Human Fibroblasts with Mutations in COL5A1 and COL3A1 Genes Do Not Organize Collagens and Fibronectin in the Extracellular Matrix, Down-regulate α2β1 Integrin, and Recruit αvβ3 Instead of α5β1 Integrin

Decreased expression of periostin encoded by POSTN in cEDS fibroblasts may contribute to the generalized ECM disarray and in vitro poor wound healing.

“In cEDS fibroblasts, the decreased expression of periostin encoded by POSTN may also contribute to the generalized ECM disarray and in vitro poor wound healing [44,48].”

cEDS cells exhibit a crosstalk involving the αvβ3 integrin and EGF receptor that rescues them from anoikis.

“cEDS cells also exhibit a reduced in vitro migration capability, an abnormal wound healing response, and a crosstalk involving the αvβ3 integrin and epidermal growth factor (EGF) receptor that rescues them from anoikis [44,45,46,47,48,49,50].”

cEDS cells exhibit an abnormal wound healing response.

“cEDS cells also exhibit a reduced in vitro migration capability, an abnormal wound healing response, and a crosstalk involving the αvβ3 integrin and epidermal growth factor (EGF) receptor that rescues them from anoikis [44,45,46,47,48,49,50].”

cEDS patients' fibroblasts show disassembly of many ECM components, including collagen V and III, fibronectin, and fibrillins.

“Our in vitro findings demonstrated that cEDS patients’ fibroblasts show disassembly of many ECM components, including collagen V and III, fibronectin, and fibrillins, and disorganization of collagen- and fibronectin-specific α2β1 and α5β1 integrin receptors [44,45,46,47].”

cEDS patients' fibroblasts show disorganization of collagen- and fibronectin-specific α2β1 and α5β1 integrin receptors.

“Our in vitro findings demonstrated that cEDS patients’ fibroblasts show disassembly of many ECM components, including collagen V and III, fibronectin, and fibrillins, and disorganization of collagen- and fibronectin-specific α2β1 and α5β1 integrin receptors [44,45,46,47].”

cEDS cells exhibit reduced in vitro migration capability.

“cEDS cells also exhibit a reduced in vitro migration capability, an abnormal wound healing response, and a crosstalk involving the αvβ3 integrin and epidermal growth factor (EGF) receptor that rescues them from anoikis [44,45,46,47,48,49,50].”

hEDS/HSD, cEDS, and vEDS fibroblasts exhibit marked disorganization of collagen and fibronectin ECM and their specific α2β1 and α5β1 integrin receptors and show preferential expression of the αvβ3 integrin.

“In particular, hEDS/HSD, cEDS, and vEDS fibroblasts exhibit a marked disorganization of collagen and fibronectin ECM and their specific α2β1 and α5β1 integrin receptors and showed the preferential expression of the αvβ3 integrin [44,49,50,123].”

Dominant negative mutations in COL3A1 lead to reduced secretion of collagen I into the ECM in cultured patients' fibroblasts.

“Our previous protein findings on cultured patients’ fibroblasts showed that dominant negative mutations in COL3A1 lead to the reduced secretion of collagen I into the ECM [44], consistent with the known regulatory role of collagen III in synthesis and deposition of heterotypic fibrils that largely contain collagen I [96].”

Expression of αvβ3 integrin is a shared feature of all EDS fibroblast types.

“but express the αvβ3 integrin that is a common trait of all types of EDS fibroblasts [8][9][10][11][12].”

Control fibroblasts do not express αvβ3 integrin under standard growth conditions but organize it preferentially in focal adhesions with hEDS/HSD conditioned medium.

“Furthermore, the evidence that control fibroblasts, which do not express this integrin in standard growth conditions ( [9,10], this work), organize it preferentially in focal adhesions in the presence of hEDS and HSD CM corroborates the involvement of αvβ3 integrin in focal contacts in the transdifferentiation of fibroblasts into myofibroblasts.”

Cultured skin fibroblasts of vEDS patients synthesize aberrant COLLIII that is not organized into the ECM as well as COLLI and fibronectin.

“Cultured skin fibroblasts of vEDS patients synthesize aberrant COLLIII that is not organized into the extracellular matrix (ECM) as well as COLLI and fibronectin (FN) [16,17].”

Our protein data indicated the disorganization of the core proteins of PGs perlecan, versican, and DCN, and their abnormal organization could contribute to the defective COLLIII fibril assembly in vEDS cells, as well as to the defective fibrillogenesis of other COLLs.

“Our protein data indicated the disorganization of the core proteins of PGs perlecan, versican, and DCN, which enhance COLL fibril formation [26], and their abnormal organization could contribute to the defective COLLIII fibril assembly in vEDS cells, as well as to the defective fibrillogenesis of other COLLs previously described in skin fibroblasts of different EDS types and in other connective”

In vEDS patients' skin fibroblasts, abnormal synthesis and deposition of COLLIII into the ECM together with disarray of FN and lack of COLLs- and FN-specific integrin receptors were previously demonstrated.

“In vEDS patients’ skin fibroblasts, we previously demonstrated an abnormal synthesis and deposition of COLLIII into the ECM together with the disarray of FN and the lack of COLLs- and FN-specific integrin receptors [16,17].”

In the present study, the abnormal folding, secretion, and ECM organization of COLLIII cause an altered deposition and disassembly of other structural constituents, such as FN, FBNs, ELN, and EMILINs.

“In the present study, we demonstrated that the abnormal folding, secretion, and ECM organization of COLLIII cause an altered deposition and the disassembly of other structural constituents, such as FN, FBNs, ELN, and EMILINs [16,25], which provide a scaffold for elastogenesis and represent the major components of elastic fibers in elastic tissues including skin and arterial walls, and are essent”

In vEDS skin fibroblasts, defective synthesis of COLLIII did not interfere with COLLV secretion and its extracellular organization, but altered the deposition and proper assembly into the ECM of COLLI, which was mainly retained in the cytoplasm.

“We previously showed that in vEDS skin fibroblasts the defective synthesis of COLLIII did not interfere with the COLLV secretion and its extracellular organization, but altered the deposition and proper assembly into the ECM of COLLI, which was mainly retained in the cytoplasm [16].”

Structural mutations in genes encoding for different COLLs, i.e., COLLI, COLLIII, and COLLV, affect not only the assembly but also the secretion pathways of other ECM components in EDS fibroblasts.

“according to the notion that structural mutations in genes encoding for different COLLs, i.e., COLLI, COLLIII, and COLLV, affect not only the assembly but also the secretion pathways of other ECM components in EDS fibroblasts [16,17,33].”