Objective To investigate the changes of dorsal root ganglia(DRG)neurons in rats with voltage-gated sodium channel 1.7 loss-of-function(Nav1.7 LOF)and its involvement in congenital insensitivity to pain.Methods Immunofluorescence,Western blot,and alternative splicing analysis were used to verify the expression deletion of DRG neurons and Nav1.7 in spinal cord of Nav1.7 LOF rats.Using antibodies for peripherin,calcitonin gene-related peptide(CGRP),isolectin B4(IB4),and neuronal nuclear antigen(NeuN)in the DRG and spinal cord tissues,immunofluorescence staining was performed to observe the differences in DRG neuronal sub-populations and central terminal projections between Nav1.7 LOF rats and wild-type rats.Bulk RNA-Seq and real-time fluorescence quantitative polymerase chain reaction(RT-qPCR)was used to detect the difference of gene expression in the DRG neurons between Nav1.7 LOF and WT rats.Following 55℃ thermal stimulation of the hind paw in Nav1.7 LOF rats,c-Fos and phospho-extracellular signal-regulated kinase(p-ERK)antibody staining was used to observe the activation of DRG neurons and spinal dorsal horn neurons.Results Nav1.7 was absent in the DRG neurons and spinal cord of Nav1.7 LOF rats.Compared with wild-type rats,Nav1.7 LOF rats exhibited a decreased proportion of IB4+non-peptidergic neurons in DRG tissues.Additionally,there was a significant loss of central projections of IB4+neurons in the spinal dorsal horn.The RNA-Seq and RT-qPCR results demonstrate that in Nav1.7 LOF rats,the gene expression of Mas-related G protein-coupled receptor(MRGPR),markers for 1B4+non-peptidergic neurons,was downregulat-ed.Compared with WT rats,there was no difference in c-Fos and p-ERK staining in DRG neurons of Nav1.7 LOF rats following ther-mal stimulation of the hindpaw.However,there was no c-Fos or p-ERK staining in spinal dorsal horn neurons,suggesting that the neu-rons were not activated.Conclusion Nav1.7 LOF rats exhibit a decreased proportion of IB4+non-peptideric neurons in DRG tissue and their central terminal projections.Noxious stimuli could activate DRG neurons,but could not activate dorsal horn neurons,suggesting the pain signal is interrupted between the central terminals of DRG neurons and the spinal dorsal horn.

Objective To investigate the changes of dorsal root ganglia(DRG)neurons in rats with voltage-gated sodium channel 1.7 loss-of-function(Nav1.7 LOF)and its involvement in congenital insensitivity to pain.Methods Immunofluorescence,Western blot,and alternative splicing analysis were used to verify the expression deletion of DRG neurons and Nav1.7 in spinal cord of Nav1.7 LOF rats.Using antibodies for peripherin,calcitonin gene-related peptide(CGRP),isolectin B4(IB4),and neuronal nuclear antigen(NeuN)in the DRG and spinal cord tissues,immunofluorescence staining was performed to observe the differences in DRG neuronal sub-populations and central terminal projections between Nav1.7 LOF rats and wild-type rats.Bulk RNA-Seq and real-time fluorescence quantitative polymerase chain reaction(RT-qPCR)was used to detect the difference of gene expression in the DRG neurons between Nav1.7 LOF and WT rats.Following 55℃ thermal stimulation of the hind paw in Nav1.7 LOF rats,c-Fos and phospho-extracellular signal-regulated kinase(p-ERK)antibody staining was used to observe the activation of DRG neurons and spinal dorsal horn neurons.Results Nav1.7 was absent in the DRG neurons and spinal cord of Nav1.7 LOF rats.Compared with wild-type rats,Nav1.7 LOF rats exhibited a decreased proportion of IB4+non-peptidergic neurons in DRG tissues.Additionally,there was a significant loss of central projections of IB4+neurons in the spinal dorsal horn.The RNA-Seq and RT-qPCR results demonstrate that in Nav1.7 LOF rats,the gene expression of Mas-related G protein-coupled receptor(MRGPR),markers for 1B4+non-peptidergic neurons,was downregulat-ed.Compared with WT rats,there was no difference in c-Fos and p-ERK staining in DRG neurons of Nav1.7 LOF rats following ther-mal stimulation of the hindpaw.However,there was no c-Fos or p-ERK staining in spinal dorsal horn neurons,suggesting that the neu-rons were not activated.Conclusion Nav1.7 LOF rats exhibit a decreased proportion of IB4+non-peptideric neurons in DRG tissue and their central terminal projections.Noxious stimuli could activate DRG neurons,but could not activate dorsal horn neurons,suggesting the pain signal is interrupted between the central terminals of DRG neurons and the spinal dorsal horn.

OBJECTIVE: To identify potential mutations of F11 gene in a pedigree affected with hereditary coagulation factor XI (FXI) deficiency and explore its molecular pathogenesis. METHODS: Prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (FIB), coagulation factor VIII activity (FVIIIC), coagulation factor IX activity (FIXC), coagulation factor XI activity (FXIC), coagulation factor XII activity (FXIIC) and lupus anticoagulation (LA) of the proband and eight family members were determined. FXI antigen (FXIAg) was determined by enzyme-linked immunosorbent assay (ELISA). For the proband, potential mutations in the exons, flanking introns and 5'-, 3'-untranslated regions of the F11 gene were screened by direct DNA sequencing. The results were confirmed by reverse sequencing. Suspected mutations were detected in other family members. ClustalX-2.1-win and four online bioinformatic tools (PolyPhen-2, PROVEAN, SIFT, and Mutation Taster) were used to study the conservation and possible impact of the mutations. The structure of the mutational sites was processed with Swiss-PdbViewer. RESULTS: The propositus had prolonged APTT (69.6 s), whose FXIC and FXIAg were reduced to 6.0% and 10.7%, respectively. Her mother, elder sister, one younger sister, little brother, daughter and son showed slightly prolonged APTT and moderate FXIC and FXIAg levels. Gene sequencing revealed that the propositus carried a heterozygous nonsense mutation c.738G>A (p.Trp228stop) in exon 7 and a heterozygous mutation c.1556G>C (p.Trp501Ser) in exon 13. Her mother, elder sister and daughter were heterozygous for the p.Trp228stop mutation, while one younger sister and little brother and son were heterozygous for p.Trp501Ser. Her husband and the youngest sister were of the wild type. Phylogenetic analysis suggested that Trp501 was highly conserved among all homologous species. The p.Trp501Ser was predicted to be "probably damaging","deleterious", "affect protein function" and "disease causing" corresponding to PolyPhen-2, PROVEAN, SIFT and Mutation Taster. Model analysis demonstrated that the non-polar Trp501 has two benzene rings, forming a hydrogen bond with Gln512 in the wild type. Once substituted by Ser501, the side chain may form another hydrogen bond with the benzene of His396. This may affect the normal space conformation and stability of FXI protein. CONCLUSION The compound heterozygous mutations of the F11 gene probably accounted for the low FXI concentration in this pedigree.
Factor XI ; genetics ; Factor XI Deficiency ; genetics ; Female ; Heterozygote ; Humans ; Male ; Mutation ; Pedigree ; Phylogeny