ABSTRACT
Objective:To construct a serine protease inhibitor Kazal type-5 (Spink5) conditional knockout mouse model, and to identify its phenotype.Methods:B cell-specific Spink5 conditional knockout mice of genotype Mb1 cre/+Spink5 floxp/floxp were constructed by using clustered regularly interspaced short palindromic repeats (CRISPR) /CRISPR-associated protein 9 (Cas9) technology, and served as the knockout group. Mice of genotype Mb1 +/+Spink5 floxp/floxp served as the control group. The mice of genotype Mb1 cre/+Spink5 floxp/floxp or Mb1 +/+Spink5 floxp/floxp were sacrificed when they were 4 to 6 weeks old, splenic mononuclear cells were isolated, and B lymphocytes and non-B lymphocytes were sorted by flow cytometry and fluorescence-activated cell sorting. Genotype identification was performed by PCR, and protein expression of lymphoepithelial Kazal-type-related inhibitor (LEKTI) was determined by Western blot analysis. Skin tissues were resected from the mice, and subjected to hematoxylin-eosin staining for measuring the epidermal thickness. Immunofluorescence staining was performed to determine fluorescence intensity of LEKTI protein in the mouse skin tissues. Paired t test or two-independent-sample t test was used for comparisons between groups. Results:Genotype identification results demonstrated that the stable B lymphocyte-specific Spink5 conditional knockout mouse model was successfully constructed. Western blot analysis revealed that the relative protein expression of LEKTI in the B lymphocytes in the knockout group was 0.01 ± 0.02, which was significantly lower than that in the non-B lymphocytes in the knockout group (0.66 ± 0.11, t = 9.99, P < 0.001) , and that in the B lymphocytes in the control group (1.08 ± 0.13, t = 13.78, P < 0.001) . Among 39 mice in the knockout group, 4 presented with dry skin and scattered scaly hypertrophic maculopapules. The epidermal thickness of the lesional skin tissues in the knockout group was 90.42 ± 21.31 μm, significantly higher than that of the non-lesional skin tissues in the knockout group (29.71 ± 3.63 μm, t = 5.05, P = 0.002) and that of normal skin tissues in the control group (12.42 ± 2.21 μm, t = 6.74, P < 0.001) . Immunofluorescence staining showed no significant difference in the fluorescence intensity of LEKTI protein among the lesional skin tissues (46.21 ± 1.21) , non-lesional skin tissues (46.62 ± 2.13) in the knockout group and normal skin tissues in the control group (47.69 ± 1.71, P > 0.05) . Conclusion:The B lymphocyte-specific Spink5 conditional knockout mouse model was successfully constructed, which provides a basis for further exploring mechanisms underlying skin barrier defects and immune dysfunction in Netherton syndrome.
ABSTRACT
A 24-year-old female patient presented with recurrent itchy annular erythema and scales on the trunk and extremities for 9 years. Histopathological study revealed hyperkeratosis with focal parakeratosis, neutrophil aggregation in the stratum corneum, blisters below the stratum corneum, and perivascular infiltration with lymphocytes, a small number of eosinophils and neutrophils in the superficial and middle dermis. Direct immunofluorescence assay showed negative staining for IgG, IgM, IgA and C3. Whole-exome sequencing of the SPINK5 gene showed a missense mutation c.2423C>T (p.T808I) in exon 25, and a splicing site mutation c.2965-1G>A in exon 31. The compound heterozygosity for the two mutations may be the cause of Netherton syndrome in the patient. Based on the clinical manifestations and genetic testing results, the patient was diagnosed with Netherton syndrome.
ABSTRACT
Objective To construct a recombinant adenovirus vector expressing mouse SPINK5 gene,and observe its curative effect on the skin lesions in atopic dermatitis mice model. Methods By recombining DNA technology,the sequence of mouse SPINK5 gene was cloned into adeno?virus shuttle plasmid. Then it was transformed into HEK 293 cells with the adenoviral backbone plasmid to obtain the recombinant adenovirus. A mouse model of atopic dermatitis was established by system and local sensitization of Balb/c mice with ovalbumin . The effect of recombinant adeno?virus on the lesions of atopic dermatitis mice model was observed. Results The SPINK5 over?expressing adenovirus vector and atopic dermatitis mice model were successfully constructed. After 2 weeks of adenovirus?mediated SPINK5 gene intracutaneous injection,the redness and edema of lesions of AD model mice were obvious relieved. The pathological detection indicated that epidermal thickness and prickle cell layer ,inflammatory cell infiltration significant decreased accompanied with the model blank control. Conclusion The adenovirus?mediated SPINK5 gene had signifi?cant therapeutic effect to the atopic dermatitis mice model ,which provided a laboratory basis of application of SPINK5 gene product to therapy atopic dermatitis.