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Gorgisen G, Ozkol H, Tuluce Y, Arslan A, Ecer Y, Keskin S, Kaya Z, Ragbetli MC. Silibinin and ellagic acid increase the expression of insulin receptor substrate 1 protein in ultraviolet irradiated rat skin. Biotech Histochem 2020; 95:641-646. [PMID: 32347127 DOI: 10.1080/10520295.2020.1753238] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
Abstract
Daily exposure to ultraviolet (UV) light induces inflammation and tumorigenesis in the skin. Silibinin and ellagic acid are natural products that exhibit anti-inflammatory and anti-tumorigenic properties. Insulin receptor substrate protein 1 (IRS1) is important for skin homeostasis and physiology, but its activity following UV radiation remains unclear. We investigated the effects of ellagic acid and silibinin on IRS1 expression in ultraviolet A (UVA) and ultraviolet B (UVB) irradiated rat skin. Forty-two female Wistar rats were divided randomly into six groups of seven animals. The dorsal skin of rats was exposed to UVA + UVB, then treated with ellagic acid and silibinin by gavage. IRS1 expression in skin tissues was determined by western blot analysis. IRS1 expression increased significantly following treatment with ellagic acid and silibinin in UVA + UVB irradiated skin compared to the UVA + UVB only group. After UVA + UVB treatment, ellagic acid effected greater induction of IRS1 expression than silibinin. Our findings suggest that the photoprotective roles of ellagic acid and silibinin may be due to induction of IRS1 expression in UVA + UVB treated rat skin.
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Affiliation(s)
- G Gorgisen
- Department of Medical Biology, Van Yuzuncu Yil University Medical School , Van, Turkey
| | - H Ozkol
- Department of Medical Biology, Van Yuzuncu Yil University Medical School , Van, Turkey
| | - Y Tuluce
- Department of Medical Biology, Van Yuzuncu Yil University Medical School , Van, Turkey
| | - A Arslan
- Department of Medical Biology, Van Yuzuncu Yil University Medical School , Van, Turkey
| | - Y Ecer
- Department of Medical Biology, Van Yuzuncu Yil University Medical School , Van, Turkey
| | - S Keskin
- Department of Medical Histology and Embryology, Van Yuzuncu Yil University Medical School , Van, Turkey
| | - Z Kaya
- Department of Medical Biology, Van Yuzuncu Yil University Medical School , Van, Turkey
| | - M C Ragbetli
- Department of Medical Histology and Embryology, Van Yuzuncu Yil University Medical School , Van, Turkey
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2
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Abstract
Diabetes mellitus contributes greatly to morbidity, mortality, and overall health care costs. In major part, these outcomes derive from the high incidence of progressive kidney dysfunction in patients with diabetes making diabetic nephropathy a leading cause of end-stage renal disease. A better understanding of the molecular mechanism involved and of the early dysfunctions observed in the diabetic kidney may permit the development of new strategies to prevent diabetic nephropathy. Here we review the pathophysiological changes that occur in the kidney in response to hyperglycemia, including the cellular responses to high glucose and the responses in vascular, glomerular, podocyte, and tubular function. The molecular basis, characteristics, and consequences of the unique growth phenotypes observed in the diabetic kidney, including glomerular structures and tubular segments, are outlined. We delineate mechanisms of early diabetic glomerular hyperfiltration including primary vascular events as well as the primary role of tubular growth, hyperreabsorption, and tubuloglomerular communication as part of a "tubulocentric" concept of early diabetic kidney function. The latter also explains the "salt paradox" of the early diabetic kidney, that is, a unique and inverse relationship between glomerular filtration rate and dietary salt intake. The mechanisms and consequences of the intrarenal activation of the renin-angiotensin system and of diabetes-induced tubular glycogen accumulation are discussed. Moreover, we aim to link the changes that occur early in the diabetic kidney including the growth phenotype, oxidative stress, hypoxia, and formation of advanced glycation end products to mechanisms involved in progressive kidney disease.
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Affiliation(s)
- Volker Vallon
- Department of Medicine, University of California San Diego & VA San Diego Healthcare System, San Diego, California, USA.
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3
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Narayanan RP, Fu B, Heald AH, Siddals KW, Oliver RL, Hudson JE, Payton A, Anderson SG, White A, Ollier WER, Gibson JM. IGFBP2 is a biomarker for predicting longitudinal deterioration in renal function in type 2 diabetes. Endocr Connect 2012; 1:95-102. [PMID: 23781310 PMCID: PMC3681324 DOI: 10.1530/ec-12-0053] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Accepted: 09/19/2012] [Indexed: 01/22/2023]
Abstract
OBJECTIVE Insulin-like growth factors are implicated in the development of diabetic nephropathy. IGF-binding protein 2 (IGFBP2) and IGF2 are expressed in the kidney, but their associations with diabetic nephropathy are unclear. We therefore tested the hypothesis that circulating levels of IGF2 and IGFBP2 predict longitudinal renal function in individuals with type 2 diabetes. DESIGN AND METHODS IGFBP2 and IGF2 measurements were performed in 436 individuals (263 males) with type 2 diabetes. Linear mixed-effect regression analysis was used to model the relationship between plasma IGFBP2 concentration and longitudinal changes in estimated glomerular filtration rate (eGFR) over an 8-year period. Analyses were also performed for IGF1, IGF2, IGFBP1 and IGFBP3 concentrations as predictors of longitudinal renal outcomes. RESULTS High IGFBP2 concentration at baseline was associated with a decreased eGFR over an 8-year period (β=-0.02, (95% confidence interval -0.03 to -0.01), P<0.001). High IGFBP1, IGFBP2 and IGFBP3 were also associated with low baseline eGFR concentration. CONCLUSION This study demonstrates that IGFBP2 is a predictor of longitudinal deterioration of renal function in type 2 diabetes.
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Affiliation(s)
- Ram P Narayanan
- Vascular Research GroupThe University of ManchesterManchester, M13 9PTUK
- Correspondence should be addressed to R P Narayanan B-202, Clinical Sciences Building, Salford Royal NHS Foundation Trust, Stott Lane, Salford M6 8HD, UK Email
| | - Bo Fu
- School of Community Based Medicine, The University of ManchesterManchester, M13 9PTUK
| | - Adrian H Heald
- Vascular Research GroupThe University of ManchesterManchester, M13 9PTUK
| | - Kirk W Siddals
- Vascular Research GroupThe University of ManchesterManchester, M13 9PTUK
| | - Robert L Oliver
- Vascular Research GroupThe University of ManchesterManchester, M13 9PTUK
| | - Julie E Hudson
- Vascular Research GroupThe University of ManchesterManchester, M13 9PTUK
| | - Antony Payton
- Centre for Integrated Genomic Medical Research, The University of ManchesterManchester, M13 9PTUK
| | - Simon G Anderson
- Cardiovascular Research GroupThe University of ManchesterManchester, M13 9PTUK
| | - Anne White
- Endocrinology and Diabetes, Faculty of Medical, Human and Life SciencesThe University of ManchesterManchester, M13 9PTUK
| | - William E R Ollier
- Centre for Integrated Genomic Medical Research, The University of ManchesterManchester, M13 9PTUK
- Salford R&D, Salford Royal Hospital NHS Foundation TrustSalford, M6 8HDUK
| | - J Martin Gibson
- Vascular Research GroupThe University of ManchesterManchester, M13 9PTUK
- Department of Endocrinology and DiabetesSalford Royal Hospital NHS Foundation TrustSalford, M6 8HDUK
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Vallon V. The proximal tubule in the pathophysiology of the diabetic kidney. Am J Physiol Regul Integr Comp Physiol 2011; 300:R1009-22. [PMID: 21228342 DOI: 10.1152/ajpregu.00809.2010] [Citation(s) in RCA: 269] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Diabetic nephropathy is a leading cause of end-stage renal disease. A better understanding of the molecular mechanism involved in the early changes of the diabetic kidney may permit the development of new strategies to prevent diabetic nephropathy. This review focuses on the proximal tubule in the early diabetic kidney, particularly on its exposure and response to high glucose levels, albuminuria, and other factors in the diabetic glomerular filtrate, the hyperreabsorption of glucose, the unique molecular signature of the tubular growth phenotype, including aspects of senescence, and the resulting cellular and functional consequences. The latter includes the local release of proinflammatory chemokines and changes in proximal tubular salt and fluid reabsorption, which form the basis for the strong tubular control of glomerular filtration in the early diabetic kidney, including glomerular hyperfiltration and odd responses like the salt paradox. Importantly, these early proximal tubular changes can set the stage for oxidative stress, inflammation, hypoxia, and tubulointerstitial fibrosis, and thereby for the progression of diabetic renal disease.
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Affiliation(s)
- Volker Vallon
- Depts. of Medicine and Pharmacology, University of California San Diego & VA San Diego Healthcare System, 3350 La Jolla Village Drive, San Diego, CA 92161, USA.
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5
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Sireesha M, Sambasivan V, Kumar VK, Radha S, Raj AY, Qurratulain H. Relevance of insulin-like growth factor 2 in the etiopathophysiology of diabetic nephropathy: possible roles of phosphatase and tensin homolog on chromosome 10 and secreted protein acidic and rich in cysteine as regulators of repair. J Diabetes 2009; 1:118-24. [PMID: 20929508 DOI: 10.1111/j.1753-0407.2009.00025.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND Diabetic nephropathy (DN) is a devastating complication of diabetes, the exact molecular pathophysiology of which is not well established. Hyperglycemia increases insulin-like growth factors (IGFs), especially IGF2, which acts via the IGF1 receptor present on renal cells. Elevated glucose levels damage the kidney, which is repaired by modulators such as secreted protein acidic and rich in cysteine (SPARC). Hence, it was hypothesized that IGF2 and SPARC may have an important role in the etiology of DN. METHODS Human renal biopsies, histopathologically categorized as normal, early Type 2 diabetes mellitus (T2DM), or established DN, were analyzed for the localization and expression of IGF2, its negative regulator phosphatase and tensin homolog on chromosome 10 (PTEN), and SPARC. RESULTS Expression of IGF2, PTEN, and SPARC was increased in renal biopsies from T2DM patients compared with normal samples. Although IGF2 protein was increased in biopsies from DN patients, PTEN and SPARC levels were decreased. Real-time reverse transcription-polymerase chain reaction indicated that transcript levels of IGF2 and PTEN were greater than those of β-actin in all human renal biopsy samples. CONCLUSION The results suggest the following molecular etiopathophysiology of DN: (i) hyperglycemia upregulates IGF2, which initiates PTEN, a regulator of IGF2 signaling; (ii) loss of this IGF2-PTEN feedback loop causes changes that are characteristic of DN; and (iii) lowered expression of the repair modulator SPARC results in the development and/or progression of DN. Hence, targeting relevant modulators, such as like IGF2, PTEN, and SPARC, may be important in the management of DN.
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Affiliation(s)
- Movva Sireesha
- Department of Genetics, Bhagwan Mahavir Hospital and Research Centre, Hyderabad, Andhra Pradesh, India
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6
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Sadagurski M, Nofech-Mozes S, Weingarten G, White MF, Kadowaki T, Wertheimer E. Insulin receptor substrate 1 (IRS-1) plays a unique role in normal epidermal physiology. J Cell Physiol 2007; 213:519-27. [PMID: 17508357 DOI: 10.1002/jcp.21131] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Insulin receptor substrate (IRS) proteins play a central role in insulin signaling. Previously we have demonstrated that insulin is essential for normal skin development and function. In the present study we investigated the involvement of the IRS-1 and IRS-2 proteins in skin physiology and in mediating insulin action in skin. For this purpose we have investigated the effects of inactivation of each of the IRSs on skin, studying skin sections and primary skin cells derived from IRS-1 or IRS-2 null mice. We have demonstrated that while the skin of the IRS-2 null mice appeared normal, the skin of the IRS-1 null mice was thinner and translucent. Histological analysis revealed that the thinning of the IRS-1 null skin was a consequence of the thinning of the spinous compartment, consisting of fewer layers. Proliferation of the IRS-1 and IRS-2 null skin epidermal cells was normal. However, the differentiation process of the IRS-1 skin and skin cells was impaired. There was a marked decrease in the induction of the expression of K1, the marker of advanced stages of skin differentiation. In contrary, IRS-2 inactivation had no effects on skin differentiation. In conclusion, we have shown for the first time that IRS-1 but not IRS-2 has an effect on skin formation and development, being one of the main activators of the differentiation process in skin keratinocytes. Furthermore, we suggest that IRS-1 and IRS-2 have distinct roles in skin physiology.
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Affiliation(s)
- Marianna Sadagurski
- Department of Pathology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
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7
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Han HJ, Kang CW, Park SH. TISSUE-SPECIFIC REGULATION OF INSULIN-LIKE GROWTH FACTORS AND INSULIN-LIKE GROWTH FACTOR BINDING PROTEINS IN MALE DIABETIC RATS IN VIVO AND IN VITRO. Clin Exp Pharmacol Physiol 2006; 33:1172-9. [PMID: 17184497 DOI: 10.1111/j.1440-1681.2006.04495.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
1. Insulin-like growth factors (IGFs) are associated with the development of diabetes mellitus. The liver, kidney and heart have been implicated as important organs in the onset of diabetes mellitus. However, the effect of diabetes on the IGF system in these organs has not been fully described. Thus, we investigated changes in IGF-I, IGF-II and IGF binding proteins (IGFBPs) in male steptozotocin-induced diabetic rats, as well as in a high glucose-induced in vitro model. 2. Serum levels of IGF-I were decreased, but the levels of IGF-II were increased, in diabetic rats compared with controls. The expression of IGFBP-3 in the serum was markedly decreased; in contrast, the expression of IGFBP-1 and -2 was increased in diabetic rats. The expression of IGF-I, IGF-II, IGFBP-1, IGFBP-2, IGFBP-3 and IGFBP-4 in the liver of the diabetic group was similar to that in the serum of diabetic rats. 3. In heart tissue of the diabetic group, IGF-I levels were decreased, but IGF-II levels were increased. In addition, the expression of IGFBP-3, IGFBP-1 and IGFBP-2 was decreased in diabetic rats. 4. In the kidney of the diabetic group, IGF-I and IGF-II levels were increased. There was only slight expression of IGFBP-3 in the kidney and this was not altered in diabetic rats. Levels of IGFBP-1 and -2 were markedly increased in the kidney of diabetic rats. 5. Insulin treatment recovered the changes in expression of IGF-I, IGF-II and IGFBPs in the serum, liver, heart and kidney. In the liver, heart and kidney, the expression of the insulin receptor was increased in male diabetic rats. 6. In conclusion, diabetes tissue-specifically alters the IGF system in the liver, heart and kidney in rats; this effect can be recovered by insulin treatment.
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Affiliation(s)
- Ho Jae Han
- Bio-Therapy Human Resources Center, College of Veterinary Medicine, Chonnam National University, Gwangju, Korea
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8
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Satriano J, Vallon V. Primary kidney growth and its consequences at the onset of diabetes mellitus. Amino Acids 2006; 31:1-9. [PMID: 16733619 DOI: 10.1007/s00726-006-0326-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2006] [Accepted: 02/09/2006] [Indexed: 12/13/2022]
Abstract
Diabetes mellitus is a primary contributor to progressive kidney dysfunction leading to end-stage renal disease (ESRD). In the early phase of diabetes, prior to the onset of further complications, both kidney size and glomerular filtration rate (GFR) increase. Glomerular hyperfiltration is considered a risk factor for downstream complications and progression to ESRD. Abnormalities in vascular control have been purported to account for the glomerular hyperfiltration in early diabetes. In this review we discuss a tubulo-centric concept in which tubular growth and subsequent hyper-reabsorption contribute to the onset of glomerular hyperfiltration that demarks the early stage of diabetes. Kidney growth, in this concept, is no longer relegated to a compensatory response to hyperfiltration, but rather plays a primary and active role in its genesis and progression. As such, components of kidney growth, such as the polyamines, may provide a means of early detection of diabetic kidney dysfunction and more effective therapeutic intervention.
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Affiliation(s)
- J Satriano
- Department of Medicine, Division of Nephrology-Hypertension, The Veterans Administration San Diego Healthcare System, University of California, San Diego, CA 92161, USA.
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9
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Cingel-Ristić V, Schrijvers BF, van Vliet AK, Rasch R, Han VKM, Drop SLS, Flyvbjerg A. Kidney growth in normal and diabetic mice is not affected by human insulin-like growth factor binding protein-1 administration. Exp Biol Med (Maywood) 2005; 230:135-43. [PMID: 15673562 DOI: 10.1177/153537020523000208] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Insulin-like growth factor I (IGF-I) accumulates in the kidney following the onset of diabetes, initiating diabetic renal hypertrophy. Increased renal IGF-I protein content, which is not reflected in messenger RNA (mRNA) levels, suggests that renal IGF-I accumulation is due to sequestration of circulating IGF-I rather than to local synthesis. It has been suggested that IGF-I is trapped in the kidney by IGF binding protein 1 (IGFBP-1). We administered purified human IGFBP-1 (hIGFBP-1) to nondiabetic and diabetic mice as three daily sc injections for 14 days, starting 6 days after induction of streptozotocin diabetes when the animals were overtly diabetic. Markers of early diabetic renal changes (i.e., increased kidney weight, glomerular volume, and albuminuria) coincided with accumulation of renal cortical IGF-I despite decreased mRNA levels in 20-day diabetic mice. Human IGFBP-1 administration had no effect on increased kidney weight or albuminuria in early diabetes, although it abolished renal cortical IGF-I accumulation and glomerular hypertrophy in diabetic mice. Increased IGF-I levels in kidneys of normal mice receiving hIGFBP-1 were not reflected on kidney parameters. IGFBP-1 administration in diabetic mice had only minor effects on diabetic renal changes. Accordingly, these results did not support the hypothesis that IGFBP-1 plays a major role in early renal changes in diabetes.
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Affiliation(s)
- Vesna Cingel-Ristić
- Laboratory of Pediatrics, Subdivision of Molecular Endocrinology, Room Ee1500, Erasmus MC, PO.Box 1738, 3000 DR Rotterdam, The Netherlands.
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10
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Cingel-Ristić V, Flyvbjerg A, Drop SLS. The physiological and pathophysiological roles of the GH/IGF-axis in the kidney: lessons from experimental rodent models. Growth Horm IGF Res 2004; 14:418-430. [PMID: 15519249 DOI: 10.1016/j.ghir.2004.06.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The growth hormone (GH)/insulin-like growth factor (IGF) system plays an important role in renal development, growth, function and pathophysiology. IGF-I has been associated with renal/glomerular hypertrophy and compensatory renal growth. Potential effects on glomerular size are of interest, since an increase in glomerular size may be permissive for the development of glomerulosclerosis. In an effort to abolish the decline of renal function and possibly to restore the renal structure, different approaches have been tested in experimental models of nephropathy, focusing mainly on early renal changes. The involvement of the GH/IGF system in renal pathophysiology has been studied in much detail in the rat. In view of the growing interest in murine physiology, occurring in large part by genetically modified animals, this review examines those aspects of GH, IGFs, their receptors and binding proteins that relate both to mouse kidney physiology and to a number of conditions characterized by pathophysiological renal changes. A deeper understanding of the role of the GH/IGF system in renal dysfunction may stimulate the development of novel therapeutic approaches aiming at preventing or retarding various kidney diseases.
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Affiliation(s)
- Vesna Cingel-Ristić
- Laboratory of Pediatrics, Subdivision of Molecular Endocrinology, P.O. Box 1738, Erasmus Medical Center, 3000 DR Rotterdam, The Netherlands.
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11
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Abstract
The insulin-like growth factors (IGFs), IGF-binding proteins (IGFBPs), and IGFBP proteases are the main regulators of somatic growth and cellular proliferation. IGFs are involved in growth pre-natally and post-natally. Dysregulation of the IGF axis can lead to growth disorders such as growth hormone deficiency and acromegaly. Pre-natally, this dysregulation can lead to IUGR or macrosomia. IGFs also have an important mitogenic action and play a role in tumorigenesis and cancer. These actions are regulated by co-interactions with IGFBPs, especially IGFBP-3. In addition to somatic growth and mitogenic activity, IGFs have hypoglycaemic and insulin sensitizing actions, and their dysregulation is involved in diabetes and its complications. In this chapter, we examine the role of IGFs and IGFBPs in growth, tumorigenesis and diabetes, and discuss treatment modalities for each disease involving the GH-IGF-IGFBP axis, including discussion of current in vitro and in vivo investigations in this field.
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Affiliation(s)
- Roshanak Monzavi
- Mattel Children's Hospital, David Geffen School Of Medicine at UCLA, 10833 Le Conte Avenue, MDCC 22-315, Los Angeles, CA 90095-1752, USA
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12
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Obineche EN, Mensah-Brown E, Chandranath SI, Arafar K, Adem A. Loss of kidney IGF-1 receptors in experimental long-term diabetic rats. Endocr Res 2001; 27:293-302. [PMID: 11678576 DOI: 10.1081/erc-100106006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The present study was undertaken to assess the long-term effects of streptozotocin-induced diabetes mellitus on insulin-like growth factor-1 (IGF-1) receptors in rat kidneys. Morphological changes were also evaluated using light and electron microscopy. Using receptor autoradiography the levels of IGF-1 were investigated in rat kidneys diabetic for eight months and controls. Sections from both diabetic and control rats were stained with haematoxylin and eosin for morphological studies. Ultra-thin kidney sections were examined using a transmission electron microscope. IGF-1 receptors were significantly lower in the cortex and the medulla of the diabetic rats compared with controls. Morphological differences between normal and diabetic kidneys were observed in both the cortex and medulla. Glomerular changes and necrosis of the renal cortical and medullary parenchyma were demonstrated in the diabetic rats. Necrosis of cells of the collecting ducts and loops of Henle could explain the loss of IGF-1 receptor concentration in the medulla. Shrinkage of glomeruli and normal proximal convoluted tubules of diabetic kidneys were also observed. Our results also revealed extensive damage to the distal convoluted tubules that have not been reported to possess any insulin-like growth factor-1 receptors. Our results demonstrate a reduction of kidney IGF-1 receptors after long-term diabetes mellitus possibly because of the extensive morphological loss of renal tissue. It could be speculated that early administration of IGF-1 might be useful in longterm diabetes mellitus to prevent the degeneration and/or help regeneration of damaged renal tissue.
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Affiliation(s)
- E N Obineche
- Department of Internal Medicine, Faculty of Medicine and Health Sciences, United Arab Emirates University, Al Ain
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13
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Haylor J, Hickling H, El Eter E, Moir A, Oldroyd S, Hardisty C, El Nahas AM. JB3, an IGF-I receptor antagonist, inhibits early renal growth in diabetic and uninephrectomized rats. J Am Soc Nephrol 2000; 11:2027-2035. [PMID: 11053478 DOI: 10.1681/asn.v11112027] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Biochemical evidence suggests that insulin-like growth factor I (IGF-I) may play an important role as a mediator of kidney growth. In the present study, an IGF-I receptor antagonist (JB3) was synthesized, and its effect on the renal growth that follows the induction of diabetes or unilateral nephrectomy (UNx) was examined. JB3 was generated by solid phase peptide synthesis. Its activity as an IGF-I antagonist was confirmed in an opossum kidney cell line from its inhibitory effect on the increase in thymidine incorporation into DNA induced by recombinant human IGF-I. Male Wistar rats were anesthetized with halothane and subjected to either the induction of diabetes by streptozotocin (intravenous 60 mg/kg) for 4 d (control animals received citrate buffer) or UNx for 11 d (control animals were sham operated). JB3 was delivered by subcutaneous infusion using an osmotic minipump implanted 3 d before the induction of diabetes or UNx. Kidney wet weight, DNA, and protein all were significantly higher 4 d after the induction of diabetes (24%) or 11 d after UNx (55%). Dose-response studies (1 to 30 microg/kg per day) showed JB3 administration to inhibit the increase in kidney growth in both diabetic and UNx rats. The increase in kidney wet weight, DNA, and protein was significantly lower in UNx rats that were treated with JB3 10 microg/kg per day (P: < 0.05) than in saline vehicle controls but was abolished in diabetic rats that were treated with JB3 3 microg/kg per day (P: < 0. 01). Increasing the dose of JB3 to 30 microg/kg per day was associated with a decrease in its inhibitory effect, resulting in bell-shaped dose-response curves. JB3 administration had no effect on the blood glucose concentration or food consumption by either diabetic or nondiabetic animals. The results support the concept of IGF-I as an important mediator of the early renal growth that follows the induction of diabetes or UNx in the rat.
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Affiliation(s)
- John Haylor
- Sheffield Kidney Institute, Northern General Hospital Trust, Sheffield, United Kingdom
| | - Helen Hickling
- Sheffield Kidney Institute, Northern General Hospital Trust, Sheffield, United Kingdom
| | - Eman El Eter
- Sheffield Kidney Institute, Northern General Hospital Trust, Sheffield, United Kingdom
| | - Arthur Moir
- Krebs Institute, University of Sheffield, Sheffield, United Kingdom
| | - Simon Oldroyd
- Sheffield Kidney Institute, Northern General Hospital Trust, Sheffield, United Kingdom
| | - Colin Hardisty
- Diabetic Centre, Northern General Hospital Trust, Sheffield, United Kingdom
| | - A Meguid El Nahas
- Sheffield Kidney Institute, Northern General Hospital Trust, Sheffield, United Kingdom
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14
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Bach LA, Dean R, Youssef S, Cooper ME. Aminoguanidine ameliorates changes in the IGF system in experimental diabetic nephropathy. Nephrol Dial Transplant 2000; 15:347-54. [PMID: 10692520 DOI: 10.1093/ndt/15.3.347] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Formation of advanced glycation end-products (AGEs) has been implicated in the development of diabetic complications. As well as causing changes in structural proteins, AGEs may also alter gene expression of growth factors in vitro. The insulin-like growth factor (IGF) system, including IGF-I and modulatory IGF binding proteins (IGFBPs), is dysregulated during the development of diabetic nephropathy. METHODS Quantitative in situ hybridization histochemistry and immunohistochemistry were used to determine the effects of aminoguanidine, an inhibitor of AGE formation, on gene expression of IGF-I and IGFBPs in kidneys of long-term (8 months duration) streptozotocin-diabetic rats. RESULTS Diabetes was associated with increased renal expression of IGFBP-1 mRNA (diabetes 824+/-236 vs control 264+/-76 arbitrary units, P<0.01) and decreased expression of mRNAs for IGF-I (diabetes 39+/-7 vs control 185+/-23 arbitrary units, P<0.001) and IGFBP-4 (diabetes 139+/-25 vs control 383+/-54 arbitrary units, P<0.001). Aminoguanidine treatment inhibited the effects of diabetes on renal expression of mRNA for IGF-I, IGFBP-1 and IGFBP-4. The changes in IGF-I and IGFBP-1 mRNA levels were reflected in altered peptide levels. In diabetic kidneys, IGFBP-5 mRNA levels were slightly decreased to 75% of control levels (P<0.01); aminoguanidine had no effect on IGFBP-5 mRNA levels. CONCLUSIONS These results suggest that amelioration of changes in the renal IGF system by aminoguanidine may contribute to the renoprotective effects of the latter, which have been previously shown to inhibit structural and functional aspects of diabetic nephropathy in the rat.
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Affiliation(s)
- L A Bach
- University of Melbourne, Department of Medicine, Austin and Repatriation Medical Centre, Heidelberg, Victoria, Australia
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15
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Thrailkill KM. Insulin-like growth factor-I in diabetes mellitus: its physiology, metabolic effects, and potential clinical utility. Diabetes Technol Ther 2000; 2:69-80. [PMID: 11467325 DOI: 10.1089/152091599316775] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Type 1 diabetes mellitus (DM) is a disease of insulin deficiency, resulting from the autoimmune-mediated destruction of pancreatic beta cells. However, as a likely consequence of intraportal insulin deficiency, patients with type 1 DM also exhibit abnormalities of the growth hormone (GH)/IGF/IGF-binding protein (IGFBP) axis, including GH hypersecretion, reduced circulating levels of insulin-like growth factor-I (IGF-I) and IGFBP-3, and elevated levels of IGFBP-1. These abnormalities not only exacerbate hyperglycemia in patients with type 1 DM, but may contribute to the pathogenesis of diabetes-specific complications, including diabetic neuropathy, nephropathy, and retinopathy. Therefore, therapeutic modalities aimed at restoring the GH-IGF-IGFBP axis are being considered. Herein, we review the efficacy of one such therapy, specifically IGF-I replacement therapy. To date, short-term beneficial metabolic effects of recombinant human IGF (rhIGF)-I therapy have been demonstrated in numerous diabetic conditions, including type 1 DM, type 2 DM, and type A insulin resistance. However, the long- term safety and metabolic efficacy of rhIGF-I therapy remains to be established. Moreover, the potential impact of rhIGF-I on the natural history of diabetic complications has yet to be explored.
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Affiliation(s)
- K M Thrailkill
- Department of Pediatrics, University of Kentucky College of Medicine, Lexington, USA.
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Horney MJ, Shirley DW, Kurtz DT, Rosenzweig SA. Elevated glucose increases mesangial cell sensitivity to insulin-like growth factor I. THE AMERICAN JOURNAL OF PHYSIOLOGY 1998; 274:F1045-53. [PMID: 9841495 DOI: 10.1152/ajprenal.1998.274.6.f1045] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
To determine the effects of glucose on insulin-like growth factor I (IGF-I)-induced mesangial cell (MC) proliferation, we have examined the relationships between IGF binding protein 2 (IGFBP-2) secretion and proliferation in murine MCs (MMCs). MMCs incubated in high glucose (HG, 25 mM) exhibited a 25-30% reduction in IGFBP-2 secretion compared with cells in normal glucose (NG, 5.6 mM). This loss was not due to cell surface binding; it correlated with a 3.1-fold decrease in IGFBP-2 mRNA. IGFBP-2 secretion was stimulated by IGF-I in NG but was unaltered in HG. Insulin treatment yielded similar results at 10-fold higher doses, indicating that this response is IGF-I receptor dependent. MMCs in HG displayed increased IGF-I-stimulated insulin receptor substrate-1/2 phosphorylation and activator protein-1 transcriptional activity compared with NG controls. Accordingly, although IGF-I was not proliferative in NG, it increased [3H]thymidine incorporation and cell number in HG to an extent proportional to the decrease in IGFBP-2. Thus hyperglycemia, as seen in diabetes, may increase MC IGF-I sensitivity by reducing IGFBP-2 expression, in turn increasing its proliferative and secretory responses and contributing to the development of diabetic glomerulosclerosis.
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Affiliation(s)
- M J Horney
- Department of Cell and Molecular Pharmacology, Medical University of South Carolina, Charleston, South Carolina 29425, USA
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