Compound heterozygous mutations in tripeptidyl peptidase 1 cause rare autosomal recessive spinocerebellar ataxia type 7:A case report

BACKGROUND Spinocerebellar ataxia recessive type 7(SCAR7)is a rare clinical manifestation beginning in childhood or adolescence.SCAR7 is caused by tripeptidyl peptidase 1(TPP1)gene mutations,and presents with cerebellar ataxia,pyramidal signs,neurocognitive impairment,deep paresthesia,and cerebellar atrophy.CASE SUMMARY Here,we describe a 25-year-old female patient in China who presented with increasing difficulty walking,falling easily,shaking limbs,instability holding items,slurred speech,coughing when drinking,palpitations,and frequent hunger and overeating.Magnetic resonance imaging showed cerebellar atrophy.Whole exome sequencing detected two compound heterozygous mutations in the TPP1 gene:c.1468G>A p.Glu490Lys and c.1417G>A p.Gly473Arg.Considering the patient’s clinical presentation and genetic test results,we hypothesized that complex heterozygous mutations cause TPP1 enzyme deficiency,which may lead to SCAR7.CONCLUSION We report the first case of SCAR7 from China.We also identify novel compound heterozygous mutations in the TPP1 gene associated with SCAR7,expanding the range of known disease-causing mutations for SCAR7.

Effect of Optimized Concentrations of Basic Fibroblast Growth Factor and Epidermal Growth Factor on Proliferation of Fibroblasts and Expression of Collagen： Related to Pelvic Floor Tissue Regeneration

Background： Fibroblasts were the main seed cells in the studies of tissue engineering of the pelvic floor ligament. Basic fibroblast growth factor （bFGF） and epidermal growth factor （EGF） were widely studied but at various concentrations. This study aimed to optimize the concentrations of combined bFGF and EGF by evaluating their effects on proliferation and collagen secretion of fibroblasts. Methods： Fibroblasts were differentiated from rat adipose mesenchymal stem cells （ADSCs）. Flow cytometry and immunohistochemistry were used for cell identification. The growth factors were applied at concentrations of 0, 1, 10, and 100 ng/ml as three groups： （1） bFGF alone, （2） EGF alone, and （3） bFGF mixed with EGF. Cell proliferation was evaluated by Cell Counting Kit-8 assays. Expression of Type I and III collagen （Col-I and Col-1II） mRNAs was evaluated by real-time quantitative reverse transcription-polymerase chain reaction. Statistical analysis was performed with SPSS software and GraphPad Prism using one-way analysis of variance and multiple t-test. Results： ADSCs were successfully isolated from rat adipose tissue as identified by expression of typical surface markers CD29, CD44, CD90, and CD45 in flow cytometry. Fibroblasts induced from ADSC, compared with ADSCs, were with higher mRNA expression levels of Col I and Col III （F = 1.29, P = 0.0390）. bFGF, EGF, and the mixture ofbFGF with EGF can enhanced fibroblasts proliferation, and the concentration of 10 ng/ml of the mixture ofbFGF with EGF displayed most effectively （all P 〈 0.05）. The expression levels of Col-I and Col-Ill mRNAs in fibroblasts displayed significant increases in the 10 ng/ml bFGF combined with EGF group （all P 〈 0.05）. Conclusions： The optimal concentration of both bFGF and EGF to promote cell proliferation and collagen expression in fibroblasts was 10 ng/ml at which fibroblasts grew faster and secreted more Type I and III collagens into the extracellular matrix, which might contribute to the stability of the pelvic floor microenvironment.