Characterization of the structural determinants of the ubiquitin-dependent proteasomal degradation of human hepatic tryptophan 2,3-dioxygenase.

Human hepatic tryptophan 2,3-dioxygenase (hTDO) is a homotetrameric hemoprotein. It is one of the most rapidly degraded liver proteins with a half-life (t1/2) of ∼2.3 h, relative to an average t1/2 of ∼2-3 days for total liver protein. The molecular mechanism underlying the poor longevity of hTDO remains elusive. Previously, we showed that hTDO could be recognized and ubiquitinated by two E3 ubiquitin (Ub) ligases, gp78/AMFR and CHIP, and subsequently degraded via Ub-dependent proteasomal degradation pathway. Additionally, we identified 15 ubiquitination K-sites and demonstrated that Trp-binding to an exosite impeded its proteolytic degradation. Here, we further established autophagic-lysosomal degradation as an alternative back-up pathway for cellular hTDO degradation. In addition, with protein kinases A and C, we identified 13 phosphorylated Ser/Thr (pS/pT) sites. Mapping these pS/pT sites on the hTDO surface revealed their propinquity to acidic Asp/Glu (D/E) residues engendering negatively charged DEpSpT clusters vicinal to the ubiquitination K-sites over the entire protein surface. Through site-directed mutagenesis of positively charged patches of gp78, previously documented to interact with the DEpSpT clusters in other target proteins, we uncovered the likely role of the DEpSpT clusters in the molecular recognition of hTDO by gp78 and plausibly other E3 Ub-ligases. Furthermore, cycloheximide-chase analyses revealed the critical structural relevance of the disordered N- and C-termini not only in the Ub-ligase recognition, but also in the proteasome engagement. Together, the surface DEpSpT clusters and the N- and C-termini constitute an intrinsic bipartite degron for hTDO physiological turnover.

Induction via Functional Protein Stabilization of Hepatic Cytochromes P450 upon gp78/Autocrine Motility Factor Receptor (AMFR) Ubiquitin E3-Ligase Genetic Ablation in Mice: Therapeutic and Toxicological Relevance.

The hepatic endoplasmic reticulum (ER)-anchored monotopic proteins, cytochromes P450 (P450s), are enzymes that metabolize endobiotics (physiologically active steroids and fatty acids), as well as xenobiotics including therapeutic/chemotherapeutic drugs, nutrients, carcinogens, and toxins. Alterations of hepatic P450 content through synthesis, inactivation, or proteolytic turnover influence their metabolic function. P450 proteolytic turnover occurs via ER-associated degradation (ERAD) involving ubiquitin (Ub)-dependent proteasomal degradation (UPD) as a major pathway. UPD critically involves P450 protein ubiquitination by E2/E3 Ub-ligase complexes. We have previously identified the ER-polytopic gp78/AMFR (autocrine motility factor receptor) as a relevant E3 in CYP3A4, CYP3A23, and CYP2E1 UPD. We now document that liver-conditional genetic ablation of gp78/AMFR in male mice disrupts P450 ERAD, resulting in statistically significant stabilization of Cyp2a5 and Cyp2c, in addition to that of Cyp3a and Cyp2e1. More importantly, we establish that such stabilization is of the functionally active P450 proteins, leading to corresponding statistically significant enhancement of their drug-metabolizing capacities. Our findings, with clinically relevant therapeutic drugs (nicotine, coumarin, chlorzoxazone, and acetaminophen) and the prodrug (tamoxifen) as P450 substrates, reveal that P450 ERAD disruption could influence therapeutic drug response and/or toxicity, warranting serious consideration as a potential source of clinically relevant drug-drug interactions (DDIs). Because gp78/AMFR is not only an E3 Ub-ligase, but also a cell-surface prometastatic oncogene that is upregulated in various malignant cancers, our finding that hepatic gp78/AMFR knockout can enhance P450-dependent bioactivation of relevant cancer chemotherapeutic prodrugs is of therapeutic relevance and noteworthy in prospective drug design and development. SIGNIFICANCE STATEMENT: The cell-surface and ER transmembrane protein gp78/AMFR, a receptor for the prometastatic autocrine motility factor (AMF), as well as an E3 ubiquitin-ligase involved in the ER-associated degradation (ERAD) of not only the tumor metastatic suppressor KAI1 but also of hepatic cytochromes P450, is upregulated in various human cancers, enhancing their invasiveness, metastatic potential, and poor prognosis. Liver-specific gp78/AMFR genetic ablation results in functional protein stabilization of several hepatic P450s and consequently enhanced drug and prodrug metabolism, a feature that could be therapeutically exploited in the bioactivation of chemotherapeutic prodrugs through design and development of novel short-term gp78/AMFR chemical inhibitors.

Human liver cytochrome P450 3A4 ubiquitination: molecular recognition by UBC7-gp78 autocrine motility factor receptor and UbcH5a-CHIP-Hsc70-Hsp40 E2-E3 ubiquitin ligase complexes.

CYP3A4 is an abundant and catalytically dominant human liver endoplasmic reticulum-anchored cytochrome P450 enzyme engaged in the biotransformation of endo- and xenobiotics, including >50% of clinically relevant drugs. Alterations of CYP3A4 protein turnover can influence clinically relevant drug metabolism and bioavailability and drug-drug interactions. This CYP3A4 turnover involves endoplasmic reticulum-associated degradation via the ubiquitin (Ub)-dependent 26 S proteasomal system that relies on two highly complementary E2 Ub-conjugating-E3 Ub-ligase (UBC7-gp78 and UbcH5a-C terminus of Hsc70-interacting protein (CHIP)-Hsc70-Hsp40) complexes, as well as protein kinases (PK) A and C. We have documented that CYP3A4 Ser/Thr phosphorylation (Ser(P)/Thr(P)) by PKA and/or PKC accelerates/enhances its Lys ubiquitination by either of these E2-E3 systems. Intriguingly, CYP3A4 Ser(P)/Thr(P) and ubiquitinated Lys residues reside within the cytosol-accessible surface loop and/or conformationally assembled acidic Asp/Glu clusters, leading us to propose that such post-translational Ser/Thr protein phosphorylation primes CYP3A4 for ubiquitination. Herein, this possibility was examined through various complementary approaches, including site-directed mutagenesis, chemical cross-linking, peptide mapping, and LC-MS/MS analyses. Our findings reveal that such CYP3A4 Asp/Glu/Ser(P)/Thr(P) surface clusters are indeed important for its intermolecular electrostatic interactions with each of these E2-E3 subcomponents. By imparting additional negative charge to these Asp/Glu clusters, such Ser/Thr phosphorylation would generate P450 phosphodegrons for molecular recognition by the E2-E3 complexes, thereby controlling the timing of CYP3A4 ubiquitination and endoplasmic reticulum-associated degradation. Although the importance of phosphodegrons in the CHIP targeting of its substrates is known, to our knowledge this is the first example of phosphodegron involvement in gp78-substrate recruitment, an important step in CYP3A4 proteasomal degradation.

Hepatic cytochromes P450: structural degrons and barcodes, posttranslational modifications and cellular adapters in the ERAD-endgame.

The endoplasmic reticulum (ER)-anchored hepatic cytochromes P450 (P450s) are enzymes that metabolize endo- and xenobiotics i.e. drugs, carcinogens, toxins, natural and chemical products. These agents modulate liver P450 content through increased synthesis or reduction via inactivation and/or proteolytic degradation, resulting in clinically significant drug-drug interactions. P450 proteolytic degradation occurs via ER-associated degradation (ERAD) involving either of two distinct routes: Ubiquitin (Ub)-dependent 26S proteasomal degradation (ERAD/UPD) or autophagic lysosomal degradation (ERAD/ALD). CYP3A4, the major human liver/intestinal P450, and the fast-turnover CYP2E1 species are degraded via ERAD/UPD entailing multisite protein phosphorylation and subsequent ubiquitination by gp78 and CHIP E3 Ub-ligases. We are gaining insight into the nature of the structural determinants involved in CYP3A4 and CYP2E1 molecular recognition in ERAD/UPD [i.e. K48-linked polyUb chains and linear and/or "conformational" phosphodegrons consisting either of consecutive sequences on surface loops and/or disordered regions, or structurally-assembled surface clusters of negatively charged acidic (Asp/Glu) and phosphorylated (Ser/Thr) residues, within or vicinal to which, Lys-residues are targeted for ubiquitination]. Structural inspection of select human liver P450s reveals that such linear or conformational phosphodegrons may indeed be a common P450-ERAD/UPD feature. By contrast, although many P450s such as the slow-turnover CYP2E1 species and rat liver CYP2B1 and CYP2C11 are degraded via ERAD/ALD, little is known about the mechanism of their ALD-targeting. On the basis of our current knowledge of ALD-substrate targeting, we propose a tripartite conjunction of K63-linked Ub-chains, P450 structural "LIR" motifs and selective cellular "cargo receptors" as plausible P450-ALD determinants.

Minimally invasive cervical foraminotomy and diskectomy for laterally located soft disk herniation.

PURPOSE: The posterior cervical foraminotomy and diskectomy (PCD) is a traditional surgical technique for patients with laterally located soft-disk herniation. Recently, tubular retractor-assisted posterior foraminotomy and diskectomy (MTPF) and posterior percutaneous endoscopic cervical foraminotomy and diskectomy (P-PECD) have been introduced, but a comparative study has not yet been performed. METHODS: Patients with foraminal soft-disk herniation and a follow-up period of >2 years were retrospectively reviewed; 22 patients underwent a MTPF and 22 patients underwent a P-PECD. The primary end-point was an improvement of arm pain more than 4.3. The clinical parameters (age, sex, disability index, neck and arm pain), radiological parameters (cervical curvature, segmental angle, anterior-/posterior-disk height and amount of facet joint removal) preoperatively and at postoperative month 24 and the surgical methods were considered as co-variates. RESULTS: Successful outcome was achieved in 19/22 (87%) of the patients after both MTPF and a P-PECD. Preoperative SA showed trend (P = 0.08; OR 1.2; 95% CI 0.98-1.4) and the cut-off SA was 1.45° (sensitivity 80%, specificity 73%). The length of the facet joint's removal was 0.02-2.49 mm (0.1-15.2%) with no difference between the MTPF and P-PECD. The surgical method was not a significant factor. CONCLUSIONS: For patients with foraminal soft-disk herniation, either MTPF or P-PECD, may be regarded as an alternative options to open surgery. Preoperative kyphotic SA (cut-off value 1.45°) seemed to be associated with poor outcome and this may be considered in selecting surgical methods.

Decreased Muc5AC expression is associated with poor prognosis in gastric cancer.

Mucins reportedly play numerous key roles in carcinogenesis, including in tumor invasion, regulation of differentiation and tumor cell proliferation. We investigated the effect of Muc5AC, a secreted mucin, on the invasiveness/migratory capability of gastric cancer cells and the prognostic significance of Muc5AC in gastric cancer patients. The clinicopathological and prognostic significance of Muc5AC expression was validated using immunohistochemical analysis in 412 gastric cancer patients. Differential gene expression was investigated using complementary DNA microarray analysis of 48 fresh tumor tissue samples. Silencing of Muc5AC by using a small hairpin RNA-containing lentivirus increased the invasion and migration of SNU216 and AGS cells as well as Akt phosphorylation and the expression of vascular endothelial growth factor and matrix metalloproteinase-7, which were blocked by inhibitors of the phosphatidylinositol 3-kinase/Akt pathway. Loss of Muc5AC expression was significantly associated with tumor progression (advanced T stage; p = 0.004), lymph node metastases (p = 0.001), lymphovascular invasion (p < 0.0001), and increased tumor size (p = 0.027). Lower MUC5AC expression was identified as an independent poor prognostic factor in diffuse-type gastric cancer by using the Cox regression proportional hazard model (hazard ratio, 2.39; p = 0.043). Complementary DNA microarray analysis revealed 86 differentially expressed genes, including genes related to metastasis and invasion, in gastric cancer tissues with high (≥25%) and low (<25%) Muc5AC expression levels. Low Muc5AC expression increased the invasion and migration of gastric cancer cells and could be a useful biomarker of poor prognosis in gastric cancer.

Hepatic cytochrome P450 ubiquitination: conformational phosphodegrons for E2/E3 recognition?

Hepatic endoplasmic reticulum (ER) integral cytochromes P450 (P450s) are monooxygenases engaged in the biotransformation and elimination of endo- as well as xenobiotics. Of the human liver P450s, CYP3A4 is the major and most dominant catalyst responsible for the biotransformation of over 50% of clinically prescribed drugs. CYP2E1 metabolizes smaller molecular weight compounds (EtOH), carcinogens, environmental toxins, and endobiotics, and is justly implicated in various toxigenic/pathogenic mechanisms of human disease. Both P450s are notorious for their potential to generate pathogenic reactive oxygen species (ROS) during futile oxidative cycling and/or oxidative uncoupling. Such ROS not only oxidatively damage the P450 catalytic cage, but on their escape into the cytosol, also the P450 outer surface and any surrounding cell organelles. Given their ER-monotopic topology coupled with this high potential to acquire oxidative lesions in their cytosolic (C) domain, not surprisingly these P450 proteins exhibit shorter lifespans and are excellent prototype substrates of ER-associated degradation ("ERAD-C") pathway. Indeed, we have shown that both CYP3A4 and CYP2E1 incur ERAD-C, during which they are first phosphorylated by protein kinases A and C, which greatly enhance/accelerate their ubiquitination by UBC7/gp78 and UbcH5a/CHIP/Hsp70/Hsp40 E2/E3 ubiquitin ligase complexes. Such P450 phosphorylation occurs on Ser/Thr residues within linear sequences as well as spatially clustered acidic (Asp/Glu) residues. We propose that such S/T phosphorylation within these clusters creates negatively charged patches or conformational phosphodegrons for interaction with positively charged E2/E3 domains. Such P450 S/T phosphorylation we posit serves as a molecular switch to turn on its ubiquitination and ERAD-C.

Early prophylactic versus late selective use of surfactant for respiratory distress syndrome in very preterm infants: a collaborative study of 53 multi-center trials in Korea.

Pulmonary surfactant (PS) therapy was proven to be highly successful for the treatment of respiratory distress syndrome in premature infants. As a results, early prophylactic (EP) PS therapy has been introduced recently in Europe, the US and Korea. However, no multi-center study was compared EP and late selective (LS) PS therapies in Korea. We performed a retrospective multi-center study to compare the outcomes of EP and LS PS therapies in very preterm infants. We analyzed clinical morbidity and mortality for 1,291 infants in 2010 (LS group) and 1,249 infants in 2011 (EP group); the infants were born <30 weeks of gestation and had birth weight ≤1,250 g, and were chosen from 53 neonatal intensive care units in Korea. Compared to the LS group (22.5%), the overall mortality was better in the EP group (19.9%) and there was no increased need for retreatment.There were additional benefits in the EP group such as fewer associated complications. To the best of knowledge, our study is the first nationwide Korean study to compare the outcomes of EP and LS therapies, and it provides evidences that EP PS therapy is important in very preterm infants to improve for survival and reduce morbidities.

Analysis of the esthetic outcome after root coverage procedures using a comprehensive approach.

STATEMENT OF THE PROBLEM: There is a reported gap between the relative satisfaction of the clinician and patient after a root coverage procedure. In addition, there may also be a disparity between objective esthetic evaluation tools and subjective satisfaction. METHODS: This study included 58 sites in 31 patients who had undergone root coverage procedures. The percentage of root coverage and the root coverage esthetic score system were used as objective measurements. A questionnaire with a five-point ordinal scale was used for subjective evaluation. Initial recession depth and width, Miller classification, tissue biotype, treatment procedures, and follow-up periods were considered as associated factors. RESULTS: After a period of at least 6 months from the procedure, the patient-perceived outcome showed a better match with the root coverage esthetic scoring system than the percentage of root coverage alone. A lower value for objective outcome was obtained for a deeper gingival recession and higher Miller class, but the subjective outcome displayed a steady trend. All four esthetic results were at their lowest after an epithelialized free soft tissue graft. CONCLUSION: An esthetic outcome according to patient satisfaction was not always consistent with that determined by professional scoring. In addition, partial root coverage may be viewed as a positive outcome by patients and clinicians in cases of deep gingival recession and high Miller class. CLINICAL SIGNIFICANCE: This study evaluates the esthetic outcome of root coverage procedures using an objective method, including the percentage of root coverage, root coverage esthetic scoring system, and subjective assessment by patient and clinician-based questionnaires. The results will be helpful for the understanding of the differences that exist in esthetic satisfaction.

Complete Genome Sequence of Ralstonia solanacearum WR-1, a Virulent Strain on Solanum lycopersicum.

Ralstonia solanacearum is a bacterial wilt pathogen of Solanum lycopersicum. Its pathogenicity is the result of coevolution during continuous interaction with its host plants under given biotic and abiotic environments. To elucidate clues for pathogenicity of our WR-1 strain, its genome sequence was analyzed.

Complete Genome Sequence of Ralstonia solanacearum Strain Bs715, a Member of Biovar 4 and a Strong Pathogen of Bacterial Wilt on Solanum lycopersicum.

Ralstonia solanacearum is a notorious pathogen of bacterial wilt on Solanum lycopersicum. Most isolates from diseased tomato tissues are biovar 3, and their genomes are publicly available; however, information on biovar 4 strains is limited. Here, the complete genome sequence of R. solanacearum Bs715, a biovar 4 strain, is presented.

Complete Genome Sequence of Ralstonia pseudosolanacearum Strain Sw698, Isolated from Solanum lycopersicum.

Ralstonia pseudosolanacearum is a member of the Ralstonia solanacearum species complex (RSSC), which is composed of three species and diverse subspecific groups. Some strains cause bacterial wilt in Solanum lycopersicum; others are beneficial for their hosts. Herein, we present the complete genome sequence of an RSSC strain, Sw698, beneficial for S. lycopersicum growth.

Regulation of mouse steroidogenesis by WHISTLE and JMJD1C through histone methylation balance.

The dynamic exchange of histone lysine methylation status by histone methyltransferases and demethylases has been previously implicated as an important factor in chromatin structure and transcriptional regulation. Using immunoaffinity TAP analysis, we purified the WHISTLE-interacting protein complexes, which include the heat shock protein HSP90α and the jumonji C-domain harboring the histone demethylase JMJD1C. In this study, we demonstrate that JMJD1C specifically demethylates histone H3K9 mono- and di-methylation, and mediates transcriptional activation. We also provide evidence suggesting that both WHISTLE and JMJD1C performs functions in the development of mouse testes by regulating the expression of the steroidogenesis marker, p450c17, via SF-1-mediated transcription. Furthermore, we demonstrate that WHISTLE is recruited to the p450c17 promoter via SF-1 and represses the transcription of prepubertal stages of steroidogenesis, after which JMJD1C replaces WHISTLE and activates the expression of target genes via SF-1-mediated interactions. Our results demonstrate that the histone methylation balance mediated by HMTase WHISTLE and demethylase JMJD1C perform a transcriptional regulatory function in mouse testis development.

Liver cytochrome P450 3A ubiquitination in vivo by gp78/autocrine motility factor receptor and C terminus of Hsp70-interacting protein (CHIP) E3 ubiquitin ligases: physiological and pharmacological relevance.

CYP3A4 is a dominant human liver cytochrome P450 enzyme engaged in the metabolism and disposition of >50% of clinically relevant drugs and held responsible for many adverse drug-drug interactions. CYP3A4 and its mammalian liver CYP3A orthologs are endoplasmic reticulum (ER)-anchored monotopic proteins that undergo ubiquitin (Ub)-dependent proteasomal degradation (UPD) in an ER-associated degradation (ERAD) process. These integral ER proteins are ubiquitinated in vivo, and in vitro studies have identified the ER-integral gp78 and the cytosolic co-chaperone, CHIP (C terminus of Hsp70-interacting protein), as the relevant E3 Ub-ligases, along with their cognate E2 Ub-conjugating enzymes UBC7 and UbcH5a, respectively. Using lentiviral shRNA templates targeted against each of these Ub-ligases, we now document that both E3s are indeed physiologically involved in CYP3A ERAD/UPD in cultured rat hepatocytes. Accordingly, specific RNAi resulted in ≈80% knockdown of each hepatic Ub-ligase, with a corresponding ≈2.5-fold CYP3A stabilization. Surprisingly, however, such stabilization resulted in increased levels of functionally active CYP3A, thereby challenging the previous notion that E3 recognition and subsequent ERAD of CYP3A proteins required ab initio their structural and/or functional inactivation. Furthermore, coexpression in HepG2 cells of both CYP3A4 and gp78, but not its functionally inactive RING-finger mutant, resulted in enhanced CYP3A4 loss greater than that in corresponding cells expressing only CYP3A4. Stabilization of a functionally active CYP3A after RNAi knockdown of either of the E3s, coupled with the increased CYP3A4 loss on gp78 or CHIP coexpression, suggests that ERAD-associated E3 Ub-ligases can influence clinically relevant drug metabolism by effectively regulating the physiological CYP3A content and consequently its function.

Bone-added osteotome technique versus lateral approach for sinus floor elevation: a comparative radiographic study.

PURPOSE: The aim of this study was to evaluate and compare the radiographic results of bone-added osteotome sinus floor elevation (BAOSFE) and lateral approach sinus floor elevation techniques. METHODS: The 43 patients who had undergone implant procedure with either BAOSFE or lateral approach method on their maxillary molar edentulous area were included. Their dental records were confirmative and the radiographic-changes using orthopantomographs were consistently checked up during 2 years after the procedure (immediately after procedure and 6 months, 12 months, and 24 months after implant placement). RESULTS: The radiographic evaluation after 2 years of implantation with sinus elevation showed the significant amount of bone formation (6.75 mm for BAOSFE and 11.36 mm for lateral approach method). Largest amount of grafted height loss occurred during the first 6 months (62.8% of total amount of bone loss), but the resorption was minimal (1.35 mm for BAOSFE and 1.36 mm for lateral approach method) for overall 24 months. CONCLUSION: Long-term stability of graft height was achieved using both BAOSFE and lateral approach sinus floor elevation. Overall, graft height decreased gradually during 2 years after procedures, but the changes were minimal.

Successful advancement of endotracheal tube with combined fiberoptic bronchoscopy and videolaryngoscopy in a patient with a huge goiter.

If the presence of a goiter causes airway deformities in the supraglottic and infraglottic areas, difficult airway should be considered and airway evaluation including physical examination, radiologic studies, and indirect laryngoscopy should be preoperatively performed to determine the airway management plan. Various methods such as direct laryngoscopy, videolaryngoscopy, awake fiberoptic intubation, tracheostomy, and extracorporeal membrane oxygenation support have been reported to secure the airway. In most previously reported goiter cases, the upper airway patency was well maintained and the endotracheal tube was easily passed even when there was severe tracheal narrowing and deviation. We describe a case of successful combined use of videolaryngoscopy and fiberoptic bronchoscopy for advancement of an endotracheal tube through a narrow trachea due to the presence of a huge goiter.

Cytochrome P450 endoplasmic reticulum-associated degradation (ERAD): therapeutic and pathophysiological implications.

The hepatic endoplasmic reticulum (ER)-anchored cytochromes P450 (P450s) are mixed-function oxidases engaged in the biotransformation of physiologically relevant endobiotics as well as of myriad xenobiotics of therapeutic and environmental relevance. P450 ER-content and hence function is regulated by their coordinated hemoprotein syntheses and proteolytic turnover. Such P450 proteolytic turnover occurs through a process known as ER-associated degradation (ERAD) that involves ubiquitin-dependent proteasomal degradation (UPD) and/or autophagic-lysosomal degradation (ALD). Herein, on the basis of available literature reports and our own recent findings of in vitro as well as in vivo experimental studies, we discuss the therapeutic and pathophysiological implications of altered P450 ERAD and its plausible clinical relevance. We specifically (i) describe the P450 ERAD-machinery and how it may be repurposed for the generation of antigenic P450 peptides involved in P450 autoantibody pathogenesis in drug-induced acute hypersensitivity reactions and liver injury, or viral hepatitis; (ii) discuss the relevance of accelerated or disrupted P450-ERAD to the pharmacological and/or toxicological effects of clinically relevant P450 drug substrates; and (iii) detail the pathophysiological consequences of disrupted P450 ERAD, contributing to non-alcoholic fatty liver disease (NAFLD)/non-alcoholic steatohepatitis (NASH) under certain synergistic cellular conditions.

Histone methyltransferase PRDM8 regulates mouse testis steroidogenesis.

A family of PRDM proteins are similar to histone methyltransferases (HMTases) with SET domain in that they modulate different cellular processes, including transcriptional regulation, through chromatin modifying activities. By applying a bioinformatic approach, we searched for proteins containing the SET domain and identified a double zinc-finger domain containing PRDM8 with HMTase activity. In vitro HMTase assay and immunoblot analysis revealed that PRDM8 specifically methylates H3K9 of histones which indicates transcriptional repression activity of PRDM8. Direct recruitment of PRDM8 to the promoter mediated transcriptional repression and indicated no involvement of HDAC. Tissue blot analyses identified PRDM8 transcripts from brain and testis in adult mouse. Consistent with these observations, we demonstrate that PRDM8 repressed the expression of steroidogenic markers, p450c17c and LHR, which indicates its regulatory role in mouse testis development.

The patient-reported outcome of chronic pain after the harvest of anterior iliac bone for anterior cervical arthrodesis.

BACKGROUND: Anterior cervical fusion (ACF) with autologous iliac bone graft is a traditional surgical method, but high rate of chronic pain (30%) at the anterior iliac crest presents a considerable hindrance to harvesting iliac bone. The memory of acute pain may become fainter as time progresses, and the incidence of chronic pain may not be as high as previously reported. The primary objective was to show the patient-reported outcome of chronic pain in the anterior iliac crest. METHODS: Telephone surveys were conducted for patients with single-level ACF (group-S; n=72; M:F=52:20; median age, 53years), multiple-level ACF (group-M; n=61; M:F=40:21; 56years) using autologous iliac bone, and single-level ACF with a stand-alone cage (group-C; n=53; M:F=38:15; 51years). Logistic regression analysis was performed to determine the risk factors, and the variables included group, age, gender, postoperative period and satisfaction with the surgical outcome. RESULTS: There was no chronic pain in 87% of the patients, with no difference among the groups (p=0.52). During the acute postoperative period, patients remembered no pain in 38/72 (53%) patients of group-S, 25/61 (41%) of group-M and 42/53 (79%) of group-C (p<0.001). Female gender (p=0.027; OR, 2.68; 95% CI, 1.12-6.41) was the risk factor for chronic pain. CONCLUSIONS: Iliac bone harvest may not cause chronic pain in 87% of patients, and the memory of acute pain was faded in 40-50% of patients. Female gender was a risk factor for chronic pain. This information should be considered before harvesting iliac bone.

Comparison of Cervical Sagittal Alignment and Kinematics after Posterior Full-endoscopic Cervical Foraminotomy and Discectomy According to Preoperative Cervical Alignment.

BACKGROUND: The progression of cervical kyphosis due to injury to the facet joints and musculature is a major concern for posterior foraminotomy especially for patients with cervical lordosis of less than 10°. However, cervical hypo-lordosis (cervical lordosis < 10°) may be improved with the alleviation of pain and muscle spasms, which corresponds with the disappearance of a positive Spurling's test. When surgery is necessary, the spontaneous recovery of cervical curvature may be minimally offset using minimally invasive surgical techniques, such as posterior percutaneous endoscopic cervical foraminotomy (P-PECF). OBJECTIVES: The primary objective was to compare the changes in cervical kinematics between patients with cervical lordosis (≥ 10°, group I) and hypo-lordosis (< 10°, group II) after P-PECF. STUDY DESIGN: This study was a retrospective nested case-control study with the IRB No. H-1210-078-434. SETTING: University Medical Center, Seoul, Korea. METHODS: P-PECFs were performed for patients with a radiculopathy due to single-level unilateral cervical foraminal soft-disc herniations or foraminal stenosis with minimal degeneration of the disc/facet joints and a positive Spurling's test. A retrospective nested case-control study was performed for 23 patients with cervical lordosis of ≥ 10° (group I; M:F = 15:8; age, 52.3 ± 9.8 years) and 23 patients with cervical lordosis of < 10°(group II; M:F = 15:8; age, 46.3 ± 12.7 years). P-PECFs were performed using the methods previously reported, and all patients were discharged the next day without limitations on neck motion. The patients were followed at one, 3, 6, and 12 months postoperatively and yearly thereafter. The follow-up period was 25.8 ± 19.6 months. Clinical outcomes were assessed using the visual analogue pain score of arms. The cervical angles (C2-7, tangential method) were measured on neutral (CA), flexion (CAF), and extension (CAE) lateral radiographs, and range of motion (C-ROM) was calculated by conducting a radiological analysis. A linear mixed model was used to assess the linearity of the changes in cervical curvatures during the postoperative 12 months between the groups. RESULTS: Significant reductions in arm pain and negative results on Spurling's test were initially achieved in 21/23 patients in group I and in 23/23 patients in group II with means of 1.7 ± 0.31 months and 1.09 ± 0.09 months, respectively. Using the mixed effect models, the interactions between group and time were significant for the CA (P = 0.004), CAE (P < 0.001), and C-ROM (P < 0.001) but not the CAF (P = 0.392). The CA (adjusted-P < 0.001), CAE (adjusted-P < 0.001), and C-ROM (adjusted-P = 0.046) exhibited significant between-group differences at the pre-operation. However, during the follow-up, these parameters were significantly changed in group II, especially during the postoperative 3 months. The CA, CAE, and C-ROM changed by -11.73°, -19.87°, and 20.32°, respectively. Postoperatively, 17/23 patients in group II and 22/23 patients in group I exhibited cervical lordosis of ≥ 10°. LIMITATIONS: This study was retrospective in design, and the inherent selection bias and limited statistical power should be considered. CONCLUSIONS: Cervical hypo-lordosis less than 10° may not be a contra-indication for P-PECF when the change of cervical curvature is not a structural change. A larger study is necessary to identify prognostic factors. Key words: Alignment, cervical vertebrae, disc, percutaneous, endoscopes, biomechanical phenomena, surgery, lordosis, kyphosis.