suggest that miR-379 plays an important role in regulating VSMCs proliferation, invasion, and migration by targeting IGF-1.
Apoptosis ; Cell Movement/*physiology ; Cell Proliferation/*physiology ; Humans ; Insulin ; Insulin-Like Growth Factor I/*physiology ; MicroRNAs/*physiology ; Muscle, Smooth, Vascular/*cytology ; Proto-Oncogene Proteins c-sis/*physiology ; RNA, Messenger/metabolism ; Real-Time Polymerase Chain Reaction ; Sincalide/physiology ; Wound Healing/physiology