Enthesitis and Dactylitis Resolution with Risankizumab for Active Psoriatic Arthritis: Integrated Analysis of the Randomized KEEPsAKE 1 and 2 Trials.

INTRODUCTION: The presence (vs absence) of enthesitis/dactylitis is associated with greater psoriatic arthritis (PsA) activity and reduced health-related quality of life. Risankizumab, an interleukin 23 antagonist, demonstrated superior treatment efficacy over placebo in patients with PsA, including enthesitis/dactylitis. Herein, we report the efficacy of risankizumab on complete resolution of enthesitis and/or dactylitis and improvements in patient-reported outcomes in patients with PsA. METHODS: This integrated post hoc analysis of data from KEEPsAKE 1 and KEEPsAKE 2 included patients with baseline enthesitis (Leeds Enthesitis Index > 0) and/or dactylitis (Leeds Dactylitis Index > 0). Efficacy outcomes at weeks 24 and 52 included proportion of patients achieving enthesitis and/or dactylitis resolution and minimal clinically important differences (MCID) in pain, Health Assessment Questionnaire-Disability Index, and Functional Assessment of Chronic Illness Therapy-Fatigue. RESULTS: Of 1407 patients, approximately 63%, 28%, and 20% had baseline enthesitis, dactylitis, and both enthesitis/dactylitis, respectively. At week 24, higher response rates were observed for risankizumab vs placebo for resolution of enthesitis, dactylitis, and both enthesitis/dactylitis (differences of 13.9%, 16.9%, and 13.3%, respectively; p < 0.05). By week 52, risankizumab treatment resulted in complete resolution of enthesitis, dactylitis, and both enthesitis and dactylitis in 55.0%, 76.1%, and 52.3% of patients; similar resolution rates occurred among patients who switched from placebo to risankizumab. Among risankizumab-treated patients who achieved resolution of enthesitis and/or dactylitis, MCIDs were also attained in patient-reported pain, disability, and fatigue at week 24 (all p < 0.05; except fatigue in patients with resolution of both enthesitis/dactylitis); responses were sustained through week 52. CONCLUSIONS: Higher proportions of risankizumab-treated (vs placebo-treated) patients achieved enthesitis and/or dactylitis resolution and meaningful improvements in patient-reported outcomes at week 24 and generally sustained responses at week 52. Thus, risankizumab may result in sustained alleviation of PsA-related pathognomonic musculoskeletal lesions of enthesitis/dactylitis. GOV IDENTIFIERS: NCT03675308, and NCT03671148.

RNA base editing therapy cures hearing loss induced by OTOF gene mutation.

Otoferlin (OTOF) gene mutations represent the primary cause of hearing impairment and deafness in auditory neuropathy. The c.2485C>T (p. Q829X) mutation variant is responsible for approximately 3% of recessive prelingual deafness cases within the Spanish population. Previous studies have used two recombinant AAV vectors to overexpress OTOF, albeit with limited efficacy. In this study, we introduce an enhanced mini-dCas13X RNA base editor (emxABE) delivered via an AAV9 variant, achieving nearly 100% transfection efficiency in inner hair cells. This approach is aimed at treating OTOFQ829X, resulting in an approximately 80% adenosine-to-inosine conversion efficiency in humanized OtofQ829X/Q829X mice. Following a single scala media injection of emxABE targeting OTOFQ829X (emxABE-T) administered during the postnatal day 0-3 period in OtofQ829X/Q829X mice, we observed OTOF expression restoration in nearly 100% of inner hair cells. Moreover, auditory function was significantly improved, reaching similar levels as in wild-type mice. This enhancement persisted for at least 7 months. We also investigated P5-P7 and P30 OtofQ829X/Q829X mice, achieving auditory function restoration through round window injection of emxABE-T. These findings not only highlight an effective therapeutic strategy for potentially addressing OTOFQ829X-induced hearing loss but also underscore emxABE as a versatile toolkit for treating other monogenic diseases characterized by premature termination codons.

Prolonged hypoxia alleviates prolyl hydroxylation-mediated suppression of RIPK1 to promote necroptosis and inflammation.

The prolyl hydroxylation of hypoxia-inducible factor 1α (HIF-1α) mediated by the EGLN-pVHL pathway represents a classic signalling mechanism that mediates cellular adaptation under hypoxia. Here we identify RIPK1, a known regulator of cell death mediated by tumour necrosis factor receptor 1 (TNFR1), as a target of EGLN1-pVHL. Prolyl hydroxylation of RIPK1 mediated by EGLN1 promotes the binding of RIPK1 with pVHL to suppress its activation under normoxic conditions. Prolonged hypoxia promotes the activation of RIPK1 kinase by modulating its proline hydroxylation, independent of the TNFα-TNFR1 pathway. As such, inhibiting proline hydroxylation of RIPK1 promotes RIPK1 activation to trigger cell death and inflammation. Hepatocyte-specific Vhl deficiency promoted RIPK1-dependent apoptosis to mediate liver pathology. Our findings illustrate a key role of the EGLN-pVHL pathway in suppressing RIPK1 activation under normoxic conditions to promote cell survival and a model by which hypoxia promotes RIPK1 activation through modulating its proline hydroxylation to mediate cell death and inflammation in human diseases, independent of TNFR1.

Development of miniature base editors using engineered IscB nickase.

As a miniature RNA-guided endonuclease, IscB is presumed to be the ancestor of Cas9 and to share similar functions. IscB is less than half the size of Cas9 and thus more suitable for in vivo delivery. However, the poor editing efficiency of IscB in eukaryotic cells limits its in vivo applications. Here we describe the engineering of OgeuIscB and its corresponding ωRNA to develop an IscB system that is highly efficient in mammalian systems, named enIscB. By fusing enIscB with T5 exonuclease (T5E), we found enIscB-T5E exhibited comparable targeting efficiency to SpG Cas9 while showing reduced chromosome translocation effects in human cells. Furthermore, by fusing cytosine or adenosine deaminase with enIscB nickase, we generated miniature IscB-derived base editors (miBEs), exhibiting robust editing efficiency (up to 92%) to induce DNA base conversions. Overall, our work establishes enIscB-T5E and miBEs as versatile tools for genome editing.

Engineered CRISPR-OsCas12f1 and RhCas12f1 with robust activities and expanded target range for genome editing.

The type V-F CRISPR-Cas12f system is a strong candidate for therapeutic applications due to the compact size of the Cas12f proteins. In this work, we identify six uncharacterized Cas12f1 proteins with nuclease activity in mammalian cells from assembled bacterial genomes. Among them, OsCas12f1 (433 aa) from Oscillibacter sp. and RhCas12f1 (415 aa) from Ruminiclostridium herbifermentans, which respectively target 5' T-rich Protospacer Adjacent Motifs (PAMs) and 5' C-rich PAMs, show the highest editing activity. Through protein and sgRNA engineering, we generate enhanced OsCas12f1 (enOsCas12f1) and enRhCas12f1 variants, with 5'-TTN and 5'-CCD (D = not C) PAMs respectively, exhibiting much higher editing efficiency and broader PAMs, compared with the engineered variant Un1Cas12f1 (Un1Cas12f1_ge4.1). Furthermore, by fusing the destabilized domain with enOsCas12f1, we generate inducible-enOsCas12f1 and demonstate its activity in vivo by single adeno-associated virus delivery. Finally, dead enOsCas12f1-based epigenetic editing and gene activation can also be achieved in mammalian cells. This study thus provides compact gene editing tools for basic research with remarkable promise for therapeutic applications.

Ptbp1 knockdown failed to induce astrocytes to neurons in vivo.

The conversion of non-neuronal cells to neurons is a promising potential strategy for the treatment of neurodegenerative diseases. Recent studies have reported that shRNA-, CasRx-, or ASO-mediated Ptbp1 suppression could reprogram resident astrocytes to neurons. However, some groups have disputed the interpretation of the data underlying the reported neuron conversion events. These controversies surrounding neuron conversion may be due to differences in the astrocyte fate-mapping systems. Here, we suppressed Ptbp1 using Cas13X and labelled astrocytes with an HA tag fused to Cas13X (Cas13X-NLS-HA). We found no astrocyte-to-neuron conversion in the mouse striatum via the HA-tagged labelling system compared with the GFAP-driven tdTomato labelling system (AAV-GFAP::tdTomato-WPRE) used in previous studies. Our findings indicate that Cas13X-mediated Ptbp1 knockdown failed to induce neuron conversion in vivo.

Mini-dCas13X-mediated RNA editing restores dystrophin expression in a humanized mouse model of Duchenne muscular dystrophy.

Approximately 10% of monogenic diseases are caused by nonsense point mutations that generate premature termination codons (PTCs), resulting in a truncated protein and nonsense-mediated decay of the mutant mRNAs. Here, we demonstrate a mini-dCas13X-mediated RNA adenine base editing (mxABE) strategy to treat nonsense mutation-related monogenic diseases via A-to-G editing in a genetically humanized mouse model of Duchenne muscular dystrophy (DMD). Initially, we identified a nonsense point mutation (c.4174C>T, p.Gln1392*) in the DMD gene of a patient and validated its pathogenicity in humanized mice. In this model, mxABE packaged in a single adeno-associated virus (AAV) reached A-to-G editing rates up to 84% in vivo, at least 20-fold greater than rates reported in previous studies using other RNA editing modalities. Furthermore, mxABE restored robust expression of dystrophin protein to over 50% of WT levels by enabling PTC read-through in multiple muscle tissues. Importantly, systemic delivery of mxABE by AAV also rescued dystrophin expression to averages of 37%, 6%, and 54% of WT levels in the diaphragm, tibialis anterior, and heart muscle, respectively, as well as rescued muscle function. Our data strongly suggest that mxABE-based strategies may be a viable new treatment modality for DMD and other monogenic diseases.

Application of Intravenous Anesthesia in Laparoscopic Hiatal Hernia Repair of Children.

In order to solve the stress problem in laparoscopic hiatal hernia repair of children, improve surgical safety, and reduce surgical risk, this study compared the perioperative changes of epinephrine, norepinephrine, IL-6, IL-10, and hemodynamics in children undergoing laparoscopic surgery under intravenous general anesthesia and general anesthesia combined with an epidural block. In this study, 40 children aged 1-3 years who planned to undergo laparoscopic ortopexy and those who planned to undergo laparoscopic high ligation of hernia sac, aged 23.84 1.6 months and weighed 14.9 1.1 kg, were randomly divided into general anesthesia combined with the epidural block group (group A) and a total intravenous anesthesia group (group B), with 20 subjects in each group. The results are as follows: There were no differences in age, gender, body weight, anesthesia time, pneumoperitoneum duration, and functional time between the two groups. Cytokines: Compared with T0, the levels of IL-6 in T2, T3, T4, and T5 groups were significantly increased (P < 0.01). IL-10 levels: T2, T3, T4, and T5 groups were further increased, and the difference was statistically significant compared with T0 (P < 0.01). There was no difference between groups (P > 0.05). The recovery time in group B was shorter than that in group A (P < 0.01), and the total amount of propofol and fentanyl in group B was less than that in group A (P < 0.01). Through research on intravenous anesthesia treatment, it has been proved that total intravenous anesthesia can relieve perioperative pressure, reduce intravenous injection, and reduce the recovery time of children. However, its effect on cytokines is not obvious, so intravenous anesthesia is the most appropriate anesthesia mode in laparoscopic hiatal hernia repair surgery, which has practical significance.

Endogenous promoter-driven sgRNA for monitoring the expression of low-abundance transcripts and lncRNAs.

Detection of endogenous signals and precise control of genetic circuits in the natural context are essential to understand biological processes. However, the tools to process endogenous information are limited. Here we developed a generalizable endogenous transcription-gated switch that releases single-guide RNAs in the presence of an endogenous promoter. When the endogenous transcription-gated switch is coupled with the highly sensitive CRISPR-activator-associated reporter we developed, we can reliably detect the activity of endogenous genes, including genes with very low expression (<0.001 relative to Gapdh; quantitative-PCR analysis). Notably, we could also monitor the transcriptional activity of typically long non-coding RNAs expressed at low levels in living cells using this approach. Together, our method provides a powerful platform to sense the activity of endogenous genetic elements underlying cellular functions.

Ubiquitination of RIPK1 regulates its activation mediated by TNFR1 and TLRs signaling in distinct manners.

RIPK1 is a death-domain (DD) containing kinase involved in regulating apoptosis, necroptosis and inflammation. RIPK1 activation is known to be regulated by its DD-mediated interaction and ubiquitination, though underlying mechanisms remain incompletely understood. Here we show that K627 in human RIPK1-DD and its equivalent K612 in murine RIPK1-DD is a key ubiquitination site that regulates the overall ubiquitination pattern of RIPK1 and its DD-mediated interactions with other DD-containing proteins. K627R/K612R mutation inhibits the activation of RIPK1 and blocks both apoptosis and necroptosis mediated by TNFR1 signaling. However, Ripk1K612R/K612R mutation sensitizes cells to necroptosis and caspase-1 activation in response to TLRs signaling. Ripk1K612R/K612R mice are viable, but develop age-dependent reduction of RIPK1 expression, spontaneous intestinal inflammation and splenomegaly, which can be rescued by antibiotic treatment and partially by Ripk3 deficiency. Furthermore, we show that the interaction of RIPK1 with FADD contributes to suppressing the activation of RIPK3 mediated by TLRs signaling. Our study demonstrates the distinct roles of K612 ubiquitination in mRIPK1/K627 ubiquitination in hRIPK1 in regulating its pro-death kinase activity in response to TNFα and pro-survival activity in response to TLRs signaling.

Hepatocyte-specific TAK1 deficiency drives RIPK1 kinase-dependent inflammation to promote liver fibrosis and hepatocellular carcinoma.

Transforming growth factor ß-activated kinase1 (TAK1) encoded by the gene MAP3K7 regulates multiple important downstream effectors involved in immune response, cell death, and carcinogenesis. Hepatocyte-specific deletion of TAK1 in Tak1ΔHEP mice promotes liver fibrosis and hepatocellular carcinoma (HCC) formation. Here, we report that genetic inactivation of RIPK1 kinase using a kinase dead knockin D138N mutation in Tak1ΔHEP mice inhibits the expression of liver tumor biomarkers, liver fibrosis, and HCC formation. Inhibition of RIPK1, however, has no or minimum effect on hepatocyte loss and compensatory proliferation, which are the recognized factors important for liver fibrosis and HCC development. Using single-cell RNA sequencing, we discovered that inhibition of RIPK1 strongly suppresses inflammation induced by hepatocyte-specific loss of TAK1. Activation of RIPK1 promotes the transcription of key proinflammatory cytokines, such as CCL2, and CCR2+ macrophage infiltration. Our study demonstrates the role and mechanism of RIPK1 kinase in promoting inflammation, both cell-autonomously and cell-nonautonomously, in the development of liver fibrosis and HCC, independent of cell death, and compensatory proliferation. We suggest the possibility of inhibiting RIPK1 kinase as a therapeutic strategy for reducing liver fibrosis and HCC development by inhibiting inflammation.

Glia-to-Neuron Conversion by CRISPR-CasRx Alleviates Symptoms of Neurological Disease in Mice.

Conversion of glial cells into functional neurons represents a potential therapeutic approach for replenishing neuronal loss associated with neurodegenerative diseases and brain injury. Previous attempts in this area using expression of transcription factors were hindered by the low conversion efficiency and failure of generating desired neuronal types in vivo. Here, we report that downregulation of a single RNA-binding protein, polypyrimidine tract-binding protein 1 (Ptbp1), using in vivo viral delivery of a recently developed RNA-targeting CRISPR system CasRx, resulted in the conversion of Müller glia into retinal ganglion cells (RGCs) with a high efficiency, leading to the alleviation of disease symptoms associated with RGC loss. Furthermore, this approach also induced neurons with dopaminergic features in the striatum and alleviated motor defects in a Parkinson's disease mouse model. Thus, glia-to-neuron conversion by CasRx-mediated Ptbp1 knockdown represents a promising in vivo genetic approach for treating a variety of disorders due to neuronal loss.

CRISPR/Cas9-mediated targeted chromosome elimination.

BACKGROUND: The CRISPR/Cas9 system has become an efficient gene editing method for generating cells carrying precise gene mutations, including the rearrangement and deletion of chromosomal segments. However, whether an entire chromosome could be eliminated by this technology is still unknown. RESULTS: Here we demonstrate the use of the CRISPR/Cas9 system to eliminate targeted chromosomes. Using either multiple cleavages induced by a single-guide RNA (sgRNA) that targets multiple chromosome-specific sites or a cocktail of multiple sgRNAs, each targeting one specific site, we found that a sex chromosome could be selectively eliminated in cultured cells, embryos, and tissues in vivo. Furthermore, this approach was able to produce a targeted autosome loss in aneuploid mouse embryonic stem cells with an extra human chromosome and human induced pluripotent stem cells with trisomy 21, as well as cancer cells. CONCLUSIONS: CRISPR/Cas9-mediated targeted chromosome elimination offers a new approach to develop animal models with chromosome deletions, and a potential therapeutic strategy for human aneuploidy diseases involving additional chromosomes.

Regulation of RIPK1 activation by TAK1-mediated phosphorylation dictates apoptosis and necroptosis.

Stimulation of TNFR1 by TNFα can promote three distinct alternative mechanisms of cell death: necroptosis, RIPK1-independent and -dependent apoptosis. How cells decide which way to die is unclear. Here, we report that TNFα-induced phosphorylation of RIPK1 in the intermediate domain by TAK1 plays a key role in regulating this critical decision. Using phospho-Ser321 as a marker, we show that the transient phosphorylation of RIPK1 intermediate domain induced by TNFα leads to RIPK1-independent apoptosis when NF-κB activation is inhibited by cycloheximide. On the other hand, blocking Ser321 phosphorylation promotes RIPK1 activation and its interaction with FADD to mediate RIPK1-dependent apoptosis (RDA). Finally, sustained phosphorylation of RIPK1 intermediate domain at multiple sites by TAK1 promotes its interaction with RIPK3 and necroptosis. Thus, absent, transient and sustained levels of TAK1-mediated RIPK1 phosphorylation may represent distinct states in TNF-RSC to dictate the activation of three alternative cell death mechanisms, RDA, RIPK1-independent apoptosis and necroptosis.TNFα can promote three distinct mechanisms of cell death: necroptosis, RIPK1-independent and dependent apoptosis. Here the authors show that TNFα-induced phosphorylation of RIPK1 in the intermediate domain by TAK1 plays a key role in regulating this decision.

Homology-mediated end joining-based targeted integration using CRISPR/Cas9.

Targeted integration of transgenes can be achieved by strategies based on homologous recombination (HR), microhomology-mediated end joining (MMEJ) or non-homologous end joining (NHEJ). The more generally used HR is inefficient for achieving gene integration in animal embryos and tissues, because it occurs only during cell division, although MMEJ and NHEJ can elevate the efficiency in some systems. Here we devise a homology-mediated end joining (HMEJ)-based strategy, using CRISPR/Cas9-mediated cleavage of both transgene donor vector that contains guide RNA target sites and ∼800 bp of homology arms, and the targeted genome. We found no significant improvement of the targeting efficiency by the HMEJ-based method in either mouse embryonic stem cells or the neuroblastoma cell line, N2a, compared to the HR-based method. However, the HMEJ-based method yielded a higher knock-in efficiency in HEK293T cells, primary astrocytes and neurons. More importantly, this approach achieved transgene integration in mouse and monkey embryos, as well as in hepatocytes and neurons in vivo, with an efficiency much greater than HR-, NHEJ- and MMEJ-based strategies. Thus, the HMEJ-based strategy may be useful for a variety of applications, including gene editing to generate animal models and for targeted gene therapies.

A Single Intrathecal or Intraperitoneal Injection of CB2 Receptor Agonist Attenuates Bone Cancer Pain and Induces a Time-Dependent Modification of GRK2.

The objective of this study was to explore the potential role of G-protein-coupled receptor kinase 2 (GRK2) in the progression of cannabinoid 2 receptor (CB2) agonist-induced analgesic effects of bone cancer pain. Female Sprague-Dawley rats, weighing 160-180 g, were utilized to establish a model of bone cancer pain induced by intra-tibia inoculation of Walker 256 mammary gland carcinoma cells. JWH-015, a selective CB2 agonist, was injected intrathecally or intraperitoneally on postoperative day 10. Bone cancer-induced pain behaviors-mechanical allodynia and ambulatory pain-were assessed on postoperative days -1 (baseline), 4, 7, and 10 and at post-treatment hours 2, 6, 24, 48, and 72. The expressions of spinal CB2 and GRK2 protein were detected by Western Blotting on postoperative days -1 (baseline), 4, 7, and 10 and at post-treatment hours 6, 24, and 72. The procedure produced prolonged mechanical allodynia, ambulatory pain, and different changes in spinal CB2 and GRK2 expression levels. Intrathecal or intraperitoneal administration of JWH-015 alleviated the induced mechanical allodynia and ambulatory pain, and inhibited the downregulation of spinal GRK2 expression. These effects were in a time-dependent manner and reversed by pretreatment of CB2 selective antagonist AM630. The results affirmed CB2 receptor agonists might serve as new treatment targets for bone cancer pain. Moreover, spinal GRK2 was an important regulator of CB2 receptor agonist-analgesia pathway.

Phosphorylation and activation of ubiquitin-specific protease-14 by Akt regulates the ubiquitin-proteasome system.

Regulation of ubiquitin-proteasome system (UPS), which controls the turnover of short-lived proteins in eukaryotic cells, is critical in maintaining cellular proteostasis. Here we show that USP14, a major deubiquitinating enzyme that regulates the UPS, is a substrate of Akt, a serine/threonine-specific protein kinase critical in mediating intracellular signaling transducer for growth factors. We report that Akt-mediated phosphorylation of USP14 at Ser432, which normally blocks its catalytic site in the inactive conformation, activates its deubiquitinating activity in vitro and in cells. We also demonstrate that phosphorylation of USP14 is critical for Akt to regulate proteasome activity and consequently global protein degradation. Since Akt can be activated by a wide range of growth factors and is under negative control by phosphoinosotide phosphatase PTEN, we suggest that regulation of UPS by Akt-mediated phosphorylation of USP14 may provide a common mechanism for growth factors to control global proteostasis and for promoting tumorigenesis in PTEN-negative cancer cells.

Neuron-restrictive silencer factor in periaqueductal gray contributes to remifentanil-induced postoperative hyperalgesia via repression of the mu-opioid receptor.

BACKGROUND: The ultra-short-acting mu-opioid receptor (MOR) agonist remifentanil induces postoperative hyperalgesia both in preclinical and clinical research studies. However, the precise mechanisms remain unclear, although changes in opioid receptor expression might be a correlative feature. Neuron-restrictive silencer factor (NRSF) functions as a crucial regulator of MOR expression in specific neuronal cells. Using a mouse model of incisional postoperative pain, we assessed the expression of MOR and NRSF and investigated whether disruption of NRSF expression could prevent the postoperative nociceptive sensitization induced by surgical incision and subcutaneous infusion of remifentanil. METHODS: Paw withdrawal mechanical threshold (PWMT) and paw withdrawal thermal latency (PWTL) were independently used to assess mechanical allodynia and thermal hyperalgesia after surgery and cerebral ventricle injection of NRSF antisense oligonucleotide. Western blotting analyses were preformed to assess the expression levels of MOR and NRSF. RESULTS: NRSF expression levels were enhanced after intraoperative infusion of remifentanil, resulting in repression of MOR expression in the periaqueductal gray (PAG). NRSF blockade with an NRSF antisense oligonucleotide significantly enhanced the expression levels of MOR and alleviated mechanical allodynia and thermal hyperalgesia induced by intraoperative infusion of remifentanil. CONCLUSION: NRSF functions as a negative regulator of MOR in PAG and contributes to remifentanil-induced postoperative hyperalgesia. NRSF in PAG may be a potential target for this pain therapy.

Kinesin superfamily protein 17 contributes to the development of bone cancer pain by participating in NR2B transport in the spinal cord of mice.

Τreatment of bone cancer pain remains a challenge, while the mechanisms causing the pain remain elusive. We demonstrated that the expression of the N­methyl­D­aspartate (NMDA) receptor NR2B subunit was upregulated in mice with bone cancer pain. Kinesin superfamily protein 17 (KIF17), a recently characterized member of the kinesin superfamily proteins, has been demonstrated to transport and deliver the NR2B subunit to dendrites in mammalian neurons. In the present study, we induced bone cancer pain via femur bone cavity osteosarcoma NCTC 2472 tumor cell implantation (TCI) in mice. The results showed that TCI in mice increased the number of spontaneous flinches, mechanical allodynia events, expression of spinal KIF17 and NR2B subunits. Intrathecal administration of KIF17 antisense oligodeoxynucleotide (ODN) attenuated the behavioral signs of bone cancer pain and suppressed the increased expression of NR2B induced by TCI. In addition, KIF17 binds to a protein complex that contains mLin­10 to transport NR2B, and we determined that the increase of mLin­10 was suppressed following admini-stration. Thus, these findings suggested that KIF17 contributed to the development of bone cancer pain in the spinal cord through NR2B transport and that mLin­10 may also play a role in pain development.

The role of Tet3 DNA dioxygenase in epigenetic reprogramming by oocytes.

Sperm and eggs carry distinctive epigenetic modifications that are adjusted by reprogramming after fertilization. The paternal genome in a zygote undergoes active DNA demethylation before the first mitosis. The biological significance and mechanisms of this paternal epigenome remodelling have remained unclear. Here we report that, within mouse zygotes, oxidation of 5-methylcytosine (5mC) occurs on the paternal genome, changing 5mC into 5-hydroxymethylcytosine (5hmC). Furthermore, we demonstrate that the dioxygenase Tet3 (ref. 5) is enriched specifically in the male pronucleus. In Tet3-deficient zygotes from conditional knockout mice, paternal-genome conversion of 5mC into 5hmC fails to occur and the level of 5mC remains constant. Deficiency of Tet3 also impedes the demethylation process of the paternal Oct4 and Nanog genes and delays the subsequent activation of a paternally derived Oct4 transgene in early embryos. Female mice depleted of Tet3 in the germ line show severely reduced fecundity and their heterozygous mutant offspring lacking maternal Tet3 suffer an increased incidence of developmental failure. Oocytes lacking Tet3 also seem to have a reduced ability to reprogram the injected nuclei from somatic cells. Therefore, Tet3-mediated DNA hydroxylation is involved in epigenetic reprogramming of the zygotic paternal DNA following natural fertilization and may also contribute to somatic cell nuclear reprogramming during animal cloning.