Lysine Acetyltransferase PCAF Is a Key Regulator of Arteriogenesis

Abstract

Objective-Therapeutic arteriogenesis, that is, expansive remodeling of preexisting collaterals, using single-action factor therapies has not been as successful as anticipated. Modulation of factors that act as a master switch for relevant gene programs may prove more effective. Transcriptional coactivator p300-CBP-associated factor (PCAF) has histone acetylating activity and promotes transcription of multiple inflammatory genes. Because arteriogenesis is an inflammationdriven process, we hypothesized that PCAF acts as multifactorial regulator of arteriogenesis. Approach and Results-After induction of hindlimb ischemia, blood flow recovery was impaired in both PCAF −/− mice and healthy wild-type mice treated with the pharmacological PCAF inhibitor Garcinol, demonstrating an important role for PCAF in arteriogenesis. PCAF deficiency reduced the in vitro inflammatory response in leukocytes and vascular cells involved in arteriogenesis. In vivo gene expression profiling revealed that PCAF deficiency results in differential expression of 3505 genes during arteriogenesis and, more specifically, in impaired induction of multiple proinflammatory genes. Additionally, recruitment from the bone marrow of inflammatory cells, in particular proinflammatory Ly6C Bastiaansen et al PCAF Regulates Arteriogenesis 1903growth are multifactorial and too complex to be modulated by therapeutics that target a single gene or pathway. In contrast, modulation of a factor that acts as a master switch for multiple relevant gene programs may be a more effective strategy to augment arteriogenesis.A protein with such master switch potential is p300-CBPassociated factor (PCAF), a transcriptional coactivator with intrinsic histone acetyltransferase activity. PCAF acetylates histones H3 and H4, but there is also increasing evidence that PCAF modulates nonhistone proteins, [13][14][15][16] including hypoxiainducible factor 1α 17 and Notch. 18 Furthermore, the histone acetylating activity of PCAF is essential for nuclear factor κB (NF-κB)-mediated gene transcription 19 and facilitates inflammatory gene regulation. 20 Because arteriogenesis is an inflammatory-like process, we hypothesized that PCAF acts as master switch that stimulates multiple inflammatory processes important for collateral remodeling.Recently, it was shown in a large patient population study (>3000 individuals)21 that a variation in the promoter region of PCAF is associated with coronary heart disease-related mortality. 22 In support of this observation, we recently demonstrated a role for PCAF in vascular remodeling in a mouse model for reactive stenosis. However, whether PCAF participates in arteriogenesis has not yet been investigated.In the present study, we investigated the contribution of PCAF to postischemic neovascularization in a hindlimb ischemia (HLI) model, 23 using PCAF-deficient (PCAF −/− ) mice. When studying arteriogenesis in a knockout model, it is possible that the gene deletion may affect vascular development in the embryo, including collaterogenesis, thus affec...

A functional genomics screen identifies PCAF and ADA3 as regulators of human granzyme B-mediated apoptosis and Bid cleavage

“…Next we used an shRNA directed against PACS2 to determine whether a reduction in PACS2 expression (Figure 8b) was sufficient to induce resistance to perforin/ hGrzB-mediated cell death. PACS2 depletion led to significant protection against perforin/hGrzB (Po0.01), as demonstrated by reduced 51 Cr release (Figure 8ci). Furthermore, PACS2-KD also reduced Bid processing following perforin/hGrzB exposure (Figure 8cii).…”

“…After recovering for 48 h and resuming proliferation in selective medium, cells were exposed to a normally lethal concentration of recombinant hGrzB (60 nM), combined with a sublytic quantity of recombinant perforin (1 nM). This concentration of hGrzB was chosen as it is sufficient to induce 480% specific 51 Cr release from non-silencing (NS)-shRNAmir transduced control cells in a standard 4-hour assay, or render 480% of cells permeable to the vital dye Alamar blue (AB) 24 h after treatment (data not shown). By contrast, the same concentration of perforin applied alone produced o10% specific 51 Cr release and had no significant effect on long-term viability (data not shown).…”

“…This concentration of hGrzB was chosen as it is sufficient to induce 480% specific 51 Cr release from non-silencing (NS)-shRNAmir transduced control cells in a standard 4-hour assay, or render 480% of cells permeable to the vital dye Alamar blue (AB) 24 h after treatment (data not shown). By contrast, the same concentration of perforin applied alone produced o10% specific 51 Cr release and had no significant effect on long-term viability (data not shown). To select for cells that had acquired resistance to perforin/ hGrzB, pools of transduced HeLa were expanded and exposed to three further rounds of selection ( Supplementary Figure 1), to produce cell populations significantly resistant to hGrzB-induced apoptosis (Hit 4), compared with NS controls (Po0.05, Supplementary Figure 2a).…”

“…47 In contrast to ADA3, PCAF-null mice develop normally, 48 but PCAF is implicated in a number of disease states including arteriosclerosis (including aneurysm formation) and Alzheimer's disease. [49][50][51] A specific PCAF gene polymorphism has also been linked to hepatocellular carcinoma. 52 Malignancies associated with BRCA2 gene mutation may be linked to deregulated PCAF recruitment to target genes, leading to disordered cell division and aneuploidy.…”

Intracranial aneurysm risk factor genes: relationship with intracranial aneurysm risk in a Chinese Han population

“…PCAF has histone acetylating activity, promotes transcription of multiple inflammatory genes, and acts as master switch that stimulates multiple inflammatory processes. Its deficiency reportedly results in a repressed in vitro inflammatory response in many cell types known to be involved in arteriogenesis (Bastiaansen et al, 2013). MYH9 is associated with a spectrum of kidney diseases in African Americans, including essential hypertension and nephropathy attributed to hypertension, and focal segmental glomerulosclerosis (Murea and Freedman, 2010).…”