Modification of nitrilase based on computer screening and efficient biosynthesis of 4-cyanobenzoic acid.

4-cyanobenzoic acid serves as a crucial intermediate for the synthesis of various high-value organic compounds. The enzymatic hydrolysis of terephthalonitrile to produce 4-cyanobenzoic acid using nitrilase offers the advantages of a simple reaction pathway, environmental friendliness, and easy product separation. In order to efficiently develop nitrilases that meet industrial production requirements, the virtual screening method used in the study is established and mature. From a total of 371 amino acids in the nitrilase AfNIT, which exhibits activity in terephthalonitrile hydrolysis, three candidate sites (F168, S192, and T201) were identified, and a "small and accurate" mutant library was constructed. The triple mutant F168V/T201N/S192F was screened from this small mutant library with a specific activity of 227.3 U mg-1 , which was 3.8 times higher than that of the wild-type AfNIT. Using the whole-cell biocatalyst containing the mutant F168V/T201N/S192F, terephthalonitrile was successfully hydrolyzed at a concentration of 150 g L-1 to produce 4-cyanobenzoic acid with a final yield of 170.3 g L-1 and a conversion rate of 98.7%. The obtained nitrilase mutant F168V/T201N/S192F in this study can be effectively applied in the biomanufacturing of 4-cyanobenzoic acid using terephthalonitrile as a substrate. Furthermore, the results also demonstrate the significant improvement in predictive accuracy achieved through the latest AI-assisted computer simulation methods. This approach represents a promising and feasible new technological pathway for assisting enzyme engineering research, laying a theoretical foundation for other related studies.

Genome-Wide Association Study Reveals the Genetic Basis of Total Flavonoid Content in Brown Rice.

Flavonoids have anti-inflammatory, antioxidative, and anticarcinogenic effects. Breeding rice varieties rich in flavonoids can prevent chronic diseases such as cancer and cardio-cerebrovascular diseases. However, most of the genes reported are known to regulate flavonoid content in leaves or seedlings. To further elucidate the genetic basis of flavonoid content in rice grains and identify germplasm rich in flavonoids in grains, a set of rice core collections containing 633 accessions from 32 countries was used to determine total flavonoid content (TFC) in brown rice. We identified ten excellent germplasms with TFC exceeding 300 mg/100 g. Using a compressed mixed linear model, a total of 53 quantitative trait loci (QTLs) were detected through a genome-wide association study (GWAS). By combining linkage disequilibrium (LD) analysis, location of significant single nucleotide polymorphisms (SNPs), gene expression, and haplotype analysis, eight candidate genes were identified from two important QTLs (qTFC1-6 and qTFC9-7), among which LOC_Os01g59440 and LOC_Os09g24260 are the most likely candidate genes. We also analyzed the geographic distribution and breeding utilization of favorable haplotypes of the two genes. Our findings provide insights into the genetic basis of TFC in brown rice and could facilitate the breeding of flavonoid-rich varieties, which may be a prevention and adjuvant treatment for cancer and cardio-cerebrovascular diseases.

Reverse-QTY code design of active human serum albumin self-assembled amphiphilic nanoparticles for effective anti-tumor drug doxorubicin release in mice.

Human serum albumin (HSA) is a highly water-soluble protein with 67% alpha-helix content and three distinct domains (I, II, and III). HSA offers a great promise in drug delivery with enhanced permeability and retention effect. But it is hindered by protein denaturation during drug entrapment or conjugation that result in distinct cellular transport pathways and reduction of biological activities. Here we report using a protein design approach named reverse-QTY (rQTY) code to convert specific hydrophilic alpha-helices to hydrophobic to alpha-helices. The designed HSA undergo self-assembly of well-ordered nanoparticles with highly biological actives. The hydrophilic amino acids, asparagine (N), glutamine (Q), threonine (T), and tyrosine (Y) in the helical B-subdomains of HSA were systematically replaced by hydrophobic leucine (L), valine (V), and phenylalanine (F). HSArQTY nanoparticles exhibited efficient cellular internalization through the cell membrane albumin binding protein GP60, or SPARC (secreted protein, acidic and rich in cysteine)-mediated pathways. The designed HSArQTY variants displayed superior biological activities including: i) encapsulation of drug doxorubicin, ii) receptor-mediated cellular transport, iii) tumor cell targeting, and iv) antitumor efficiency compare to denatured HSA nanoparticles. HSArQTY nanoparticles provided superior tumor targeting and antitumor therapeutic effects compared to the albumin nanoparticles fabricated by antisolvent precipitation method. We believe that the rQTY code is a robust platform for specific hydrophobic modification of functional hydrophilic proteins with clear-defined binding interfaces.

C1-2 Fusion in Atlantoaxial Dislocation and Basilar Invagination with and without Chiari Malformation: Clinical/Radiological and Craniometric Results.

OBJECTIVE: Patients with Chiari malformation (CM) associated with atlantoaxial dislocation (AAD) and basilar invagination (BI) may present with a small posterior cranial fossa, but data on the volumetric analysis are lacking. Additionally, whether additional foramen magnum decompression (FMD) is needed together with atlantoaxial fusion remains controversial. This study evaluated the volumetric alterations of the posterior cranial fossa in these patients and analyzed the radiological and clinical outcomes after posterior C1-C2 reduction and fixation plus C1 posterior arch resection. METHODS: Thirty-two adult CM patients with AAD and BI (CM-AAD/BI group) and 21 AAD and BI patients without CM (AAD/BI-only group) who received posterior atlantoaxial fusion plus C1 posterior arch resection were retrospectively studied. The clinical and radiological outcomes and volumetric measurements of the posterior cranial fossa were evaluated. RESULTS: The majority of CM-AAD/BI patients (94%) improved clinically and radiologically at 12 mo postoperatively, and none required additional FMD. Morphological analysis revealed a significant reduction in the bony posterior cranial fossa volumes of the CM-AAD/BI group (P < 0.01) and the AAD/BI-only group (P < 0.01) relative to those of the CM group. No significant differences were observed between the CM-AAD/BI and AAD/BI groups. CONCLUSIONS: Compared with patients with simple CM, patients with AAD/BI with or without CM demonstrated a considerably and equally reduced bony posterior cranial fossa volume. No additional FMD is needed in the treatment of CM-AAD/BI patients after posterior reduction and fusion plus C1 posterior arch resection.

A survival nomogram model constructed with common clinical characteristics to assist clinical decisions for diffuse low-grade gliomas: A population analysis based on SEER database.

Background: The prognosis of diffuse low-grade gliomas (DLGGs, WHO grade 2) is highly variable, making it difficult to evaluate individual patient outcomes. In this study, we used common clinical characteristics to construct a predictive model with multiple indicators. Methods: We identified 2459 patients diagnosed with astrocytoma and oligodendroglioma from 2000 to 2018 in the SEER database. After removing invalid information, we randomly divided the cleaned patient data into training and validation groups. We performed univariate and multivariate Cox regression analyses and constructed a nomogram. Receiver operating characteristic (ROC) curve, c-index, calibration curve, and subgroup analyses were used to assess the accuracy of the nomogram by internal and external validation. Results: After univariate and multivariate Cox regression analyses, we identified seven independent prognostic factors, namely, age (P<0.001), sex (P<0.05), histological type (P<0.001), surgery (P<0.01), radiotherapy (P<0.001), chemotherapy (P<0.05) and tumor size (P<0.001). The ROC curve, c-index, calibration curve, and subgroup analyses of the training group and the validation group showed that the model had good predictive value. The nomogram for DLGGs predicted patients' 3-, 5- and 10-year survival rates based on these seven variables. Conclusions: The nomogram constructed with common clinical characteristics has good prognostic value for patients with DLGGs and can help physicians make clinical decisions.

Computational identification of immune-related lncRNA signature for predicting the prognosis and immune landscape of human glioblastoma multiforme.

Emerging evidence shows immune-related long noncoding RNAs (ir-lncRNAs) perform critical roles in tumor progression and prognosis assessment. However, the identification of ir-lncRNAs and their clinical significance in human glioblastoma multiforme (GBM) remain largely unexplored. Here, a designed computational frame based on immune score was used to identify differentially expressed ir-lncRNAs (DEir-lncRNAs) from The Cancer Genome Atlas (TCGA) GBM program. The immune-related lncRNA signature (IRLncSig) composed of prognosis-related DEir-lncRNAs selected by Cox regression analysis and its clinical predictive values were verified, which was further validated by another dataset from the Gene Expression Omnibus database (GEO). Subsequently, the association between IRLncSig and immune cell infiltration, immune checkpoint inhibitor (ICI) biomarkers, O6-methylguanine-DNA methyltransferase (MGMT) gene expression, and biological function were also analyzed. After calculation, five prognosis-related ir-lncRNAs were included in the establishment of IRLncSig. The risk assessment based on IRLncSig indicated that the high-IRLncSig-score group was significantly associated with poor prognosis (p < 0.001), significant aggregation of macrophages (p < 0.05), higher ICI biomarker expression, and MGMT gene expression (p < 0.05). Signature-related lncRNAs may be involved in immune activities in the tumorigenesis and progression of GBM. In summary, the novel IRLncSig shows a promising clinical value in predicting the prognosis and immune landscape of GBM.

Morphometric and volumetric analysis of the posterior cranial fossa in adult Chiari malformation type I with and without group B basilar invagination.

BACKGROUND: The frequent association of basilar invagination (BI) makes the understanding of the pathogenesis of Chiari malformation type I (CMI) difficult. The influence of group B type of BI (the BI without obvious atlantoaxial instability) on the skeletal morphology has not been thoroughly studied. The objective of this study is to evaluate the skeletal alterations in the posterior cranial fossa (PCF) of adult CMI cases with and without group B BI. METHODS: Fifty-four adult CMI without BI cases (CMI-only group) and 30 adult CMI with group B BI cases (CMI-BI group) were retrospectively studied. Fifty-six adult patients with unruptured intracranial aneurysms were included as the controls. Several linear and angular variables, and the bony volume of the PCF were analyzed based on thin-slice computed tomography data. RESULTS: Morphological analysis revealed a significant difference in several variables from controls compared to CMI-only, and CMI-BI patients. The clivus and occipital bone, shortened and elevated in CMI-only patients, were further flattened in BI-associated CMI patients. Furthermore, although out of the scope for the diagnostic threshold of BI, the CMI-only cases also had a tendency to form BI. The association of BI modified several variables, without further reducing the bony PCF volume. CONCLUSIONS: These findings indicate that the variables associated with group B BI tend to be a continuum of the same pathological abnormalities that originate from the same pathological alterations in CMI patients.

Chromobox Homolog 8 (CBX8) in Human Tumor Carcinogenesis and Prognosis: A Pancancer Analysis Using Multiple Databases.

Some emerging studies have suggested that chromobox homolog 8 (CBX8) may play a critical role in carcinogenesis and prognosis in human cancer. Based on The Cancer Genome Atlas (TCGA)'s available data and the Gene Expression Omnibus (GEO) database, we conducted a systematic analysis of the carcinogenic effects of the CBX8 gene. We used TIMER2, GEPIA2, UALCAN, cBioPortal, Kaplan-Meier plotter, OncoLnc, STRING, HPA, and Oncomine data analysis websites and R data analysis software to analyze available data. The results show that the level of expression of CBX8 was significantly different among 27 different types of tumors and adjacent normal tissues. Moreover, we found that CBX8 expression had a close relationship with prognosis in some kinds of cancers. The phosphorylation level of some protein sites (such as S256) was significantly increased in tumors. CD8 + T-cell, B-cell and cancer-associated fibroblast infiltration levels were associated with CBX8 expression. The results of enrichment analysis indicated that the main biological activities of CBX8 are connected to gene transcription and repair of DNA damage. In conclusion, the level of expression of CBX8 was closely related to carcinogenesis and prognosis of some kinds of tumors, which needs further experimental verification.

Preparation of the Key Dolutegravir Intermediate via MgBr2-Promoted Cyclization.

A novel approach for synthesizing the key dolutegravir intermediate is described via MgBr2-promoted intramolecular cyclization. Condensation of commercially available methyl oxalyl chloride and ethyl 3-(N,N-dimethylamino)acrylate afforded the vinylogous amide in an excellent yield. Subsequent substitution by aminoacetaldehyde dimethyl acetal and methyl bromoacetate gave rise to the expected precursor for cyclization, which was promoted by MgBr2 to highly selectively convert into pyridinone diester. The key dolutegravir intermediate was finally prepared by the selective hydrolysis of the corresponding diester via LiOH.

Diabetes increases the risk of meningioma: A systematic review and meta-analysis of observational studies.

BACKGROUND: Increasing epidemiological evidence suggests that diabetes may be associated with meningioma risk, but the evidence supporting this association is still inconclusive. Therefore, we performed a meta-analysis of all eligible observational studies to evaluate the potential association of diabetes with meningioma risk. METHODS: A comprehensive literature search was performed in the PubMed, Web of Science and Cochrane Library databases up to November 30, 2020. A random-effects model was applied to calculate the pooled effect size (ES) and its 95 % confidence interval (CI). RESULTS: Eight studies were included in this study. In a random-effects pooled analysis, the results showed that DM (diabetes mellitus) increased the risk of meningioma (ES 1.17, 95 % CI: 1.02-1.35, P = 0.027). In subgroup analyses, DM increased the risk of meningioma in women (ES: 1.19, 95 % CI: 1.02-1.40, P = 0.027) and men (ES: 1.53, 95 % CI: 1.25-1.88, P = 0.000). This effect was not observed in the postmenopausal group (ES: 1.18, 95 % CI: 0.64-2.18, P = 0.597). CONCLUSION: Our meta-analysis showed that DM increases the risk of meningioma, but the association was only present in some subgroups. This conclusion should be further confirmed.

Sporadic Solid/Cystic Hemangioblastomas in the Cerebellum: Retrospective Study of More Than Ten Years of Experience in a Single Center.

BACKGROUND: Solid/cystic hemangioblastomas are rare, and they lack a systematic description. We clarify the epidemiology, clinical features, imaging characteristics, and surgical outcomes of sporadic solid/cystic hemangioblastomas in the cerebellum. METHODS: A total of 75 patients with sporadic hemangioblastomas from 2006 to 2018 were enrolled in this retrospective study and divided into solid (26/75), cystic (40/75), and solid/cystic (9/75) groups according to the imaging findings. All patients underwent microsurgical resection and had a definite 31 pathologic diagnosis. RESULTS: The age at diagnosis in the solid/cystic group was the highest among the 3 groups (P < 0.05). The solid/cystic group showed the shortest symptom duration (P < 0.05), which was related to obvious peritumoral brain edema (P < 0.05). The combination of computed tomography angiography and magnetic resonance imaging helped with the differential diagnosis. The solid/cystic group showed the lowest rate of gross total resection (P < 0.05) as a result of the obscure brain-tumor interface, and the guidance of intraoperative ultrasonography helped with the microsurgical procedures to a certain extent. Patients in the solid/cystic group showed greater intraoperative blood loss (P < 0.05), a lower ratio of symptom improvement (P < 0.05), and a longer mean hospital stay (P < 0.05) than did patients in the cystic group. CONCLUSIONS: Cerebellar sporadic solid/cystic hemangioblastomas are rare and usually affect elderly people. The combination of computed tomography angiography and magnetic resonance imaging may improve the preoperative diagnosis. Solid/cystic hemangioblastomas showed the lowest rate of gross total resection as a result of the obscure brain-tumor interface.

ASK1 phosphorylation regulates astrocytic reactive gliosis in vitro and in vivo.

Apoptosis signal-regulating kinase 1 (ASK1) may play a pivotal role in reactive gliosis. To assess the role of ASK1 in trauma-induced reactive gliosis, we examined the phosphorylation of ASK1 and the expression of glial fibrillary acidic protein (GFAP) and vimentin after scratch injury in cultured astrocytes and spinal cord injury (SCI) in rats. Enhanced phosphorylation of ASK1 was detected during reactive gliosis both in vitro and in vivo, and P38 MAPK relayed the signal from phosphorylated ASK1 to the activation of astrocytes. Immunoprecipitation analyses suggested that 14-3-3 was dissociated from ASK1 during astrocyte activation. Finally, treatment with thioredoxin reduced ASK1 phosphorylation and reactive gliosis and promoted hindlimb locomotion recovery in SCI rats. These results indicated that ASK1 may play an important role in mechanical-injury-induced reactive gliosis.

Antidepressant effect of venlafaxine in chronic unpredictable stress: Evidence of the involvement of key enzymes responsible for monoamine neurotransmitter synthesis and metabolism.

A number of studies have linked abnormalities in the function of the serotonergic and noradrenergic systems to the pathophysiology of depression. It has been reported that selective serotonin reuptake inhibitors promote the expression of tryptophan hydroxylase (TPH), which is involved in the synthesis of serotonin. However, limited evidence of TPH alteration has been found in selective serotonin and noradrenaline reuptake inhibitors (SNRIs), and more key enzymes need to be investigated. The aim of the present study was to determine whether venlafaxine (VLX; a classical SNRI) regulates TPH and other key enzymes responsible for the synthesis and metabolism of monoaminergic transmitters in rats with chronic unpredictable stress (CUS). The present results suggested that CUS­exposed rats exhibited decreased locomotor activity in the open­field test and increased immobility time in the forced swim test, as compared with the controls. Pretreatment with VLX (20 mg/kg) significantly increased locomotor activity and reduced immobility time in the CUS­exposed rats. In addition, VLX (20 mg/kg) treatment prevented the CUS­induced reduction in tyrosine hydroxylase and TPH expression in the cortex and hippocampus. Furthermore, VLX alleviated the CUS­induced oxidative stress in the serum, cortex and hippocampus. However, VLX administration did not have an effect on indoleamine­2,3­dioxygenase overexpression in the hippocampus. It was therefore concluded that the regulation of abnormalities in the synthesis and metabolism of monoaminergic transmitters may be associated with the antidepressant effects of VLX, suggesting that multimodal pharmacological treatments can efficiently treat depression.

Medulloblastomas in cerebellopontine angle: Epidemiology, clinical manifestations, imaging features, molecular analysis and surgical outcome.

Cerebellopontine angle (CPA) medulloblastoma is rare and short of system description. We attempted to clarify its epidemiology, clinical manifestations, imaging features, pathological and molecular types, and surgical outcomes. 8 patients from 7 to 52 years old were enrolled in this retrospective study, with mean age 21.6 ±â€¯16.4 years. The most frequent symptoms were raised intracranial pressure (100%), followed by cerebellar signs (50%), decreased hearing (50%), facial paralysis (50%), abducent paralysis (50%), and facial paresthesia (37.5%). MRI demonstrated a solid CPA lesion with heterogeneously weak or significant enhancement after gadolinium administration, accompanied with peritumoral oedema (75%), cystic change (62.5%) and dural tail sign (50%), while CT showed petrous bone and internal auditory canal intact. All cases received tumor excision, with 6 (75%) cases undergoing gross total resection, and the remaining (25%) getting partial excision. Pathological examination confirmed 5 (62.5%) classic, 2 (25%) desmoplastic, and 1 (12.5%) anaplastic. Further molecular analysis identified 5 (62.5%) WNT and 3 (37.5%) SHH. Immediately after the primary surgery, 7 (87.5%) cases gained improvement of the symptoms and signs and 1 (12.5%) kept the preoperative status stable. Follow up was available ranged from 5 to 34 months, during that period 5 cases kept symptom free and 3 cases recurred/progressed. In conclusion, CPA medulloblastoma is rare and lacking of special clinical manifestations and radiological features, and should be considered in the differential diagnosis of CPA lesions. In this series the most frequent pathological and molecular type is classic and WNT. Microsurgery excision is effective to prevent progressive decline of neurological status.

Finite element analysis for blood accumulation in intracerebral hemorrhage.

Biomechanical methods may provide a novel way to understand blood accumulation in intracerebral hemorrhage (ICH). The current study presents the results of a biomechanical analysis of blood accumulation in ICH using a finite element analysis, with an emphasis on the pressure exerted by the mass effect of blood in early ICH. A two-dimensional finite model of the human brain parenchyma and the human ventricular system was developed and analyzed under two preloading conditions. The material properties of the human parenchyma were derived from previous reports. Ogden's theory was applied to describe the stress-strain association in soft tissue. The results of the present study indicated that maximal stress was located at the two ends of the hemorrhage cavity, with the majority of stresses distributed on the zone surrounding the bleed. The two load environments demonstrated similar stress distributions. The loads put on the detached edges were not less than the intracranial pressure (ICP) when the stress threshold was reached. The results of the present study suggest that the direction of blood accumulation can be determined by the shape of the initial blood mass. Mechanical factors (blood pressure and ICP) did not serve a definitive role in preventing blood from accumulating in the early stages of ICH. The present study may aid in understanding the effects of mechanical factors in blood accumulation and hemostasis in patients with early ICH.

An in vitro study of non-aligned or aligned electrospun poly(methyl methacrylate) nanofibers as primary rat astrocytes-loading scaffold.

After spinal cord injury (SCI), functional regeneration of neurites is hard to achieve due to the existence of glial scar, meanwhile astrocytes are believed important for post injury neuroregeneration, therefore how to handle the contradictory roles of astrocytes remains a problem for better neurogenesis. In this report, aligned electrospun poly(methyl methacrylate) (PMMA) nanofibers were assessed as an astrocytes-loading scaffold in vitro. We found that cell adherence and cell expansion of astrocytes could be supported by PMMA nanofibers, which topographic features could obviously influence the growth manner of astrocytes, and cells on aligned nanofibers finally formed longer and highly aligned processes along the axis of substrate fibers compared with cells cultured on film and non-aligned nanofibers. Regarding the relationship between astrocytes and substratum nanofibers, different topographic feature of substrate nanofibers showed varying degree of impact on cell expansion. On non-aligned nanofibers astrocytes expanded along the orientation of nanofibers early, while on aligned nanofibers astrocytes complied with the cues of nanofibers gradually with time. The results strengthen the rationale that aligned nanofibers could serve as the candidate of implantable scaffold after SCI, and it may relieve the stress of proliferated astrocytes by manipulating the growth pattern of astrocytes through its topographic features.

Intraneural Injection of ATP Stimulates Regeneration of Primary Sensory Axons in the Spinal Cord.

Injury to the peripheral axons of sensory neurons strongly enhances the regeneration of their central axons in the spinal cord. It remains unclear on what molecules that initiate such conditioning effect. Because ATP is released extracellularly by nerve and other tissue injury, we hypothesize that injection of ATP into a peripheral nerve might mimic the stimulatory effect of nerve injury on the regenerative state of the primary sensory neurons. We found that a single injection of 6 µl of 150 µm ATP into female rat sciatic nerve quadrupled the number of axons growing into a lesion epicenter in spinal cord after a concomitant dorsal column transection. A second boost ATP injection 1 week after the first one markedly reinforced the stimulatory effect of a single injection. Single ATP injection increased expression of phospho-STAT3 and GAP43, two markers of regenerative activity, in sensory neurons. Double ATP injections sustained the activation of phospho-STAT3 and GAP43, which may account for the marked axonal growth across the lesion epicenter. Similar studies performed on P2X7 or P2Y2 receptor knock-out mice indicate P2Y2 receptors are involved in the activation of STAT3 after ATP injection or conditioning lesion, whereas P2X7 receptors are not. Injection of ATP at 150 µm caused little Wallerian degeneration and behavioral tests showed no significant long-term adverse effects on sciatic nerve functions. The results in this study reveal possible mechanisms underlying the stimulation of regenerative programs and suggest a practical strategy for stimulating axonal regeneration following spinal cord injury.SIGNIFICANCE STATEMENT Injury of peripheral axons of sensory neurons has been known to strongly enhance the regeneration of their central axons in the spinal cord. In this study, we found that injection of ATP into a peripheral nerve can mimic the effect of peripheral nerve injury and significantly increase the number of sensory axons growing across lesion epicenter in the spinal cord. ATP injection increased expression of several markers for regenerative activity in sensory neurons, including phospho-STAT3 and GAP43. ATP injection did not cause significant long-term adverse effects on the functions of the injected nerve. These results may lead to clinically applicable strategies for enhancing neuronal responses that support regeneration of injured axons.

In situ hydrogels enhancing postoperative functional recovery by reducing iron overload after intracerebral haemorrhage.

The role of surgery for most patients with spontaneous intracerebral haemorrhage (ICH) remains controversial due to the continuous occurrence of postoperative iron overload induced by low clot clearance rate. In this study, human hair keratose hydrogel (KG) loading with minocycline hydrochloride (MH) were prepared to reduce iron overload for the improvement of the postoperative functional recovery after ICH aspiration surgery. Hemoglobin-induced iron accumulation in rat primary neuronal culture was delayed by the adsorptive capacity of blank KG, while MH-loaded KG displayed a stronger and more thorough cytoprotective effect than blank KG due to the combined effect of absorptive action to iron and sustained release of the iron chelator. Moreover, high iron-chelating efficiency in the hematoma region supplied by MH-loaded KG significantly reduced dose strength of iron chelator. In situ injection of KG with different MH loadings (2, 20, and 200µg) into the hematoma region after aspiration surgery showed a stronger effect on the reduction of ICH-induced iron accumulation, edema, and neurological deficits in rats compared to the postoperative intraperitoneal administration of MH (approximately 15mg). These results suggested that the in situ KG not only could effectively reduce the ICH postoperative iron overload and improve the postoperative functional recovery via the iron adsorption and sustained release of MH, but also has great potential to reduce the systemic adverse effects by decreasing the dose strength of iron chelator.

Mechanisms of autophagy and apoptosis mediated by JAK2 signaling pathway after spinal cord injury of rats.

The aim of this study was to investigate the pathogenesis of autophagy and apoptosis mediated by Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) signal pathway after the onset of acute spinal cord injury (ASCI). A total of 45 Sprague-Dawley adult rats of either sex were selected for this study. The age of rats ranged from 8 to 10 weeks, and the average weight was 245 g. These rats were randomly divided into three groups, i.e. sham-operated group, model group, and the AG-490 intervention group (AG-490 is an inhibitor of JAK2). Each group contained 15 rats. Models were prepared using the modified Allen method. Five rats in each group were sacrificed at 6, 12 and 24 h, respectively, and the expression levels of p-JAK2 and p-STAT3 were detected in spinal cord tissue via western blot analysis. The levels of proinflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were detected via ELISA, positive expression of light chain 3 (LC3)-II of microtubule-associated protein 1 via immunofluorescence labeling method, and mRNA expression levels of caspase-3 and Bax/Bcl-2 via RT-PCR. In the model group, the expression levels of p-JAK2, p-STAT3, IL-6, TNF-α and LC3-II, and the mRNA expression levels of caspase-3 and Bax/Bcl-2 at all time-points were significantly higher than those in the AG-490 intervention group, and the levels in the sham-operated group were the lowest (p<0.05). In the model group, peak levels of p-JAK2 and p-STAT3 were attained at 12 h, but a decline was seen at 24 h; while increasing trend was seen in other indicators. In conclusion, JAK2/STAT3 signal pathway can mediate the activity of autophagy and apoptosis in an early stage after the onset of ASCI of rat.

Serotonergic projections to lumbar levels and its plasticity following spinal cord injury.

The descending serotonergic pathway, which originates in various populations of brainstem neurons, plays an important role in generating the rhythmic motor pattern associated with locomotor movement. Although the development of its innervation has been studied in rodent spinal cord, it has not been clearly identified how the projection of serotonergic pathway is related to its function. Here, we evaluated the pattern of serotonergic innervation on the lumbar spinal cord from embryonic day 14.5 (E14.5) to adulthood. Before birth, we found that 5-hydroxytryptamine (5-HT) fibers invade the lumbar cord as early as E14.5, penetrate into the gray matter from lateral funiculus by E16.5, and then mainly occupied the ventral horn by E18.5 before localizing in the dorsal horn. After birth, we found that 5-HT invasion of both dorsal horn and ventral horn were present by the 7th postnatal day (P7). Additionally, the 5-HT innervation of these two areas evolved progressively from a diffuse network to a more restricted pattern, particularly at the ventral horn within the motoneuron area from P21 to adulthood. This 5-HT innervation pattern in the lumbar cord provides anatomical evidence that serotonergic fibers establish direct connections with lumbar motoneurons, which offers us a solid foundation that enhancing the plasticity of serotonergic pathway following SCI may facilitate locomotor functional recovery. Therefore, we employed treadmill training to activate serotonergic plasticity after SCI. We found that mice which underwent treadmill training exhibited a better locomotor functional recovery. Meanwhile, the density of 5-HT fibers in the ventral horn was significantly increased and the synaptic formation of 5-HT fibers with lumbar motoneurons was also significantly rescued in the training group mice after SCI. These findings demonstrate that the descending serotonergic projection is a robust and flexible parallel pathway for modulating spinal locomotor function.