Rice false smut virulence protein subverts host chitin perception and signaling at lemma and palea for floral infection.

The flower-infecting fungus Ustilaginoidea virens causes rice false smut, which is a severe emerging disease threatening rice (Oryza sativa) production worldwide. False smut not only reduces yield, but more importantly produces toxins on grains, posing a great threat to food safety. U. virens invades spikelets via the gap between the 2 bracts (lemma and palea) enclosing the floret and specifically infects the stamen and pistil. Molecular mechanisms for the U. virens-rice interaction are largely unknown. Here, we demonstrate that rice flowers predominantly employ chitin-triggered immunity against U. virens in the lemma and palea, rather than in the stamen and pistil. We identify a crucial U. virens virulence factor, named UvGH18.1, which carries glycoside hydrolase activity. Mechanistically, UvGH18.1 functions by binding to and hydrolyzing immune elicitor chitin and interacting with the chitin receptor CHITIN ELICITOR BINDING PROTEIN (OsCEBiP) and co-receptor CHITIN ELICITOR RECEPTOR KINASE1 (OsCERK1) to impair their chitin-induced dimerization, suppressing host immunity exerted at the lemma and palea for gaining access to the stamen and pistil. Conversely, pretreatment on spikelets with chitin induces a defense response in the lemma and palea, promoting resistance against U. virens. Collectively, our data uncover a mechanism for a U. virens virulence factor and the critical location of the host-pathogen interaction in flowers and provide a potential strategy to control rice false smut disease.

Broad-spectrum resistance gene RPW8.1 balances immunity and growth via feedback regulation of WRKYs.

Arabidopsis RESISTANCE TO POWDERY MILDEW 8.1 (RPW8.1) is an important tool for engineering broad-spectrum disease resistance against multiple pathogens. Ectopic expression of RPW8.1 leads to enhanced disease resistance with cell death at leaves and compromised plant growth, implying a regulatory mechanism balancing RPW8.1-mediated resistance and growth. Here, we show that RPW8.1 constitutively enhances the expression of transcription factor WRKY51 and activates salicylic acid and ethylene signalling pathways; WRKY51 in turn suppresses RPW8.1 expression, forming a feedback regulation loop. RPW8.1 and WRKY51 are both induced by pathogen infection and pathogen-/microbe-associated molecular patterns. In ectopic expression of RPW8.1 background (R1Y4), overexpression of WRKY51 not only rescues the growth suppression and cell death caused by RPW8.1, but also suppresses RPW8.1-mediated broad-spectrum disease resistance and pattern-triggered immunity. Mechanistically, WRKY51 directly binds to and represses RPW8.1 promoter, thus limiting the expression amplitude of RPW8.1. Moreover, WRKY6, WRKY28 and WRKY41 play a role redundant to WRKY51 in the suppression of RPW8.1 expression and are constitutively upregulated in R1Y4 plants with WRKY51 being knocked out (wrky51 R1Y4) plants. Notably, WRKY51 has no significant effects on disease resistance or plant growth in wild type without RPW8.1, indicating a specific role in RPW8.1-mediated disease resistance. Altogether, our results reveal a regulatory circuit controlling the accumulation of RPW8.1 to an appropriate level to precisely balance growth and disease resistance during pathogen invasion.

Organocatalytic Atroposelective Synthesis of Axially Chiral Indolyl Ketosulfoxonium Ylides.

Despite recent advancements in catalytic synthesis of axial chirality, reports on non-biaryl atropisomers remain limited because of the stringent steric requirements necessary to establish effective rotational brakes. In this study, we present a novel class of monoaryl atropisomers, indolyl ketosulfoxonium ylides, and describe an organocatalytic protocol for their synthesis. We discovered that a chiral phosphoric acid (CPA) serves as an effective catalyst for the highly enantioselective iodination of ortho-aminophenylethynyl sulfoxonium ylides. Under the optimized reaction conditions, a strong preference for the intended iodination process over the competing protonation was observed. Subsequently, intramolecular amide cyclization enabled the formation of sterically congested indole fragments. Furthermore, the synthetic utility of the products was demonstrated by showcasing versatile transformations into other chiral scaffolds with complete retention of optical purity.

Osa-miR535 targets SQUAMOSA promoter binding protein-like 4 to regulate blast disease resistance in rice.

Many rice microRNAs have been identified as fine-tuning factors in the regulation of agronomic traits and immunity. Among them, Osa-miR535 targets SQUAMOSA promoter binding protein-like 14 (OsSPL14) to positively regulate tillers but negatively regulate yield and immunity. Here, we uncovered that Osa-miR535 targets another SPL gene, OsSPL4, to suppress rice immunity against Magnaporthe oryzae. Overexpression of Osa-miR535 significantly decreased the accumulation of the fusion protein SPL4TBS -YFP that contains the target site of Osa-miR535 in OsSPL4. Consistently, Osa-miR535 mediated the cleavage of OsSPL4 mRNA between the 10th and 11th base pair of the predicted binding site at the 3' untranslated region. Transgenic rice lines overexpressing OsSPL4 (OXSPL4) displayed enhanced blast disease resistance accompanied by enhanced immune responses, including increased expression of defense-relative genes and up-accumulated H2 O2 . By contrast, the knockout mutant osspl4 exhibited susceptibility. Moreover, OsSPL4 binds to the promoter of GH3.2, an indole-3-acetic acid-amido synthetase, and promotes its expression. Together, these data indicate that Os-miR535 targets OsSPL4 and OsSPL4-GH3.2, which may parallel the OsSPL14-WRKY45 module in rice blast disease resistance.

Golovinomyces cichoracearum effector-associated nuclear localization of RPW8.2 amplifies its expression to boost immunity in Arabidopsis.

Arabidopsis RESISTANCE TO POWDERY MILDEW 8.2 (RPW8.2) is specifically induced by the powdery mildew (PM) fungus (Golovinomyces cichoracearum) in the infected epidermal cells to activate immunity. However, the mechanism of RPW8.2-induction is not well understood. Here, we identify a G. cichoracearum effector that interacts with RPW8.2, named Gc-RPW8.2 interacting protein 1 (GcR8IP1), by a yeast two-hybrid screen of an Arabidopsis cDNA library. GcR8IP1 is physically associated with RPW8.2 with its REALLY INTERESTING NEW GENE finger domain that is essential and sufficient for the association. GcR8IP1 was secreted and translocated into the nucleus of host cell infected with PM. Association of GcR8IP1 with RPW8.2 led to an increase in RPW8.2 in the nucleus. In turn, the nucleus-localized RPW8.2 promoted the activity of the RPW8.2 promoter, resulting in transcriptional self-amplification of RPW8.2 to boost immunity at infection sites. Additionally, ectopic expression or host-induced gene silencing of GcR8IP1 supported its role as a virulence factor in PM. Altogether, our results reveal a mechanism of RPW8.2-dependent defense strengthening via altered partitioning of RPW8.2 and transcriptional self-amplification triggered by a PM fungal effector, which exemplifies an atypical form of effector-triggered immunity.

Blocking Osa-miR1871 enhances rice resistance against Magnaporthe oryzae and yield.

MicroRNAs (miRNAs) play vital roles in plant development and defence responses against various stresses. Here, we show that blocking miR1871 improves rice resistance against Magnaporthe oryzae and enhances grain yield simultaneously. The transgenic lines overexpressing miR1871 (OX1871) exhibit compromised resistance, suppressed defence responses and reduced panicle number resulting in slightly decreased yield. In contrast, the transgenic lines blocking miR1871 (MIM1871) show improved resistance, enhanced defence responses and significantly increased panicle number leading to enhanced yield per plant. The RNA-seq assay and defence response assays reveal that blocking miR1871 resulted in the enhancement of PAMP-triggered immunity (PTI). Intriguingly, miR1871 suppresses the expression of LOC_Os06g22850, which encodes a microfibrillar-associated protein (MFAP1) locating nearby the cell wall and positively regulating PTI responses. The mutants of MFAP1 resemble the phenotype of OX1871. Conversely, the transgenic lines overexpressing MFAP1 (OXMFAP1) or overexpressing both MFAP1 and miR1871 (OXMFAP1/OX1871) resemble the resistance of MIM1871. The time-course experiment data reveal that the expression of miR1871 and MFAP1 in rice leaves, panicles and basal internode is dynamic during the whole growth period to manipulate the resistance and yield traits. Our results suggest that miR1871 regulates rice yield and immunity via MFAP1, and the miR8171-MFAP1 module could be used in rice breeding to improve both immunity and yield.

Osa-miR160a confers broad-spectrum resistance to fungal and bacterial pathogens in rice.

Rice production is threatened by multiple pathogens. Breeding cultivars with broad-spectrum disease resistance is necessary to maintain and improve crop production. Previously we found that overexpression of miR160a enhanced rice blast disease resistance. However, it is unclear whether miR160a also regulates resistance against other pathogens, and what the downstream signaling pathways are. Here, we demonstrate that miR160a positively regulates broad-spectrum resistance against the causative agents of blast, leaf blight and sheath blight in rice. Mutations of miR160a-targeted Auxin Response Factors result in different alteration of resistance conferred by miR160a. miR160a enhances disease resistance partially by suppressing ARF8, as mutation of ARF8 in MIM160 background partially restores the compromised resistance resulting from MIM160. ARF8 protein binds directly to the promoter and suppresses the expression of WRKY45, which acts as a positive regulator of rice immunity. Mutation of WRKY45 compromises the enhanced blast resistance and bacterial leaf blight resistance conferred by arf8 mutant. Overall, our results reveal that a microRNA coordinates rice broad-spectrum disease resistance by suppressing multiple target genes that play different roles in disease resistance, and uncover a new regulatory pathway mediated by the miR160a-ARF8 module. These findings provide new resources to potentially improve disease resistance for breeding in rice.

Chiral Phosphoric Acid-Catalyzed Remote Control of Axial Chirality at Boron-Carbon Bond.

The previously elusive catalytic enantioselective construction of axially chiral B-aryl-1,2-azaborines with a C-B stereogenic axis has been realized through a chiral phosphoric acid-catalyzed desymmetrization strategy reported herein. The electrophilic aromatic substitution reaction of 3,5-disubsituted phenols with diazodicarboxamides could afford these axially chiral structures in good efficiency with excellent enantiocontrol. The efficient long-range stereochemical control is achieved by multiple well-defined H-bonding interactions between chiral phosphoric acid and both substrates. Meanwhile, the reaction duration could be markedly shortened with weakly acidic N-H in 1,2-azaborine acting as H-bond donor. The scalability of the reaction and facile cleavage of the N-N bond in the product further demonstrated the practicality of this method.

Copper-Catalyzed Synthesis of Axially Chiral Biaryls with Diaryliodonium Salts as Arylation Reagents.

NOBIN and BINAM derivatives harboring biaryl frameworks are recognized as a class of important atropisomers with versatile applications. Here, we present an efficient synthetic route to access such compounds through copper-catalyzed domino arylation of N-arylhydroxylamines or N-arylhydrazines with diaryliodonium salts and [3,3]-sigmatropic rearrangement. This reaction features mild conditions, good substrate compatibility, and excellent efficiency. The practicality of this protocol was further extended by the synthesis of biaryl amino alcohols.

Chemical Constituents and Bioactivities of Starfishes: An Update.

Starfishes produce various structurally unique secondary metabolites with diverse biological activities. This review is an update summary of the new compounds and their bioactivities from starfish (the Asteroidea Class) with 71 references covering from January 2007 to December 2018. During this period, 216 new compounds were obtained from 36 species. The chemical constituents are mostly steroids, steroidal glycosides, and gangliosides. These components have been found to possess various bioactivities, including anticancer, anti-inflammation, etc.

Osa-miR1873 fine-tunes rice immunity against Magnaporthe oryzae and yield traits.

MicroRNAs (miRNAs) are known to fine-tune growth, development, and stress-induced responses. Osa-miR1873 is a rice-specific miRNA targeting LOC_Os05g01790. Here, we show that Osa-miR1873 fine-tunes rice immunity against Magnaporthe oryzae and yield traits via LOC_Os05g01790. Osa-miR1873 was significantly upregulated in a susceptible accession but downregulated in a resistance accession at 24 h post-inoculation (hpi) of M. oryzae. Overexpressing Osa-miR1873 enhanced susceptibility to M. oryzae and compromised induction of defense responses. In contrast, blocking Osa-miR1873 through target mimicry compromised susceptibility to M. oryzae and enhanced induction of defense responses. Altered expression of Osa-miR1873 also resulted in some defects in yield traits, including grain numbers and seed setting rate. Moreover, overexpression of the target gene LOC_Os05g01790 increased rice blast disease resistance but severely penalized growth and yield. Taken together, we demonstrate that Osa-miR1873 fine-tunes the rice immunity-growth trade-off via LOC_Os05g01790, and blocking Osa-miR1873 could improve blast disease resistance without significant yield penalty. Thus, the Osa-miR1873-LOC_Os05g01790 regulatory module is valuable in balancing yield traits and blast resistance.

[Effect and safety of the Chinese medicine Qianlieshutong Capsules in the treatment of benign prostatic hyperplasia: A meta-analysis].

OBJECTIVE: To evaluate the effect and safety of Qianlieshutong Capsules (QC) in the treatment of BPH. METHODS: We searched 10 Chinese and English databases up to July 2019 for randomized controlled trials (RCT) on treatment of BPH with QC followed by a meta-analysis on the included articles using Cochrane Handbook 5.1.0 and Revman5.3 software. RESULTS: A total of 18 RCTs involving 1 802 cases of BPH were included out of the 175 articles identified. The baseline data from the RCTs were all comparable. Compared with the controls, the patients treated with QC showed a significantly higher rate of clinical effectiveness and better improvement in IPSS as well as in the maximum urinary flow rate (Qmax), postvoid residual urine (PVR) and prostate volume after 3 months of medication. No serious adverse drug events or reactions were reported. CONCLUSIONS: The existing data and methodology indicate the efficacy and safety of Qianlieshutong Capsules in the treatment of BPH, which, however, has to be further verified by more well-designed large-sample multi-center high-quality randomized controlled trials.

[Linggui Fang protects the reproductive system of asthenospermia rats: An experimental study based on the L-carnitine pathway].

OBJECTIVE: To explore the protective effect of the Chinese medicinal prescription Linggui Fang (LGF) on the reproductive system of the ornidazole-induced asthenospermia (AS) rat and its possible action mechanisms. METHODS: Forty male SD rats weighing 200－230 g were equally randomized into four groups, blank control, AS model control, LGF treatment and L-carnitine (LC) intervention. The AS models were made in the latter three groups by intragastrical administration of ornidazole at 400 mg/kg. Meanwhile, the rats in the LGF group were treated intragastrically with LGF at 17.5 g/kg, those in the LC group with LC at 100 mg/kg, and the control animals with 0.5% sodium carboxymethylcellulose (CMC-Na), all once a day for 4 successive weeks. Then, all the rats were sacrificed for examination of the semen parameters, determination of the LC content and OCTN2 mRNA expression in the epididymis and observation of the histopathological changes in the testis. RESULTS: Compared with the AS model controls, the rats in the other groups showed significantly higher percentages of progressively motile sperm and total motile sperm (P < 0.01) as well as a higher LC content in the epididymis (P < 0.01), but no statistically significant difference in sperm concentration (P > 0.05). The expression of OCTN2 mRNA was remarkably upregulated in the LGF and LC groups in comparison with that in the AS model control (P < 0.05). Compared with the rats in the blank control group, the AS model controls exhibited markedly increased morphologically abnormal seminiferous tubules, irregularly arranged, with narrowed lumens and reduced numbers of sperm and sperm cells, as well as significantly increased hollow seminiferous tubules with deficient and disorderly arranged spermatogenic cells and partial epithelial degeneration and vacuolization. Those in the LGF and LC groups, however, manifested almost normal testicular histomorphology, with basically regular arrangement of different layers of seminiferous tubules. CONCLUSIONS: ①Ornidazole induces AS in rats by reducing the LC content in the epididymis, while LGF can improve the sperm motility and testicular morphology of the rats and upregulate the expression of OCTN2 mRNA in the epididymis by increasing the LC concentration.

FOXP3 Is a HCC suppressor gene and Acts through regulating the TGF-ß/Smad2/3 signaling pathway.

BACKGROUND: FOXP3 has been discovered to be expressed in tumor cells and participate in the regulation of tumor behavior. Herein, we investigated the clinical relevance and biological significance of FOXP3 expression in human hepatocellular carcinoma (HCC). METHODS: Expression profile of FOXP3 was analyzed using real-time RT-PCR, western blotting and immunofluorescence on HCC cell lines, and immunostaing of a tissue microarray containing of 240 primary HCC samples. The potential regulatory roles of FOXP3 were dissected by an integrated approach, combining biochemical assays, analysis of patient survival, genetic manipulation of HCC cell lines, mouse xenograft tumor models and chromatin immunoprecipitation (ChIP) sequencing. RESULTS: FOXP3 was constitutively expressed in HCC cells with the existence of splice variants (especially exon 3 and 4 deleted, Δ3,4-FOXP3). High expression of FOXP3 significantly correlated with low serum α-fetoprotein (AFP) level, absence of vascular invasion and early TNM stage. Survival analyses revealed that increased FOXP3 expression was significantly associated with better survival and reduced recurrence, and served as an independent prognosticator for HCC patients. Furthermore, FOXP3 could potently suppress the proliferation and invasion of HCC cells in vitro and reduce tumor growth in vivo. However, Δ3,4-FOXP3 showed a significant reduction in the tumor-inhibiting effect. The inhibition of FOXP3 on HCC aggressiveness was acted probably by enhancing the TGF-ß/Smad2/3 signaling pathway. CONCLUSION: Our findings suggest that FOXP3 suppresses tumor progression in HCC via TGF-ß/Smad2/3 signaling pathway, highlighting the role of FOXP3 as a prognostic factor and novel target for an optimal therapy against this fatal malignancy.

Phosphoric Acid-Catalyzed Asymmetric Synthesis of SPINOL Derivatives.

Axially chiral 1,1'-spirobiindane-7,7'-diol (SPINOL) is the most fundamental and important privileged structure from which other chiral ligands containing a 1,1'-spirobiindane backbone are synthesized. Driven by the development of enantioselective syntheses of axially chiral SPINOL derivatives, we have successfully developed the first phosphoric acid-catalyzed asymmetric approach. This approach is highly convergent and functional group tolerant, efficiently providing SPINOLs in good yield with excellent enantioselectivity, thus delivering a practical and straightforward access to this privileged structure. It should be emphasized that the catalyst loading could be decreased to only 0.1 mol% for the preparative-scale synthesis. Furthermore, 4,4'-dimethyl-SPINOL-phosphoric acid was synthesized and applied to catalyze the model reaction for synthesis of enantioenriched SPINOL derivatives.

Synthetic and Structural Studies of 2-Acylmethyl-6-R-Difunctionalized Pyridine Ligand-Containing Iron Complexes Related to [Fe]-Hydrogenase.

As active site models of [Fe]-hydrogenase, tridentate 2-acylmethyl-6-methoxymethoxy-difunctionalized pyridine-containing complexes η(3)-(2-COCH2-6-MeOCH2OC5H3N)Fe(CO)2(L1) (4, L1 = I; 5, SCN; 6, PhCS2) were prepared via the following multistep reactions: (i) etherification of 2-MeO2C-6-HOC5H3N with ClCH2OMe to give 2-MeO2C-6-MeOCH2OC5H3N (1), (ii) reduction of 1 with NaBH4 to give 2-HOCH2-6-MeOCH2OC5H3N (2), (iii) esterification of 2 with 4-toluenesulfonyl chloride to give 2-TsOCH2-6-MeOCH2OC5H3N (3), (iv) nucleophilic substitution of 3 with Na2Fe(CO)4 followed by treatment of the resulting Fe(0) intermediate Na[(2-CH2-6-MeOCH2OC5H3N)Fe(CO)4] (M1) with I2 to give complex 4, and (v) condensation of 4 with KSCN and PhCS2K to give complexes 5 and 6, respectively. In contrast to the preparation of complexes 4-6, bidentate 2-acylmethyl-6-methoxymethoxy-difunctionalized pyridine-containing model complexes η(2)-(2-COCH2-6-MeOCH2OC5H3N)Fe(CO)2(I)(L2) (7, L2 = PPh3; 8, Cy-C6H11NC) and η(2)-(2-COCH2-6-MeOCH2OC5H3N)Fe(CO)2(L3) (9, L3 = 2-SC5H4N; 10, 8-SC9H6N) were prepared by ligand exchange reactions of 4 with PPh3, Cy-C6H11NC, 2-KSC5H4N, and 8-KSC9H6N, respectively. Particularly interesting is that the tridentate 2,6-bis(acylmethyl)pyridine- and 2-acylmethyl-6-arylthiomethylpyridine-containing model complexes η(3)-[2,6-(COCH2)2C5H3N]Fe(CO)2(L4) (11, L4 = PPh3; 12, CO) and η(3)-2-(COCH2-6-ArSCH2C5H3N)Fe(CO)2(ArS) (13, ArS = PhS; 14, 2-S-5-MeC4H2O) were obtained, unexpectedly, when 2,6-(TsOCH2)2C5H3N reacted with Na2Fe(CO)4 followed by treatment of the resulting mixture with ligands PPh3 and CO or disulfides (PhS)2 and (2-S-5-MeC4H2O)2. Reactions of ligand precursors 3 and 2,6-(TsOCH2)2C5H3N with Na2Fe(CO)4 were monitored by in situ IR spectroscopy, and the possible pathways for producing complexes 4 and 11-14 via intermediates Na[(2-CH2-6-MeOCH2OC5H3N)Fe(CO)4] (M1), Na[(2-CH2-6-TsOCH2C5H3N)Fe(CO)4] (M2), and (2-COCH2-6-CH2C5H3N)Fe(CO)3 (M3) are suggested. New compounds 1-14 were characterized by elemental analysis, spectroscopy, and, for some of them, X-ray crystallography.

[Combined transurethral procedure for bladder outlet obstruction induced by small-volume prostatic hyperplasia].

Objective: To investigate the clinical effect of transurethral resection of the prostate(TURP) combined with transurethral incision of the bladder neck( TUIBN) in the treatment of bladder outlet obstruction( BOO) caused by small-volume benign prostatic hyperplasia( BPH). Methods: We retrospectively analyzed the clinical data about 56 cases of small-volume BPH. The patients,aged 45- 71( mean 59. 6) years,all showed varied degrees of dysuria and 20 of them had a history of chronic prostatitis. Preoperative examinations included the obtainment of International Prostate Symptom Score( IPSS),evaluation of the quality of life(QOL),ultrasonography, urodynamic examination, and cystoscopy. All the patients received alpha-blockers for 3- 6 months without obvious response and therefore underwent TURP + TUIBN. Results: Postoperative follow-up lasted 12- 24 months. Urinary tract stricture was found in 2 cases(3. 57%) at 1 month after surgery, which was improved after urethral dilation,and bladder neck contracture occurred in 1 case(1. 79%) at 3 months, which was relieved by repeated TUIBN. Compared with the baseline, the IPSS was dramatically decreased at 12 months postoperatively(25. 54 ± 2. 33 vs 12. 76 ± 2. 37,P < 0. 01),and so was the postvoid residual([68. 07 ± 17. 09]vs [31. 02 ± 9. 75] ml. P < 0. 01),while the maximum urinary flow rate(Qmax) was significantly increased([8. 47 ± 0. 96]vs [15. 83 ± 1. 47]ml/s, P < 0. 01). Conclusion: TURP + TUIBN is superior to either TURP or TUIBN alone in the treatment of BOO induced by small-volume BPH for its higher effectiveness and safety.

Construction of Tropane Derivatives by the Organocatalytic Asymmetric Dearomatization of Isoquinolines.

A chiral-NHC-catalyzed highly diastereo- and enantioselective dearomatizing double Mannich reaction of isoquinolines was developed that provides a powerful and straightforward synthetic route toward substituted tropane derivatives with four contiguous stereocenters. A unique feature of this strategy is the use of readily available isoquinolines to provide two reactive sites for dearomatization, thus opening up an unprecedented approach to tropane derivatives with excellent stereoselectivity. The four-component reactions proceeded smoothly with good results. Thus, the present method is suitable for the diversity-oriented synthesis of useful tropane derivatives with high efficiency.

Effects of tetrathiomolybdate and penicillamine on brain hydroxyl radical and free copper levels: a microdialysis study in vivo.

Wilson disease is an inherited disorder of excessive copper accumulation. The commonly used drug d-penicillamine (PA) or trientine both cause a high incidence (10-50%) of neurological worsening, which rarely occurs with tetrathiomolybdate (TM) treatment. To investigate the mechanisms of neurologic deterioration after the initiation of chelation therapy, brain hydroxyl radical and free copper were assessed in vivo in this study. On days 3, 7, 14, and 21 after PA or TM administration, striatal hydroxyl radical levels of both TX mice and controls were assessed by terephthalic acid (TA) combined with microdialysis and high-performance liquid chromatography (HPLC). Within the same microdialysis samples, free copper was measured by inductively coupled plasma mass spectrometry (ICP-MS). The results showed that both hydroxyl radical and free copper markedly increased in the striatum of TX mice during PA administration but were not elevated when administering TM. These results suggested that the further increased free copper in the brain and oxidative stress caused by some chelators might contribute to the neurological deterioration.

Co-Graft of Bone Marrow Stromal Cells and Schwann Cells Into Acellular Nerve Scaffold for Sciatic Nerve Regeneration in Rats.

PURPOSE: The conventional strategy for bridging large nerve defects, namely nerve autograft transplantation, results in donor-site morbidity. This detrimental consequence currently drives the search for alternatives. The authors used an acellular nerve scaffold filled with bone marrow stromal cells (BMSCs) and Schwann cells (SCs) to enhance regeneration. MATERIALS AND METHODS: In 60 adult rats, a 10-mm sciatic nerve defect was bridged with a nerve autograft (positive control), an acellular nerve scaffold (negative control), an acellular nerve scaffold with BMSCs (group I), an acellular nerve scaffold with SCs (group II), or an acellular nerve scaffold with BMSCs plus SCs (group III). After regenerating for 4 and 16 weeks after surgery, nerve regeneration was functionally assessed by a walking track analysis. The compound muscle action potential (CMAP), nerve conduction velocity (NCV) along regenerated sciatic nerves, and gastrocnemius muscle index (GMI) were recorded to assess the conduction properties and extent of denervation atrophy. The number of retrograde-labeled lumbar motor neurons identified by fluorescent dyes in the ipsilateral ventral horn and spinal ganglia were counted to assess the regeneration of axons. RESULTS: After 4 and 16 weeks, improvement of the sciatic function index of the sciatic nerve in group III was statistically greater than that of the negative control group, group I, and group II. At 16 weeks after grafting, obvious differences in the GMI were found among groups. Group III had a statistical increase in GMI compared with the negative control group, group I, and group II. The CMAP and NCV measurements showed comparable results at 16 weeks after reconstruction: group III had statistically better results compared with the negative control group, group I, and group II. Fluorescent dye analysis of the retrograde-labeled lumbar motoneurons in the ipsilateral ventral horn and spinal ganglia showed that more motor neurons in the ipsilateral ventral horns and spinal ganglia were labeled in group III than in the negative control group, group I, and group II at 16 weeks after the operation. All results consistently showed that when BMSCs and SCs were loaded together in an acellular nerve scaffold, functional recovery of the sciatic nerve was enhanced to the greatest degree among the 3 cell-treated groups; furthermore, its beneficial effect on sciatic injury regeneration was similar to the autograft group, although it never exceeded it. CONCLUSIONS: This study is a step forward in the search for an alternative to the nerve autograft because it showed that co-grafting of BMSCs and SCs into an acellular nerve scaffold enhanced sciatic nerve functional recovery in rats. Its beneficial effect on sciatic injury regeneration was similar to the autograft group, although it did not exceed it.