Gender differences in collagen diseases

Sex differences in the incidence of skin and skin-related diseases in Olmsted County, Minnesota, United States, and a comparison with other rates published worldwide

Many skin and skin-related diseases affect the sexes unequally, with attendant implications for public health and resource allocation. To evaluate better the incidence of skin and skin-related diseases affecting males vs. females, we reviewed published population-based epidemiology studies of skin disorders performed utilizing Rochester Epidemiology Project data. Females had a higher incidence of the following diseases: connective tissue diseases (scleroderma, morphea, dermatomyositis, primary Sjögren syndrome, systemic lupus erythematosus [not in all studies]), pityriasis rosea, herpes progenitalis, condyloma acuminatum, hidradenitis suppurativa, herpes zoster (except in children), erythromelalgia, venous stasis syndrome, and venous ulcers. Males had a higher incidence of psoriasis and psoriatic arthritis, basal cell carcinoma (exception, females aged ≤40 years), squamous cell carcinoma, and lentigo maligna. Incidence rates were equal in males and females for cutaneous malignant melanoma (exception, higher in females aged 18-39 years), lower-extremity cellulitis, cutaneous nontuberculous mycobacterial infection, Behçet disease, delusional infestation, alopecia areata, and bullous pemphigoid. Many of the population-based sex-specific incidence rates of skin and skin-related diseases derived from the Rochester Epidemiology Project are strikingly different from those estimated elsewhere. In general, females are more commonly affected by skin and skin-related diseases. The reasons for this imbalance remain to be determined and are likely multifactorial.

Human collagen produced in plants: more than just another molecule

Consequential to its essential role as a mechanical support and affinity regulator in extracellular matrices, collagen constitutes a highly sought after scaffolding material for regeneration and healing applications. However, substantiated concerns have been raised with regard to quality and safety of animal tissue-extracted collagen, particularly in relation to its immunogenicity, risk of disease transmission and overall quality and consistency. In parallel, contamination with undesirable cellular factors can significantly impair its bioactivity, vis-a-vis its impact on cell recruitment, proliferation and differentiation. High-scale production of recombinant human collagen Type I (rhCOL1) in the tobacco plant provides a source of an homogenic, heterotrimeric, thermally stable "virgin" collagen which self assembles to fine homogenous fibrils displaying intact binding sites and has been applied to form numerous functional scaffolds for tissue engineering and regenerative medicine. In addition, rhCOL1 can form liquid crystal structures, yielding a well-organized and mechanically strong membrane, two properties indispensable to extracellular matrix (ECM) mimicry. Overall, the shortcomings of animal- and cadaver-derived collagens arising from their source diversity and recycled nature are fully overcome in the plant setting, constituting a collagen source ideal for tissue engineering and regenerative medicine applications.