Emerging evidence indicates the early growth response 1 (Egr1) plays an important role in the pathogenesis of chronic pain. However, the regulation of Egr1 expression in the DRG and spinal cord in ...neuropathic pain remains unclear. In the current study, the neuropathic pain was conducted by lumber 5 spinal nerve ligation (SNL) in rats. The role of miR‐124‐3p in Egr1 expression was examined. Our results showed that the SNL led to a significant increase in the expression of Egr1 mRNA and protein in the DRG and dorsal horn. This increased expression of Egr1 correlated with a reduction of miR‐124‐3p in the same region. Prior i.t. injection of Egr1 decoy AYX1 inhibited the expression of Egr1 and attenuated the neuropathic pain‐like hypersensitivity following SNL. The dual‐luciferase reporter assay revealed the luciferase activity of the Egr1 3′‐UTR plasmid was inhibited by the miR‐124‐3p agomir. But this inhibition was completely reversed in the mutant 3′‐UTR Egr1 group. In vivo, the SNL‐induced behavioral signs of neuropathic pain and the increases in Egr1 mRNA and protein in the DRG and dorsal horn were prevented by prior to i.t. injection of miR‐124‐3p agomir. While, i.t. injection of miR‐124‐3p antagomir in naïve rats resulted in mechanical allodynia and thermal hyperalgesia and an overexpression of Egr1 in the DRG and dorsal horn. Together, our results suggest that the miR‐124‐3p‐regulated Egr1 expression in the DRG and dorsal horn contributes to the development of neuropathic pain. Targeting miR‐124‐3p might be a promising therapeutic strategy in the treatment of chronic pain.
The Egr1 has been implicated in regulating a variety of genes’ expression. MicroRNAs (MiRNAs) have emerged as key regulators in the maladaptive plasticity of chronic pain. However, whether miRNA‐124 involves in the modulation of Egr1 expression in neuropathic pain remains elusive. In the current study, we found the spinal nerve injury‐induced down‐regulation of miR‐124‐3p via promoting Egr1 expression in the dorsal root ganglion (DRG) and the spinal dorsal horn contributed to the development of neuropathic pain. Targeting DRG and spinal miR‐124‐3p might be a promising therapeutic strategy for the prevention and treatment of chronic pain.
Emerging evidence has implicated an important role of synapse-associated protein-97 (SAP97)-regulated GluA1-containing AMPARs membrane trafficking in cocaine restate and in contextual episodic memory ...of schizophrenia. Herein, we investigated the role of SAP97 in neuropathic pain following lumbar 5 spinal nerve transection (SNT) in rats. Our results showed that SNT led to upregulation of SAP97, enhanced the interaction between SAP97 and GluA1, and increased GluA1-containing AMPARs membrane trafficking in the dorsal horn. Microinjection of AAV-EGFP-SAP97 shRNA in lumbar 5 spinal dorsal horn inhibited SAP97 production, decreased SAP97-GluA1 interaction, reduced the membrane trafficking of GluA1-containing AMPARs, and partially attenuated neuropathic pain following SNT. Intrathecal injections of SAP97 siRNA or NASPM, an antagonist of GluA1-containing AMPARs, also partially reversed neuropathic pain on day 7, but not on day 14, after SNT. Spinal overexpression of SAP97 by AAV-EGFP-SAP97 enhanced SAP97-GluA1 interaction, increased the membrane insertion of GluA1-containing AMPARs, and induced abnormal pain in naïve rats. In addition, treatment with SAP97 siRNA or NASPM i.t. injection alleviated SNT-induced allodynia and hyperalgesia and exhibited a longer effect in female rats. Together, our results indicate that the SNT-induced upregulation of SAP97 via promoting GluA1-containing AMPARs membrane trafficking in the dorsal horn contributes to the pathogenesis of neuropathic pain. Targeting spinal SAP97 might be a promising therapeutic strategy to treatment of chronic pain.
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•SNT induced upregulation of SAP97 and increased membrane trafficking of GluA1-containing AMPARs.•Spinal knockdown SAP97 reduced membrane insertion of GluA1-AMPARs.•Spinal knockdown SAP97 or blockade of GluA1-AMPARs alleviated neuropathic pain.
A highly efficient and chemoselective transfer hydrogenation of ketones in water has been successfully achieved with our newly developed catalyst. Simple ketones, as well as α- or β-functionalized ...ketones, are readily reduced. Formic acid is used as a traceless hydride source. At very low catalyst loading (
S
/
C
= 10 000 in most cases;
S
/
C
= 50 000 or 100 000 in some cases), the iridium catalyst is impressively efficient at reducing ketones in good to excellent yields. The TOF value can be as high as up to 26 000 mol mol
−1
h
−1
. A variety of functional groups are well tolerated, for example, heteroaryl, aryloxy, alkyloxy, halogen, cyano, nitro, ester, especially acidic methylene, phenol and carboxylic acid groups.
Lysine-specific demethylase 6B (KDM6B) serves as a key mediator of gene transcription. It regulates expression of proinflammatory cytokines and chemokines in variety of diseases. Herein, the role and ...the underlying mechanisms of KDM6B in inflammatory pain were studied.
The inflammatory pain was conducted by intraplantar injection of complete Freund's adjuvant (CFA) in rats. Immunofluorescence, Western blotting, qRT-PCR, and chromatin immunoprecipitation (ChIP)-PCR were performed to investigate the underlying mechanisms.
CFA injection led to upregulation of KDM6B and decrease in the level of H3K27me3 in the dorsal root ganglia (DRG) and spinal dorsal horn. The mechanical allodynia and thermal hyperalgesia following CFA were alleviated by the treatment of intrathecal injection of GSK-J4, and by microinjection of AAV-EGFP-KDM6B shRNA in the sciatic nerve or in lumbar 5 dorsal horn. The increased production of tumor necrosis factor-α (TNF-α) following CFA in the DRGs and dorsal horn was inhibited by these treatments. ChIP-PCR showed that CFA-induced increased binding of nuclear factor κB with TNF-α promoter was repressed by the treatment of microinjection of AAV-EGFP-KDM6B shRNA.
These results suggest that upregulated KDM6B via facilitating TNF-α expression in the DRG and spinal dorsal horn aggravates inflammatory pain.
Chromosome engineering has been attempted successfully in yeast but remains challenging in higher eukaryotes, including mammals. Here, we report programmed chromosome ligation in mice that resulted ...in the creation of new karyotypes in the lab. Using haploid embryonic stem cells and gene editing, we fused the two largest mouse chromosomes, chromosomes 1 and 2, and two medium-size chromosomes, chromosomes 4 and 5. Chromatin conformation and stem cell differentiation were minimally affected. However, karyotypes carrying fused chromosomes 1 and 2 resulted in arrested mitosis, polyploidization, and embryonic lethality, whereas a smaller fused chromosome composed of chromosomes 4 and 5 was able to be passed on to homozygous offspring. Our results suggest the feasibility of chromosome-level engineering in mammals.
Designer chromosomes
One of the goals in synthetic biology is to generate complex multicellular life with designed DNA sequences. Being able to manipulate DNA at large scales, including at the chromosome level, is an important step toward this goal. So far, chromosome-level genetic engineering has been accomplished only in haploid yeast. By applying gene editing to haploid embryonic stem cells, Wang
et al
. achieved whole-chromosome ligations in mice, and successfully derived animals with 19 pairs of chromosomes, one pair fewer than is standard in this species. —DJ
The ability to perform karyotype engineering in laboratory mice has been developed using haploid stem cells and gene editing.
Robust allogeneic immune reactions after transplantation impede the translational pace of human embryonic stem cells (hESCs)‐based therapies. Selective genetic editing of human leucocyte antigen ...(HLA) molecules has been proposed to generate hESCs with immunocompatibility, which, however, has not been specifically designed for the Chinese population yet. Herein, we explored the possibility of customizing immunocompatible hESCs based on Chinese HLA typing characteristics. We generated an immunocompatible hESC line by disrupting HLA‐B, HLA‐C, and CIITA genes while retaining HLA‐A*11:01 (HLA‐A*11:01‐retained, HLA‐A11R), which covers ~21% of the Chinese population. The immunocompatibility of HLA‐A11R hESCs was verified by in vitro co‐culture and confirmed in humanized mice with established human immunity. Moreover, we precisely knocked an inducible caspase‐9 suicide cassette into HLA‐A11R hESCs (iC9‐HLA‐A11R) to promote safety. Compared with wide‐type hESCs, HLA‐A11R hESC‐derived endothelial cells elicited much weaker immune responses to human HLA‐A11+ T cells, while maintaining HLA‐I molecule‐mediated inhibitory signals to natural killer (NK) cells. Additionally, iC9‐HLA‐A11R hESCs could be induced to undergo apoptosis efficiently by AP1903. Both cell lines displayed genomic integrity and low risks of off‐target effects. In conclusion, we customized a pilot immunocompatible hESC cell line based on Chinese HLA typing characteristics with safety insurance. This approach provides a basis for establishment of a universal HLA‐AR bank of hESCs covering broad populations worldwide and may speed up the clinical application of hESC‐based therapies.
Here, we first selected an human embryonic stem cell (hESC) line with homozygous human leucocyte antigen (HLA)‐A*11:01 allele, the most popular HLA‐I allele of the Chinese population, then generated a hypoimmunogenic hESC line by disrupting HLA‐B, HLA‐C, and CIITA genes while retaining HLA‐A*11:01 (named as HLA‐A11R hESCs), covering ~21% of the Chinese population. The immunocompatibility of the HLA‐A11R hESCs was verified by in vitro co‐culture assays and confirmed in humanized mice with an established human immune system. Moreover, to address safety issues, we precisely knocked a clinical trial‐grade drug‐induced caspase‐9 suicide cassette into HLA‐A11R hESCs, generating iC9‐HLA‐A11R hESCs, which were efficiently induced to apoptosis by AP1903. In summary, we customized an immunocompatible hESC cell line based on the HLA typing characteristics of the Chinese population with safety insurance, which provided the basis for the establishment of an HLA‐AR bank of hESCs covering broader populations in the world, speeding up the clinical application of a range of hESC‐based therapies.
Analgesic tolerance and hyperalgesia hinder the long-term utility of opioids. We examined whether spinal high mobility group box 1 (HMGB1) is involved in morphine tolerance and its underlying ...mechanisms by using a model of repeated intrathecal (i.t.) injections of morphine. The results showed that chronic i.t. morphine exposure led to increased expression of HMGB1, Toll-like receptor 4 (TLR4), and receptor for advanced glycation end products (RAGE) and their mRNAs in the dorsal horn. Morphine challenge also promoted HMGB1 expression and release in cultured spinal neurons, but these effects were inhibited by TAK-242, naloxone (antagonists of TLR4), and TLR4 siRNA. Intrathecal coadministration of morphine with TAK-242 or PDTC (inhibitor of NF-κB activation) also reduced HMGB1 expression in the spinal cord. Repeated i.t. coinjections of morphine with glycyrrhizin (GL, an HMGB1 inhibitor) or HMGB1 siRNA prevented reduction of the maximal possible analgesic effect (MPAE) of morphine and alleviated morphine withdrawal-induced hyperalgesia. The established morphine tolerance and hyperalgesia were partially reversed when i.t. injections of GL or HMGB1 antibody started at day 7 of morphine injection. Repeated i.t. injections of morphine with HMGB1 siRNA inhibited the activation of NF-κB, but not that of JNK and p38. A single i.t. injection of HMGB1 in naïve rats caused pain-related hypersensitivity and reduction in MPAE. Moreover, phosphorylated NF-κB p65, TNF-α, and IL-1β levels in the dorsal horn were upregulated following this treatment, but this upregulation was prevented by coinjection with TAK-242. Together, these results suggest that morphine-mediated upregulation of spinal HMGB1 contributes to analgesic tolerance and hyperalgesia via activation of TLR4/NF-κB signaling, and the HMGB1 inhibitor might be a promising adjuvant to morphine in the treatment of intractable pain in the clinic.
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•Tetraphenylethylene based macrocycles were successfully synthesized, their luminescence behavior showed the chain length effect.•The compounds were used to monitor the kinetics of ...silicon-oxygen bond hydrolysis in real-time by the AIE method with the RIR mechanism.•The half-life and reaction kinetic data of Si-O bond-breaking with different pH were obtained to provide a reference in industrial production.
The preparation of silicone material is generally carried out by hydrolytic condensation, and various methods have been tried so far to study the kinetics of silicon-oxygen bond hydrolysis. However, the process and kinetics of silicon-oxygen bond hydrolysis cannot be efficiently monitored in real-time due to the limitations of traditional testing methods. In the present study, we have successfully designed and synthesized a series of circular tetraphenylethylene (TPE) derivatives connected with different lengths of the siloxanes chain. As the chain length gets longer, the restriction on phenyl rotation in TPE derivatives becomes weaker, which induced fluorescence quenching gradually at the molecular level. Hence, it provides the most direct and convincing evidence for the effect of chain lengths in the popular restricted intramolecular rotation (RIR) mechanism with aggregation-induced emission (AIE) phenomenon. The strong fluorescent molecule was used to monitor the kinetics of silicon-oxygen bond hydrolysis in real-time successfully by the AIE method with the RIR mechanism. The high sensitivity and efficiency of fluorescence provide an unparalleled “visualization” window for real-time monitoring of the kinetic control of Si-O bond hydrolysis. Furthermore, the half-life and reaction kinetic data of Si-O bond-breaking reaction by different pH are obtained to provide a reference for scientists and engineers not only in fundamental research but also in industrial production. Finally, the aggregation-induced color-tunable emission was obtained with the different aggregation forms of molecules, exhibiting a promising potential for intelligent luminescent materials.
Intermetallics or ordered alloys are catalytically more advantageous than solid solution alloys. The B2 phase Pd2Cu intermetallics exhibit excellent catalytic properties for CO2 hydrogenation to ...ethanol and other reactions. However, the crystal structure of Pd2Cu is unknown. With a self-coded program based on symmetry and atomic ratio, we combed and identified the Pd2Cu structure. The calculated (110) interlayer distance agrees with the experimental result acceptably. Lattice dynamics and AIMD simulations demonstrate the identified structure is stable. The calculated bond strength indicates that among the five types of bonds, the shorter Pd–Cu bond (SPd–Cu) plays the most important role in stabilizing the structure. Crystal orbital Hamilton population (COHP) analyses reveal that the 5s(Pd)–4p(Cu) interaction dominates the Pd–Cu bonding and the 5s(Pd)–5s(Pd) or the 4p(Cu)–4p(Cu) interaction contributes the most in the homonuclear Pd–Pd and Cu–Cu bonds. Investigations on the reaction mechanism proposed for CO2 hydrogenation to CH3CH2OH show that CH2OH to CH2+OH is the key step determining the production of ethanol, followed by CO2+H to COOH and COOH to CO+OH.
Soluble amyloid-β-protein (Aβ) oligomers, a major hallmark of AD, trigger the integrated stress response (ISR) via multiple pathologies including neuronal hyperactivation, microvascular hypoxia, and ...neuroinflammation. Increasing eIF2α phosphorylation, the core event of ISR, facilitates metabotropic glutamate receptor (mGluR)-dependent long-term depression (LTD), and suppressing its phosphorylation has the opposite effect. Having found the facilitation of mGluR5-LTD by Aβ in live rats, we wondered if suppressing eIF2α phosphorylation cascade would protect against the synaptic plasticity and cognitive disrupting effects of Aβ. We demonstrate here that the facilitation of mGluR5-LTD in a delayed rat model by single i.c.v. injection of synthetic Aβ
. Systemic administration of the small-molecule inhibitor of the ISR called ISRIB (trans-isomer) prevents Aβ-facilitated LTD and abrogates spatial learning and memory deficits in the hippocampus in exogenous synthetic Aβ-injected rats. Moreover, ex vivo evidence indicates that ISRIB normalizes protein synthesis in the hippocampus. Targeting the ISR by suppressing the eIF2α phosphorylation cascade with the eIF2B activator ISRIB may provide protective effects against the synaptic and cognitive disruptive effects of Aβ which likely mediate the early stage of sporadic AD.
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