Cardiovascular diseases include any disease that affects the heart or circulatory vessels. It usually refers to hypertension, angina, atherosclerosis, coronary artery disease, myocardial infarction (heart attack), heart failure, cerebrovascular diseases and accident (stroke), arrhythmia, heart valve diseases, and peripheral vascular diseases such as obstructions of large arteries in the arms and legs. See details here.
Coronary arterial disease is the main cause of angina, a severe chest pain
due to obstruction or spasm of the coronary arteries that causes a lack of blood
and hence oxygen supply to the heart muscle. Atherosclerosis (arterial
hardening) is a syndrome affecting arteries including coronary arteries, in
which an artery wall thickens and forms multiple plaques. Plaque can suddenly
rupture, causing the formation of thrombosis that will rapidly slow or stop
blood flow, leading to death of the tissues fed by the artery in a few minutes.
All of these may lead to eventual myocardial infarction (heart attack). The same
process in an artery to the brain can cause stroke. Persistent hypertension is
one of the risk factors for atherosclerosis, stroke, heart attack, and heart
failure. Hypertension is considered to be present when a person's blood pressure
is consistently at least 140 mmHg systolic or 90 mmHg diastolic.
Cardiovascular risk factors include smoking, high LDL, cholesterol,
hypertension, obesity, and dysfunctional glucose metabolism. Total fat intake,
especially saturated fat and unsaturated fat (trans fat), plays a larger role in
blood cholesterol than intake of cholesterol itself. Cholesterol is an important
component of mammalian cell membranes, steroid hormones, and several fat-soluble
vitamins. It is oxidized by the liver into a variety of bile acids. Cholesterol
is only slightly soluble in water. Therefore blood contains several types of
lipoproteins that carry cholesterol such as low-density lipoprotein (LDL) and
high-density lipoprotein (HDL). The more cholesterol and less protein a
lipoprotein has, the less dense it is. LDL molecules are the major carriers of
cholesterol in the blood. When a cell has abundant cholesterol, LDL receptor
synthesis is blocked so that new cholesterol in the form of LDL molecules cannot
be taken up. Conversely, more LDL receptors are made when the cell is deficient
in cholesterol. When this system is deregulated, many LDL molecules appear in
the blood without receptors on the peripheral tissues. These LDL molecules are
oxidized and taken up by macrophages, which become engorged and form foam cells.
These cells are often trapped in the walls of blood vessels and contribute to
artherosclerotic plaque formation. HDL particles are thought to transport
cholesterol back to the liver for excretion or to other tissues that use
cholesterol to synthesize hormones. Therefore low HDL is associated with
artherosclerosis. QIAGEN provides a broad range of PCR arrays covering
Atherosclerosis, Hypertension, Diabetes, Obesity, Lipoprotein Signaling & Cholesterol
Metabolism, Endothelial Cell Biology, Fatty Acid Metabolism, Glucose Metabolism,
and Hypoxia Signaling Pathway.
Several key dietary modifications that can lower the risk of heart disease
include: lowering LDL cholesterol by reducing saturated fat intake; lowering
triglyceride levels by reducing consumption of sugary and processed foods;
reducing homocysteine levels by supplementation with vitamins B6 and B12, and
folic acid; increasing antioxidant activity by increasing consumption of fruits
and vegetables; lowering fibrinogen and growth factors by reducing consumption
of red meat, dairy products, and eggs. The prevention of cardiovascular diseases
is primarily focused on diet and stress reduction. Please use QIAGEN's
Oxidative Stress and Antioxidant Defense PCR array to profile stress gene
expressions.
Circulating biomarkers for cardiovascular diseases are troponin I and troponin T
for myocardial infarction (heart attack) and brain natriuretic peptide (BNP) for
heart failure. Biomarkers associated with inflammation (C-reactive protein,
interleukin-6 and lipoprotein-associated phospholipase A2), hemostasis /
thrombosis (fibrinogen and plasminogen-activator inhibitor 1), neurohormone
activation (renin and BNP), insulin resistance (insulin and hemoglobin A1C), and
endothelial dysfunction (homocysteine and urinary albumin) are also being
evaluated.
The application of transcriptional approaches, such as microarrays or PCR
arrays for the identification of new cardiac biomarkers in humans, is limited by
the availability of the most relevant tissue - the heart and the blood vessels.
To bypass this difficulty, ST2, a member of the interleukin-1-receptor family,
which can be detected in human serum, can predict outcomes in patients with
heart failure. An increase in soluble ST2 concentration is associated with poor
prognosis of myocardial overload such as congestive heart failure.
Transcriptional profiling of platelets, which lack nuclear DNA but contain
megakaryocyte-derived mRNAs, can also provide insight of gene expression under
abnormal cardiovascular conditions without the need of heart mRNAs. Using this
approach, one of the strongest discriminators between patients with acute
myocardial infarction and patients with stable coronary heart disease has been
identified. Myeloid-related protein 14 (MRP14) serves as a biomarker that can
predict the risk of future cardiovascular events in healthy individuals.
Using genome-wide association studies, a locus on chromosome 9p21 has been
identified as being associated with early-onset myocardial infarction. This
locus does not contain genes related to the classic risk factors such as plasma
lipoproteins, hypertension, or diabetes. However, it encodes the cyclin-dependent
kinase (CDK) inhibitors INK4A and INK4B - which are known to affect cellular
senescence, apoptosis, and stem-cell function. Using the same method, variants
of the chemokine CXCL12 gene are also associated with premature atherosclerosis.
QIAGEN not only provides Cell Cycle PCR arrays and Chemokines and
Receptors PCR arrays, but also offers gene expression, CGH, and genotyping
service with Illumina beadchips. Simply send samples to us!
MicroRNAs used as potential therapeutic targets or diagnostic biomarkers are
being investigated. The full potential of microRNAs in clinical practice is not
completely known, nonetheless, recent advances in microRNA delivery and
inhibition hold great promise in treating atherosclerosis and regulating
cholesterol. QIAGEN's whole genome RT² microRNA PCR arrays are currently
available for the human, mouse, and rat samples, and individual microRNAs can be
analyzed independently with RT² miRNA PCR Assays.