Target type: biologicalprocess
Any process that stops, prevents or reduces the frequency, rate or extent of vascular smooth muscle cell differentiation. [GO_REF:0000058, GOC:BHF, GOC:BHF_miRNA, GOC:rph, GOC:TermGenie, PMID:19088079]
Negative regulation of vascular associated smooth muscle cell differentiation is a complex biological process that involves a coordinated interplay of multiple signaling pathways and transcription factors. It ensures that smooth muscle cells (SMCs), the primary cell type responsible for the contractility of blood vessels, maintain their differentiated state and avoid inappropriate proliferation or dedifferentiation. This process is crucial for maintaining vascular homeostasis and preventing disease development, such as atherosclerosis.
**Key Players in the Regulation of SMC Differentiation:**
* **Growth Factors:** Transforming growth factor-β (TGF-β) and platelet-derived growth factor (PDGF) are critical regulators of SMC differentiation. TGF-β promotes SMC differentiation, while PDGF inhibits it. These factors exert their effects by activating downstream signaling cascades that ultimately influence the expression of genes involved in SMC differentiation.
* **Transcription Factors:** Myocardin, serum response factor (SRF), and KLF4 are key transcription factors that control SMC differentiation. Myocardin and SRF act synergistically to activate the expression of smooth muscle-specific genes, while KLF4 can act as either a promoter or inhibitor of SMC differentiation depending on the context.
* **MicroRNAs:** Small non-coding RNAs called microRNAs (miRNAs) can fine-tune SMC differentiation by targeting specific mRNAs involved in this process. Some miRNAs promote SMC differentiation, while others suppress it.
**Mechanisms of Negative Regulation of SMC Differentiation:**
* **Inhibition of TGF-β Signaling:** Certain signaling pathways, such as the Wnt/β-catenin pathway, can inhibit TGF-β signaling, leading to a reduction in SMC differentiation.
* **Activation of PDGF Signaling:** PDGF signaling promotes SMC proliferation and inhibits differentiation. The activation of PDGF receptors by PDGF triggers downstream signaling cascades that inhibit the expression of smooth muscle-specific genes.
* **Repression of Myocardin and SRF Activity:** Factors like Krüppel-like factor 4 (KLF4) and GATA6 can repress the activity of Myocardin and SRF, thereby reducing the expression of smooth muscle-specific genes.
* **Induction of Dedifferentiation:** Certain stimuli, like inflammatory cytokines, can induce SMC dedifferentiation, causing them to lose their differentiated characteristics and potentially contributing to disease development.
**Consequences of Dysregulated SMC Differentiation:**
* **Atherosclerosis:** Dysregulated SMC differentiation can contribute to the development of atherosclerosis, a disease characterized by the formation of plaque in blood vessels. In atherosclerosis, SMCs lose their contractile function and may even proliferate abnormally, contributing to plaque formation and narrowing of blood vessels.
* **Hypertension:** Altered SMC differentiation can lead to changes in vascular tone, contributing to hypertension.
* **Vascular Remodeling:** Inappropriate SMC differentiation can cause vascular remodeling, a process that can lead to changes in blood vessel structure and function.
**Therapeutic Implications:**
Understanding the mechanisms of negative regulation of SMC differentiation is crucial for developing therapeutic strategies to treat vascular diseases. Targeting the signaling pathways and transcription factors involved in this process could potentially lead to new treatments that promote SMC differentiation, restore vascular homeostasis, and prevent disease progression.'
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Protein | Definition | Taxonomy |
---|---|---|
Programmed cell death protein 4 | A programmed cell death protein 4 that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q53EL6] | Homo sapiens (human) |
Compound | Definition | Classes | Roles |
---|---|---|---|
tubercidin | tubercidin : An N-glycosylpyrrolopyrimidine that is adenosine in which the in the 5-membered ring that is not attached to the ribose moiety is replaced by a carbon. Tubercidin is produced in the culture broth of Streptomyces tubericidus. Tubercidin: An antibiotic purine ribonucleoside that readily substitutes for adenosine in the biological system, but its incorporation into DNA and RNA has an inhibitory effect on the metabolism of these nucleic acids. | antibiotic antifungal agent; N-glycosylpyrrolopyrimidine; ribonucleoside | antimetabolite; antineoplastic agent; bacterial metabolite |
sirolimus | sirolimus : A macrolide lactam isolated from Streptomyces hygroscopicus consisting of a 29-membered ring containing 4 trans double bonds, three of which are conjugated. It is an antibiotic, immunosupressive and antineoplastic agent. Sirolimus: A macrolide compound obtained from Streptomyces hygroscopicus that acts by selectively blocking the transcriptional activation of cytokines thereby inhibiting cytokine production. It is bioactive only when bound to IMMUNOPHILINS. Sirolimus is a potent immunosuppressant and possesses both antifungal and antineoplastic properties. | antibiotic antifungal drug; cyclic acetal; cyclic ketone; ether; macrolide lactam; organic heterotricyclic compound; secondary alcohol | antibacterial drug; anticoronaviral agent; antineoplastic agent; bacterial metabolite; geroprotector; immunosuppressive agent; mTOR inhibitor |