Effect of retinoic acid signaling on Ripply3 expression and pharyngeal arch morphogenesis in mouse embryos.

BACKGROUND: Pharyngeal arches (PA) are sequentially generated in an anterior-to-posterior order. Ripply3 is essential for posterior PA development in mouse embryos and its expression is sequentially activated in ectoderm and endoderm prior to formation of each PA. Since the PA phenotype of Ripply3 knockout (KO) mice is similar to that of retinoic acid (RA) signal-deficient embryos, we investigated the relationship between RA signaling and Ripply3 in mouse embryos. RESULTS: In BMS493 (pan-RAR antagonist) treated embryos, which are defective in third and fourth PA development, Ripply3 expression is decreased in the region posterior to PA2 at E9.0. This expression remains and its distribution is expanded posteriorly at E9.5. Conversely, high dose RA exposure does not apparently change its expression at E9.0 and 9.5. Knockout of retinaldehyde dehydrogenase 2 (Raldh2), which causes more severe PA defect, attenuates sequential Ripply3 expression at PA1 and reduces its expression level. EGFP reporter expression driven by a 6 kb Ripply3 promoter fragment recapitulates the endogenous Ripply3 mRNA expression during PA development in wild-type, but its distribution is expanded posteriorly in BMS493-treated and Raldh2 KO embryos. CONCLUSION: Spatio-temporal regulation of Ripply3 expression by RA signaling is indispensable for the posterior PA development in mouse.

TGF-ß regulates nerve growth factor expression in a mouse intervertebral disc injury model.

BACKGROUND: Intervertebral disc (IVD) degeneration is a major cause of low back pain (LBP). Following disc injury, nerve growth factor (NGF) concentrations rise in IVDs, and anti-NGF therapy has been shown to attenuate LBP in humans. Increased levels of tumor necrosis factor-α (TNF-α) and transforming growth factor-ß (TGF-ß) in degenerative IVDs and in in vitro studies suggest that these factors promote NGF production. However, whether these factors regulate NGF in vivo remains unclear. Thus, we studied NGF regulation in a mouse model of IVD injury. METHODS: After inducing IVD injury, we examined mRNA levels of Tnfa, Tgfb, and Ngf in IVDs from control and IVD-injured mice across 7 days. To do this, we used magnetic cell separation to isolate CD11b ( +) (macrophage-rich) and CD11b (-) (IVD cell-rich) cell fractions from injured IVDs. To study the effect of TNF-α on Ngf expression, we examined Ngf expression in injured IVDs from C57BL/6 J and Tnfa-knockout (KO) mice (C57BL/6 J background). To study the effect of TGF-ß on Ngf expression, C57/BL6J mice were given an intraperitoneal injection of either the TGF-ß inhibitor SB431542 or DMSO solution (vehicle) one and two days before harvesting IVDs. RESULTS: mRNA expression of Tnfa, Tgfb, and Ngf was significantly increased in injured IVDs. Tnfa was predominantly expressed in the CD11b ( +) fraction, and Tgfb in the CD11b (-) fraction. Ngf expression was comparable between CD11b ( +) and CD11b (-) fractions, and between wild-type and Tnfa-KO mice at post-injury day (PID) 1, 3, and 7. SB431542 suppressed TGF-ß-mediated Ngf expression and NGF production in vitro. Further, administration of SB431542 significantly reduced Ngf expression in IVDs such that levels were below those observed in vehicle-treated animals at PID3 and PID7. CONCLUSION: A TGF-ß inhibitor reduced Ngf expression in a mouse model of IVD injury, suggesting that TGF-ß may regulate NGF expression in vivo.

Ripply3 is required for the maintenance of epithelial sheets in the morphogenesis of pharyngeal pouches.

During tissue development, the morphogenesis of epithelial sheets is regulated by many factors, including mechanical force, although the underlying mechanisms remain largely unknown. In the pharyngeal region of the vertebrate embryo, endodermal epithelium is reiteratively folded outward to form pharyngeal pouches, making partitions between the pharyngeal arches. Ripply3, encoding a member of the Ripply family of adaptor proteins, is required for the pouch formation posterior to the 2nd pharyngeal pouch. In this study, we found that the expression of mouse Ripply3 was specifically activated in accordance with the bending of the endodermal epithelium during the pouch formation. In Ripply3-deficient embryos, a continuous monolayer of the endodermal epithelium was not maintained posterior to the 2nd pharyngeal pouch. Corresponding to the endodermal region of the deformed epithelium, the activated form of Integrin ß1, which was localized at the basal side of the epithelial cells in the wild-type embryos, was not persistently observed in the mutants. On the other hand, cell proliferation and apoptotic cell death in the endoderm were not obviously affected by the Ripply3 deficiency. Significantly, Ripply3 expressed in cultured cells was found to be preferentially accumulated in the focal adhesions, which are Integrin-mediated adhesive contact sites transmitting mechanical force between the extracellular matrix and attached cells. Furthermore, Ripply3 promoted the maturation of focal adhesions in these cells. Thus, Ripply3 appears to have been activated to enhance the connection between the extracellular matrix and endodermal epithelial cells, as a mechanism to resist the mechanical stress generated during the bending of the epithelial sheets.

Insm1 promotes endocrine cell differentiation by modulating the expression of a network of genes that includes Neurog3 and Ripply3.

Insulinoma associated 1 (Insm1) plays an important role in regulating the development of cells in the central and peripheral nervous systems, olfactory epithelium and endocrine pancreas. To better define the role of Insm1 in pancreatic endocrine cell development we generated mice with an Insm1(GFPCre) reporter allele and used them to study Insm1-expressing and null populations. Endocrine progenitor cells lacking Insm1 were less differentiated and exhibited broad defects in hormone production, cell proliferation and cell migration. Embryos lacking Insm1 contained greater amounts of a non-coding Neurog3 mRNA splice variant and had fewer Neurog3/Insm1 co-expressing progenitor cells, suggesting that Insm1 positively regulates Neurog3. Moreover, endocrine progenitor cells that express either high or low levels of Pdx1, and thus may be biased towards the formation of specific cell lineages, exhibited cell type-specific differences in the genes regulated by Insm1. Analysis of the function of Ripply3, an Insm1-regulated gene enriched in the Pdx1-high cell population, revealed that it negatively regulates the proliferation of early endocrine cells. Taken together, these findings indicate that in developing pancreatic endocrine cells Insm1 promotes the transition from a ductal progenitor to a committed endocrine cell by repressing a progenitor cell program and activating genes essential for RNA splicing, cell migration, controlled cellular proliferation, vasculogenesis, extracellular matrix and hormone secretion.

Pharyngeal arch deficiencies affect taste bud development in the circumvallate papilla with aberrant glossopharyngeal nerve formation.

BACKGROUND: The pharyngeal arches (PAs) generate cranial organs including the tongue. The taste placodes, formed in particular locations on the embryonic tongue surface, differentiate into taste buds harbored in distinct gustatory papillae. The developing tongue also has a complex supply of cranial nerves through each PA. However, the relationship between the PAs and taste bud development is not fully understood. RESULTS: Ripply3 homozygous mutant mice, which have impaired third/fourth PAs, display a hypoplastic circumvallate papilla and lack taste buds, although the taste placode is normally formed. Formation of the glossopharyngeal ganglia is defective and innervation toward the posterior tongue is completely missing in Ripply3 mutant embryos at E12.5. Moreover, the distribution of neuroblasts derived from the epibranchial placode is severely, but not completely, atenuated, and the neural crest cells are diminished in the third PA region of Ripply3 mutant embryos at E9.5-E10.5. In Tbx1 homozygous mutant embryos, which exhibit another type of deficiency in PA development, the hypoplastic circumvallate papilla is observed along with abnormal formation of the glossopharyngeal ganglia and severely impaired innervation. CONCLUSIONS: PA deficiencies affect multiple aspects of taste bud development, including formation of the cranial ganglia and innervation to the posterior tongue.

Ripply3, a Tbx1 repressor, is required for development of the pharyngeal apparatus and its derivatives in mice.

The pharyngeal apparatus is a transient structure that gives rise to the thymus and the parathyroid glands and also contributes to the development of arteries and the cardiac outflow tract. A typical developmental disorder of the pharyngeal apparatus is the 22q11 deletion syndrome (22q11DS), for which Tbx1 is responsible. Here, we show that Ripply3 can modulate Tbx1 activity and plays a role in the development of the pharyngeal apparatus. Ripply3 expression is observed in the pharyngeal ectoderm and endoderm and overlaps with strong expression of Tbx1 in the caudal pharyngeal endoderm. Ripply3 suppresses transcriptional activation by Tbx1 in luciferase assays in vitro. Ripply3-deficient mice exhibit abnormal development of pharyngeal derivatives, including ectopic formation of the thymus and the parathyroid gland, as well as cardiovascular malformation. Corresponding with these defects, Ripply3-deficient embryos show hypotrophy of the caudal pharyngeal apparatus. Ripply3 represses Tbx1-induced expression of Pax9 in luciferase assays in vitro, and Ripply3-deficient embryos exhibit upregulated Pax9 expression. Together, our results show that Ripply3 plays a role in pharyngeal development, probably by regulating Tbx1 activity.

[Usefulness of echocardiography for detecting prosthetic valve dysfunction; report of a case].

A 78-year-old woman with a history of mitral valve stenosis underwent open mitral commissurotomy in 1976. In 1990, she underwent mitral valve replacement (Medtronic-Hall 29 mm), tricuspid annuloplasty(DeVega method), and pacemaker implantation for bradycardiac atrial fibrillation. However, in June 2012, she developed anemia of unknown cause. Prosthetic valve dysfunction was suspected, because intermittent changes in the left ventricular inflow was detected by echocardiography. Fluoroscopy actually confirmed the presence of prosthetic valve dysfunction. Therefore mitral valve re-replacement(ATS Medical, Inc. 29 mm) and tricuspid annuloplasty (Cosgrove ring 30 mm) were performed. Monitoring the changes in the left ventricular inflow is recommended when prosthetic valve dysfunction in a single leaflet is suspected.

[Early calcification of bioprosthetic valve in a hemodialysis patient with secondary hyperparathyroidism;report of a case].

Aortic valve replacement using CEP Magna 21 mm bioprosthetic valve was performed because of aortic valve stenosis in a 75-year-old man with maintenance dialysis. In the 39th postoperative month, the bioprosthetic valve malfunction due to calcification was noted, and it was replaced. Judging from the previously reported cases, malfunction of an artificial valve in the 39th month is thought to be relatively early. Early-stage calcification of a bioprosthetic valve is considered to be caused by secondary hyperparathyroidism due to artificial dialysis. Therefore, careful consideration is necessary in selecting an artificial valve in a dialysis patient. To prevent early-stage calcification of a bioprosthetic valve in a dialysis patient, strict control of parathyroid hormones, blood phosphorus and calcium levels is necessary. In addition, due to the attendant risk of calcification of bioprosthetic valves, mechanical valves are recommended to dialysis patients, who are expected to survive for more than 3 years and who are not expected to develop hemorrhagic complications.

Mice lacking nucleotide sugar transporter SLC35A3 exhibit lethal chondrodysplasia with vertebral anomalies and impaired glycosaminoglycan biosynthesis.

SLC35A3 is considered an uridine diphosphate N-acetylglucosamine (UDP-GlcNAc) transporter in mammals and regulates the branching of N-glycans. A missense mutation in SLC35A3 causes complex vertebral malformation (CVM) in cattle. However, the biological functions of SLC35A3 have not been fully clarified. To address these issues, we have established Slc35a3-/-mice using CRISPR/Cas9 genome editing system. The generated mutant mice were perinatal lethal and exhibited chondrodysplasia recapitulating CVM-like vertebral anomalies. During embryogenesis, Slc35a3 mRNA was expressed in the presomitic mesoderm of wild-type mice, suggesting that SLC35A3 transports UDP-GlcNAc used for the sugar modification that is essential for somite formation. In the growth plate cartilage of Slc35a3-/-embryos, extracellular space was drastically reduced, and many flat proliferative chondrocytes were reshaped. Proliferation, apoptosis and differentiation were not affected in the chondrocytes of Slc35a3-/-mice, suggesting that the chondrodysplasia phenotypes were mainly caused by the abnormal extracellular matrix quality. Because these histological abnormalities were similar to those observed in several mutant mice accompanying the impaired glycosaminoglycan (GAG) biosynthesis, GAG levels were measured in the spine and limbs of Slc35a3-/-mice using disaccharide composition analysis. Compared with control mice, the amounts of heparan sulfate, keratan sulfate, and chondroitin sulfate/dermatan sulfate, were significantly decreased in Slc35a3-/-mice. These findings suggest that SLC35A3 regulates GAG biosynthesis and the chondrodysplasia phenotypes were partially caused by the decreased GAG synthesis. Hence, Slc35a3-/- mice would be a useful model for investigating the in vivo roles of SLC35A3 and the pathological mechanisms of SLC35A3-associated diseases.

Regulation of Tumor Necrosis Factor-α by Peptide Lv in Bone Marrow Macrophages and Synovium.

Background: Bone marrow-derived monocytes/macrophages are recruited into synovial tissue, where they contribute to synovial inflammation in osteoarthritis through inflammatory cytokine production. Recent studies have suggested that V-Set and transmembrane domain-containing 4 (VSTM4) and its fragment, peptide Lv, exhibit immunosuppressive activity on T cells and vascular endothelial growth factor (VEGF)-like activity, respectively. Given that evidence suggests that VEGF may play a role in macrophage function, we investigated peptide Lv-mediated regulation of inflammatory cytokines in bone marrow macrophages (BMMs) and synovial inflammation. Method: To investigate the effects of peptide Lv, BMMs were stimulated with vehicle, LPS, or LPS + peptide Lv, and Tnfa, Il1b, Il6, and Ifng expression were evaluated using quantitative PCR (qPCR). TNF-α and IFN-γ production was measured using ELISA. To examine the effect of peptide Lv deficiency on macrophages and synovitis, peptide Lv-deficient mice were generated using genome editing. LPS-induced Tnfa and Ifng expression and TNF-α and IFN-γ production were evaluated in BMM isolated from wild-type and peptide Lv-deficient mice. Additionally, Tnfa and Ifng expression levels were compared between wild-type and peptide Lv-deficient mice before and after knee injury. Results: Peptide Lv suppressed the LPS-mediated elevation in TNF-α and IFN-γ. LPS stimulation significantly increased TNF-α and IFN-γ production in BMM derived from peptide Lv-deficient mice compared to wild-type mice. Synovial TNF-α expression in the injured knee was elevated in peptide Lv-deficient compared to wild-type mice. Conclusion: Peptide Lv suppressed TNF-α in macrophages and plays a role in synovial inflammation. Thus, peptide Lv may be a useful therapeutic target for synovitis.

Cell lineage mapping of taste bud cells and keratinocytes in the mouse tongue and soft palate.

The epithelium of the mouse tongue and soft palate consists of at least three distinct epithelial cell populations: basal cells, keratinized cells organized into filiform and fungiform papillae, and taste receptor cells present in tight clusters known as taste buds in the fungiform and circumvallate papillae and soft palate. All three cell types develop from the simple epithelium of the embryonic tongue and palate, and are continually replaced in the adult by cell turnover. Previous studies using pulse-chase tritiated thymidine labeling in the adult mouse provided evidence for a high rate of cell turnover in the keratinocytes (5-7 days) and taste buds (10 days). However, little is known about the localization and phenotype of the long-term stem or progenitor cells that give rise to the mature taste bud cells and surrounding keratinocytes in these gustatory tissues. Here, we make use of a tamoxifen-inducible K14-CreER transgene and the ROSA26 LacZ reporter allele to lineage trace the mature keratinocytes and taste bud cells of the early postnatal and adult mouse tongue and soft palate. Our results support the hypothesis that both the pore keratinocytes and receptor cells of the taste bud are derived from a common K14(+)K5(+)Trp63(+)Sox2(+) population of bipotential progenitor cells located outside the taste bud. The results are also compatible with models in which the keratinocytes of the filiform and fungiform papillae are derived from basal progenitor cells localized at the base of these structures.

[Evaluation of a new method of pericardial drainage after cardiac surgery].

Recently pericardial drainage after cardiac surgery has been done using silicon tubes of small diameter. For more effective drainage, we set one of the drainage tubes circularly, coursing behind the left ventricle, through the transverse sinus, and ending at the right side of the atrium (circular pericardial drainage). As compared to conventional drainage using 28 Fr chloroethilene tubes, drainage time was shorter and no late tamponade had occurred. Circular pericardial drainage may be useful.

Mice lacking EFA6C/Psd2, a guanine nucleotide exchange factor for Arf6, exhibit lower Purkinje cell synaptic density but normal cerebellar motor functions.

ADP ribosylation factor 6 (Arf6) is a small GTPase that regulates various neuronal events including formation of the axon, dendrites and dendritic spines, and synaptic plasticity through actin cytoskeleton remodeling and endosomal trafficking. EFA6C, also known as Psd2, is a guanine nucleotide exchange factor for Arf6 that is preferentially expressed in the cerebellar cortex of adult mice, particularly in Purkinje cells. However, the roles of EFA6C in cerebellar development and functions remain unknown. In this study, we generated global EFA6C knockout (KO) mice using the CRISPR/Cas9 system and investigated their cerebellar phenotypes by histological and behavioral analyses. Histological analyses revealed that EFA6C KO mice exhibited normal gross anatomy of the cerebellar cortex, in terms of the thickness and cellularity of each layer, morphology of Purkinje cells, and distribution patterns of parallel fibers, climbing fibers, and inhibitory synapses. Electron microscopic observation of the cerebellar molecular layer revealed that the density of asymmetric synapses of Purkinje cells was significantly lower in EFA6C KO mice compared with wild-type control mice. However, behavioral analyses using accelerating rotarod and horizontal optokinetic response tests failed to detect any differences in motor coordination, learning or adaptation between the control and EFA6C KO mice. These results suggest that EFA6C plays ancillary roles in cerebellar development and motor functions.

Integrated proteomic and transcriptomic profiling of mouse lung development and Nmyc target genes.

Although microarray analysis has provided information regarding the dynamics of gene expression during development of the mouse lung, no extensive correlations have been made to the levels of corresponding protein products. Here, we present a global survey of protein expression during mouse lung organogenesis from embryonic day E13.5 until adulthood using gel-free two-dimensional liquid chromatography coupled to shotgun tandem mass spectrometry (MudPIT). Mathematical modeling of the proteomic profiles with parallel DNA microarray data identified large groups of gene products with statistically significant correlation or divergence in coregulation of protein and transcript levels during lung development. We also present an integrative analysis of mRNA and protein expression in Nmyc loss- and gain-of-function mutants. This revealed a set of 90 positively and negatively regulated putative target genes. These targets are evidence that Nmyc is a regulator of genes involved in mRNA processing and a repressor of the imprinted gene Igf2r in the developing lung.

Differential behavioral phenotypes of dopamine D1 receptor knockdown mice at the embryonic, postnatal, and adult stages.

Dopamine is widely involved in behaviors related to motor activity, cognition, motivation, and reward. Dopamine signal is transduced through the dopamine receptor gene family. The dopamine D1 receptor (D1R) is highly expressed in the striatum, and is responsible for regulating the motor function. Recently, we have reported that the knockdown (KD) mice in which D1R was conditionally eliminated at adult stage, displayed a hypoactivity in the home cage than wild type mice; however, conventional D1R knockout (KO) mice show hyperactive phenotypes. In order to assess whether the difference in the time of eliminating D1R expression affects the behavioral phenotypes, we generated D1R KD mice at the postnatal and adult stages, and compared their motor function with D1R KO mice. Consequently, D1R KD at postnatal and adult stages resulted in severe locomotive defects compared with D1R KO mice. These results suggested that D1R has versatile functions, and the knockdown timing greatly influences the normal motor activity in the adolescent to adult stages.

Stromal cells modulate ephrinB2 expression and transmigration of hematopoietic cells.

OBJECTIVE: Ephrin ligands and Eph receptors play important roles for cell behavior and movement by transducing bidirectional signaling into interacting cells. Since we found that the expression of ephrinB2 in the hematopoietic progenitor cell line was changed by coculture with stromal cells, we tried to examine the function of ephrinB2 in the hematopoietic microenvironment. METHODS: Expression of ephrinB2 was measured by flow cytometry and reverse transcriptase polymerase chain reaction in the bone marrow (BM) hematopoietic cells and the stroma-dependent hematopoietic cell line (DFC-28) cocultured with stromal cells. Effect of ephrinB2 on the cells' behavior was monitored by overexpression of ephrinB2 cDNA in mouse pre-B-cell line (70z/3). RESULTS: EphrinB2 expression in DFC-28 cells was modulated by two different stromal cells; ephrinB2 expression was high in DFC-28 cells when cocultured with MSS62 cells, whereas it was low when they were cocultured with TBR31-1 cells. Expression of EphB4, a receptor for ephrinB2, was detected in MSS62 cells but not in TBR31-1 cells. Similarly, BM hematopoietic cells did not express ephrinB2, but most of the BM cells expressed ephrinB2 after coculture with stromal cells. Ectopic expression of ephrinB2 in 70z/3 cells acquires specific binding to EphB4 and leads to significant decline in the locomotive activity underneath stromal cells. CONCLUSION: These results indicate that expression of ephrinB2 in hematopoietic cells is regulated by interaction with particular stromal cells, and ephrinB2-EphB4 interaction modulates the migration and colonization of the hematopoietic cells in the local stromal microenvironment.

Reversible switching of expression of c-kit and Pax-5 in immature hematopoietic progenitor cells by stromal cells.

OBJECTIVE: Bone marrow stromal cells provide the microenvironment for self-renewal and differentiation of hematopoietic stem/progenitor cells through complex cell-cell interaction. To elucidate the regulatory mechanisms of hematopoiesis by stromal cells, we established a novel stroma-dependent hematopoietic cell line and explored the phenotypic changes regulated by the two stromal cells. MATERIALS AND METHODS: DFC-28 cells clonally established from long-term bone marrow culture of C57BL/6 mice were sustained by coculture on MSS62 cells (mouse spleen stromal cell line). When DFC-28 cells were transferred to TBR31-1 cells (mouse bone marrow stromal cell line), their phenotypic changes were analyzed by flow cytometry and reverse transcriptase polymerase chain reaction. RESULTS: DFC-28 cells on MSS62 cells exhibited surface phenotypes of the immature hematopoietic progenitor cells (Lin(-)AA4.1(+)c-kit(+)Sca-1(-)). By stroma-replacement from MSS62 cells to TBR31-1 cells, DFC-28 cells were differentiated into very early B-lymphoid stage characterized by c-kit down-regulation and induction of BP-1 and B-lymphoid-associated genes (Pax-5, CD19, TdT, Rag-1, and Rag-2). In addition, the differentiation phenotypes reverted to the immature state characterized by c-kit induction and down-regulation of BP-1 and B-lymphoid-associated genes by replacing stroma back to MSS62 from TBR31-1. Interleukin-7 stimulation and conditioned medium of TBR31-1 cells were ineffective in converting the differentiation phenotypes of DFC-28 cells. CONCLUSIONS: The results demonstrate that the differentiation phenotypes and growth potential of stroma-dependent hematopoietic progenitor cells we established could be reversibly controlled via direct contact with stromal cells in the microenvironment.

Genome structure and differential expression of two isoforms of a novel PDZ-containing myosin (MysPDZ) (Myo18A).

We previously cloned a gene for a novel myosin (called MysPDZ) containing a PDZ-domain from bone marrow stromal cells. This new myosin is found in humans and classified as one of the class XVIII myosins (Myo18A). Here, we report the hematopoietic cell-specific splicing isoform (MysPDZbeta) in addition to the previously reported isoform (MysPDZalpha). Combined with mouse genome sequence data, the overall genome structure and generation of the two spliced isoforms are deduced. The MysPDZbeta protein lacks a PDZ-domain in the N-terminal region. Studies of the subcellular localization of the two spliced isoforms indicated that MysPDZalpha containing the PDZ domain co-localizes with the ER-Golgi complex, while MysPDZbeta, which lacks the PDZ domain, localizes diffusely in the cytoplasm. These results suggest that the isoforms differ in their subcellular localization and may have different functions in membrane ruffling and membrane traffic pathways. The PDZ-containing spliced isoform (MysPDZalpha) is not expressed in bone marrow hematopoietic cells, whereas MysPDZbeta lacking the PDZ is specifically expressed in most hematopoietic cells. It is noted that neither isoform is expressed in red blood cells. Interestingly, MysPDZalpha was detected in mature but not in immature macrophages, and its level increased after the induction of differentiation of M1 cells, suggesting a functional role of PDZ-containing myosin in macrophages.

Single-stage transmedial approach to a Stanford type B dissection in a patient with Marfan's syndrome.

We report the case of a patient with Marfan's syndrome and a Stanford type B chronic aortic dissection in which replacement of the ascending aorta, aortic arch and descending aorta was accomplished in a single stage via median sternotomy. The patient was a 51-year-old woman with a 70 mm Stanford type B chronic aortic dissection and Marfan's syndrome. Median sternotomy and replacement of the ascending aorta, aortic arch, and descending aorta were performed under deep hypothermic circulatory arrest. Postoperatively, the patient developed paraplegia. However, after immediate placement of an intrathecal catheter and drainage of cerebrospinal fluid for 72 hours, the neurologic deficit fully resolved. Despite concerns related to the complexity of the procedure and neurological protection during the procedure, we believe that single-stage replacement of the ascending aorta, aortic arch, and descending aorta is possible and is one of several surgical choices for patients such as ours.