Identification and 3D architecture analysis of the LIPC gene mutation in a pedigree with familial hypercholesterolemia-like phenotype / 中华心血管病杂志

Objective: To identify and analyze 3D architecture of the mutational sites of susceptible genes in a pedigree with familial hypercholesterolemia-like phenotype (FHLP). Methods: This is a case series study. A pedigree with suspected familial hypercholesterolemia was surveyed. The proband admitted in Beijing Anzhen Hospital in April 2019. Whole-exome sequencing was performed to determine the mutational sites of susceptible genes in the proband. Polymerase chain reaction (PCR) sequencing was used to verify the pathogenic variant on proband's relatives. The structural and functional changes of the proteins were analyzed and predicted by Discovery Studio 4.0 and PyMol 2.0. Results: The patients in the pedigree showed abnormal lipid profiles, especially elevated levels of total cholesterol(TC). The genetic screening detected the c.1330C>T SNP in the exon 8 of lipase C (LIPC) gene, this mutation leads to an amino acid substitution from arginine to cysteine at position 444 (Arg444Cys), in the proband and proband's father and brother. In this family, members with this mutation exhibited elevated TC, whereas lipid profile was normal from the proband's mother without this mutation. This finding indicated that LIPC: c.1330C>T mutation might be the mutational sites of susceptible genes. The analysis showed that Arg444Cys predominantly affected the ligand-binding property of the protein, but had a limited impact on catalytic function. Conclusion: LIPC: c.1330C>T is a new mutational site of susceptible genes in this FHLP pedigree.

The relationship between genotype of familial hypercholesterolemia and the efficacy of PCSK9 inhibitors / 中华心血管病杂志

Objective: This study intends to explore the difference in the efficacy of PCSK9 inhibitors in patients with different FH phenotypes by analyzing the level of blood lipids before and after treatment with PCSK9 inhibitors in patients with familial hypercholesterolemia (FH) with different allele grades. Methods: Patients with FH phenotype, who admitted to Beijing Anzhen Hospital from January 2019 to October 2020, were enrolled. Age, sex and other clinical information were collected from enrolled, and the pathogenic genes were detected by the second generation sequencing technique. The patients were divided into five groups according to the number of alleles involved and the degree of gene damage: single allele-null mutation group, single allele-defect mutation group, multi-allele-null mutation group, multi-allele-defect mutation group and no major pathogenic gene mutation group. The results of blood lipids were collected before medication, 4-6 weeks of intensive statin treatment and one month after combined treatment with PCSK9 inhibitor (PCSK9i). The LDL-C level were compared among groups. ASCVD risk stratification was performed in all patients, and the proportion of LDL-C level reaching the corresponding risk stratification target value of each genotype group after treatment was analyzed. Results: A total of 66 patients with FH phenotype were included, including 47 males (71.2%) and 19 females (28.8%),the mean age was(43.1±13.4 years). There were 7 cases in single allele-null mutation group (10.6%), 25 cases in single allele-defect mutation group (37.9%), 8 cases in multi-allele-null mutation group (12.1%), 18 cases in multi-allele-defect mutation group (27.3%) and 8 cases in no major pathogenic mutation group (12.1%). The degree of LDL-C reduction post combined PCSK9 inhibitor therapy was as follows: single allele mutation group>no major pathogenic mutation group>multi-allele mutation group, general distribution was in the range of 0-90.0%. Two groups of single allele mutation and no major pathogenic mutation group>50.0%>multi-allele mutation group. Under the combined treatment of PCSK9 inhibitors, the further decrease of LDL-C was in the order of single allele mutation group>non-major pathogenic mutant group>multi-allele mutation group. The efficacy of combined therapy on reducing LDL-C at 1 month after treatment decreased with the increase of baseline LDL-C level (r = 0.46, P<0.001) in patients with FH phenotype. In addition, the further decrease of LDL-C level post high-intensity statin therapy combined with PCSK9 inhibitors decreased with the increase of baseline LDL-C levels (r = 0.40, P<0.001). The degree of LDL-C decrease was high and stable by statin combined with PCSK9 inhibitor therapy in single allele mutation group. In the single allele-defect mutant group, the decrease of LDL-C increased with the increase of baseline LDL-C level post intensive statin treatment and combined PCSK9 inhibitor treatment ((r=0.54, P=0.009); r=0.45,P=0.030), and the further decrease of LDL-C level decreased with the increase of baseline LDL-C level in single allele-defect mutant group post combined therapy with PCSK9 inhibitor (r=0.43, P=0.040). The decrease of LDL-C in patients with the multi-allele mutation group varied with different pathogenic gene loci and combinations post combined therapy with PCSK9 inhibitor. There was no significant difference in the level of blood lipids between the group without major pathogenic gene mutation and the group with single allele mutation before and after treatment. The percentage of patients achieving LDL-C goals with different genotypes of phenotypic FH were as follows: single allele mutation group (86.7%), non-major pathogenic mutant group (75.0%) and multi-allele mutation grou (<5.0%). Conclusions: All patients with different FH phenotypes could benefit from the intensive lipid-lowering therapy with statins and PCSK9 inhibitors, however, there are significant differences in the efficacy of lowering LDL-C in Chinese patients with FH phenotype with different molecular etiologies. Therefore, the pathogenic gene analysis may suggest the lipid-lowering effect of PCSK9 inhibitors in patients with FH.

Different active ingredients of medicinal plant based on function differentiation of homologous gene / 中国中药杂志

In the research field of quality control in Chinese medicinal materials, variation in active ingredients of medicinal plant is always the key and hot issues. With the development of high-throughput sequencing technologies and reducing cost, a large numbers of genes from medicinal plant were cloning and provide a solid foundation for further research of gene structure and its biological function, and also provides conditions for explore active ingredient variation and its quality control from the perspective of molecular pharmacognosy. This paper introduces the concept of homologous gene, gene duplication and classification. We prospect the function of duplicated genes in the role of molecular mechanism research about variation in active ingredients, aiming at providing a new way for medicinal materials quality control.

Advances in high-throughput transcriptome research of traditional Chinese medicines / 中国中药杂志

Traditional Chinese medicine is a treasure of Chinese culture, absorbing the wisdom of the Chinese people. Continuous application of new technologies makes traditional Chinese medicine research advance with the times. After several years of development, high-throughput transcriptome study has become a mature research tool in biology. This paper reviewed the advances in medicine transcriptome study, and compared two sequencing platforms, Roche's GS FLX platform and Illumina's HiSeq 2000 platform. Moreover, this paper introduced medicine transcriptome analysis process, with Panax quinquefolius and Lonicera japonica for examples, showing the characteristics of traditional Chinese medicine transcriptome studies. High-throughput transcriptome studies facilitate traditional Chinese medicine research with overall understand of functional genes, give clear elucidation of metabolic pathways, lay molecular foundation for the traditional Chinese medicine research and offer modern interpretation for traditional Chinese medicine theory. However, the current study faces several difficulties, including weak molecular basis, high sequencing cost and staff shortages in data anaysis. In the future, with the development in sequencing technology, the combination of transcriptome and other genomics, such as proteome and metabolome, will lay a solid foundation for the new high-throughput screening and developing model for the traditional Chinese medicine industry.

EST-SSR identification of Lonicera japonica Thunb / 药学学报

Simple and effective methods are needed for the identification of Chinese medicinal material species and their variety. Lonicera japonica Thunb. is one of Chinese herbal medicines widely demanded. A total of 3 705 EST-SSRs of L. japonica and 2 818 EST-SSRs of L. japonica var. chinensis Thunb. were identified from EST database in our lab. In average, there was one EST-SSR per 4.05 kb in L. japonica ESTs and per 7.49 kb in L. japonica var. chinensis ESTs, separately. The identified SSRs in L. japonica were consisted of 51.98% dinucleotide and 34.61% trinucleotide repeats, while SSRs in L. japonica var. chinensis had 57.45% dinucleotide and 30.09% trinucleotide. The results reviewed that the classes AG/TC and GAG/TCT were predominant in the dinucleotide motifs and the trinucleotide motifs, respectively. Total 87 EST-SSRs were identified of significant difference between L. japonica and L. japonica var. chinensis. PCR products were obtained from 52 L. japonica samples in 13 out of 15 SSR markers tested. The polymorphism in L. japonica, L. japonica var. chinensis and other honeysuckles could be distinguished by three markers (jp.ssr4, jp.ssr64 and jp.ssr65) tested.

A novel mutation in proprotein convertase subtilisin/kexin type 9 gene leads to familial hypercholesterolemia in a Chinese family / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Familial hypercholesterolemia (FH) is an autosomal disorder associated with elevated plasma low density lipoprotein (LDL) levels leading to premature coronary heart disease (CHD). As a result of long-term hyperlipemia, FH patients will present endarterium thickening and artherosclerosis. In the present study we scanned the related gene of a clinically diagnosed autosomal genetic hypercholesterolemia family for the possible mutations and established eukaryotic expression vector of mutation of proprotein convertase subtilisin/kexin type 9 (PCSK9) gene with gene recombination technique to investigate the contributions of the variation on low density lipoprotein receptor (LDL-R) metabolism and function alternation.</p><p><b>METHODS</b>Mutation detection was conducted for LDL-R, apolipoprotein B(100) (apoB(100)) and PCSK9 gene with nucleotide sequencing in a Chinese FH family. The full-length cDNA of wild type PCSK9 gene (WT-PCSK9) was obtained from Bel-7402. Site mutagenesis was used to establish the recombinant eukaryotic expression vector carrying pathogenic type of PCSK9 gene and the inserted fragment was sequenced. With the blank vector as control, liposome transfection method was used to transfect the Bel-7402 cells with recombinant plasmid. The expression of LDL-R mRNA was examined by RT-PCR. PCSK9 and the expression of LDL-R protein were determined by Western blotting.</p><p><b>RESULTS</b>The G-->T mutation at the 918 nucleotide of PCSK9 gene resulted in the substitution of the arginine by a serine at the codon 306 of exon 6. After sequencing, it was confirmed that the inserted fragment of established expression vector had correct size and sequence and the mutant was highly expressed in Bel-7402 cells. There was no significant variation in the levels of LDL-R mRNA. LDL-R mature protein was decreased by 57% after the cells were transfected by WT-PCSK9 plasmid. Mature LDL-R was significantly decreased by 12% after the cells were transfected by R306S mutant as evidenced by gray scale scanning, suggesting that the new mutant R306S can significantly decrease the expression of mature LDL-R protein.</p><p><b>CONCLUSIONS</b>A novel missense mutation of PCSK9 gene, R306S, was found and the eukaryotic expression vectors of mutant and wild-type of PCSK9 gene were established. There was no significant variation in the levels of LDL-R mRNA. The R306S mutation could significantly lead to the decrease of LDL-R mature protein expression, which might be the pathogenic gene of the FH family.</p>

Establishment of lymphocyte cell lines with abnormal chromosome karyotypes and its application in external quality assesment for chromosome karyotype analysis / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To develop chromosome abnormal karyotype quality control cell and to explore the external quality assessment (EQA) method for chromosome karyotype analysis.</p><p><b>METHODS</b>The chromosome abnormal karyotype quality control cells were prepared by EB virus (EBV) transfection of human B lymphocyte strain establishment and were distributed to participating labs for EQA test of chromosome karyotype analysis project at appointed time. The evaluation results were obtained through 4 grades scoring.</p><p><b>RESULTS</b>Six kinds of chromosome abnormal karyotype quality control cells were initially developed, the karyotypes of which were 46,X, t(Y;5)(q12;q21), 46, XY, 15p +, 46, XX, t(13;18)(q12;q21), 46, X, r(Xp), 46,X,t(Y;Y), 46,XX,t(9;20)(p13;p13) respectively. In the external quality assessment, feedbacks from the participating labs on the sequencing results of the six kinds of quality control cells showed that the wholly overlapping rate were 82.1%, 92.0%, 84.6%, 80.8%, 86.2%, 74.1% and the wholly deviation rate were 10.7%, 8.0%, 11.5%, 19.2%, 13.8%, 18.5%. The overall wholly overlapping rate, partial overlapping rate, partial deviation rate and wholly deviation rate turned out to be 83.2%, 0.6%, 2.5% and 13.7% respectively.</p><p><b>CONCLUSION</b>The misdiagnose rate of chromosome karyotype analysis is rather high and regular external quality assessment is necessary to achieve dynamic information and improve diagnosis quality.</p>