Parvovirus B19 induces cellular senescence in human dermal fibroblasts: putative role in systemic sclerosis–associated fibrosis

Abstract

Objective Emerging evidence demonstrates that excessive accumulation of senescent cells is associated with some chronic diseases and suggests a pathogenic role of cellular senescence in fibrotic processes, such as that occurring in aging or in systemic sclerosis (SSc). Recently, we demonstrated that parvovirus B19 (B19V) activates normal human dermal fibroblasts and induces expression of different profibrotic/proinflammatory genes. This observation prompted us to investigate whether it is also able to induce fibroblast senescence as a potential pathogenetic mechanism in B19V-induced fibrosis. Methods Primary cultures of fibroblasts were infected with B19V and analyzed for the acquisition of senescence markers, such as morphological modifications, senescence-associated beta-galactosidase (SA-β-gal) activity, DNA damage response (DDR) and expression of senescence-associated secretory phenotype (SASP)-related factors. Results We demonstrated that B19V-infected fibroblasts develop typical senescence features such as enlarged and flat-shaped morphology and SA-β-gal activity similar to that observed in SSc skin fibroblasts. They also developed a SASP-like phenotype characterized by mRNA expression and release of some proinflammatory cytokines, along with activation of transcription factor NFkB. Moreover, we observed B19V-induced DNA damage with the comet assay: a subpopulation of fibroblasts from B19V-infected cultures showed a significant higher level of DNA strand breaks and oxidative damage compared with mock-infected cells. Increased level and nuclear localization of ɣH2AX, a hallmark of DNA damage response, were also found. Conclusions B19V-induced senescence and production of SASP-like factors in normal dermal fibroblasts could represent a new pathogenic mechanism of non-productive B19V infection, which may have a role in the fibrotic process.

Biomarkers in Systemic Sclerosis: An Overview

“…Recent studies supported the role of a genetic predisposition and both endogenous and/or exogenous environmental triggers may be promoter for epigenetic mechanisms in genetically predisposed population [1][2][3][4][5][6][7][8][9][10][68][69][70][71][72][73][74][75]. Interestingly, a recent study supported the role of infectious triggers in SSc pathogenesis; in particular, the authors reported a possible role of Parvovirus B19 in this disease [15].…”

“…The SSc vascular damage is characterized by the presence of a characteristic processes with a vasomotor instability with an imbalance of vasoactive factors: overproduction of vasoconstrictors (ET-1) and underproduction of vasodilators (NO and prostacyclin) [6][7][8][9][10][11][12][13][22][23][24][25][106][107][108][109]. The free radical nitric oxide (NO) is a potent vasodilator and is synthesized from L-arginine by NO synthase (NOS) [10][11][12][13][14][15][16][17][18][19][22][23][24][25][40][41][42][43][44][45][46][47][48][106][107][108][109][110][111][112][113]. Endothelial isoforms of NOS (eNOS or NOS 3) has been identified with a constitutive expression, other isoforms are shown...…”

“…Endothelial isoforms of NOS (eNOS or NOS 3) has been identified with a constitutive expression, other isoforms are shown in other cell types. Furthermore, an inducible expression (iNOS or NOS 2) in response to a variety of stimuli is possible, with NO-mediated signalling apparent in the skin [10][11][12][13][14][15][16][17][18][19][40][41][42][43][44][45][46][47][48][106][107][108][109][110][111][112][113]. Several studies reported that NO have a biphasic effect in physiological and pathological conditions, being both beneficial and detrimental depending on the concentration and local environment [10][11][12][13][14][15][16][17][18][19][40][41][42][43][44][45][46][47][48].…”

“…Furthermore, an inducible expression (iNOS or NOS 2) in response to a variety of stimuli is possible, with NO-mediated signalling apparent in the skin [10][11][12][13][14][15][16][17][18][19][40][41][42][43][44][45][46][47][48][106][107][108][109][110][111][112][113]. Several studies reported that NO have a biphasic effect in physiological and pathological conditions, being both beneficial and detrimental depending on the concentration and local environment [10][11][12][13][14][15][16][17][18][19][40][41][42][43][44][45][46][47][48]. Recently observation proposed the regulation of NO by endogenous levels of the NOS inhibitor asymmetric dimethylarginine (ADMA) [10]…”

“…The pathogenesis of SSc is complex and not yet completely understood, however the events involved in SSc pathogenesis can be schematically summarized in three main phases: (a) vascular damage, mainly of microcirculation; (b) immune system activation/autoimmunity/inflammation and (c) fibrosis [4][5][6][7][8][9][10]. Fibrosis of the skin and internal organs may be considered the main clinical hallmark of the disease and it is due to fibroblasts activation and dysfunction with the acquisition of a "myofibroblast phenotype" [1,2,[11][12][13][14][15][16][17][18]. Skin manifestations can be recognized and studied by using the modified Rodnan skin score (mRss), the validated method for assessing the severity of skin involvement in SSc and distinguishing the different subsets of skin involvement in SSc [6][7][8][9][10].…”