Two staphylococcal lipases were obtained from Staphylococcus epidermidis S2 and Staphylococcus aureus S11 isolated from sebaceous areas on the skin of the human face. The molecular mass of both enzymes was estimated to be 45 kDa by SDS-PAGE. S2 lipase displayed its highest activity in the hydrolysis of olive oil at 32 o C and pH 8, whereas S11 lipase showed optimal activity at 31 o C and pH 8.5. The S2 lipase showed the property of cold-adaptation, with activation energy of 6.52 kcal/mol. In contrast, S11 lipase's activation energy, at 21 kcal/mol, was more characteristic of mesophilic lipases. S2 lipase was stable up to 45 o C and within the pH range from 5 to 9, whereas S11 lipase was stable up to 50 o C and from pH 6 to 10. Both enzymes had high activity against tributyrin, waste soybean oil, and fish oil. Sequence analysis of the S2 lipase gene showed an open reading frame of 2,067 bp encoding a signal peptide (35 aa), a pro-peptide (267 aa), and a mature enzyme (386 aa); the S11 lipase gene, at 2,076 bp, also encoded a signal peptide (37 aa), pro-peptide (255 aa), and mature enzyme (399 aa). The two enzymes maintained amino acid sequence identity of 98-99% with other similar staphylococcal lipases. Their microbial origins and biochemical properties may make these staphylococcal lipases isolated from facial sebaceous skin suitable for use as catalysts in the cosmetic, medicinal, food, or detergent industries.

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While genetic analyses have revealed ~100 risk loci associated with osteoarthritis (OA), only eight have been linked to hand OA. Besides, these studies were performed in predominantly European and Caucasian ancestries. Here, we conducted a genome-wide association study in the Han Chinese population to identify genetic variations associated with the disease. We recruited a total of 1136 individuals (n = 420 hand OA-affected; n = 716 unaffected control subjects) of Han Chinese ancestry. We carried out genotyping using Axiom Asia Precisi on Medicine Research Array, and we employed the RegulomeDB database and RoadMap DNase I Hypersensitivity Sites annotations to further narrow down our potential candidate variants. Genetic variants identified were tested in the Geisinger’s hand OA cohort selected from the Geisinger MyCode community health initiative (MyCode®). We also performed a luciferase reporter assay to confirm the potential impact of top candidate single-nucleotide polymorphisms (SNPs) on hand OA. We identified six associated SNPs (p-value = 6.76 × 10−7–7.31 × 10−6) clustered at 2p13.2 downstream of the CYP26B1 gene. The strongest association signal identified was rs883313 (p-value = 6.76 × 10−7, odds ratio (OR) = 1.76), followed by rs12713768 (p-value = 1.36 × 10−6, OR = 1.74), near or within the enhancer region closest to the CYP26B1 gene. Our findings showed that the major risk-conferring CC haplotype of SNPs rs12713768 and rs10208040 [strong linkage disequilibrium (LD); D’ = 1, r2 = 0.651] drives 18.9% of enhancer expression activity. Our findings highlight that the SNP rs12713768 is associated with susceptibility to and severity of hand OA in the Han Chinese population and that the suggested retinoic acid signaling pathway may play an important role in its pathogenesis.