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1.
Spine Deform ; 12(3): 829-842, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38427156

RESUMO

PURPOSE: Spinopelvic fixation (SPF) using traditional iliac screws has provided biomechanical advantages compared to previous constructs, but common complications include screw prominence and wound complications. The newer S2 alar-iliac (S2AI) screw may provide a lower profile option with lower rates of complications and revisions for adult spinal deformity (ASD). The purpose of this study was to compare rates of complications and revision following SPF between S2AI and traditional iliac screws in patients with ASD. METHODS: A PRISMA-compliant systematic literature review was conducted using Cochrane, Embase, and PubMed. Included studies reported primary data on adult patients undergoing S2AI screw fixation or traditional IS fixation for ASD. Primary outcomes of interest were rates of revision and complications, which included screw failure (fracture and loosening), symptomatic screw prominence, wound complications (dehiscence and infection), and L5-S1 pseudarthrosis. RESULTS: Fifteen retrospective studies with a total of 1502 patients (iliac screws: 889 [59.2%]; S2AI screws: 613 [40.8%]) were included. Pooled analysis indicated that iliac screws had significantly higher odds of revision (17.1% vs 9.1%, OR = 2.45 [1.25-4.77]), symptomatic screw prominence (9.9% vs 2.2%, OR = 6.26 [2.75-14.27]), and wound complications (20.1% vs 4.4%, OR = 5.94 [1.55-22.79]). S2AI screws also led to a larger preoperative to postoperative decrease in pain (SMD = - 0.26, 95% CI = -0.50, - 0.011). CONCLUSION: The findings from this review demonstrate higher rates of revision, symptomatic screw prominence, and wound complications with traditional iliac screws. Current data supports the use of S2AI screws specifically for ASD. PROSPERO ID: CRD42022336515. LEVEL OF EVIDENCE: III.


Assuntos
Parafusos Ósseos , Ílio , Sacro , Humanos , Ílio/cirurgia , Sacro/cirurgia , Curvaturas da Coluna Vertebral/cirurgia , Curvaturas da Coluna Vertebral/diagnóstico por imagem , Fusão Vertebral/instrumentação , Fusão Vertebral/métodos , Fusão Vertebral/efeitos adversos , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/epidemiologia , Reoperação/estatística & dados numéricos , Adulto
2.
N Am Spine Soc J ; 17: 100295, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38204918

RESUMO

Background: Venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE), is a potentially devastating complication after surgery. Spine surgery is associated with an increased risk of postoperative bleeding, such as spinal epidural hematomas (SEH), which complicates the use of anticoagulation. Despite this dilemma, there is a lack of consensus around perioperative VTE prophylaxis. This systematic review investigates the relationship between chemoprophylaxis and the incidence rates of VTE and SEH in the elective spine surgical population. Methods: A comprehensive literature search was performed using PubMed, Embase, and Cochrane databases to identify studies published after 2,000 that compared VTE chemoprophylaxis use in elective spine surgery. Studies involving patients aged < 18 years or with known trauma, cancer, or spinal cord injuries were excluded. Pooled incidence rates of VTE and SEH were calculated for all eligible studies, and meta-analyses were performed to assess the relationship between chemoprophylaxis and the incidences of VTE and SEH. Results: Nineteen studies met our eligibility criteria, comprising a total of 220,932 patients. The overall pooled incidence of VTE was 3.2%, including 3.3% for DVT and 0.4% for PE. A comparison of VTE incidence between patients that did and did not receive chemoprophylaxis was not statistically significant (OR 0.97, p=.95, 95% CI 0.43-2.19). The overall pooled incidence of SEH was 0.4%, and there was also no significant difference between patients that did and did not receive chemoprophylaxis (OR 1.57, p=.06, 95% CI 0.99-2.50). Conclusions: The use of perioperative chemoprophylaxis may not significantly alter rates of VTE or SEH in the elective spine surgery population. This review highlights the need for additional randomized controlled trials to better define the risks and benefits of specific chemoprophylactic protocols in various subpopulations of elective spine surgery.

3.
J Arthroplasty ; 39(2): 433-440.e4, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37572725

RESUMO

BACKGROUND: Total hip arthroplasty (THA) can improve sexual satisfaction, but fear of dislocation can lead to sexual difficulties following this procedure. Previous kinematic research identified 4 sexual positions in women and 2 in men that were considered at risk for impingement. This study aimed to validate these findings using current robotic THA simulations. METHODS: The 3-dimensional renderings from 12 patients who received computed tomography (CT)-based robotic THA were used to assess for prosthetic and/or bony impingement among 12 popular sexual positions. There were 9 cup orientations tested for each position (a combination of anteversion [0 °, 15 °, and 30 °] and inclination [40 °, 45 °, and 60 °]). The at-risk positions were tested again using the unique hip positions and cup orientations where previous geometric modeling data found impingement to occur. RESULTS: Using mean hip positions, impingement occurred in at least 1 patient in 1 of the 12 positions for women (position 5) and 5 of the 12 positions for men (positions 1, 5, 8, 10, and 11). Among the at-risk positions, impingement occurred in none of the 2 at-risk women positions (0 of 17 cup orientations) and in both at-risk men positions (9 of 9 cup orientations for position 8 and 1 of 1 for position 11). CONCLUSION: Recreating popular and at-risk sexual positions following THA with a CT-based robotics system yielded results that were inconsistent with previous geometric modeling data. Resolving these discrepancies is crucial for surgeons to provide accurate postoperative patient education. The CT-based robotic systems may provide necessary input to feasibly individualize such recommendations, but current limitations in CT-based robotics require continued attention and innovation.


Assuntos
Artroplastia de Quadril , Prótese de Quadril , Masculino , Humanos , Feminino , Artroplastia de Quadril/métodos , Articulação do Quadril/diagnóstico por imagem , Articulação do Quadril/cirurgia , Sexo Seguro , Tomografia Computadorizada por Raios X
4.
J Orthop ; 45: 37-42, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37841905

RESUMO

Introduction: Following closed reduction of hip dislocations, computed tomography (CT) is considered standard of care to identify occult fractures or intra-articular loose bodies that may be missed on X-ray. The purpose of this study was to evaluate the sensitivity of post-reduction X-rays and the usefulness of subsequent post-reduction CT imaging. Methods: All patients presenting to our hospital system for traumatic hip dislocations from 2013 to 2022 were retrospectively reviewed. Participants were included if they had a simple dislocation of a native hip, underwent closed reduction, and received post-reduction X-ray and CT imaging. A sensitivity analysis was performed for the detection of associated fractures and intraarticular loose bodies by post-reduction X-ray, using CT as a reference standard. Results: Thirty-five subjects with a mean age of 26 years were included. Post-reduction CT revealed 6 fractures and 3 loose bodies, whereas post-reduction X-ray identified 3/6 (50%) fractures and 3/3 (100%) loose bodies. Four cases received operative management, all of which were identified by X-ray. Post-reduction X-ray had a sensitivity of 67% for identifying pathology that was subsequently found on CT, and a sensitivity of 100% for identifying pathology requiring surgery. Of the 13 cases with pre-reduction CT scans, none had new findings identified on post-reduction CT. Conclusions: Post-reduction X-rays are effective in the evaluation of acute pathology associated with closed reduction of traumatic hip dislocations, especially for cases requiring operative management. Our findings suggest that if a fracture or loose body was not identified on post-reduction X-ray, a post-reduction CT added no value in surgical decision-making and was not necessary.

5.
J Orthop ; 45: 72-77, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37872978

RESUMO

Introduction: Robotic-assisted total knee arthroplasty (RA-TKA) has become increasingly popular, although an associated learning curve can be a deterrent for some surgeons. Prior studies have addressed this learning curve in fellowship-trained arthroplasty surgeons, however the learning curve among non-fellowship-trained surgeons remains unclear. The objective of this study was to investigate the learning curve for imageless RA-TKA related to operative time and rates of complications among two non-arthroplasty-trained orthopedic surgeons. Methods: This retrospective case series included 200 RA-TKA consecutive cases performed by two non-arthroplasty-trained orthopedic surgeons (100 each). Cases were divided into 2 cohorts for each surgeon: the first 50 consecutive cases and the second 50 cases. These cohorts were then compared to assess for trends in each surgeon as well as in both surgeons combined. Mean operative times were compared, as were hospital length of stay, complications, readmission, and reoperations. Results: For both surgeons, the mean operative time significantly decreased from the first 50 cases to the next 50 cases (116.5 vs 108.4 min for surgeon 1, P = 0.031; 125.7 vs 109.1 min for surgeon 2, P = 0.001). No significant differences were found among length of stay, complications, readmissions, or reoperations between cohorts. Conclusion: General orthopedic surgeons can expect to optimize operative time within 50 cases, while not carrying associated risks of related complications during the early learning period.

6.
JBJS Case Connect ; 13(2)2023 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-37235705

RESUMO

CASE: A 60-year-old woman sustained a type IV capitellum fracture from falling on an outstretched arm. Open reduction internal fixation (ORIF) was performed using an anconeus approach, and a transolecranon tunnel was created to place a trochlear screw. The patient showed good clinical outcomes with almost full range of motion at 6 months. CONCLUSION: With type IV capitellum fractures, the olecranon often obstructs the screw trajectory necessary for anterior-to-posterior fixation of trochlear fragments. Drilling a transolecranon tunnel through the proximal olecranon with the elbow flexed creates a viable pathway for screw placement from a more medial starting point than what is possible with traditional techniques.


Assuntos
Articulação do Cotovelo , Fraturas do Úmero , Feminino , Humanos , Pessoa de Meia-Idade , Fraturas do Úmero/diagnóstico por imagem , Fraturas do Úmero/cirurgia , Fixação Interna de Fraturas/métodos , Redução Aberta , Articulação do Cotovelo/diagnóstico por imagem , Articulação do Cotovelo/cirurgia , Parafusos Ósseos
7.
Neurotherapeutics ; 20(4): 1177-1197, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37208551

RESUMO

Perturbations in synaptic function are major determinants of several neurological diseases and have been associated with cognitive impairments after cerebral ischemia (CI). Although the mechanisms underlying CI-induced synaptic dysfunction have not been well defined, evidence suggests that early hyperactivation of the actin-binding protein, cofilin, plays a role. Given that synaptic impairments manifest shortly after CI, prophylactic strategies may offer a better approach to prevent/mitigate synaptic damage following an ischemic event. Our laboratory has previously demonstrated that resveratrol preconditioning (RPC) promotes cerebral ischemic tolerance, with many groups highlighting beneficial effects of resveratrol treatment on synaptic and cognitive function in other neurological conditions. Herein, we hypothesized that RPC would mitigate hippocampal synaptic dysfunction and pathological cofilin hyperactivation in an ex vivo model of ischemia. Various electrophysiological parameters and synaptic-related protein expression changes were measured under normal and ischemic conditions utilizing acute hippocampal slices derived from adult male mice treated with resveratrol (10 mg/kg) or vehicle 48 h prior. Remarkably, RPC significantly increased the latency to anoxic depolarization, decreased cytosolic calcium accumulation, prevented aberrant increases in synaptic transmission, and rescued deficits in long-term potentiation following ischemia. Additionally, RPC upregulated the expression of the activity-regulated cytoskeleton associated protein, Arc, which was partially required for RPC-mediated attenuation of cofilin hyperactivation. Taken together, these findings support a role for RPC in mitigating CI-induced excitotoxicity, synaptic dysfunction, and pathological over-activation of cofilin. Our study provides further insight into mechanisms underlying RPC-mediated neuroprotection against CI and implicates RPC as a promising strategy to preserve synaptic function after ischemia.


Assuntos
Fatores de Despolimerização de Actina , Isquemia Encefálica , Camundongos , Masculino , Animais , Resveratrol/farmacologia , Isquemia , Hipocampo/patologia
9.
JBJS Case Connect ; 13(1)2023 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-36928114

RESUMO

CASE: A 53-year-old woman with a history of transfemoral amputation presented to the emergency department with an ipsilateral intertrochanteric femur fracture. Standard fracture tables that use a boot to pull traction are not helpful in these cases, which makes achieving adequate traction for reduction difficult. CONCLUSION: We describe a unique technique to manipulate an amputated extremity using 2 Schanz pins attached to a weight through a traction rope. This practical technique provided adequate skeletal traction for reduction and internal fixation in our case and can be performed on a standard radiolucent table without the need for special table attachments.


Assuntos
Fraturas do Quadril , Tração , Feminino , Humanos , Pessoa de Meia-Idade , Tração/métodos , Fraturas do Quadril/cirurgia , Fixação Interna de Fraturas , Amputação Cirúrgica , Fêmur/cirurgia
10.
J Orthop Surg Res ; 18(1): 226, 2023 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-36945061

RESUMO

BACKGROUND: Dual mobility components can be implanted during total hip arthroplasty (THA) for primary osteoarthritis via a direct anterior approach (DAA), anterolateral approach (ALA), direct lateral approach (DLA), or posterior/posterolateral approach (PLA). This review compares dual mobility hip dislocation rates using these approaches for elective primary THA. METHODS: PubMed, Embase, and Cochrane databases were systematically searched for articles published after January 1, 2006 that reported dislocation rates for adult patients after primary THA with dual mobility implants. Articles were excluded if they reported revision procedures, nonelective THA for femoral neck fractures, acetabular defects requiring supplemental implants, prior surgery, or ≤ 5 patients. The primary outcome was hip dislocation rate. Secondary outcomes included infection, Harris Hip Score (HHS), and Postel-Merle d'Aubigné (PMA) score. RESULTS: After screening 542 articles, 63 met inclusion criteria. Due to study heterogeneity, we did not perform a meta-analysis. Eight studies reported DAA, 5 reported ALA, 6 reported the DLA, and 56 reported PLA. Study size ranged from 41 to 2,601 patients. Mean follow-up time ranged from 6 months to 25 years. Rates of infection and dislocation were low; 80% of ALA, 87.5% of DAA, 100% of DLA, and 82.1% of PLA studies reported zero postoperative dislocations. Studies reporting postoperative HHS and PMA scores showed considerable improvement for all approaches. CONCLUSIONS: Patients undergoing primary THA with dual mobility implants rarely experience postoperative dislocation, regardless of surgical approach. Additional studies directly comparing DAA, ALA, DLA, and PLA are needed to confirm these findings.


Assuntos
Artroplastia de Quadril , Luxação do Quadril , Prótese de Quadril , Adulto , Humanos , Artroplastia de Quadril/efeitos adversos , Artroplastia de Quadril/métodos , Luxação do Quadril/epidemiologia , Luxação do Quadril/etiologia , Luxação do Quadril/prevenção & controle , Prótese de Quadril/efeitos adversos , Falha de Prótese , Reoperação , Estudos Retrospectivos , Desenho de Prótese
11.
Eur J Orthop Surg Traumatol ; 33(6): 2555-2563, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36645494

RESUMO

INTRODUCTION: Hip fractures are common injuries in the elderly, with an incidence that continues to rise. The femoral neck system (FNS) recently emerged as a novel treatment option for femoral neck fractures, but long-term survivability of the implant remains uncertain. The purpose of this study is to evaluate survivability of the FNS and assess risk factors for implant failure. METHODS: One hundred five adult patients who received the FNS (DePuy Synthes, Raynham, MA) for femoral neck fractures (AO/OTA 31B) were included. Surgeries were performed within a regional hospital system comprising 18 facilities. All patients had a minimum follow-up of 1 year. The primary outcome measures were cumulative incidence of implant failure and 1-year mortality, including risk factor analysis. RESULTS: Twelve implants failed at a follow-up ranging from 17 days to 8 months, and 7 failed within 90 days. Cumulative incidence of implant failure was 2% at 30 days, 7% at 90 days, 12% at 6 months, and 13% at 1 year. Causes of implant failure included cut-out (n = 5), non-union (n = 4), peri-implant fracture (n = 2), and avascular necrosis (n = 1). Univariate Cox regression identified Pauwels type III fractures and an increasing AP Parker ratio as significant risk factors for failure. Pauwels type III fractures showed a 5.48 times higher risk compared to Pauwels types I & II. Every 10% increase in AP Parker ratio increased risk of failure by 2.39 times. The 1-year mortality rate was 21%, and univariate logistic regression identified age as the only risk factor (odds ratio = 3.71). CONCLUSIONS: The incidence of implant failure and 1-year mortality rate in this study suggests that the FNS can provide reliable fixation compared to rates in the literature, but complications are not uncommon. Avoiding Pauwels type III fractures and optimizing implant placement appear crucial to preventing implant failure. LEVEL OF EVIDENCE: Therapeutic Level IV.


Assuntos
Fraturas do Colo Femoral , Osteonecrose , Humanos , Adulto , Idoso , Colo do Fêmur , Fixação Interna de Fraturas/efeitos adversos , Fraturas do Colo Femoral/cirurgia , Fatores de Risco , Resultado do Tratamento , Estudos Retrospectivos
12.
J Orthop ; 34: 160-165, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36090784

RESUMO

Background: The incidence of distal lower extremity fractures in National Basketball Association (NBA) athletes continues to increase. There is a paucity of data regarding return-to-play (RTP) rates and performance after sustaining foot fractures in these athletes. The purpose of this study is to quantify RTP rates and performance in NBA players after sustaining a foot fracture. Methods: Sixty-two NBA athletes suffered foot fractures between 2005 and 2021 according to publicly accessible online data. Each athlete was matched to a control player based on age at start of career, age at index injury year, body mass index (BMI), and position played. Performance statistics from 3 seasons prior and 3 seasons following the index injury season were recorded. Results: We found that players who suffered foot fracture injuries are expected to make a full recovery and reach their previous level of performance within three years. 100% of players treated nonoperatively returned to play; meanwhile only 90% of players who were treated operatively returned to play. This difference is statistically significant. Conclusion: NBA athletes have a high RTP rate after sustaining a foot fracture. Players may experience an initial decrease in playing time and performance when returning to play, however, these variables were found to return to baseline over time. After three seasons, player statistics returned to baseline in mostly every category, including player efficiency rating (PER). We found that players are expected to make a full recovery and return to their previous level of performance, regardless of whether they were treated operatively or not. Players treated nonoperatively returned to play at a rate of 100% meanwhile those treated operatively returned at a rate of 90%. Therefore, it is our recommendation that players opt for nonoperative treatment when possible.

13.
Spine J ; 22(12): 2050-2058, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-35944827

RESUMO

BACKGROUND CONTEXT: Prophylactic vertebroplasty (VP) is performed at the upper level of instrumentation during spinal fusion to reduce the risk of proximal junctional kyphosis (PJK), proximal junctional fracture (PJFx), and proximal junctional failure (PJF). This study investigated the effect of VP on patient outcomes after spinal fusion. PURPOSE: The aim of this systematic review was to evaluate the effect of prophylactic VP on the incidence of PJK in patients with spinal fusion. STUDY DESIGN/SETTING: Level III, systematic review without meta-analysis. PATIENT SAMPLE: Adult patients undergoing spinal fusion with VP. METHODS: A PRISMA-compliant systematic literature review was conducted using PubMed/MEDLINE, Cochrane, and Embase. Included studies were published in English between January 1, 2001, and May 27, 2021, and reported primary data on adult patients undergoing spinal fusion with VP. Studies were excluded for insufficient surgical details; treatment for vertebral compression fracture; and case series and/or reports with <5 patients. The Newcastle-Ottawa Scale was used to assess risk of bias. The primary outcome of interest was PJK. Other outcomes included PJFx, PJF, and adverse events (eg, cement extravasation). Data were expressed as descriptive statistics. RESULTS: Eight studies with 685 total patients (VP: 293 [42.8%]; No VP: 392 (57.2%)) were included. Five studies were comparative and three were single-arm. PJK incidence was reported in five studies (three comparatives, two single-arm) and ranged from 7.9% to 46.4%; incidence was lower in patients with VP in two of three (66.7%) comparative studies, and equal in one of three (33.3%). PJFx was reported in five studies (four comparatives, one single-arm) and ranged from 0.0% to 39.3%; incidence was lower in the VP group in two of four (50.0%) comparative studies, equal in one of four (25.0%), and higher in one of four (25.0%). PJF was reported in five studies (three comparatives, two single-arm) and ranged from 0.0% to 39.3%; incidence was lower in the VP group in two of three (66.7%) comparative studies and equal in one of three (33.3%). Cement extravasation was reported by four studies and ranged from 0% (0/36) to 48.3% (57/118) in patients with prophylactic VP. CONCLUSIONS: Evidence on whether prophylactic VP decreases the incidence of PJK, PJFx, and PJF after spinal fusion is inconclusive and conflicting. Additionally, the risk of cement extravasation following prophylactic VP could not be evaluated due to insufficient evidence. Further research is needed to determine whether VP has a significant impact on patient outcomes and risks.


Assuntos
Fraturas por Compressão , Cifose , Fraturas da Coluna Vertebral , Fusão Vertebral , Vertebroplastia , Adulto , Humanos , Fusão Vertebral/efeitos adversos , Fraturas por Compressão/complicações , Fraturas da Coluna Vertebral/prevenção & controle , Fraturas da Coluna Vertebral/cirurgia , Fraturas da Coluna Vertebral/complicações , Cifose/cirurgia , Vertebroplastia/efeitos adversos , Cimentos Ósseos , Estudos Retrospectivos , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/prevenção & controle , Complicações Pós-Operatórias/cirurgia
14.
Childs Nerv Syst ; 37(10): 3073-3081, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34263339

RESUMO

PURPOSE: Intrathecal baclofen (ITB) has been an effective therapy since the 1980s, with widely reported revision, infection, and complication rates. Publications targeting surgical workflow have resulted in decreased infection and revision rates, but a standard workflow for the entire pathway has not been described. To present, define, and test standard work tools for patients receiving ITB to promote uniformity and standard of care in the field. METHODS: A multidisciplinary approach from the movement disorder program of a tertiary care center defined all steps comprising the ITB pathway, and then developed standard work tools to decrease variability with respect to preoperative workup, day of surgery protocol, post-operative care, and also evaluation and treatment with respect to pump infection or malfunction. RESULTS: Defined steps used at specific points of ITB pathway are presented with a single institution's outcome using the protocol from July 2017 to November 2020. A total of 60 procedures were performed. The overall complication rate was 14.5% at 6 months. Complications included an infection rate of 3.6% at 6 months, wound revision rate of 1.8% at 6 months, CSF leak rate of 1.7% at 6 months, and a 30-day readmission rate related to initial surgery of 6.7%. CONCLUSIONS: Workflow efficiency and optimization for ITB patients can be used to obtain lower complication rates compared to historical cohorts in literature. A single-center, retrospective review highlights this.


Assuntos
Baclofeno , Relaxantes Musculares Centrais , Baclofeno/uso terapêutico , Humanos , Bombas de Infusão Implantáveis , Injeções Espinhais , Relaxantes Musculares Centrais/uso terapêutico , Espasticidade Muscular/tratamento farmacológico , Estudos Retrospectivos , Resultado do Tratamento
15.
Transl Stroke Res ; 11(3): 418-432, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-31473978

RESUMO

The preservation of mitochondrial function is a major protective strategy for cerebral ischemic injuries. Previously, our laboratory demonstrated that protein kinase C epsilon (PKCε) promotes the synthesis of mitochondrial nicotinamide adenine dinucleotide (NAD+). NAD+ along with its reducing equivalent, NADH, is an essential co-factor needed for energy production from glycolysis and oxidative phosphorylation. Yet, NAD+/NADH are impermeable to the inner mitochondrial membrane and their import into the mitochondria requires the activity of specific shuttles. The most important neuronal NAD+/NADH shuttle is the malate-aspartate shuttle (MAS). The MAS has been implicated in synaptic function and is potentially dysregulated during cerebral ischemia. The aim of this study was to determine if metabolic changes induced by PKCε preconditioning involved regulation of the MAS. Using primary neuronal cultures, we observed that the activation of PKCε enhanced mitochondrial respiration and glycolysis in vitro. Conversely, inhibition of the MAS resulted in decreased oxidative phosphorylation and glycolytic capacity. We further demonstrated that activation of PKCε increased the phosphorylation of key components of the MAS in rat brain synaptosomal fractions. Additionally, PKCε increased the enzyme activity of glutamic oxaloacetic transaminase 2 (GOT2), an effect that was dependent on the import of PKCε into the mitochondria and phosphorylation of GOT2. Furthermore, PKCε activation was able to rescue decreased GOT2 activity induced by ischemia. These findings reveal novel protective targets and mechanisms against ischemic injury, which involves PKCε-mediated phosphorylation and activation of GOT2 in the MAS.


Assuntos
Aspartato Aminotransferase Mitocondrial/metabolismo , Isquemia Encefálica/enzimologia , NAD/metabolismo , Neurônios/enzimologia , Proteína Quinase C-épsilon/metabolismo , Animais , Malatos/metabolismo , Masculino , Fosforilação , Cultura Primária de Células , Ratos Sprague-Dawley
16.
Mol Neurobiol ; 56(6): 4549-4565, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30343466

RESUMO

Neuroprotective agents administered post-cerebral ischemia have failed so far in the clinic to promote significant recovery. Thus, numerous efforts were redirected toward prophylactic approaches such as preconditioning as an alternative therapeutic strategy. Our laboratory has revealed a novel long-term window of cerebral ischemic tolerance mediated by resveratrol preconditioning (RPC) that lasts for 2 weeks in mice. To identify its mediators, we conducted an RNA-seq experiment on the cortex of mice 2 weeks post-RPC, which revealed 136 differentially expressed genes. The majority of genes (116/136) were downregulated upon RPC and clustered into biological processes involved in transcription, synaptic signaling, and neurotransmission. The downregulation in these processes was reminiscent of metabolic depression, an adaptation used by hibernating animals to survive severe ischemic states by downregulating energy-consuming pathways. Thus, to assess metabolism, we used a neuronal-astrocytic co-culture model and measured the cellular respiration rate at the long-term window post-RPC. Remarkably, we observed an increase in glycolysis and mitochondrial respiration efficiency upon RPC. We also observed an increase in the expression of genes involved in pyruvate uptake, TCA cycle, and oxidative phosphorylation, all of which indicated an increased reliance on energy-producing pathways. We then revealed that these nuclear and mitochondrial adaptations, which reduce the reliance on energy-consuming pathways and increase the reliance on energy-producing pathways, are epigenetically coupled through acetyl-CoA metabolism and ultimately increase baseline ATP levels. This increase in ATP would then allow the brain, a highly metabolic organ, to endure prolonged durations of energy deprivation encountered during cerebral ischemia.


Assuntos
Adaptação Fisiológica/efeitos dos fármacos , Isquemia Encefálica/genética , Isquemia Encefálica/fisiopatologia , Metabolismo Energético , Genoma , Precondicionamento Isquêmico , Resveratrol/farmacologia , Acetilcoenzima A/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Astrócitos/efeitos dos fármacos , Astrócitos/metabolismo , Isquemia Encefálica/patologia , Respiração Celular/efeitos dos fármacos , Técnicas de Cocultura , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/genética , Metabolismo Energético/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Modelos Biológicos , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Ratos Sprague-Dawley , Fatores de Tempo , Transcriptoma/genética
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