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1.
Transplantation ; 105(2): 443-450, 2021 02 01.
Article in English | MEDLINE | ID: mdl-32265417

ABSTRACT

BACKGROUND: Patients (20%-50%) undergoing renal transplantation experience acute kidney injury resulting in delayed graft function. ANG-3777 is an hepatocyte growth factor mimetic that binds to the c-MET receptor. In animal models, ANG-3777 decreases apoptosis, increases proliferation, and promotes organ repair and function. METHODS: This was a randomized, double-blind, placebo-controlled, phase 2 trial of patients undergoing renal transplantation with <50 cc/h urine output for 8 consecutive hours over the first 24 hours posttransplantation, or creatinine reduction ratio <30% from pretransplantation to 24 hours posttransplantation. Subjects were randomized as 2:1 to 3, once-daily IV infusions of ANG-3777, 2 mg/kg (n = 19), or placebo (n = 9). Primary endpoint: time in days to achieve ≥1200 cc urine for 24 hours. RESULTS: Patients treated with ANG-3777 were more likely to achieve the primary endpoint of 1200 cc urine for 24 hours by 28 days posttransplantation (83.3% versus 50% placebo; log-rank test: χ2 = 2.799, P = 0.09). Compared with placebo, patients in the ANG-3777 arm had larger increases in urine output; lower serum creatinine; greater reduction in C-reactive protein and neutrophil gelatinase-associated lipocalin; fewer dialysis sessions and shorter duration of dialysis; fewer hospital days; significantly less graft failure; and higher estimated glomerular filtration rate. Adverse events occurred in a similar percentage of subjects in both arms. Events per subject were twice as high in the placebo arm. CONCLUSIONS: There was an efficacy signal for improved renal function in subjects treated with ANG-3777 relative to placebo, with a good safety profile.


Subject(s)
Acute Kidney Injury/drug therapy , Delayed Graft Function/drug therapy , Kidney Transplantation/adverse effects , Kidney/drug effects , Kidney/surgery , Pyrazoles/therapeutic use , Thiophenes/therapeutic use , Acute Kidney Injury/etiology , Acute Kidney Injury/physiopathology , Adult , Aged , Creatinine/blood , Delayed Graft Function/etiology , Delayed Graft Function/physiopathology , Double-Blind Method , Female , Glomerular Filtration Rate/drug effects , Humans , Kidney/physiopathology , Male , Middle Aged , Pyrazoles/adverse effects , Recovery of Function , Thiophenes/adverse effects , Time Factors , Treatment Outcome , United States , Urodynamics/drug effects
2.
World J Nephrol ; 7(5): 96-107, 2018 Sep 07.
Article in English | MEDLINE | ID: mdl-30211028

ABSTRACT

AIM: To evaluate the novel platelet-derived growth factor receptor and vascular endothelial growth factor receptor dual kinase inhibitor ANG3070 in a polycystic kidney disease-congenital hepatic fibrosis model. METHODS: At 6 wk of age, PCK rats were randomized to vehicle or ANG3070 for 4 wk. At 10 wk, 24 h urine and left kidneys were collected and rats were continued on treatment for 4 wk. At 14 wk, 24 h urine was collected, rats were sacrificed, and liver and right kidneys were collected for histological evaluation. For Western blot studies, PCK rats were treated with vehicle or ANG3070 for 7 d and sacrificed approximately 30 min after the last treatments. RESULTS: Compared to the wild-type cohort, the PCK kidney (Vehicle cohort) exhibited a marked increase in kidney and liver mass, hepato-renal cystic volume, hepato-renal fibrosis and hepato-renal injury biomarkers. Intervention with ANG3070 in PCK rats decreased kidney weight, reduced renal cystic volume and reduced total kidney hydroxyproline, indicating significantly reduced rental interstitial fibrosis compared to the PCK-Vehicle cohort. ANG3070 treatment also mitigated several markers of kidney injury, including urinary neutrophil gelatinase-associated lipocalin, kidney injury molecule-1, cystatin C and interleukin-18 levels. In addition, this treatment attenuated key indices of renal dysfunction, including proteinuria, albuminuria and serum blood urea nitrogen and creatinine, and significantly improved renal function compared to the PCK-Vehicle cohort. ANG3070 treatment also significantly decreased liver enlargement, hepatic lesions, and liver fibrosis, and mitigated liver dysfunction compared to the PCK-Vehicle cohort. CONCLUSION: These results suggest that ANG3070 has the potential to slow disease, and may serve as a bridge toward hepato-renal transplantation in patients with fibropolycystic disease.

3.
Molecules ; 23(9)2018 Sep 18.
Article in English | MEDLINE | ID: mdl-30231499

ABSTRACT

The practice of medicine is ever evolving. Diagnosing disease, which is often the first step in a cure, has seen a sea change from the discerning hands of the neighborhood physician to the use of sophisticated machines to use of information gleaned from biomarkers obtained by the most minimally invasive of means. The last 100 or so years have borne witness to the enormous success story of allopathy, a practice that found favor over earlier practices of medical purgatory and homeopathy. Nevertheless, failures of this approach coupled with the omics and bioinformatics revolution spurred precision medicine, a platform wherein the molecular profile of an individual patient drives the selection of therapy. Indeed, precision medicine-based therapies that first found their place in oncology are rapidly finding uses in autoimmune, renal and other diseases. More recently a new renaissance that is shaping everyday life is making its way into healthcare. Drug discovery and medicine that started with Ayurveda in India are now benefiting from an altogether different artificial intelligence (AI)-one which is automating the invention of new chemical entities and the mining of large databases in health-privacy-protected vaults. Indeed, disciplines as diverse as language, neurophysiology, chemistry, toxicology, biostatistics, medicine and computing have come together to harness algorithms based on transfer learning and recurrent neural networks to design novel drug candidates, a priori inform on their safety, metabolism and clearance, and engineer their delivery but only on demand, all the while cataloging and comparing omics signatures across traditionally classified diseases to enable basket treatment strategies. This review highlights inroads made and being made in directed-drug design and molecular therapy.


Subject(s)
Deep Learning , Drug Discovery , Precision Medicine , Artificial Intelligence , Drug Design , Drug Repositioning , Neural Networks, Computer , Point-of-Care Systems
4.
PLoS One ; 13(6): e0198937, 2018.
Article in English | MEDLINE | ID: mdl-29944670

ABSTRACT

Although cirrhosis is a key risk factor for the development of hepatocellular carcinoma (HCC), mounting evidence indicates that in a subset of patients presenting with non-alcoholic steatohepatitis (NASH) HCC manifests in the absence of cirrhosis. Given the sheer size of the ongoing non-alcoholic fatty liver disease (NAFLD) epidemic and the dismal prognosis associated with late-stage primary liver cancer there is an urgent need for HCC surveillance in the NASH population. Using serum levels of HCC biomarkers as vectors and biopsy-proven HCC or no HCC as outputs / binary classifier, a supervised learning campaign was undertaken to develop a minimally invasive technique for making a diagnosis of HCC in a clinically relevant model of NASH. Adult mice randomized to control diet or a fast food diet (FFD) were followed for up to 14 mo and serum level of a panel of HCC-relevant biomarkers was compared with liver biopsies at 3 and 14 mo. Both NAFLD Activity Score (NAS) and hepatic hydroxyproline content were elevated at 3 and 14 mo on FFD. Picrosirius red staining of liver sections revealed a filigree pattern of fibrillar collagen deposition with no cirrhosis at 14 mo on FFD. Nevertheless, 46% of animals bore one or more tumors on their livers confirmed as HCC in hematoxylin-eosin-stained liver sections. In this training set, receiver operating characteristic (ROC) curves analysis for serum levels of the HCC biomarkers osteopontin (OPN), alpha-fetoprotein (AFP) and Dickkopf-1 (DKK1) returned concordance-statistic/area under ROC curve of ≥ 0.89. Serum levels of OPN (threshold, 218 ng/mL; sensitivity, 82%; specificity, 86%), AFP (136 ng/mL; 91%; 97%) and DKK1 (2.4 ng/mL; 82%; 81%) diagnostic for HCC were confirmed in a test set comprising mice on control diet or FFD and mice subjected to hepatic ischemia-reperfusion injury. These data suggest that levels of circulating OPN, AFP and DKK1 can be used to make a diagnosis of HCC in a clinically relevant model of NASH.


Subject(s)
Carcinoma, Hepatocellular/blood , Liver Neoplasms/blood , Liver/pathology , Non-alcoholic Fatty Liver Disease/blood , Animals , Biomarkers, Tumor/blood , Carcinoma, Hepatocellular/diagnosis , Carcinoma, Hepatocellular/pathology , Disease Models, Animal , Humans , Liver Neoplasms/diagnosis , Liver Neoplasms/pathology , Male , Mice, Inbred C57BL , Non-alcoholic Fatty Liver Disease/diagnosis , Non-alcoholic Fatty Liver Disease/pathology , Supervised Machine Learning
5.
PLoS One ; 13(1): e0190815, 2018.
Article in English | MEDLINE | ID: mdl-29351309

ABSTRACT

The extent of scarring or renal interstitial collagen deposition in chronic kidney disease (CKD) can only be ascertained by highly invasive, painful and sometimes risky, tissue biopsy. Interestingly, while CKD-related abnormalities in kidney size can often be visualized using ultrasound, not only does the ellipsoid formula used today underestimate true renal size, but the calculated renal size does not inform tubulointerstitial collagen content. We used coronal kidney sections from healthy mice and mice with kidney disease to develop a new formula for estimating renal parenchymal area. While treating the kidney as an ellipse with the major axis (a) the polar distance, this technique involves extending the minor axis (b) into the renal pelvis to obtain a new minor axis, be. The calculated renal parenchymal area is remarkably similar to the true or measured area. Biochemically determined kidney collagen content revealed a strong and positive correlation with the calculated renal parenchymal area. Picrosirius red staining for tubulointerstitial collagen also correlated with calculated renal parenchymal area. The extent of renal scarring, i.e. kidney interstitial collagen content, can now be computed by making just two axial measurements which can easily be accomplished via noninvasive imaging of this organ.


Subject(s)
Collagen/metabolism , Kidney/metabolism , Renal Insufficiency, Chronic/metabolism , Animals , Azo Compounds , Coloring Agents , Disease Models, Animal , Fibrosis , Humans , Kidney/diagnostic imaging , Kidney/pathology , Male , Mice , Models, Biological , Organ Size , Renal Insufficiency, Chronic/diagnostic imaging , Renal Insufficiency, Chronic/pathology
6.
World J Gastroenterol ; 23(23): 4181-4190, 2017 Jun 21.
Article in English | MEDLINE | ID: mdl-28694658

ABSTRACT

AIM: To evaluate a calcium activated potassium channel (KCa3.1) inhibitor attenuates liver disease in models of non-alcoholic fatty liver disease (NAFLD). METHODS: We have performed a series of in vitro and in vivo studies using the KCa3.1 channel inhibitor, Senicapoc. Efficacy studies of Senicapoc were conducted in toxin-, thioacetamide (TAA) and high fat diet (HFD)-induced models of liver fibrosis in rats. Efficacy and pharmacodynamic effects of Senicapoc was determined through biomarkers of apoptosis, inflammation, steatosis and fibrosis. RESULTS: Upregulation of KCa3.1 expression was recorded in TAA-induced and high fat diet-induced liver disease. Treatment with Senicapoc decreased palmitic acid-driven HepG2 cell death. (P < 0.05 vs control) supporting the finding that Senicapoc reduces lipid-driven apoptosis in HepG2 cell cultures. In animals fed a HFD for 6 wk, co-treatment with Senicapoc, (1) reduced non-alcoholic fatty liver disease (NAFLD) activity score (NAS) (0-8 scale), (2) decreased steatosis and (3) decreased hepatic lipid content (Oil Red O, P < 0.05 vs vehicle). Randomization of TAA animals and HFD fed animals to Senicapoc was associated with a decrease in liver fibrosis as evidenced by hydroxyproline and Masson's trichrome staining (P < 0.05 vs vehicle). These results demonstrated that Senicapoc mitigates both steatosis and fibrosis in liver fibrosis models. CONCLUSION: These data suggest that Senicapoc interrupts more than one node in progressive fatty liver disease by its anti-steatotic and anti-fibrotic activities, serving as a double-edged therapeutic sword.


Subject(s)
Acetamides/pharmacology , Gene Expression Regulation, Neoplastic , Intermediate-Conductance Calcium-Activated Potassium Channels/antagonists & inhibitors , Non-alcoholic Fatty Liver Disease/drug therapy , Trityl Compounds/pharmacology , Animals , Apoptosis , Biomarkers, Tumor/metabolism , Diet, High-Fat , Fibrosis , Hep G2 Cells , Humans , Inflammation , Intermediate-Conductance Calcium-Activated Potassium Channels/metabolism , Liver Cirrhosis/metabolism , Male , Mice , Mice, Inbred C57BL , Palmitic Acid , Rats , Rats, Wistar , Thioacetamide , Up-Regulation
7.
PLoS One ; 11(10): e0163063, 2016.
Article in English | MEDLINE | ID: mdl-27695033

ABSTRACT

Autosomal recessive polycystic kidney disease (ARPKD) is associated with progressive enlargement of the kidneys fuelled by the formation and expansion of fluid-filled cysts. The disease is congenital and children that do not succumb to it during the neonatal period will, by age 10 years, more often than not, require nephrectomy+renal replacement therapy for management of both pain and renal insufficiency. Since increasing cystic index (CI; percent of kidney occupied by cysts) drives both renal expansion and organ dysfunction, management of these patients, including decisions such as elective nephrectomy and prioritization on the transplant waitlist, could clearly benefit from serial determination of CI. So also, clinical trials in ARPKD evaluating the efficacy of novel drug candidates could benefit from serial determination of CI. Although ultrasound is currently the imaging modality of choice for diagnosis of ARPKD, its utilization for assessing disease progression is highly limited. Magnetic resonance imaging or computed tomography, although more reliable for determination of CI, are expensive, time-consuming and somewhat impractical in the pediatric population. Using a well-established mammalian model of ARPKD, we undertook a big data-like analysis of minimally- or non-invasive blood and urine biomarkers of renal injury/dysfunction to derive a family of equations for estimating CI. We then applied a signal averaging protocol to distill these equations to a single empirical formula for calculation of CI. Such a formula will eventually find use in identifying and monitoring patients at high risk for progressing to end-stage renal disease and aid in the conduct of clinical trials.


Subject(s)
Biomarkers , Polycystic Kidney, Autosomal Recessive/blood , Polycystic Kidney, Autosomal Recessive/urine , Renal Insufficiency/blood , Renal Insufficiency/urine , Animals , Biomarkers/blood , Biomarkers/urine , Blood Urea Nitrogen , Child , Creatinine/blood , Cystatin C/blood , Cysts/pathology , Hepatitis A Virus Cellular Receptor 1/blood , Humans , Interleukin-18/blood , Kidney/diagnostic imaging , Kidney/metabolism , Kidney/physiopathology , Kidney Transplantation , Lipocalin-2/blood , Magnetic Resonance Imaging , Mice , Polycystic Kidney, Autosomal Recessive/diagnostic imaging , Polycystic Kidney, Autosomal Recessive/pathology , Rats , Renal Insufficiency/pathology , Severity of Illness Index , Ultrasonography
8.
Am J Physiol Renal Physiol ; 311(2): F352-61, 2016 08 01.
Article in English | MEDLINE | ID: mdl-27252491

ABSTRACT

Ischemia-reperfusion-mediated acute kidney injury can necessitate renal replacement therapy and is a major cause of morbidity and mortality. We have identified BB3, a small molecule, which when first administered at 24 h after renal ischemia in rats, improved survival, augmented urine output, and reduced the increase in serum creatinine and blood urea nitrogen. Compared with control kidneys, the kidneys of BB3-treated animals exhibited reduced levels of kidney injury molecule-1, neutrophil gelatinase-associated lipocalin, and reduced tubular apoptosis and acute tubular necrosis but enhanced tubular regeneration. Consistent with its hepatocyte growth factor-like mode of action, BB3 treatment promoted phosphorylation of renal cMet and Akt and upregulated renal expression of the survival protein Bcl-2. These data suggest that the kidney is amenable to pharmacotherapy even 24 h after ischemia-reperfusion and that activation of the hepatocyte growth factor signaling pathway with the small molecule BB3 confers interventional benefits late into ischemia-reperfusion injury. These data formed, in part, the basis for the use of BB3 in a clinical trial in kidney recipients presenting with delayed graft function.


Subject(s)
Acute Kidney Injury/prevention & control , Reperfusion Injury/prevention & control , Acute Kidney Injury/pathology , Animals , Apoptosis , Hepatocyte Growth Factor/metabolism , Kidney Tubules/pathology , Male , Rats , Rats, Sprague-Dawley , Regeneration/drug effects , Reperfusion Injury/pathology
9.
Mol Med ; 19: 195-202, 2013 Jul 24.
Article in English | MEDLINE | ID: mdl-23648638

ABSTRACT

Erythropoietin (EPO), a type I cytokine originally identified for its critical role in hematopoiesis, has been shown to have nonhematopoietic, tissue-protective effects, including suppression of atherosclerosis. However, prothrombotic effects of EPO hinder its potential clinical use in nonanemic patients. In the present study, we investigated the antiatherosclerotic effects of helix B surface peptide (HBSP), a nonerythropoietic, tissue-protective compound derived from EPO, by using human umbilical vein endothelial cells (HUVECs) and human monocytic THP-1 cells in vitro and Watanabe heritable hyperlipidemic spontaneous myocardial infarction (WHHLMI) rabbits in vivo. In HUVECs, HBSP inhibited apoptosis (≈70%) induced by C-reactive protein (CRP), a direct mediator of atherosclerosis. By using a small interfering RNA approach, Akt was shown to be a key molecule in HBSP-mediated prevention of apoptosis. HBSP also attenuated CRP-induced production of tumor necrosis factor (TNF)-α and matrix metalloproteinase-9 in THP-1 cells. In the WHHLMI rabbit, HBSP significantly suppressed progression of coronary atherosclerotic lesions as assessed by mean cross-sectional stenosis (HBSP 21.3 ± 2.2% versus control peptide 38.0 ± 2.7%) and inhibited coronary artery endothelial cell apoptosis with increased activation of Akt. Furthermore, TNF-α expression and the number of M1 macrophages and M1/M2 macrophage ratio in coronary atherosclerotic lesions were markedly reduced in HBSP-treated animals. In conclusion, these data demonstrate that HBSP suppresses coronary atherosclerosis, in part by inhibiting endothelial cell apoptosis through activation of Akt and in association with decreased TNF-α production and modified macrophage polarization in coronary atherosclerotic lesions. Because HBSP does not have the prothrombotic effects of EPO, our study may provide a novel therapeutic strategy that prevents progression of coronary artery disease.


Subject(s)
Cardiovascular Agents/therapeutic use , Coronary Artery Disease/drug therapy , Erythropoietin/therapeutic use , Peptide Fragments/therapeutic use , Animals , Apoptosis , Cardiovascular Agents/pharmacology , Cell Line , Coronary Artery Disease/metabolism , Coronary Artery Disease/pathology , Disease Models, Animal , Erythropoietin/pharmacology , Female , Human Umbilical Vein Endothelial Cells/drug effects , Human Umbilical Vein Endothelial Cells/metabolism , Humans , Male , Matrix Metalloproteinase 9/metabolism , Peptide Fragments/pharmacology , Proto-Oncogene Proteins c-akt/metabolism , Rabbits , Tumor Necrosis Factor-alpha/metabolism
10.
Exp Neurol ; 232(2): 126-35, 2011 Dec.
Article in English | MEDLINE | ID: mdl-21872588

ABSTRACT

The Akita mouse is a robust model of diabetic autonomic neuropathy which develops severe diabetes following beta cell death, which occurs reproducibly at 3-4 weeks of age, and maintains the diabetic state without therapy for as long as 11 additional months. Neuritic dystrophy and neuronopathy involving prevertebral sympathetic superior mesenteric and celiac ganglia begin to develop within the first two months of onset of diabetes and are progressive with time. We have examined the effect of insulin implants resulting in normoglycemia and injections of ARA290, a small erythropoietin peptide which has no effect on glycemic parameters, on the reversal of established neuritic dystrophy and neuronopathy. We have found that 4 weeks of insulin therapy beginning at 2 months of diabetes resulted in normalization of blood glucose, body weight and HbA1c. Insulin therapy successfully reversed established neuritic dystrophy and neuronopathy to control levels. Numbers of sympathetic neurons were not significantly changed in either 3 month diabetic or insulin-treated Akita mice. Treatment with ARA290 for 7 weeks beginning at 4 months of diabetes did not result in altered metabolic severity of diabetes as measured by blood glucose, body weight or HbA1c levels. ARA290 treatment was able to decrease neuritic dystrophy by 55-74% compared to untreated diabetics or in comparison to a separate group of diabetic animals representing the 4 month treatment onset point. Surprisingly, there was no effect of ARA290 on ganglionic neuron number or ongoing neuronopathy (pale/degenerating neurons) in diabetic Akita mice during this time period. The development of neuroprotective EPO-like peptides may provide a possible future therapy for this debilitating complication of diabetes; however, it appears that discrete elements may be differentially targeted by the diabetic state and may require selective therapy.


Subject(s)
Diabetes Mellitus, Type 1/drug therapy , Diabetic Neuropathies/drug therapy , Erythropoietin/analogs & derivatives , Ganglia, Sympathetic/drug effects , Insulin/pharmacology , Peptides/pharmacology , Animals , Blood Glucose/drug effects , Body Weight/drug effects , Diabetes Mellitus, Type 1/genetics , Diabetes Mellitus, Type 1/pathology , Diabetic Neuropathies/genetics , Diabetic Neuropathies/pathology , Disease Models, Animal , Erythropoietin/pharmacology , Ganglia, Sympathetic/pathology , Hypoglycemic Agents/pharmacology , Insulin/genetics , Male , Mice , Mice, Inbred C57BL , Mice, Mutant Strains , Microscopy, Electron , Nerve Degeneration/drug therapy , Nerve Degeneration/genetics , Nerve Degeneration/pathology , Neurites/pathology , Neurites/ultrastructure
11.
Proc Natl Acad Sci U S A ; 107(32): 14357-62, 2010 Aug 10.
Article in English | MEDLINE | ID: mdl-20660739

ABSTRACT

Erythropoietin (EPO), originally identified for its critical hormonal role in regulating production and survival of erythrocytes, is a member of the type 1 cytokine superfamily. Recent studies have shown that EPO has cytoprotective effects in a wide variety of tissues, including the heart, by preventing apoptosis. However, EPO also has undesirable effects, such as thrombogenesis. In the present study, we investigated whether a helix B-surface peptide (HBSP), a nonerythropoietic, tissue-protective peptide mimicking the 3D structure of erythropoietin, protects cardiomyocytes from apoptosis in vitro and in vivo. In cultured neonatal rat cardiomyocytes, HBSP clearly inhibited apoptosis (approximately 80%) induced by TNF-alpha, which was comparable with the effect of EPO, and activated critical signaling pathways of cell survival, including Akt, ERK1/2, and STAT3. Among these pathways, Akt was shown to play an essential role in HBSP-induced prevention of apoptosis, as assessed by using a small interfering RNA approach. In the dilated cardiomyopathic hamster (J2N-k), whose cardiac tissues diffusely expressed TNF-alpha, HBSP also inhibited apoptosis (approximately 70%) and activated Akt in cardiomyocytes. Furthermore, the levels of serum creatine kinase activity and of cardiac expression of atrial natriuretic peptide, a marker of chronic heart failure, were down-regulated in animals treated with HBSP. These data demonstrate that HBSP protects cardiomyocytes from apoptosis and leads to a favorable outcome in failing hearts through an Akt-dependent pathway. Because HBSP does not have the undesirable effects of EPO, it could be a promising alternative for EPO to treat cardiovascular diseases, such as myocardial infarction and heart failure.


Subject(s)
Cardiotonic Agents/chemistry , Erythropoietin/chemistry , Peptides/therapeutic use , Animals , Apoptosis/drug effects , Cardiotonic Agents/pharmacology , Erythropoietin/therapeutic use , Molecular Mimicry , Myocytes, Cardiac/cytology , Myocytes, Cardiac/drug effects , Peptides/chemistry , Peptides/pharmacology , Protein Conformation , Proto-Oncogene Proteins c-akt/metabolism , Rats
12.
Proc Natl Acad Sci U S A ; 105(31): 10925-30, 2008 Aug 05.
Article in English | MEDLINE | ID: mdl-18676614

ABSTRACT

Erythropoietin (EPO), a member of the type 1 cytokine superfamily, plays a critical hormonal role regulating erythrocyte production as well as a paracrine/autocrine role in which locally produced EPO protects a wide variety of tissues from diverse injuries. Significantly, these functions are mediated by distinct receptors: hematopoiesis via the EPO receptor homodimer and tissue protection via a heterocomplex composed of the EPO receptor and CD131, the beta common receptor. In the present work, we have delimited tissue-protective domains within EPO to short peptide sequences. We demonstrate that helix B (amino acid residues 58-82) of EPO, which faces the aqueous medium when EPO is bound to the receptor homodimer, is both neuroprotective in vitro and tissue protective in vivo in a variety of models, including ischemic stroke, diabetes-induced retinal edema, and peripheral nerve trauma. Remarkably, an 11-aa peptide composed of adjacent amino acids forming the aqueous face of helix B is also tissue protective, as confirmed by its therapeutic benefit in models of ischemic stroke and renal ischemia-reperfusion. Further, this peptide simulating the aqueous surface of helix B also exhibits EPO's trophic effects by accelerating wound healing and augmenting cognitive function in rodents. As anticipated, neither helix B nor the 11-aa peptide is erythropoietic in vitro or in vivo. Thus, the tissue-protective activities of EPO are mimicked by small, nonerythropoietic peptides that simulate a portion of EPO's three-dimensional structure.


Subject(s)
Erythropoietin/therapeutic use , Papilledema/drug therapy , Pattern Recognition, Visual/physiology , Peptides/metabolism , Reperfusion Injury/drug therapy , Wound Healing/genetics , Animals , Cytokine Receptor Common beta Subunit/metabolism , Erythropoietin/genetics , Kidney/injuries , Male , Mice , Mice, Inbred C57BL , Peptides/genetics , Rats , Rats, Sprague-Dawley
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