Presentation for the Strategic Dialogue on the Future of Agriculture, Brussel...
Role of HIF-1α in Cardio-Renal Syndrome Pathophysiology
1. Hypoxia Inducible Factor-1 alpha (HIF-1a) is a
protein involved in cellular adaptation to hypoxia and
induces transcription of Erythropoietin (EPO) and
Vascular Endothelial Growth Factor (VEGF).
Studies suggest that hypoxic signaling plays a
critical role in tissue adaptation and remodeling
secondary to injury at early and late stages of heart
and kidney disease.
The evidence regarding involvement of HIF-1a in
both cardiac and renal diseases, raise the possibility
of HIF-1a signaling being involved in the
pathophysiology of Cardio-Renal Syndrome (CRS), a
condition of coexisting cardiac and renal failure.
Investigating HIF-1a expression and HIF-1a induced
signaling in CRS, may help identify patient/disease
specific parameters. We are interested in the role of
hypoxic signaling via HIF-1a in the pathophysiology
of CRS.
Introduction
1. Resar JR, Roguin A, Voner J, Nasir K, Hennebry TA, Miller JM, et
al. Hypoxia-inducible factor 1alpha polymorphism and coronary
collaterals in patients with ischemic heart disease. Chest 2005
Aug;128(2):787-91. PMID: 16100168.
2. Semenza GL. Hydroxylation of HIF-1: oxygen sensing at the
molecular level. Physiology (Bethesda) 2004 Aug;19:176-82. PMID:
15304631.
3. Tanaka T, Nangaku M. Drug discovery for overcoming chronic
kidney disease (CKD): prolyl-hydroxylase inhibitors to activate
hypoxia-inducible factor (HIF) as a novel therapeutic approach in
CKD.J Pharmacol Sci. 2009 Jan;109(1):24-31. Review. PMID:
19151537.
4. Inamoto S, Hayashi T, Tazawa N, Mori T, Yamashita C, Nakano D,
Matsumura Y, Okuda N, Sohmiya K, Sakai A, Furuya E, Kitaura Y.
Angiotensin-II receptor blocker exerts cardioprotection in diabetic rats
exposed to hypoxia. Circ J. 2006 Jun;70(6):787-92. PMID: 16723804
Comparison of plasma EPO and VEGF levels between chronic kidney disease and cardio-renal syndrome patients
Negar Seisan Pharm. D. candidate, Cameron Asgharpour Pharm. D. candidate and Shahrzad Movafagh, Pharm. D., PhD
Bernard J. Dunn School of Pharmacy, Shenandoah University, Ashburn, VA
Objective
Primary Outcomes
References
Methods
The objective of this study is to assess differential
transcriptional activity of HIF-1a by quantifying EPO and
VEGF through Enzyme Linked Immunosorbent Assay
(ELISA) in CRS vs. Chronic Kidney Disease (CKD)
patients.
We propose that hypoxic signaling via HIF-1a is
altered in CRS compared to patients with CKD alone
and that will effect their EPO and VEGF protein levels in
plasma.
1) Comparison of plasma VEGF and EPO levels
between CKD and CRS populations.
2) Correlation of VEGF and EPO plasma protein levels
with previously quantified HIF-1a subunit mRNA values
in urine.
3) Correlation of eGFR and ejection fraction with
plasma levels of VEGF and EPO in CKD and CRS
patients.
This study has been reviewed by the Shenandoah University Institutional Review Board for approval.
Study groups for CKD and CRS ( n =100 in both groups) are patients with chronic kidney disease of stage 2-4 and patients with chronic
cardio-renal syndrome being treated at a kidney and hypertension specialist clinic in Manassas, VA.
Patient Blood samples will be collected at routine visits and centrifuged to separate plasma to be stored at -80 degrees Celsius.
We will quantify and compare EPO and VEGF protein levels through ELISA in blood plasma samples of both groups.
Statistical Analysis
Stage CrCl (ml/min/1.73
m2)
Stage 1 eGFR > 90
Stage 2 eGFR 60-89
Stage 3 eGFR 30-59
Stage 4 eGFR <15 or dialysis
Inclusion
Patients between the ages of 18 and 90
years with existing renal failure (CKD
stages 2-4) with or without co-existing
cardiac dysfunction.
CRS Inclusion: a confirmed diagnosis
of left or right heart failure or
cardiomyopathy with or without ejection
fraction of <60.
Exclusion
Patients under the following criteria will not
be eligible for the study: renal
transplantation, hemodialysis,
immunocompromised, HIV, hepatitis,
amyloidosis, sarcoidosis, renal replacement
therapy, autoimmune diseases (except
diabetes type I and II), active infection, valvular
heart diseases, diagnosed pulmonary
hypertension, active illicit drug use, age < 18
yrs, diabetic ketoacidosis, requiring BiPAP,
poisoning, sickle cell anemia, active cancer,
Fabry disease, erythropoietin injection in past
7 days.
Protein levels between groups will be compared using a
t-test with p values of 0.05 indicating significance.
Correlation of previously measured HIF-1a urinary
expression of EPO and VEGF protein levels that were
quantified by the means of Reverse Transcription
Polymerase Chain Reaction (RT-PCR) will be performed
using Pearson correlation analysis.
Table 1. CKD staging as defined
by the National Kidney Foundation with
eGFR determined by the Modification
of Diet in Renal Disease (MDRD)
equation.
MDRD =175 x (Cr-1.154 x age-0.203)
[x 1.212 if African-American] [x 0.742 if
Female]
Table 2. Subject
Demographics
CKD
n=37
CRS
n=20
Race (%)
Caucasian 59 55
African-American 32 30
Other: 9 15
Gender (%)
Female 54 55
Male 46 45
Average age(in
years)
65±12 71±14
eGFR (MDRD) 39±15 39±20
Co-existing
Conditions (%)
Diabetes 57 50
Systemic
Hypertension
100 85
Pulmonary
Condition
3 30
Left Heart Failure 85
Right Heart failure 10
Cardiomyopathy 5
Anemia 41 35
Hypothesis
Disclosure
The authors of this poster have no financial or personal disclosures
to make.
Negar Seisan: Nothing to disclose
Cameron Asgharpour: Nothing to disclose
Dr Shahrzad Movafagh: Nothing to disclose
Acknowledgements:
Debbie Lynn
Figure 1. Plasma sample ELISA with
row A serving as a control for EPO or
VEGF.