Table 1.
Selected Mouse Mutants with a Cicatricial Alopecia Phenotype
| Mouse model (symbol) | Gene defect [mouse chromosome] | Type | Phenotype | Histology | Compared to human disease | Reference |
|---|---|---|---|---|---|---|
| Asebia (Scd1ab) Asebia Jackson (Scd1ab-J) Asebia Jackson-2 (Scd1ab-2J) | Stearoyl-CoA desaturase 1 enzyme [Ch 19] | S | Recessive inheritance; Scd1ab = reduced hair growth apparent by day 7; sparse coat in adults; scaly skin; reduced growth; reduced eye lubrication; Scd1ab-J; Scd1ab-2J = progressive scarring alopecia; scaly skin; runted growth; photophobia | Scarring alopecia; hypoplasia of sebaceous glands; abnormally long anagen follicle; retained IRS and hair follicle plugging; short shaft at surface; retrograde movement of the hair shaft with shaft penetration of the bulb and resultant; foreign body reaction; increased mast cell numbers | n.s. | 62, 63 |
| Alopecia 1 (Alo-1) | Mapped to Bsk locus 11 Mb region [Ch 11] | ENU | Dominant inheritance; early onset progressive alopecia; complete alopecia by 20 weeks; occasional excoriation/erosions in older mice | Thickened epidermis; early sebaceous gland loss; early infiltrate of mononuclear cells in dermis only; follicles deep into sc fat; destruction of follicles with necrosis; MHC I- and ICAM-1-positive in proximal follicle ( = IP collapse) | n.s. | 64 |
| Alopecia 2 (Alo-2) | Mapped to Bsk locus 24 Mb region [Ch 11] | ENU | Identical to Alo-1 | See Alo-1. Infiltrate and ICAM-1 expression down to sc fat; infiltrate deeper than that seen in Alo-1 | n.s. | 64 |
| Male NZ black/KN (NZB/KN) | Unknown | Tg | Normal onset hair cycle; initial lesions around tail; indurated skin with alopecia; progressive hair loss on back; severity and incidence of alopecia increases with age (77% developed alopecia lesions by 6 months) | Reduced follicle density; atrophic epidermis; intra- and peri-follicular mononuclear cell infiltrate; CD3+ and CD4+ increased around bulge; peri-vascular infiltrate; increased total number (and degranulated) mast cells; positive direct immunofluorescence for Ig M in 75% | Auto-immune-induced permanent alopecia | 65 |
| PPARγ conditional null (Pparg) | Peroxisome proliferator activated receptor-γ [Ch 6] | Tg | Progressive alopecia with spare and matted hair; marked pruritus and scratching behaviour; scaly skin; smaller size to uninvolved littermates | Hyperkeratosis; plugged follicles; follicular destruction; peri-follicular fibrosis; inflammatory infiltrate comprising T cells, macrophages, plasma cells and mast cells; abnormal sebaceous glands; abnormal lipid accumulation within follicle | LPP | 66 |
| Keratin 15 transgenic (Krtl-15-HSV-TK ROSA26) | Keratin 15 [Ch = 11] (NB. mice died within 7 days due to gastrointestinal toxicity) | Tg | Krtl-15-HSV-TK ROSA26 mice skin grafted onto immune-deficient mice; bulge suicide gene activated by ganciclovir at 3 months; complete hair loss within 8 days; no visible inflammation; normal looking epidermis; graft survives long-term. | Complete loss of follicles; no inflammation | n.s. | 22 |
| CD200 null (CD200−/−) | CD200 (OX-2) [Ch = 16] | Tg | CD200−/− skin grafted onto sex-matched WT hosts; hair lost in grafts after 40 days; epidermis normal; long-term graft survival | Peri- and intra-follicular mononuclear inflammatory infiltrate; intra-follicular edema and apoptosis; inflammation resolved after hair loss; residual scarring | n.s. | 33, 67 |
| Lympho-proliferation (Faspr) | Fas antigen [Ch 19] | S | Patchy hair loss; CCLE-like skin lesions in 80% by 5 months; photo-sensitive; SLE-like symptoms | Progressive dermal T-lymphocyte infiltration; similar histology to CCLE; direct immunofluorescence shows IgG at the dermo-epidermal junction | CCLE/SLE | 68 |
Ch, chromosome; ENU, N-ethyl-N-nitrosurea mutagenesis; Bsk, bareskin; IRS, inner root sheath; n.s., not specified; S, spontaneous; Tg, transgenic; N.M., not mapped; MHC 1, major histocompatability class 1; ICAM-1, intercellular adhesion molecule 1; LPP, lichen planopilaris; CCLE, chronic cutaneous lupus erythematosus; SLE, systemic lupus erythematosus; CA, cicatricial alopecia.