Isaridin E Protects against Sepsis by Inhibiting Von Willebrand Factor-Induced Endothelial Hyperpermeability and Platelet-Endothelium Interaction.

Endothelial hyperpermeability is pivotal in sepsis-associated multi-organ dysfunction. Increased von Willebrand factor (vWF) plasma levels, stemming from activated platelets and endothelium injury during sepsis, can bind to integrin αvß3, exacerbating endothelial permeability. Hence, targeting this pathway presents a potential therapeutic avenue for sepsis. Recently, we identified isaridin E (ISE), a marine-derived fungal cyclohexadepsipeptide, as a promising antiplatelet and antithrombotic agent with a low bleeding risk. ISE's influence on septic mortality and sepsis-induced lung injury in a mouse model of sepsis, induced by caecal ligation and puncture, is investigated in this study. ISE dose-dependently improved survival rates, mitigating lung injury, thrombocytopenia, pulmonary endothelial permeability, and vascular inflammation in the mouse model. ISE markedly curtailed vWF release from activated platelets in septic mice by suppressing vesicle-associated membrane protein 8 and soluble N-ethylmaleide-sensitive factor attachment protein 23 overexpression. Moreover, ISE inhibited healthy human platelet adhesion to cultured lipopolysaccharide (LPS)-stimulated human umbilical vein endothelial cells (HUVECs), thereby significantly decreasing vWF secretion and endothelial hyperpermeability. Using cilengitide, a selective integrin αvß3 inhibitor, it was found that ISE can improve endothelial hyperpermeability by inhibiting vWF binding to αvß3. Activation of the integrin αvß3-FAK/Src pathway likely underlies vWF-induced endothelial dysfunction in sepsis. In conclusion, ISE protects against sepsis by inhibiting endothelial hyperpermeability and platelet-endothelium interactions.

[Phenotypic and genetic analysis of a Chinese pedigree affected with Hereditary antithrombin deficiency due to a novel variant of SERPINC1 gene].

OBJECTIVE: To analyze the clinical phenotype and genetic characteristics of a Chinese pedigree affected with Hereditary antithrombin deficiency. METHODS: A pedigree diagnosed at the the Second Affiliated Hospital of Wenzhou Medical University, Yuying Children's Hospital in June, 2020 was selected as the study subject. Plasma prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (FIB), and thrombin time (TT) of the probands and their pedigree members were determined using a STA-R automatic coagulation analyzer. Antithrombin activity (AT: A) and antithrombin antigen (AT: Ag) in plasma were determined with chromogenic substrate and immunonephelometry assays. All exons and flanking sequences of the anticoagulant protein gene SERPINC1 were amplified by PCR and subjected to Sanger sequencing. Candidate variants were verified with bioinformatic tools (PolyPhen-2, SIFT, Mutation Taster and PYMOL) to explore their effect on the function and structural conformation of the protein. RESULTS: The probands (II-2, II-10), their brother (II-5) and sons (III-1, III-8) had shown normal PT, APTT, FIB, and TT, but significantly decreased AT: A and AT: Ag, with their levels being 34%, 57%, 56%, 48%, 53% and 13.51 mg/dL, 13.44 mg/dL, 18.39 mg/dL, 17.36 mg/dL, 17.71 mg/dL, respectively. The remaining pedigree members had normal values. Sanger sequencing revealed that the probands and all affected pedigree members had harbored a heterozygous c.851T>C (p.Met284Thr) missense variant in exon 5 of the SERPINC1 gene. Bioinformatic analysis and simulation suggested that the variant has resulted in alteration of hydrogen bonds at the c.851 position, which may affect the structure of the protein. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was classified as pathogenic (PS1+PM1+PM5+PP1+PP4). CONCLUSION: The probands and other affected members were all diagnosed with type I hereditary AT deficiency, for which the c.851T>C (p.Met284Thr) variant of the SERPINC1 gene may be accountable.

Identification of the RNase-binding site of SARS-CoV-2 RNA for anchor primer-PCR detection of viral loading in 306 COVID-19 patients.

The pandemic of coronavirus disease 2019 (COVID-19) urgently calls for more sensitive molecular diagnosis to improve sensitivity of current viral nuclear acid detection. We have developed an anchor primer (AP)-based assay to improve viral RNA stability by bioinformatics identification of RNase-binding site of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA and implementing AP dually targeting the N gene of SARS-CoV-2 RNA and RNase 1, 3, 6. The arbitrarily primed polymerase chain reaction (AP-PCR) improvement of viral RNA integrity was supported by (a) the AP increased resistance of the targeted gene (N gene) of SARS-CoV-2 RNA to RNase treatment; (b) the detection of SARS-CoV-2 RNA by AP-PCR with lower cycle threshold values (-2.7 cycles) compared to two commercially available assays; (c) improvement of the viral RNA stability of the ORF gene upon targeting of the N gene and RNase. Furthermore, the improved sensitivity by AP-PCR was demonstrated by detection of SARS-CoV-2 RNA in 70-80% of sputum, nasal, pharyngeal swabs and feces and 36% (4/11) of urine of the confirmed cases (n = 252), 7% convalescent cases (n = 54) and none of 300 negative cases. Lastly, AP-PCR analysis of 306 confirmed and convalescent cases revealed prolonged presence of viral loading for >20 days after the first positive diagnosis. Thus, the AP dually targeting SARS-CoV-2 RNA and RNase improves molecular detection by preserving SARS-CoV-2 RNA integrity and reveals the prolonged viral loading associated with older age and male gender in COVID-19 patients.

Shikimate-Derived Meroterpenoids from the Ascidian-Derived Fungus Amphichorda felina SYSU-MS7908 and Their Anti-Glioma Activity.

Glioma is a clinically heterogeneous type of brain tumor with a poor prognosis. Current treatment approaches have limited effectiveness in treating glioma, highlighting the need for novel drugs. One approach is to explore marine natural products for their therapeutic potential. In this study, we isolated nine shikimate-derived diisoprenyl-cyclohexene/ane-type meroterpenoids (1-9), including four new ones, amphicordins A-D (1-4) from the ascidian-derived fungus Amphichorda felina SYSU-MS7908, and further semisynthesized four derivatives (10-13). Their structures were extensively characterized using 1D and 2D NMR, modified Mosher's method, HR-ESIMS, NMR and ECD calculations, and X-ray crystallography. Notably, amphicordin C (3) possesses a unique benzo[g]chromene (6/6/6) skeleton in this meroterpenoid family. In an anti-glioma assay, oxirapentyn A (7) effectively inhibited the proliferation, migration, and invasion of glioma cells and induced their apoptosis. Furthermore, an in silico analysis suggested that oxirapentyn A has the potential to penetrate the blood-brain barrier. These findings highlight the potential of oxirapentyn A as a candidate for the development of novel anti-glioma drugs.

Anti-inflammatory acetylenic meroterpenoids from the ascidian-derived fungus Amphichorda felina SYSU-MS7908.

A combination strategy of 13C NMR and bioinformatics was established to expedite the discovery of acetylenic meroterpenoids from the ascidian-derived fungus Amphichorda felina SYSU-MS7908. This approach led to the identification of 13 acetylenic meroterpenoids (1-13) and four biogenic analogs (14-17), including five new ones named felinoids A-E (1-4 and 15). Their structures and absolute configurations were elucidated using extensive spectroscopy, ECD quantum chemical calculations, and single-crystal X-ray diffraction analysis. Compound 1 possessed a rare cyclic carbonate in natural acetylenic meroterpenoids. The plausible shikimate-terpenoid biosynthetic pathways of 1-4 were also postulated. Five of these isolates exhibited anti-inflammatory activity by inhibiting NO production in LPS-induced RAW264.7 cells (IC50 = 11.6-19.5 µM). Moreover, oxirapentyn E diacetate showed a dose-dependent inhibition of pro-inflammatory cytokines IL-6 and TNF-α. Structural modification of oxirapentyn B yielded 29 new derivatives, among which seven showed improved activity (IC50 < 3 µM) and higher selectivity index (SI > 22). The structure-activity relationship study indicated that 7, 8-epoxy, and 6-acylation were crucial for the activity. These findings may provide a powerful tool to accelerate the discovery of new fungal acetylenic meroterpenoids for future anti-inflammatory drug development.

Absolute configuration of cyclopropanes and the structural revision of pyrones from Marine-derived fungus Stagonospora sp. SYSU-MS7888.

Two new cyclopropane derivatives (1-2) and seven undescribed α-pyrone derivatives (3-9), along with one known congener (10) were obtained from the marine fungus Stagonospora sp. SYSU-MS7888, which was isolated from the South China Sea. Their planar structures were established through extensive spectroscopic analyses including 1D and 2D NMR and HR-ESIMS. The absolute configurations were identified on basis of the quantum chemical calculations of ECD and NMR, as well as the modified Mosher's method. It's particularly noteworthy that the tetrasubstituted furopyrans, chenopodolans A-F, possessing phytotoxicity and zootoxicity, were structural misassignments. The structures of chenopodolans featuring with furopyran skeleton were revised as common trisubstituted α-pyrones by computational chemistry, NMR spectroscopic method, and empirical rule. Compounds 1, 2, 7, and 9 showed significant anti-inflammatory activity with IC50 values ranging from 3.6 to 22.8 µM, which is better than the positive control indomethacin (IC50 = 26.5 ± 1.13 µM). This discovery holds potential for the development of new anti-inflammatory agents.

YY1 promotes pancreatic cancer cell proliferation by enhancing mitochondrial respiration.

KRAS-driven metabolic reprogramming is a known peculiarity features of pancreatic ductal adenocarcinoma (PDAC) cells. However, the metabolic roles of other oncogenic genes, such as YY1, in PDAC development are still unclear. In this study, we observed significantly elevated expression of YY1 in human PDAC tissues, which positively correlated with a poor disease progression. Furthermore, in vitro studies confirmed that YY1 deletion inhibited PDAC cell proliferation and tumorigenicity. Moreover, YY1 deletion led to impaired mitochondrial RNA expression, which further inhibited mitochondrial oxidative phosphorylation (OXPHOS) complex assembly and altered cellular nucleotide homeostasis. Mechanistically, the impairment of mitochondrial OXPHOS function reduced the generation of aspartate, an output of the tricarboxylic acid cycle (TCA), and resulted in the inhibition of cell proliferation owing to unavailability of aspartate-associated nucleotides. Conversely, exogenous supplementation with aspartate fully restored PDAC cell proliferation. Our findings suggest that YY1 promotes PDAC cell proliferation by enhancing mitochondrial respiration and the TCA, which favors aspartate-associated nucleotide synthesis. Thus, targeting nucleotide biosynthesis is a promising strategy for PDAC treatment.

Construction of azaspirocyclic skeletons mediated by the carbonyl of the Weinreb amide: formal total synthesis of (±)-cephalotaxine.

A facile Stevens rearrangement of the Weinreb amide and the subsequent key steps mediated by the carbonyl of the Weinreb amide led to the construction of azaspirocyclic skeletons of some typical alkaloids. And the formal total synthesis of (±)-cephalotaxine was completed via a shorter synthetic route by this efficient method. Further studies on the development and asymmetric synthesis application of this strategy are underway.

Effects of IL-32 polymorphisms and IL-32 levels on the susceptibility and severity of coronary artery disease.

BACKGROUND: Interleukin-32 (IL-32) has long been proposed as a biomarker for coronary artery disease (CAD). We aimed to evaluate the association between IL-32 levels and coronary stenosis severity, IL-32 polymorphisms rs28372698 and rs4786370, and CAD susceptibility. METHODS: A total of 362 patients with definite or suspected CAD that underwent angiography were recruited (CAD group, n = 175; nonobstructive CAD group, n = 56; control group, n = 131). The severity of coronary stenosis was assessed using the Gensini score and the number of diseased vessels. IL-32 levels were determined using enzyme-linked immunosorbent assay. Gene polymorphisms were genotyped using PCR and sequencing techniques. RESULTS: IL-32 levels were significantly different at different levels of coronary artery stenosis (p < 0.05), and logIL-32 was positively correlated with the Gensini score (r = 0.357, p < 0.01). Multivariate logistic regression analysis revealed that IL-32 was independently associated with CAD (OR = 6.526, 95% CI: 3.344-12.739, p < 0.01). The receiver operating characteristic analysis revealed the area under the curve for discriminating the CAD and Gensini score were 0.605 and 0.613, respectively. Furthermore, IL-32 levels were significantly higher before percutaneous coronary intervention (PCI) than at 7 days post-PCI (p = 0.012). The homozygous TT genotype and T allele of rs28372698 were found to be associated with increased risk of CAD, while TT homozygosity and the T allele of rs4786370 with reduced risk of CAD (p < 0.05). However, both SNPs had no obvious effect on IL-32 levels or coronary stenosis severity in patients with CAD. CONCLUSION: To the best of our knowledge, our study is the first to show that rs28372698 and rs4786370 are associated with CAD susceptibility in Chinese Han population. We also suggest that plasma IL-32 levels may be indicative of coronary artery stenosis and the efficacy of PCI and provide guidance for risk stratification and disease management.

Bioactive Monoterpenes and Polyketides from the Ascidian-Derived Fungus Diaporthe sp. SYSU-MS4722.

There has been a tremendous increase in the rate of new terpenoids from marine-derived fungi being discovered, while new monoterpenes were rarely isolated from marine-derived fungi in the past two decades. Three new monoterpenes, diaporterpenes A-C (1-3), and one new α-pyrones, diaporpyrone A (6), along with nine known polyketides 4, 5, and 7-13 were isolated from the ascidian-derived fungus Diaporthe sp. SYSU-MS4722. Their planar structures were elucidated based on extensive spectroscopic analyses (1D and 2D NMR and HR-ESIMS). The absolute configurations of 1 and 3 were identified by an X-ray crystallographic diffraction experiment using Cu-Ka radiation, and those of compound 2 were assigned by calculating NMR chemical shifts and ECD spectra. It afforded an example of natural epimers with different physical properties, especially crystallization, due to the difference in intermolecular hydrogen bonding. Compounds 9, 10, and 13 showed moderate total antioxidant capacity (0.82 of 9; 0.70 of 10; 0.48 of 13) with Trolox (total antioxidant capacity: 1.0) as a positive control, and compounds 5 and 7 showed anti-inflammatory activity with IC50 values of 35.4 and 40.8 µM, respectively (positive control indomethacin: IC50 = 35.8 µM).

Mono- and Dimeric Xanthones with Anti-Glioma and Anti-Inflammatory Activities from the Ascidian-Derived Fungus Diaporthe sp. SYSU-MS4722.

Seven new xanthones, diaporthones A-G (1-7), together with 13 known analogues, including five mono- (8-14) and six dimeric xanthones (15-20), were obtained from the ascidian-derived fungus Diaporthe sp. SYSU-MS4722. Their planar structures were established by extensive spectroscopic analyses, including 1D and 2D NMR and high-resolution mass spectrometry (HR-ESIMS). The absolute configurations of 1-7 were clearly identified by X-ray crystallographic analysis and calculation of the ECD Spectra. Compounds 15-20 showed significant anti-inflammatory activity with IC50 values between 6.3 and 8.0 µM. In addition, dimeric xanthones (15-20) showed selective cytotoxicity against T98G cell lines with IC50 values ranging from 19.5 to 78.0 µM.

Genome Mining of α-Pyrone Natural Products from Ascidian-Derived Fungus Amphichordafelina SYSU-MS7908.

Culturing ascidian-derived fungus Amphichorda felina SYSU-MS7908 under standard laboratory conditions mainly yielded meroterpenoid, and nonribosomal peptide-type natural products. We sequenced the genome of Amphichorda felina SYSU-MS7908 and found 56 biosynthetic gene clusters (BGCs) after bioinformatics analysis, suggesting that the majority of those BGCSs are silent. Here we report our genome mining effort on one cryptic BGC by heterologous expression in Aspergillus oryzae NSAR1, and the identification of two new α-pyrone derivatives, amphichopyrone A (1) and B (2), along with a known compound, udagawanone A (3). Anti-inflammatory activities were performed, and amphichopyrone A (1) and B (2) displayed potent anti-inflammatory activity by inhibiting nitric oxide (NO) production in RAW264.7 cells with IC50 values 18.09 ± 4.83 and 7.18 ± 0.93 µM, respectively.

Two New Picoline-Derived Meroterpenoids with Anti-Acetylcholinesterase Activity from Ascidian-Derived Fungus Amphichorda felina.

Amphichoterpenoids D (1) and E (2), two new picoline-derived meroterpenoids with a rare 6/6/6 tricyclic pyrano[3,2-c]pyridinyl-γ-pyranone scaffold, were isolated from the ascidian-derived fungus Amphichorda felina SYSU-MS7908. Their structures, including the absolute configurations, were established by extensive spectroscopic methods (1D and 2D NMR and high-resolution mass spectrometry) and ECD calculations. Compounds 1 and 2 showed anti-acetylcholinesterase (anti-AChE) activities with IC50 values of 12.5 µM and 11.6 µM, respectively. The binding interactions between 1, 2, and AChE were investigated using molecular docking analyses.

[Analysis of two pedigrees affected with inherited dysfibrinogenemia due to a novel c.1115 T>A variant of the FGB gene].

OBJECTIVE: To analyze the phenotype and genotype of two Chinese family with inherited dysfibrinogenemia and the molecular pathogenic mechanism. METHODS: In the probands and their family members, coagulation routine, fibrinogen activity (Fg: A) and fibrinogen antigen (Fg: Ag) were detected. To find the mutation and exclude single nucleotide polymorphisms, all the exons and exons-intron boundaries of fibrinogen genes (FGA, FGB and FGG) were amplified by Ploymerase Chain Reaction (PCR), then sequenced. Bioinformatics prediction softwares were used to predict and score the change of function caused by the variant. PyMol were used to analyze the structure of protein caused by the variant. Clustal X software was used to analyze the conservation of the mutant amino acids. RESULTS: The thrombin time (TT) of the two was slightly prolonged and could not be corrected by protamine sulfate, and the fibrinogen activity was significantly reduced (1.25 g/L and 1.17 g/L), but the fibrinogen antigen content was normal, respectively (3.50 g /L and 3.81 g/L). Genetic analysis showed that both probands were heterozygous missense variants (FGB exon 7 c.1115T>A (p.Val372Glu)), both of which originated from the paternal line. The prediction results of the four bioinformatics softwares indicate that this variant could be disease causing. Clustal X software showed that Val372 is highly conserved among homologous species. Based on the guidelines of the American College of Medical Genetics and Genomics, c.1115T>A was predicted to be likely pathgenic (PM2+PP1+PP2+PP3+PP4). PyMol showed that the secondary structure and three-dimensional structure of fibrinogen protein were changed by p.Val372Glu variant. CONCLUSION: Inherited dysfibrinogenemia of the probands maybe caused by variant of FGB c.1115 T>A (p.Val372Glu), and the variant was firstly reported.

The chemistry and biology of fungal meroterpenoids (2009-2019).

Fungal meroterpenoids are secondary metabolites from mixed terpene-biosynthetic origins. Their intriguing chemical structural diversification and complexity, potential bioactivities, and pharmacological significance make them attractive targets in natural product chemistry, organic synthesis, and biosynthesis. This review provides a systematic overview of the isolation, chemical structural features, biological activities, and fungal biodiversity of 1585 novel meroterpenoids from 79 genera terrestrial and marine-derived fungi including macrofungi, Basidiomycetes, in 441 research papers in 2009-2019. Based on the nonterpenoid starting moiety in their biosynthesis pathway, meroterpenoids were classified into four categories (polyketide-terpenoid, indole-, shikimate-, and miscellaneous-) with polyketide-terpenoids (mainly tetraketide-) and shikimate-terpenoids as the primary source. Basidiomycota produced 37.5% of meroterpenoids, mostly shikimate-terpenoids. The genera of Ganoderma, Penicillium, Aspergillus, and Stachybotrys are the four dominant producers. Moreover, about 56% of meroterpenoids display various pronounced bioactivities, including cytotoxicity, enzyme inhibition, antibacterial, anti-inflammatory, antiviral, antifungal activities. It's exciting that several meroterpenoids including antroquinonol and 4-acetyl antroquinonol B were developed into phase II clinically used drugs. We assume that the chemical diversity and therapeutic potential of these fungal meroterpenoids will provide biologists and medicinal chemists with a large promising sustainable treasure-trove for drug discovery.

Absolute configuration of polypropionate derivatives: Decempyrones A-J and their MptpA inhibition and anti-inflammatory activities.

Under guidance of 1H NMR, ten new polypropionate derivatives, decempyrones A-J (1-10) along with two known analogues (11 and 12), were isolated from the marine-derived fungusFusarium decemcellulare SYSU-MS6716. The planar structures were elucidated on the basis of extensive spectroscopic analyses (1D and 2D NMR, and HR-ESIMS). The absolute configuration of the chiral centers in the side chain is a major obstacle for the structure identification of natural polypropionate derivatives. Herein, the J-based configurational analysis (JBCA), chemical degradation, geminal proton rule, and the modified Mosher's method were adopted to fix their absolute configurations in the side chain. Compounds 3 and 10 exhibited potent anti-inflammatory activity by inhibiting the production of NO in RAW264.7 cells activated by lipopolysaccharide with IC50values 22.4 ± 1.8 and 21.7 ± 1.1 µM. In addition, compounds 3 and 10 displayed MptpA inhibitory activity with an IC50 value of 19.2 ± 0.9 and 33.1 ± 2.9 µM. Structure-activity relationships of the polypropionate derivatives were discussed.

Isochromosome 11q is Associated with Unique Characteristics and Poor Prognosis in Patients with Acute Myeloid Leukemia.

BACKGROUND: Isochromosome 11q in patients with acute myeloid leukemia is rarely reported, and little is known about its main features. METHODS: The presence of isochromosome 11q was identified in four patients (three adults and one child) from screening 441 patients with an acute myeloid leukemia diagnosis between 2009 and 2018 by using R-banding and fluorescence in situ hybridization. RESULTS: The child, patient 1 with unreported isochromosome (partial 11q isochromosome), accompanied with t(1;11) translocation, initially achieved remission after receiving chemotherapy. However, 4 months later this patient experienced a relapse. While multiple treatments were tried, it had no effect and the patient survived for 16 months. The remaining patients with isochromosome 11q exhibited numerical/structural chromosomal abnormal-ities involving myelodysplastic syndrome-related chromosomes 5, 7, 8, and 20. In patients 2 and 3, we found a derivative chromosome 21. Patient 3 was newly diagnosed with acute myeloid leukemia and was treated with many chemotherapy protocols, unfortunately with no effect. The patient then received traditional Chinese medicine and survived for 10 months, although she still has not achieved complete remission. Patients 2 and 4 received chemotherapy but experienced rapid disease progression and died within 2 months. CONCLUSIONS: In summary, patients with isochromosome 11q/partial 11q isochromosome have a poorer prognosis, especially for isochromosome 11q. Furthermore, these chromosome aberrations may be risk factors for the presence of isochromosome 11q or myelodysplastic syndrome-related genes, both of them may be associated with a failure to respond to treatment and poor outcomes. Hence, these discoveries may lay a foundation to study mechanisms and explore treatments.

Antiplatelet and Antithrombotic Effects of Isaridin E Isolated from the Marine-Derived Fungus via Downregulating the PI3K/Akt Signaling Pathway.

Isaridin E, a cyclodepsipeptide isolated from the marine-derived fungus Amphichorda felina (syn. Beauveria felina) SYSU-MS7908, has been demonstrated to possess anti-inflammatory and insecticidal activities. Here, we first found that isaridin E concentration-dependently inhibited ADP-induced platelet aggregation, activation, and secretion in vitro, but did not affect collagen- or thrombin-induced platelet aggregation. Furthermore, isaridin E dose-dependently reduced thrombosis formation in an FeCl3-induced mouse carotid model without increasing the bleeding time. Mechanistically, isaridin E significantly decreased the ADP-mediated phosphorylation of PI3K and Akt. In conclusion, these results suggest that isaridin E exerts potent antithrombotic effects in vivo without increasing the risk of bleeding, which may be due to its important role in inhibiting ADP-induced platelet activation, secretion and aggregation via the PI3K/Akt pathways.

[Phenotypic and genotypic analysis of a pedigree affected with hereditary protein C deficiency].

OBJECTIVE: To analyze the phenotype and genetic variant in a pedigree affected with inherited protein C (PC) deficiency. METHODS: The proband and her family members (7 individuals from 3 generations) were tested for plasma protein C activity (PC:A), protein C antigen (PC:Ag) content and other coagulation indicators. All of the 9 exons and flanking sequences of the proband's PROC gene were amplified by PCR and sequenced. Suspected variants were verified by reverse sequencing of the proband and her family members. Bioinformatic software was used to analyze the pathogenicity and conservation of the variant site. Swiss-PdbViewer was used to analyze the three-dimensional model and the interaction with the mutant amino acid. RESULTS: The PC:A and PC:Ag of the proband, her grandmother, father and elder brother were decreased to 55%, 52%, 48%, 51% and 53%, 55%, 50%, 56%, respectively. Genetic analysis showed that the four individuals have all carried heterozygous c.1318C>T (p.Arg398Cys) missense mutation in exon 9 of the PROC gene. The score of MutationTaster was 0.991, PROVEAN was -3.72, and FATHMM was -2.49, all predicted it to be a harmful mutation. Phylogenetic analysis also showed that Arg398 was weakly conservative among homologous species. Protein model analysis showed that, in the wild type, Arg398 can form a hydrogen bond with Glu341 and Lys395 respectively, when it was mutated to Cys398, the hydrogen bond with Glu341 disappears and an additional hydrogen bond was formed with Lys395, which has changed the spatial structure of the protein. CONCLUSION: The heterozygous missense mutation c.1318C>T (p.Arg398Cys) of the PROC gene probably underlay the decreased PC:A and PC:Ag in this pedigree.

A Closed-Tube Nested Quantitative PCR Assay for Rapid Detection of Intron 22 Inversions in the Factor VIII Gene.

BACKGROUND: An inversion of intron 22 in the Factor VIII gene (Inv22) is the causative mutation for 45% of severe hemophilia A cases. Available methods for molecular diagnosis of Inv22 are generally tedious and not ideal for routine clinical use. METHODS: We report here a new method using a single closed-tube nested quantitative PCR (CN-qPCR) for rapid detection of Inv22. This method combines a 12-cycle long-distance PCR (LD-PCR) amplifying the int22h regions, followed by a duplex qPCR targeting two specific regions close to the int22h regions. All reagents were added to a single PCR mixture for the closed-tube assay. Sequential LD-PCR and qPCR was achieved by designing primers at substantially different melting temperatures and optimizing PCR conditions. RESULTS: Seventy-nine male hemophilia A patients of different disease severity were tested by both the CN-qPCR assay and the standard LD-PCR assay. CN-qPCR successfully made calls for all samples, whereas LD-PCR failed in eight samples. For the 71 samples where both methods made calls, the concordance was 100%. Inv22 was detected in 17 out of the 79 samples. Additionally, CN-qPCR achieved clear separation for 10 female carriers and 10 non-Inv22 females, suggesting the assay may also be useful for molecular diagnosis of female carriers. CONCLUSIONS: This new CN-qPCR method may provide a convenient and accurate F8 Inv22 test suitable for clinical use.