Table 1.
Candidate genes and their functions in hypertensive LHV pathogenesis
Gene | Gene map locus | Gene function |
---|---|---|
RENAL-ANGIOTENSIN SYSTEM/G-COUPLED PROTEIN RECEPTORS: | ||
ATP6AP2 |
Xp11.4 |
Muscular smooth muscle contraction. Renin and prorenin cellular receptor. May mediate renin-dependent cellular responses by activating ERK1 and ERK2. By increasing the catalytic efficiency of renin in AGT/angiotensinogen conversion to angiotensin I, it may also play a role in the renin-angiotensin system (RAS). |
Estrogen receptor signaling: |
|
|
EGFR |
7p11.2 |
Receptor binding to epidermal growth factor. Required by AngII to mediate ERK activation thus plays a critical role in the LVH induced by Ang II. |
EGF |
4q25 |
Shedding of heparin-binding EGF by ADAM12, induce hypertrophic signaling via EGFR activation downstream through small G proteins and the MAPK pathway. |
ADAM12 |
10q26.2 |
Involved in skeletal muscle regeneration, specifically at the onset of cell fusion and macrophage-derived giant cells (MGC) and osteoclast formation from mononuclear precursors. Plays a centre role in cardiac hypertrophy by interacting with HB-EGF. |
ERBB2 |
17q21.1 |
A member of the epidermal growth factor (EGF) receptor family of receptor tyrosine kinases. Essential in cardiac development. Involved in the EGFR signaling that drives many cellular responses, including changes in gene expression, cytoskeletal rearrangement, anti-apoptosis and increased cell proliferation. |
ITGB2 (Beta-integrin) |
21q22.3 |
Involved in cell adhesion as well as cell-surface mediated signalling. Links the extracellular matrix to the intracelluar cytoskeleton. Stretch sensor. Deletion of this gene/protein leads to cardiac pathology. Gene expression profile is upregulated in ERbeta knockout mice with cardiac hypertrophy. |
ITGB1BP2 (Melusin) |
Xq13.1 |
Integrin interacting protein. Sensor of mechanical stress in cardiac myocytes. An essential component for the phosphorylation (inactivation) of GSK3-beta. Deletion of this gene leads to cardiac pathology. |
CALCINEURIN-CALMODULIN Ca2+ Signaling: | ||
PPP3CA (calcineurin A-alpha) |
4q24 |
Calcium dependent, calmodulin stimulated protein phosphatase.Ca2+/calmodulin binding. |
CALM1 (calmodulin 1) |
14q32.11 |
Mediates the control of large number of enzymes and other proteins by Ca2+. Involved in a genetic pathway that regulates the centrosome cycle and progression via cytokinesis. |
CALM3 (calmodulin 3) |
19q13.2 |
Together with CALM1 and CALM2, these calmodulin genes give rise to five transcripts that are present in most tissues. This gene may be specifically and differently regulated during cardiac cell proliferation and/or hypertrophy. |
CAMK2B (calmodulin kinase) |
7p14.3 |
Calmodulin/Ca2+ signaling. At basal Ca2+ levels, CaMKs are maintained in a dormant state through autoinhibition. Increase in Ca2+ levels allows calmodulin to relieve this autoinhibition and activate the kinase activity. |
Ion channel pathway: |
|
Sodium-Calcium exchange pathway |
SLC8A1 (NCX1) |
2p22.1 |
|
SLC9A2 (NHE) |
2q12.1 |
Sodium-Hydrogen exchange pathway |
KCNB2 |
8q13.3 |
Regulate the smooth muscle contraction by controlling the influx of Ca2+ through voltage-gated Ca2+ channels |
NFAT SIGNALING & OTHERS TRANSCRIPTION FACTORS: | ||
NFATC3 |
16q22.1 |
Required in muscle cell, and heart development, as well as smooth muscle differentiation. Rapid nuclear exit of NFATC is thought to be onemechanism by which cells distinguish between sustained and transient calcium signals. |
ILF3 |
19p13.2 |
Involved in the NFAT transcription signaling. A subunit of the nuclear factor of activated T-cells (NFAT). |
ITPR3@ IPR3 |
6p21.31 |
Inositol 1,4,5-triphosphate receptor type 3. Involved in mediating the release of intracellular calcium. |
GATA4 |
8p23.1 |
Transcription factors that regulate genes critical for myocardial differentiation and function, regulates hypertrophic gene expression. |
MCIP-1 (RCAN1) |
21q22.12 |
Modulatory calcineurin interacting protein. Serves as calcineurin–regulatory protein that inhibit calcineurin when over expressed. |
MEF2A |
15q26.3 |
Transcription factor of cardiac hypertrophy cascade. Involved in the activation of numerous growth factor- and stress-induced genes. Mediates cellular functions in skeletal and cardiac muscle development. |
MAPK3 |
16p11.2 |
Act as a signaling cascade that regulates various cellular processes including proliferation, differentiation and cell cycle progression in response to a variety of extracellular signals. |
JAK2 |
9p24.1 |
Involved in a specific subset of cytokine receptor signaling pathways. Uponreceptor activation JAKs phosphorylate the transcription factors known as STATs and initiate the JAK-STATsignaling pathway. |
CTNNB1 (Beta-catenin) | 3p22.1 | Cadherin-associated protein. Part of a complex of proteins that constitute adherens junctions. Involved in the regulation of cell adhesion. Predominantly localized to the cell membrane, and is part of E-cadherin/catenin adhesion complexes which are believed to couple cadherins to the actin cytoskeleton. Structural changes of the extracellular matrix in LVH are significantly modulated by B-catenin associated signaling pathways. |