Strongly Adhesive, Self-Healing, Hemostatic Hydrogel for the Repair of Traumatic Brain Injury.

With wide clinical demands, therapies for traumatic brain injury (TBI) are a major problem in surgical procedures and after major trauma. Due to the difficulty in regeneration of neurons or axons after injury, as well as the inhibition of blood vessel growth by the formation of neural scars, existing treatment measures have limited effectiveness in repairing brain tissue. Herein, the biomultifunctional hydrogels are developed for TBI treatment based on the Schiff base reaction of calcium ion (Ca2+)-cross-linked oxidized sodium alginate (OSA) and carboxymethyl chitosan (CMCS). The obtained COCS hydrogel exhibits excellent adhesion to wet tissues, self-repair capability, and antimicrobial properties. What's particularly interesting is that the addition of Ca2+ increases the hydrogel's extensibility, enhancing its hemostatic capabilities. Biological assessments indicate that the COCS hydrogel demonstrates excellent biocompatibility, hemostatic properties, and the ability to promote arterial vessel repair. Importantly, the COCS hydrogel promotes the growth of cerebral microvessels by upregulating CD31, accelerates the proliferation of astrocytes, enhances the expression of GFAP, and stimulates the expression of neuron-specific markers such as NEUN and ß-tubulin. All of these findings highlight that the strongly adhesive, self-healing, hemostatic hydrogel shows great potential for the repair of traumatic brain injury and other tissue repair therapy.

Porous gelatin microsphere-based scaffolds containing MC3T3-E1 cells and calcitriol for the repair of skull defect.

There is an increasing demand for biomaterials with skull regeneration for clinical application. However, most of the current skull repair materials still have limitations, such as inadequate sources, poor cell adherence, differentiation, tissue infiltration, and foreign body sensation. Therefore, this study developed porous microsphere-based scaffolds containing mouse embryonic osteoblast precursor cells (MC3T3-E1 cells) and calcitriol (Cal) using gelatin and gelatin/hydroxyapatite through green freeze-crosslinking and freeze-drying. Gelatin was employed to prepare porous microspheres with a particle size of 100-300 µm, containing open pores of 2-70 µm and interconnected paths. Furthermore, the addition of Cal to porous gelatin microsphere-based scaffolds containing MC3T3-E1 cells (PGMSs-MC) and porous gelatin/hydroxyapatite composite microspheres containing MC3T3-E1 cells (HPGMSs-MC) improved their osteoinductivity and cell proliferation and promoted the formation of mature and well-organized bone. The developed Cal-HPGMSs-MC and Cal-PGMSs-MC displayed a good porous structure and cytocompatibility, histocompatibility, osteoconductivity, and osteoinduction. Thus, the designed scaffolds provide a promising prospect for tissue-engineered constructs with skull growth and integration, laying a foundation for further research on the reconstruction of skull defects.

Ultrasonography for Serial Monitoring and Management of Cerebrospinal Fluid Dynamic Disorders After Decompressive Craniectomy.

OBJECTIVE: Decompressive craniectomy (DC) is widely used to treat intracranial hypertension following severe head injury. However, impairments of cerebrospinal fluid (CSF) hydrodynamics such as hydrocephalus and subdural effusion are common complications that occur after DC. Therefore, monitoring of intracranial pressure is a staple of neurocritical care post-DC. The aim of this study was to assess the usefulness of transcranial duplex sonography (TDS) for serial monitoring and management of CSF disorders after DC. METHODS: A total of 100 patients who underwent DC between June 2016 and May 2019 were recruited for the study. Transcranial duplex sonography examinations were performed between 1-day and 1-year post-DC. Transcranial duplex sonography was mainly used for monitoring changes in ventricle size and morphology, and also to monitor intraventricular hemorrhage, hydrocephalus, intracranial hygromas, and ventricle changes during CSF release procedures. RESULTS: A total of 456 TDS examinations were performed on patients after DC. Of these, 402 were performed in the neuro-intensive care unit. Two patients had intraventricular hemorrhage and underwent TDS-guided external ventricular drainage. Twenty-nine patients were diagnosed with hydrocephalus. The results of TDS were consistent with those of cranial computed tomography. Three cases of ventriculoperitoneal shunt and 1 case of lumbar peritoneal shunt underwent valve pressure reset according to TDS, to obtain satisfactory ventricle size. Transcranial duplex sonography was used to monitor ventricle changes and control drainage volume during CSF release procedures, including 2 external ventricular drainage, 6 external lumbar drainage, and 10 lumbar punctures. Eighteen patients were detected with single or multiple intracranial effusions, including 16 subdural hygromas, 5 longitudinal fissure hygromas, and 6 brain cysts. CONCLUSIONS: Transcranial duplex sonography can efficiently help monitor changes in ventricle size and morphology and intracranial effusions. Due to its noninvasive nature, suitability for bedside application, real-time, and inexpensiveness, TDS can significantly replace cranial computed tomography and become part of the patient's daily inspection work after DC.

Effect of Different Treatments for Intracranial Solitary Fibrous Tumors: Retrospective Analysis of 31 Patients.

OBJECTIVE: An intracranial solitary fibrous tumor (SFT) is a rare mesenchymal neoplasm with a high predisposition toward recurrence and metastasis. The definition of SFT was updated according to the 2021 World Health Organization (WHO) classification. Given its rarity and resemblance to meningiomas, SFT is often misdiagnosed and there remains a debate on the treatment for it. We provide a retrospective analysis of SFTs and conclude the outcomes of different treatments. METHODS: Patients who accepted operation and were diagnosed with intracranial SFTs in our hospital were included between 2008 and 2021. The medical records on clinical characteristics and outcomes were summarized for analysis. Cox regressions were used to determine the hazard ratio (HR). RESULTS: Thirty-one SFT patients were included with a median follow-up time of 67 months. Tumor recurrence was observed in 12 (38.7%) patients, with 1 and 5-year recurrence rates of 6.5% and 22.6%, respectively. In univariate analysis, gross total resection (GTR) was significantly associated with decreased recurrence (P = 0.022), while subtotal resection (STR) (HR = 9.237; P = 0.020) and tumor location of tentorium (HR = 4.692; P = 0.022) were correlated with increased recurrence. In multivariate analysis, GTR (P = 0.040) and GTR plus radiotherapy (GTR + RT) (HR = 0.002; P = 0.020) were associated with reduced recurrence, while STR (HR = 40.835; P = 0.012) was a risk factor for recurrence. CONCLUSIONS: GTR and postoperative RT are beneficial for preventing tumor recurrence. Larger studies and long-term follow-up are warranted to further identify the effect of postoperative RT.

Association of E-Selectin gene rs5361 polymorphism with ischemic stroke susceptibility: a systematic review and Meta-analysis.

BACKGROUND: Over the years, a number of published studies showed that E-Selectin gene rs5361 (S128R, Ser128Arg, A561C) variants were associated with the risk of ischemic stroke (IS). However, the results of those case-control studies were still equivocal. Therefore, we performed this meta-analysis to clarify the relationship between E-Selectin gene rs5361 polymorphism and IS risk. METHODS: We searched the Web of Science, PubMed, VIP, CNKI (China National Knowledge Infrastructure) and Wanfang databases for obtainning the eligible studies according to the inclusion and exclusion criteria. Odds ratios (ORs) with its 95% confidence intervals (CIs) were calculated to evaluate the relationship of E-Selectin gene rs5361 polymorphism with IS susceptibility under the dominant and allelic model with fixed or random effects model. RESULTS: Totally, 13 studies with 2888 cases and 2976 controls were selected in this systematic review and meta-analysis This meta-analysis obtained that E-Selectin gene rs5361variants contributed to increase the risk of IS (C vs. A: OR = 2.23, 95%CI = 1.70-2.92, p < 0.001). We also performed a sub-analysis by ethnicity, the results indicated that rs5361 variants were related to an increased risk of IS (East Asian population: C vs. A: OR = 1.97, 95%CI =1.58-2.45, p < 0.001; African population: C vs. A: OR = 5.52, 95%CI = 3.48-8.76, p < 0.001; Caucasian population: C vs. A: OR =1.67, 95%CI =1.32-2.10, p < 0.001). CONCLUSIONS: Therefore, our meta-analysis suggested that C allele, AA and AC genotypes of E-Selectin gene rs5361 variants were related to an increased risk of IS in overall populations.

Corrigendum: Development and Validation of a Prognostic Nomogram to Predict Cancer-Specific Survival in Adult Patients With Pineoblastoma.

[This corrects the article DOI: 10.3389/fonc.2020.01021.].

Development and Validation of a Prognostic Nomogram to Predict Cancer-Specific Survival in Adult Patients With Pineoblastoma.

Pineoblastoma (PB) is a rare neoplasm of the central nervous system. This analysis aimed to identify factors and establish a predictive model for the prognosis of adult patients with PB. Data for 213 adult patients with PB (Surveillance, Epidemiology, and End Results database) were randomly divided into primary and validation cohorts. A predictive model was established and optimized based on the Akaike Information Criterion and visualized by a nomogram. Its predictive performance (concordance index and receiver operating characteristic curve) and clinical utility (decision curve analyses) were evaluated. We internally and externally validated the model using calibration curves. Multivariate Cox regression analysis identified age, year of diagnosis, therapy, tumor size, and tumor extension as independent predictors of PB. The model exhibited great discriminative ability (concordance index of the nomogram: 0.802; 95% confidence interval: 0.78-0.83; area under the receiver operating characteristic curve: ranging from 0.7 to 0.8). Calibration plots (probability of survival) showed good consistency between the actual observation and the nomogram prediction in both cohorts, and the decision curve analyses demonstrated great clinical utility of the nomogram. The nomogram is a useful and practical tool for evaluating prognosis and determining appropriate therapy strategies.

Association between a DJ-1 polymorphism and the risk of Parkinson's disease: a PRISMA-compliant systematic review and meta-analysis.

OBJECTIVE: In recent years, a number of case-control studies have focused on the association between the DJ-1 g.168_185del polymorphism and the risk of Parkinson's disease (PD). However, the results have been conflicting. To estimate the relationship between the DJ-1 g.168_185del polymorphism and PD susceptibility, a comprehensive meta-analysis was performed. METHODS: Eligible studies concerning the DJ-1 g.168_185del polymorphism and PD susceptibility were searched for in the PubMed, Web of Science, Embase, Wanfang, CNKI, and VIP databases. Odds ratios and 95% confidence intervals were calculated to estimate the strength of the associations. In total, 11 studies were included in this meta-analysis, including 13 case-control studies with 2890 cases and 3043 controls. RESULTS: This meta-analysis revealed that DJ-1 g.168_185del variants are associated with PD susceptibility in the non-Asian population, but not in the Asian population. CONCLUSIONS: Our meta-analysis suggests that DJ-1 gene variants are not associated with the risk of PD in the overall population.

Cross-linked gelatin microsphere-based scaffolds as a delivery vehicle of MC3T3-E1 cells: in vitro and in vivo evaluation.

Scaffolding plays a crucial role in bone tissue engineering by not only providing interfaces for cell adhesion, proliferation, and differentiation but also guiding neotissue formation. For this purpose, microspheres (MSs) are being increasingly used alone or in combination with other scaffolds. However, few researchers have used MSs to prepare 3D scaffolds by culture with delivered cells. In this study, we have developed covalent cross-linked gelatin MSs (ccG-MSs) (average diameter = 100-300 µm) to load mouse osteoblast MC3T3-E1 cells, which exhibit attachment and spreading on surfaces of ccG-MSs after co-culture. Significantly, the ccG-MSs can be integrated into a macroscopic construct with MC3T3-E1 cells after 5 days of cultivation. The MC3T3-E1 cells within ccG-MSs constructs show a higher viability and proliferation activity than those in the micro-cavitary gelatin gel (MCG) constructs. Calcium deposition, alkaline phosphatase activity as well as osteocalcin secretion within both ccG-MSs and MCG constructs have been evaluated in vitro and in vivo, respectively. Compared to MCG scaffolds, ccG-MS-based scaffolds can provide better cellular microenvironments for cell proliferation and osteogenic differentiation. Our findings will lay the foundation for understanding cellular behaviors in MS-based 3D constructs and help in designing MS-based bone tissue engineering scaffolds.

Biointerface topography mediates the interplay between endothelial cells and monocytes.

Endothelial cell (EC) monolayers located in the inner lining of blood vessels serve as a semipermeable barrier between circulating blood and surrounding tissues. The structure and function of the EC monolayer affect the recruitment and adhesion of monocytes, which plays a pivotal role in the development of inflammation and atherosclerosis. Here we investigate the effect of material wrinkled topographies on the responses of human umbilical vein endothelial cells (HUVECs) and adhesion of monocytes to HUVECs. It is found that HUVEC responses are non-linearly mediated by surface topographies with different dimensions. Specifically, more cell elongation and better cell orientation on the wrinkled surface with a 3.5 µm amplitude and 10 µm wavelength (W10) are observed compared to other surfaces. The proliferation rate of HUVECs on the W10 surface is higher than that on other surfaces due to more 5-ethynyl-2'-deoxyuridine (EdU) detected on the W10 surface. Also, greater expression of inflammatory cytokines from HUVECs and adhesion of monocytes to HUVECs on the W10 surface is shown than other surfaces due to greater expression of p-AKT and ICAM, respectively. This study offers a new in vitro system to understand the interplay between HUVEC monolayers and monocytes mediated by aligned topographies, which may be useful for vascular repair and disease modeling for drug testing.

A novel cell encapsulatable cryogel (CECG) with macro-porous structures and high permeability: a three-dimensional cell culture scaffold for enhanced cell adhesion and proliferation.

Hydrogel scaffold is a popular cell delivery vehicle in tissue engineering and regenerative medicine due to its capability to encapsulate cells as well as its modifiable properties. However, the inherent submicron- or nano-sized polymer networks of conventional hydrogel will produce spatial constraints on cellular activities of encapsulated cells. In this study, we endeavor to develop an innovative cell encapsulatable cryogel (CECG) platform with interconnected macro-pores, by combining cell cryopreservation technique with cryogel preparation process. The hyaluronan (HA) CECG constructs are fabricated under the freezing conditions via UV photo-crosslinking of the HA methacrylate (HA-MA) that are dissolved in the 'freezing solvent', namely the phosphate buffered saline supplemented with dimethyl sulphoxide and fetal bovine serum. Two model cell types, chondrocytes and human mesenchymal stem cells (hMSCs), can be uniformly three-dimensionally encapsulated into HA CECG constructs with high cell viability, respectively. The macro-porous structures, generated from phase separation under freezing, endow HA CECG constructs with higher permeability and more living space for cell growth. The chondrocytes encapsulated in HA CECG possess enhanced proliferation and extracellular matrix secretion than those in conventional HA hydrogels. In addition, the HA-Gel CECG constructs, fabricated with HA-MA and gelatin methacrylate precursors, provide cell-adhesive interfaces to facilitate hMSCs attachment and proliferation. The results of this work may lay the foundation for us to explore the applications of the CECG-based scaffolds in the field of tissue engineering and regenerative medicine.

Effects of NOTCH1 signaling inhibitor γ-secretase inhibitor II on growth of cancer stem cells.

The present study aimed to observe the effect of the Notch1 signaling inhibitor γ-secretase inhibitor II (GSI II) on the growth and differentiation of tumor cells. The tumor cell line U87 was grown in serum-free media, and cell growth was evaluated using immunofluorescence. Single-cell wall-adherent growing conditions were prepared, GSI II was added, and the differentiation and growth of single tumor cells was evaluated. Immunofluorescence demonstrated positive results for the expression of Nestin and cluster of differentiation 133. The cell proliferation rate was reduced following the addition of GSI II (P<0.05). GSI II may significantly inhibit the proliferation and differentiation of U87 tumor stem cells.

Cryopreservation of Autologous Cranial Bone Flaps for Cranioplasty: A Large Sample Retrospective Study.

OBJECTIVE: To clarify the clinical outcomes of cranioplasty with cryopreserved bone flaps and identify risk factors related to bone flap infection and resorption after cranioplasty with cryopreserved bone flaps. METHODS: A total of 946 patients (989 bone flaps) underwent decompressive craniectomy and delayed cranioplasty via the use of cryopreserved autogenous cranial bone flaps. Cranial bone flaps were removed during the initial craniectomy and reserved in liquid nitrogen (-196°C) with dimethyl sulfoxide as a cryoprotectant. Cranioplasty subsequently was performed once the brain injury had healed. Data regarding complications and clinical outcomes were recorded and the potential risk factors were analyzed. RESULTS: Data from 960 flaps were available for analysis. The overall complication rate was 15.83% (152 of 960). Bone resorption occurred in 42 flaps in 37 patients (4.38%). The bone flaps resorption rate was greater in patients ≤18 years than in patients >18 years (9.38% vs. 3.61%, P < 0.05). Cryopreservation for more than 365 days tended to result in a greater bone resorption rate (6.88% vs. 2.92%, P < 0.01). Skull bone grafts infection occurred in 39 flaps in 34 patients (4.06%). The bone graft infection rate was greater in emergency craniectomy cases (8.81% vs. 2.59%, P < 0.01) and in patients with diabetes (10.53% vs. 3.07%, P < 0.01). CONCLUSIONS: Cryopreservation of autologous cranial bone flaps is safe and effective for cranioplasty. Cranioplasty with cryopreserved autologous cranial bone flaps should be performed no more than 1 year after craniectomy. Emergency craniectomy and patients with diabetes require special attention.

Association between apolipoprotein E gene polymorphism and mild cognitive impairment: a meta-analysis.

A number of published case-control studies reported that the apolipoprotein E (ApoE) gene polymorphism was associated with the mild cognitive impairment (MCI). However, previous reports still remain conflicting. To estimate the association between ApoE polymorphism and MCI susceptibility, we searched the electronic databases including PubMed, Wanfang, CNKI (China National Knowledge Infrastructure), VIP, and EMBASE to retrieve all available studies. A total of 18 studies with 2,004 cases and 3,705 controls were included in this meta-analysis. The pooled analysis based on selected studies showed that statistically significant risk association was found between ApoE gene polymorphism and MCI in overall population (ε4 vs ε3: odds ratio [OR] =2.38, 95% confidence interval [CI]: 2.11-2.68; ε4/ε4 vs ε3/ε3: OR =4.45, 95% CI: 3.06-6.48; ε2/ε4 vs ε3/ε3: OR =2.57, 95% CI: 1.77-3.73; ε3/ε4 vs ε3/ε3: OR =2.31, 95% CI: 1.99-2.69). However, no significant association was detected in two genetic models: ε2 versus ε3 (OR =0.90, 95% CI: 0.77-1.05) and ε2/ε2 versus ε3/ε3 (OR =0.91, 95% CI: 0.50-1.65). Furthermore, ApoE ε2/ε3 genotype provided a slight protection for MCI in overall population (ε2/ε3 vs ε3/ε3: OR =0.80, 95% CI: 0.66-0.97). In the stratified analysis based on ethnicity, similar results were also observed in Chinese population (significant risk: ε4 vs ε3: OR =2.52, 95% CI: 2.19-2.90; ε4/ε4 vs ε3/ε3: OR =5.45, 95% CI: 3.41-8.70; ε2/ε4 vs ε3/ε3: OR =2.59, 95% CI: 1.74-3.86; ε3/ε4 vs ε3/ε3: OR =2.34, 95% CI: 1.97-2.79; slight protection: ε2/ε3 vs ε3/ε3: OR =0.79, 95% CI: 0.64-0.98; no association: ε2 vs ε3: OR =0.92, 95% CI: 0.78-1.09; and ε2/ε2 vs ε3/ε3: OR =1.04, 95% CI: 0.55-1.99). In summary, this meta-analysis of 5,709 subjects suggested that ApoE ε4 allele was associated with an increased risk of MCI. In addition, ApoE ε2/ε3 genotype provided a slight protection for MCI.

Association between PARK16 and Parkinson's disease: A meta-analysis.

Recent years, several case-control studies reported that two polymorphisms (rs947211 and 1572913) within the PARK16 locus were associated with the Parkinson's disease (PD). However, the results were still controversial. Herein, we conducted a comprehensive meta-analysis to estimate the associations between two polymorphisms and PD. Seven databases (PubMed, Google Scholar, EMBASE, Web of Science, CNKI (China National Knowledge Infrastructure), VIP and Wanfang) were searched to identify the eligible studies. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to evaluate the associations of two polymorphisms with PD susceptibility. Totally, 15 studies with 6637 cases and 6774 controls were included in our meta-analysis. The results showed that rs947211 variants were associated with a decreased risk of PD in overall population. Stratified analysis found that rs947211 variants were associated with a significantly decreased risk of PD in Northeast Asian population, but a slightly decreased risk of PD in Southeast Asian and Caucasian population. With regard to rs1572913 polymorphism, the results suggested that rs1572913 variants contribute to decrease the risk of PD. Therefore, our meta-analysis suggested that rs947211 variants (A allele, AG and GG genotypes) may decrease the risk of PD in overall population, particularly in Northeast Asian population; and T allele, TC and TT genotypes of rs1572913 variants contributed to decrease the risk of PD.

Association between Lipoprotein Lipase Polymorphism and the Risk of Stroke: A Meta-analysis.

BACKGROUND: Several studies have studied the relationship between lipoprotein lipase (LPL) HindIII gene polymorphism and stroke susceptibility. However, the conclusions remain controversial. To clarify the association of LPL gene HindIII polymorphism and stroke susceptibility, we therefore conducted a comprehensive meta-analysis. MATERIALS AND METHODS: The PubMed, Web of Science, EMBASE, and Google Scholar databases were systemically searched to indentify available studies. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated under the allelic, dominant, homozygous, heterozygous, and recessive models. The data were analyzed by using Stata 12.0 (StataCorp, College Station, TX). RESULTS: Ten studies were enrolled, including a total of 2122 cases and 2235 controls. The overall results showed that LPL HindIII variants were associated with a decreased risk of stroke (G versus T: OR = .78, 95% CI = .70-.87, P < .001; GG + TG versus TT: OR = .76, 95% CI = .67-.87, P < .001; GG versus TT: OR = .69, 95% CI = .53-.90, P = .006; TG versus TT: OR = .78, 95% CI = .68-.90, P <.001; GG versus TG + TT: OR = .74, 95% CI = .57-.95, P = .02). Stratified analysis by ethnicity (Asian and non-Asian) indicated that LPL HindIII variants were associated with a decreased risk of stroke in the Asian population, but not in the non-Asian population. In the subgroup analysis by stroke subtype, the results suggested that LPL HindIII variants contributed to a decrease in both ischemic stroke and hemorrhagic stroke risks. CONCLUSION: Our meta-analysis suggested that LPL HindIII variants were associated with a decreased risk of stroke in the Asian population, but not in the non-Asian population.

Association between the Matrix Metalloproteinase-9 rs3918242 Polymorphism and Ischemic Stroke Susceptibility: A Meta-Analysis.

BACKGROUND: In recent years, dozens of case-control studies showed that matrix metalloproteinase (MMP)-9 rs3918242 variants were associated with ischemic stroke (IS) susceptibility. However, the conclusions of case-control studies that evaluated the relationship between MMP-9 rs3918242 variants and the risk of IS were still equivocal. Herein, we conducted a comprehensive meta-analysis to investigate the association between MMP-9 rs3918242 variants and the risk of IS. METHODS: We searched 5 databases (PubMed, EMBASE, Google Scholar, Web of Science, and Chinese Biomedical Literature Database) to identify the eligible studies up to October of 2016. The pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to evaluate the association of MMP-9 rs3918242 variants with IS susceptibility under the allelic model (T versus C) and the dominant model (TT + CT versus CC). RESULTS: A total of 14 studies with 3233 cases and 3123 controls were included in this meta-analysis. Our meta-analysis indicated that MMP-9 rs3918242 variants were associated with significantly increased risk of IS in overall populations (T versus C: OR = 1.43, 95% CI = 1.20-1.71, P < .001; TT + CT versus CC: OR = 1.39, 95% CI = 1.16-1.67, P < .001). Subgroup analysis based on ethnicity (Chinese and Caucasian) suggested that MMP-9 rs3918242 variants contributed to increase the risk of IS in Chinese population; However, no association was detected between MMP-9 rs3918242 variants and the risk of IS in Caucasian population. CONCLUSION: Therefore, our meta-analysis suggested that MMP-9 rs3918242 variants (T allele, TT and CT genotypes) contributed to significantly increase the risk of IS in the Chinese population.

Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels regulate firing of globus pallidus neurons in vivo.

The globus pallidus plays a significant role in motor control under both health and pathological states. Recent studies have revealed that hyperpolarization-activated cyclic nucleotide-gated (HCN) channels occupy a critical position in globus pallidus pacemaking activity. Morphological studies have shown the expression of HCN channels in the globus pallidus. To investigate the in vivo effects of HCN channels in the globus pallidus, extracellular recordings and behavioral tests were performed in the present study. In normal rats, micro-pressure ejection of 0.05mM ZD7288, the selective HCN channel blocker, decreased the frequency of spontaneous firing in 21 out of the 40 pallidal neurons. The average decrease was 50.4±5.4%. Interestingly, in another 18 out of the 40 pallidal neurons, ZD7288 increased the firing rate by 137.1±27.6%. Similar bidirectional modulation on the firing rate was observed by a higher concentration of ZD7288 (0.5mM) as well as another HCN channel blocker, CsCl. Furthermore, activation of HCN channels by 8-Br-cAMP increased the firing rate by 63.0±9.3% in 15 out of the 25 pallidal neurons and decreased the firing rate by 46.9±9.4% in another 8 out of the 25 pallidal neurons. Further experiments revealed that modulation of glutamatergic but not GABAergic transmission may be involved in ZD7288-induced increase in firing rate. Consistent with electrophysiological results, further studies revealed that modulation of HCN channels also had bidirectional effects on behavior. Taken together, the present studies suggest that HCN channels may modulate the activity of pallidal neurons by different pathways in vivo.

HCN channels modulate the activity of the subthalamic nucleus in vivo.

The subthalamic nucleus is a key component in the indirect pathway of the basal ganglia, which mediates a variety of motor functions. The subthalamic nucleus neurons have intrinsic pacemaking properties. Hyperpolarization-activated, cyclic nucleotide-gated (HCN) channels are expressed in the central nervous system, including the subthalamic nucleus. However, the in vivo modulation of HCN channels in the subthalamic nucleus remains relatively obscure. To investigate the direct effects of HCN channels in the subthalamic nucleus, multi-barrel extracellular recordings and behavioral tests were performed in the present study. In 42 out of the 89 subthalamic nucleus neurons, micropressure ejection of HCN channel inhibitor, ZD7288 (0.05 mM), decreased the spontaneous firing rate from 11.6 ± 1.8 to 5.7 ± 1.3 Hz (P < 0.001). The average decrease was 56.7 ± 5.3 %. In another 47 out of the 89 subthalamic nucleus neurons, micropressure ejection of ZD7288 increased the spontaneous firing rate from 9.5 ± 1.6 to 16.3 ± 2.4 Hz (P < 0.001), with the average increase of 142.2 ± 29.8 %. Activation of HCN channels by 8-Br-cAMP also produced bidirectional modulation on the firing rate of the subthalamic nucleus neurons. Furthermore, unilateral microinjection of ZD7288 or 8-Br-cAMP produced postural behavior in awake rats. The present electrophysiological and behavioral findings demonstrated that the pharmacological blockade or activation of HCN channels produces bidirectional modulation on the excitability of the subthalamic nucleus.

The effect of lentivirus-mediated PSPN genetic engineering bone marrow mesenchymal stem cells on Parkinson's disease rat model.

Persephin (PSPN) is one of the neurotrophic factors of the glial cell line-derived neurotrophic factor (GDNF) family ligands (GFLs) which have been found to promote the survival of specific populations of neurons. The aim of this study was to assess the potential therapeutic function of gene-modified mesenchymal stem cells (MSCs)-Lv-PSPN-MSCs in 6-OHDA-induced Parkinson's disease (PD) rats models. Here, we worked on the isolation, purification, identification and amplification of MSCs in vitro. The expression analysis revealed that several of the neural marker proteins like nestin, GFAP and S100 were expressed by rat MSCs. MES23.5 cells co-cultured with Lv-PSPN-MSCs showed less 6-OHDA induced cell death than control cells in vitro. When Lv-PSPN-MSCs were injected into the striatum of PD rats, we observed the survival rate, migration, differentiation and the behavior change of PD rats. We found that Lv-PSPN-MSCs showed higher survival rate in rat brain compared with Lv-null-MSCs. Rotational behavior showed that rats receiving Lv-PSPN-MSCs showed the most significant improvement compared with those in other groups. HPLC results showed the content of DA in striatum of rats which received Lv-PSPN-MSCs was highest compared with those in other groups. In conclusion, our results suggest that transplantation of Lv-PSPN-MSCs can lead to remarkable therapeutic effects in PD rats.