| Model Type | Species/Model Name | Genetic Background | Phenotype Recapitulation | Research Applications | Model Advantages | Model Limitations | Key Resources/References |
|---|---|---|---|---|---|---|---|
| Mammalian knockout model | **Abcc6-/- mouse** | Targeted deletion of **Abcc6**; widely used knockout line, including congenic strains; earliest calcification readout is the connective tissue sheath of vibrissae/muzzle skin (pqac-00000011, pqac-00000016) | Recapitulates ectopic calcification in **skin, vasculature, ocular tissues, and kidneys**; mineralization of vibrissae capsule is a robust biomarker; mirrors PPi deficiency and progressive soft-tissue mineralization seen in human PXE (pqac-00000005, pqac-00000011, pqac-00000016) | Pathomechanism studies of **PPi deficiency**, testing anti-calcification therapies (etidronate, INZ-701, minocycline), biomarker development, natural-history studies, and tissue-level histopathology (pqac-00000011, pqac-00000015, pqac-00000005) | Best-established mammalian PXE model; strong face validity for systemic calcification; supports longitudinal intervention studies and quantitative histology/biochemistry (pqac-00000011, pqac-00000015) | Does not fully capture all human chronic ocular/vascular outcomes; vibrissae calcification is a convenient biomarker but not a direct human anatomical correlate; murine disease course differs from human timing/severity (pqac-00000005, pqac-00000015) | INZ-701 prevention study; minocycline proof-of-concept; general PXE pathway reviews (pqac-00000011, pqac-00000015, pqac-00000007) |
| Mammalian rat model | **Abcc6-/- rat** | Rat knockout for **Abcc6**; cited as sharing many commonalities with human ABCC6 deficiency (pqac-00000016) | Shows ectopic mineralization of **blood vessels, Bruch's membrane, and skin**, with hallmark **vibrissae sheath mineralization** similar to mouse; also shows reduced plasma PPi and kidney PPi excretion data (pqac-00000016) | Comparative mammalian physiology, systemic PPi biology, ocular histology, and validation of liver-kidney contributions to mineralization homeostasis (pqac-00000016) | Larger size may benefit imaging, tissue sampling, and some physiology studies; closer procedural flexibility than mouse for some assays (pqac-00000016) | Much less extensively characterized than the mouse in retrieved PXE literature; fewer intervention datasets and fewer standardized community resources noted here (pqac-00000016) | ABCC6 cross-species review and comparative biology discussion (pqac-00000016) |
| Zebrafish genetic model | **abcc6a-/- zebrafish** | Loss of **abcc6a**, regarded as the most likely zebrafish ortholog of human **ABCC6**; abcc6a expressed locally by osteoblast-like cells at craniofacial and skeletal mineralization sites (pqac-00000016) | Recapitulates **aberrant mineralization**, though with a more skeletal/local developmental pattern than classic human hepatic-systemic PXE; used as calcification-readout model for anti-mineralization compounds (pqac-00000011, pqac-00000016) | Rapid in vivo screening of anti-calcification compounds such as **minocycline** and **SNF472/CSL525**; developmental mineralization studies; pathway probing (pqac-00000011, pqac-00000014, pqac-00000016) | Fast, scalable, transparent vertebrate model suitable for higher-throughput drug screening and early mechanism studies (pqac-00000011, pqac-00000014) | Mineralization pattern is not fully homologous to human PXE because zebrafish **abcc6a** acts more locally in skeletal mineralization than mammalian liver-driven systemic PXE; limited direct translation for skin/eye phenotypes (pqac-00000016) | Comparative ABCC6 review; drug-testing studies using zebrafish mineralization endpoints (pqac-00000016, pqac-00000014, pqac-00000011) |
| Zebrafish paralog model / comparative system | **abcc6b(1/2) zebrafish** | Zebrafish paralogs **abcc6b1/abcc6b2**; **abcc6b** expressed in renal proximal tubules, with function less clearly defined (pqac-00000016) | No fully defined PXE-like phenotype summarized in retrieved contexts; mainly relevant as a comparative paralog system for understanding tissue-specific ABCC6 evolution and function (pqac-00000016) | Comparative genomics, functional dissection of paralog specialization, and kidney-related ABCC6 biology (pqac-00000016) | Useful for evolutionary and orthology questions that cannot be addressed in mammalian single-gene systems (pqac-00000016) | Unclear disease validity for human PXE; limited direct phenotypic application in retrieved studies (pqac-00000016) | ABCC6 phylogenetics and zebrafish paralog discussion (pqac-00000016) |
| Primary cellular model | **PXE patient dermal fibroblasts** | Fibroblasts isolated from lesional or non-lesional skin of individuals with biallelic **ABCC6** pathogenic variants; often compared with control dermal fibroblasts (pqac-00000017, pqac-00000010) | Show **pro-calcification phenotype**, lower cytosolic/extracellular PPi, lower **ENPP1** expression, altered ECM remodeling, elevated **MMPs**, altered lipid metabolism/senescence-related features, and skin microenvironment differences between calcified and non-calcified areas (pqac-00000017, pqac-00000010, pqac-00000017) | ECM remodeling studies, secretome analysis, MMP biology, calcification induction assays, biomarker discovery, testing inhibitors such as **Marimastat** and mechanistic work on local dermal drivers of mineralization (pqac-00000017, pqac-00000010) | Human patient-derived system captures cell-autonomous and microenvironmental features of PXE skin; useful for mechanistic and translational in vitro assays (pqac-00000017, pqac-00000010) | Peripheral fibroblasts express much lower ABCC6 than liver, so they do not model the full systemic liver-driven component of PXE; culture artifacts and inter-patient variability can be substantial (pqac-00000018, pqac-00000017) | MMP overexpression study; fibroblast secretome study; older pathophysiology review (pqac-00000017, pqac-00000010, pqac-00000018) |
| Engineered cell system | **HEK293 cells expressing human or rat ABCC6** | Heterologous overexpression of **hABCC6** or **rABCC6** in HEK293 cells for transport/metabolomic studies (pqac-00000016, pqac-00000018) | Does not model tissue calcification directly; demonstrates **ABCC6-associated extracellular nucleotide changes** and supports the link between ABCC6 activity, ATP-related efflux, and PPi biology (pqac-00000016, pqac-00000018) | Transport assays, substrate discovery, untargeted metabolomics, mechanistic analysis of ATP/PPi-related signaling, and variant-function interrogation (pqac-00000016, pqac-00000018) | Highly manipulable system for biochemical and transport-focused studies; useful for dissecting upstream molecular function of ABCC6 (pqac-00000016) | Low physiological context; no connective tissue matrix or whole-organism mineralization phenotype; substrate identity remains unresolved despite these systems (pqac-00000016, pqac-00000018) | ABCC6 transport/function reviews and mechanistic summaries (pqac-00000016, pqac-00000018, pqac-00000001) |


*Table: This table summarizes the main in vivo and in vitro model systems used in pseudoxanthoma elasticum research, including what parts of the human disease they capture and where they are most useful. It helps compare mammalian, zebrafish, and cellular platforms for mechanism, biomarker, and therapeutic studies.*