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1.
Autophagy ; : 1-21, 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38953310

RESUMO

Co-occurring mutations in KEAP1 in STK11/LKB1-mutant NSCLC activate NFE2L2/NRF2 to compensate for the loss of STK11-AMPK activity during metabolic adaptation. Characterizing the regulatory crosstalk between the STK11-AMPK and KEAP1-NFE2L2 pathways during metabolic stress is crucial for understanding the implications of co-occurring mutations. Here, we found that metabolic stress increased the expression and phosphorylation of SQSTM1/p62, which is essential for the activation of NFE2L2 and AMPK, synergizing antioxidant defense and tumor growth. The SQSTM1-driven dual activation of NFE2L2 and AMPK was achieved by inducing macroautophagic/autophagic degradation of KEAP1 and facilitating the AXIN-STK11-AMPK complex formation on the lysosomal membrane, respectively. In contrast, the STK11-AMPK activity was also required for metabolic stress-induced expression and phosphorylation of SQSTM1, suggesting a double-positive feedback loop between AMPK and SQSTM1. Mechanistically, SQSTM1 expression was increased by the PPP2/PP2A-dependent dephosphorylation of TFEB and TFE3, which was induced by the lysosomal deacidification caused by low glucose metabolism and AMPK-dependent proton reduction. Furthermore, SQSTM1 phosphorylation was increased by MAP3K7/TAK1, which was activated by ROS and pH-dependent secretion of lysosomal Ca2+. Importantly, phosphorylation of SQSTM1 at S24 and S226 was critical for the activation of AMPK and NFE2L2. Notably, the effects caused by metabolic stress were abrogated by the protons provided by lactic acid. Collectively, our data reveal a novel double-positive feedback loop between AMPK and SQSTM1 leading to the dual activation of AMPK and NFE2L2, potentially explaining why co-occurring mutations in STK11 and KEAP1 happen and providing promising therapeutic strategies for lung cancer.Abbreviations: AMPK: AMP-activated protein kinase; BAF1: bafilomycin A1; ConA: concanamycin A; DOX: doxycycline; IP: immunoprecipitation; KEAP1: kelch like ECH associated protein 1; LN: low nutrient; MAP3K7/TAK1: mitogen-activated protein kinase kinase kinase 7; MCOLN1/TRPML1: mucolipin TRP cation channel 1; MEFs: mouse embryonic fibroblasts; MTORC1: mechanistic target of rapamycin kinase complex 1; NAC: N-acetylcysteine; NFE2L2/NRF2: NFE2 like bZIP transcription factor 2; NSCLC: non-small cell lung cancer; PRKAA/AMPKα: protein kinase AMP-activated catalytic subunit alpha; PPP2/PP2A: protein phosphatase 2; ROS: reactive oxygen species; PPP3/calcineurin: protein phosphatase 3; RPS6KB1/p70S6K: ribosomal protein S6 kinase B1; SQSTM1/p62: sequestosome 1; STK11/LKB1: serine/threonine kinase 11; TCL: total cell lysate; TFEB: transcription factor EB; TFE3: transcription factor binding to IGHM enhancer 3; V-ATPase: vacuolar-type H+-translocating ATPase.

2.
Cells ; 13(11)2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38891087

RESUMO

Ubiquitin-specific protease 14 (USP14), one of the three major proteasome-associated deubiquitinating enzymes (DUBs), is known to be activated by the AKT-mediated phosphorylation at Ser432. Thereby, AKT can regulate global protein degradation by controlling the ubiquitin-proteasome system (UPS). However, the exact molecular mechanism of USP14 activation by AKT phosphorylation at the atomic level remains unknown. By performing the molecular dynamics (MD) simulation of the USP14 catalytic domain at three different states (inactive, active, and USP14-ubiquitin complex), we characterized the change in structural dynamics by phosphorylation. We observed that the Ser432 phosphorylation induced substantial conformational changes of USP14 in the blocking loop (BL) region to fold it from an open loop into a ß-sheet, which is critical for USP14 activation. Furthermore, phosphorylation also increased the frequency of critical hydrogen bonding and salt bridge interactions between USP14 and ubiquitin, which is essential for DUB activity. Structural dynamics insights from this study pinpoint the important local conformational landscape of USP14 by the phosphorylation event, which would be critical for understanding USP14-mediated proteasome regulation and designing future therapeutics.


Assuntos
Simulação de Dinâmica Molecular , Proteínas Proto-Oncogênicas c-akt , Ubiquitina Tiolesterase , Fosforilação , Ubiquitina Tiolesterase/metabolismo , Ubiquitina Tiolesterase/química , Proteínas Proto-Oncogênicas c-akt/metabolismo , Humanos , Ubiquitina/metabolismo , Ativação Enzimática , Domínio Catalítico , Ligação Proteica , Conformação Proteica
3.
Sci Rep ; 14(1): 14538, 2024 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-38914709

RESUMO

Minimally invasive plate osteosynthesis is the most commonly used minimally invasive surgery technique for tibial fractures, possibly involving single or dual plate methods. Herein, we performed a finite element analysis to investigate plate strength according to the plate type, length, and presence of a fibula by constructing a three-dimensional tibia model. A thickness of 20 mm was cut 50 mm distal from the lateral plateau, and the ligaments were created. Plates were modeled with lengths of 150, 200, and 250 mm and mounted to the tibia. Screws were arranged to avoid overlapping in the dual plating. The von-Mises stress applied to the plates was measured by applying a load of 1 body weight. Dual plates showed the least stress with low displacement, followed by medial and lateral plates. As the plate length increased, the average stress gradually decreased, increasing plate safety. The difference in the influence of the fibula depending on the presence of proximal fibula osteotomy showed that the average stress increased by 35% following proximal fibula osteotomy in the D1(Plate type: Dual plate, Medial plate length: 150 mm, Lateral plate length: 200 mm, Non Proximal fibula osteotomy) and D1P(Plate type: Dual plate, Medial plate length: 150 mm, Lateral plate length: 200 mm, Proximal fibula osteotomy) models, confirming the necessity of the fibula model. There is no consensus guideline for treatment of this kind of fracture case. A single fracture plate can decrease the risk of skin damage, ligament damage, and wound infection, but because of its design, it cannot provide sufficient stability and satisfactory reduction of the condylar fragment, especially in cases of comminution or coronal fracture. So, these results will help clinicians make an informed choice on which plate to use in patients with tibial fractures.


Assuntos
Placas Ósseas , Fíbula , Análise de Elementos Finitos , Fixação Interna de Fraturas , Fraturas da Tíbia , Fraturas da Tíbia/cirurgia , Humanos , Fíbula/cirurgia , Fíbula/lesões , Fixação Interna de Fraturas/métodos , Fixação Interna de Fraturas/instrumentação , Estresse Mecânico , Fenômenos Biomecânicos , Tíbia/cirurgia , Procedimentos Cirúrgicos Minimamente Invasivos/métodos
4.
J Korean Soc Radiol ; 85(2): 428-433, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38617848

RESUMO

Dual left anterior descending artery (LAD) is a rare congenital coronary artery anomaly with a prevalence of approximately 1% in the general population. To date, 10 types of dual LAD artery anomalies have been reported. Among these, type 4 is one of the rarest. Knowledge and recognition of the dual LAD artery are important for correct diagnosis and planning of coronary bypass surgery and percutaneous coronary intervention. We report a case of a 59-year-old male with type 4 dual LAD artery who presented with dyspepsia and sweating for several months and had approximately 50%-70% stenosis in a major diagonal branch off the short LAD artery.

5.
Antioxidants (Basel) ; 12(7)2023 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-37507973

RESUMO

Ultraviolet B (UVB) irradiation generates reactive oxygen species (ROS), which can damage exposed skin cells. Mitochondria and NADPH oxidase are the two principal producers of ROS in UVB-irradiated keratinocytes. Peroxiredoxin V (PrxV) is a mitochondrial and cytosolic cysteine-dependent peroxidase enzyme that robustly removes H2O2. We investigated PrxV's role in protecting epidermal keratinocytes against UVB-induced ROS damage. We separated mitochondrial and cytosolic H2O2 levels from other types of ROS using fluorescent H2O2 indicators. Upon UVB irradiation, PrxV-knockdown HaCaT human keratinocytes showed higher levels of mitochondrial and cytosolic H2O2 than PrxV-expressing controls. PrxV depletion enhanced hyperoxidation-mediated inactivation of mitochondrial PrxIII and cytosolic PrxI and PrxII in UVB-irradiated keratinocytes. PrxV-depleted keratinocytes exhibited mitochondrial dysfunction and were more susceptible to apoptosis through decreased oxygen consumption rate, loss of mitochondrial membrane potential, cardiolipin oxidation, cytochrome C release, and caspase activation. Our findings show that PrxV serves to protect epidermal keratinocytes from UVB-induced damage such as mitochondrial dysfunction and apoptosis, not only by directly removing mitochondrial and cytosolic H2O2 but also by indirectly improving the catalytic activity of mitochondrial PrxIII and cytosolic PrxI and PrxII. It is possible that strengthening PrxV defenses could aid in preventing UVB-induced skin damage.

6.
Mol Metab ; 76: 101784, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37524243

RESUMO

OBJECTIVE: Alterations in lipid metabolism are associated with aging and age-related diseases. Chaperone-mediated autophagy (CMA) is a lysosome-dependent process involved in specific protein degradation. Heat shock cognate 71 kDa protein (Hsc70) recognizes cytosolic proteins with KFERQ motif and allows them to enter the lysosome via lysosome-associated membrane glycoprotein 2 isoform A (LAMP2A). CMA deficiency is associated with dysregulated lipid metabolism in the liver. In this study, we examined the effect of CMA on lipid metabolism in the aged liver. METHODS: 12-week-old and 88-week-old mice were employed to assess the effect of aging on hepatic CMA activity. We generated CMA-deficient mouse primary hepatocytes using siRNA for Lamp2a and liver-specific LAMP2A knockdown mice via adeno-associated viruses expressing short hairpin RNAs to investigate the influence of CMA on lipid metabolism. RESULTS: We noted aging-induced progression toward fatty liver and a decrease in LAMP2A levels in total protein and lysosomes. The expression of genes associated with fatty acid oxidation was markedly downregulated in the aged liver, as verified in CMA-deficient mouse primary hepatocytes. In addition, the aged liver accumulated nuclear receptor corepressor 1 (NCoR1), a negative regulator of peroxisome proliferator-activated receptor α (PPARα). We found that Hsc70 binds to NCoR1 via the KFERQ motif. Lamp2a siRNA treatment accumulated NCoR1 and decreased the fatty acid oxidation rate. Pharmacological activation of CMA by AR7 treatment increased LAMP2A expression, leading to NCoR1 degradation. A liver-specific LAMP2A knockdown via adeno-associated viruses expressing short hairpin RNAs caused NCoR1 accumulation, inactivated PPARα, downregulated the expression of fatty acid oxidation-related genes and significantly increased liver triglyceride levels. CONCLUSIONS: Our results elucidated a novel PPARα regulatory mechanism involving CMA-mediated NCoR1 degradation during aging. These findings demonstrate that CMA dysregulation is crucial for the progression of aging-related fatty liver diseases.


Assuntos
Autofagia Mediada por Chaperonas , Animais , Camundongos , Autofagia , PPAR alfa/genética , Envelhecimento , Fígado , Metabolismo dos Lipídeos , Ácidos Graxos/farmacologia
7.
Blood Adv ; 7(1): 92-105, 2023 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-36269842

RESUMO

Bruton tyrosine kinase (BTK) is an important signaling hub that activates the B-cell receptor (BCR) signaling cascade. BCR activation can contribute to the growth and survival of B-cell lymphoma or leukemia. The inhibition of the BCR signaling pathway is critical for blocking downstream events and treating B-cell lymphomas. Herein, we report potent and orally available proteolysis-targeting chimeras (PROTACs) that target BTK to inactivate BCR signaling. Of the PROTACs tested, UBX-382 showed superior degradation activity for wild-type (WT) and mutant BTK proteins in a single-digit nanomolar range of half-maximal degradation concentration in diffuse large B-cell lymphoma cell line. UBX-382 was effective on 7 out of 8 known BTK mutants in in vitro experiments and was highly effective in inhibiting tumor growth in murine xenograft models harboring WT or C481S mutant BTK-expressing TMD-8 cells over ibrutinib, ARQ-531, and MT-802. Remarkably, oral dosing of UBX-382 for <2 weeks led to complete tumor regression in 3 and 10 mg/kg groups in murine xenograft models. UBX-382 also provoked the cell type-dependent and selective degradation of cereblon neosubstrates in various hematological cancer cells. These results suggest that UBX-382 treatment is a promising therapeutic strategy for B-cell-related blood cancers with improved efficacy and diverse applicability.


Assuntos
Linfoma Difuso de Grandes Células B , Pirimidinas , Humanos , Animais , Camundongos , Tirosina Quinase da Agamaglobulinemia , Pirimidinas/farmacologia , Pirimidinas/uso terapêutico , Transdução de Sinais , Modelos Animais de Doenças , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Linfoma Difuso de Grandes Células B/genética
8.
Antioxidants (Basel) ; 13(1)2023 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-38275637

RESUMO

Nonsteroidal anti-inflammatory drug (NSAID) use is associated with adverse consequences, including hepatic injury. The detrimental hepatotoxicity of diclofenac, a widely used NSAID, is primarily connected to oxidative damage in mitochondria, which are the primary source of reactive oxygen species (ROS). The primary ROS responsible for inducing diclofenac-related hepatocellular toxicity and the principal antioxidant that mitigates these ROS remain unknown. Peroxiredoxin III (PrxIII) is the most abundant and potent H2O2-eliminating enzyme in the mitochondria of mammalian cells. Here, we investigated the role of mitochondrial H2O2 and the protective function of PrxIII in diclofenac-induced mitochondrial dysfunction and apoptosis in hepatocytes. Mitochondrial H2O2 levels were differentiated from other types of ROS using a fluorescent H2O2 indicator. Upon diclofenac treatment, PrxIII-knockdown HepG2 human hepatoma cells showed higher levels of mitochondrial H2O2 than PrxIII-expressing controls. PrxIII-depleted cells exhibited higher mitochondrial dysfunction as measured by a lower oxygen consumption rate, loss of mitochondrial membrane potential, cardiolipin oxidation, and caspase activation, and were more sensitive to apoptosis. Ectopic expression of mitochondrially targeted catalase in PrxIII-knockdown HepG2 cells or in primary hepatocytes derived from PrxIII-knockout mice suppressed the diclofenac-induced accumulation of mitochondrial H2O2 and decreased apoptosis. Thus, we demonstrated that mitochondrial H2O2 is a key mediator of diclofenac-induced hepatocellular damage driven by mitochondrial dysfunction and apoptosis. We showed that PrxIII loss results in the critical accumulation of mitochondrial H2O2 and increases the harmful effects of diclofenac. PrxIII or other antioxidants targeting mitochondrial H2O2 could be explored as potential therapeutic agents to protect against the hepatotoxicity associated with NSAID use.

10.
Nat Commun ; 13(1): 838, 2022 02 11.
Artigo em Inglês | MEDLINE | ID: mdl-35149681

RESUMO

The proteasome recognizes ubiquitinated proteins and can also edit ubiquitin marks, allowing substrates to be rejected based on ubiquitin chain topology. In yeast, editing is mediated by deubiquitinating enzyme Ubp6. The proteasome activates Ubp6, whereas Ubp6 inhibits the proteasome through deubiquitination and a noncatalytic effect. Here, we report cryo-EM structures of the proteasome bound to Ubp6, based on which we identify mutants in Ubp6 and proteasome subunit Rpt1 that abrogate Ubp6 activation. The Ubp6 mutations define a conserved region that we term the ILR element. The ILR is found within the BL1 loop, which obstructs the catalytic groove in free Ubp6. Rpt1-ILR interaction opens the groove by rearranging not only BL1 but also a previously undescribed network of three interconnected active-site-blocking loops. Ubp6 activation and noncatalytic proteasome inhibition are linked in that they are eliminated by the same mutations. Ubp6 and ubiquitin together drive proteasomes into a unique conformation associated with proteasome inhibition. Thus, a multicomponent allosteric switch exerts simultaneous control over both Ubp6 and the proteasome.


Assuntos
Endopeptidases/química , Endopeptidases/metabolismo , Complexo de Endopeptidases do Proteassoma/química , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/metabolismo , Adenosina Trifosfatases/química , Adenosina Trifosfatases/metabolismo , Domínio Catalítico , Microscopia Crioeletrônica , Citoplasma , Endopeptidases/genética , Complexo de Endopeptidases do Proteassoma/genética , Conformação Proteica , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Ubiquitina/metabolismo , Proteínas Ubiquitinadas/metabolismo
11.
Knee Surg Sports Traumatol Arthrosc ; 30(2): 437-446, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32577783

RESUMO

PURPOSE: The patellofemoral (PF) joint may be adversely affected by medial open-wedge high tibial osteotomy (OWHTO). This study aimed to evaluate the PF compartmental changes using combined single-photon emission computed tomography (SPECT) and conventional computed tomography (CT) after OWHTO to provide clinical guidance regarding the PF joint pressure and force. METHODS: Patients with medial osteoarthritis and varus malalignment > 5° were treated using OWHTO. Patients with a minimum 2-year follow-up were included in the study. The patellar positions were evaluated based on the radiographic parameters. The changes in chondral lesions during second-look arthroscopic examination were evaluated, and the PF joint arthritis grade was recorded on patellar Merchant radiographs using Kellgren-Lawrence classification. The PF compartmental changes according to SPECT/CT analysis after OWHTO were evaluated in all patients. The scintigraphic uptake was graded on four scales. Patients were divided into improved and unimproved groups according to the PF compartmental grade using the SPECT/CT uptake grading system. RESULTS: At a mean follow-up period of 47.0 months (range 25-74 months), the mean mechanical femorotibial angle changed significantly from varus 6.3° (range 5-12°) to valgus 2.6° (range 0-8°); p < 0.001) postoperatively. The radiological parameters presenting patellar positions, including the tibial slope, patellar convergence angle, and lateral tilt angle, did not change significantly between the preoperative values and the 2-year follow-up values. The mean patellar height significantly decreased (0.07 ± 0.14, p = 0.001 according to the Blackburn-Peel index and 0.32 ± 0.23, p < 0.001 using the modified Insall-Salvati ratio). The average tibial tubercle to trochlear groove (TT-TG) distance significantly decreased from 14.1 to 12.2 mm (p < 0.001). The Q angle also significantly decreased from 9.8o to 7.7o (p = 0.008). Chondral lesions of the patella and trochlear groove revealed significant deterioration; at 2 years after OWHTO, the arthritic grades of the PF joints worsened significantly, as determined by radiography (p = 0.007). Scintigraphic uptake in the PF joint was significantly lower (from 2 to 1) at 2 years postoperatively compared to that immediately after the index operation (p < 0.001). Only 4 of 56 (7.1%) patients showed increased uptake. Comparison between the improved and unimproved groups according to scintigraphic uptake changes revealed that the changes in the cartilage status on the patellar undersurface and TT-TG distance were the most significant predictive factors of increased scintigraphic uptake in the PF joint after OWHTO. CONCLUSION: Alignment correction by OWHTO result in PF compartment offloading and should be considered when identifying the surgical indications for OWHTO. LEVEL OF EVIDENCE: Therapeutic, Level IV.


Assuntos
Osteoartrite do Joelho , Articulação Patelofemoral , Humanos , Articulação do Joelho/cirurgia , Osteoartrite do Joelho/diagnóstico por imagem , Osteoartrite do Joelho/cirurgia , Osteotomia/métodos , Patela/cirurgia , Articulação Patelofemoral/diagnóstico por imagem , Articulação Patelofemoral/cirurgia , Estudos Retrospectivos , Tomografia Computadorizada com Tomografia Computadorizada de Emissão de Fóton Único , Tíbia/diagnóstico por imagem , Tíbia/cirurgia , Tomografia Computadorizada de Emissão de Fóton Único
12.
Arch Orthop Trauma Surg ; 142(10): 2791-2799, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34731315

RESUMO

INTRODUCTION: This study aimed to describe an anatomic medial knee reconstruction technique for combined anterior cruciate ligament (ACL) and grade III medial collateral ligament (MCL) injuries and to assess knee function and stability restoration in patients who underwent primary MCL reconstruction compared with primary repair. METHODS: A total of 105 patients who had undergone anatomic ACL reconstruction between 2008 and 2017 were enrolled in this retrospective study and divided into two groups according to concomitant MCL ruptures. Group A included patients with isolated ACL ruptures without MCL injuries. Group B included patients with both ACL and MCL injuries, and it was subdivided into three groups according to the severity of the MCL injury and treatment modality: B-1, grade I or II MCL injury treated conservatively; B-2: grade III MCL injury treated by primary MCL repair; and B-3: grade III MCL injury treated by primary reconstruction. Knee stability was measured via Telos valgus radiography at 6-month and 2-year postoperative. The Lysholm score, Tegner activity level, Likert scales (satisfaction), and return to previous sports were evaluated at 2-year postoperative. RESULTS: At 6-month postoperative, there was no significant difference in medial laxity between the B-2 and B-3 groups. However, at 2-year postoperative, medial laxity were significantly higher both at 30° of flexion (5.2° versus 2.2°, p = 0.020) and at full extension (3.4° versus 1.1°, p < 0.001) in patients in B-2 group compared to those in B-3 group. There were no statistically significant differences between the two groups with respect to Lysholm scores, Tegner activity levels, Likert scales (satisfaction), and returning to previous sports at the 2-year follow-up. CONCLUSION: Primary medial reconstruction combined with severely injured MCL in ACL reconstruction may decrease residual medial laxity more than primary repair. LEVEL OF EVIDENCE: Retrospective observational study, IV.


Assuntos
Lesões do Ligamento Cruzado Anterior , Reconstrução do Ligamento Cruzado Anterior , Ligamento Colateral Médio do Joelho , Lesões do Ligamento Cruzado Anterior/cirurgia , Reconstrução do Ligamento Cruzado Anterior/métodos , Progressão da Doença , Seguimentos , Humanos , Articulação do Joelho/cirurgia , Ligamento Colateral Médio do Joelho/lesões , Ligamento Colateral Médio do Joelho/cirurgia , Estudos Retrospectivos , Resultado do Tratamento
13.
Knee ; 33: 93-101, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34601261

RESUMO

BACKGROUND: This study aimed (1) to introduce a computed tomography (CT)-based classification of the posterolateral compartment of the tibial plateau based on the fibula and to propose the individualized surgical approaches for each zone; and (2) to determine the surgical approach based on the classification, that would achieve a safe and effective reduction and could improve postoperative clinical outcomes. METHODS: Eighteen cases of tibia plateau fracture involving the isolated posterolateral compartment in a single institution were retrospectively analyzed. The posterolateral compartment of the tibial plateau was segmented into three zones based on the fibular position and an individualized surgical approach was proposed for each zone. In anterior Zone I, surgical treatment was performed using an extended anterolateral approach and the patient was placed in the supine position; in middle Zone II, using the transfibular approach in the supine position; in posterior Zone III, using the posteromedial approach in the prone position. RESULTS: In all cases, anatomical articular reduction (intra-articular step off in CT images <2 mm) was achieved and maintained for the follow up period. The average mechanical medial proximal tibial angle was increased from 87.6° before surgery to 88.2° in the immediate postoperative period (P = 0.060), and maintained for the follow up period (mean 89.9° at 1-year follow up). At the 1-year follow up, the knee range of motion averaged 140° and the Lysholm knee function score was 95.0 points. CONCLUSION: An individualized surgical approach and fixation according to three-zone subdivision for isolated posterolateral tibial plateau fractures provided an effective and safe method to treat posterolateral tibial plateau fractures.


Assuntos
Fixação Interna de Fraturas , Fraturas da Tíbia , Consolidação da Fratura , Humanos , Amplitude de Movimento Articular , Estudos Retrospectivos , Fraturas da Tíbia/diagnóstico por imagem , Fraturas da Tíbia/cirurgia , Resultado do Tratamento
14.
Int J Mol Sci ; 22(12)2021 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-34207520

RESUMO

The 26S proteasome is the principal protease for regulated intracellular proteolysis. This multi-subunit complex is also pivotal for clearance of harmful proteins that are produced throughout the lifetime of eukaryotes. Recent structural and kinetic studies have revealed a multitude of conformational states of the proteasome in substrate-free and substrate-engaged forms. These conformational transitions demonstrate that proteasome is a highly dynamic machinery during substrate processing that can be also controlled by a number of proteasome-associated factors. Essentially, three distinct family of deubiquitinases-USP14, RPN11, and UCH37-are associated with the 19S regulatory particle of human proteasome. USP14 and UCH37 are capable of editing ubiquitin conjugates during the process of their dynamic engagement into the proteasome prior to the catalytic commitment. In contrast, RPN11-mediated deubiquitination is directly coupled to substrate degradation by sensing the proteasome's conformational switch into the commitment steps. Therefore, proteasome-bound deubiquitinases are likely to tailor the degradation events in accordance with substrate processing steps and for dynamic proteolysis outcomes. Recent chemical screening efforts have yielded highly selective small-molecule inhibitors for targeting proteasomal deubiquitinases, such as USP14 and RPN11. USP14 inhibitors, IU1 and its progeny, were found to promote the degradation of a subset of substrates probably by overriding USP14-imposed checkpoint on the proteasome. On the other hand, capzimin, a RPN11 inhibitor, stabilized the proteasome substrates and showed the anti-proliferative effects on cancer cells. It is highly conceivable that these specific inhibitors will aid to dissect the role of each deubiquitinase on the proteasome. Moreover, customized targeting of proteasome-associated deubiquitinases may also provide versatile therapeutic strategies for induced or repressed protein degradation depending on proteolytic demand and cellular context.


Assuntos
Inibidores Enzimáticos , Proteínas de Neoplasias , Neoplasias , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteólise/efeitos dos fármacos , Pirróis , Pirrolidinas , Ubiquitina Tiolesterase , Inibidores Enzimáticos/química , Inibidores Enzimáticos/uso terapêutico , Humanos , Proteínas de Neoplasias/antagonistas & inibidores , Proteínas de Neoplasias/metabolismo , Neoplasias/tratamento farmacológico , Neoplasias/enzimologia , Neoplasias/patologia , Pirróis/química , Pirróis/uso terapêutico , Pirrolidinas/química , Pirrolidinas/uso terapêutico , Ubiquitina Tiolesterase/antagonistas & inibidores , Ubiquitina Tiolesterase/metabolismo
15.
Arthroscopy ; 37(8): 2554-2563.e1, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33745939

RESUMO

PURPOSE: To determine whether the femoral tunnel position remains in an anatomical footprint after tunnel widening and shifting. METHODS: Patients who underwent unilateral double-bundle anterior cruciate ligament reconstruction with hamstring autograft and performed computed tomography scan evaluation at the time of 5 days and 1 year postoperatively were included in this retrospective cohort study. Three-dimensional models of the femur and femoral tunnels were reconstructed from computed tomography scan data. The location of the tunnel center and tunnel margins in the anatomical coordinate system, and the mean shifting distance of tunnel center and margin were measured with image analysis software during the period. The change of tunnel center location in Bernard quadrant was confirmed if the tunnel center remained within the boundaries of anatomical position after tunnel widening. RESULTS: A total of 56 patients satisfied the inclusion criteria. The mean shifting distance of AM and PL tunnel centers were 1.7 ± 0.9 mm and 1.6 ± 0.6 mm. The Tunnel margin of the anteromedial (AM) and posteromedial (PL) tunnels were shifted to 2.5 ± 1.3 mm and 2.6 ± 1.4 mm in the anterior direction, and 1.4 ± 0.9 mm and 1.0 ± 0.7 mm in the distal direction, respectively. Among the anatomical located tunnel, 97% (32/33) and 87.1% (27/31) of AM and PL tunnel centers remained in a range of anatomical footprint. The tunnel center was shifted from the anatomical position into a nonanatomical position in 3% (1/33) of the AM tunnel and 12.9% (4/31) of PL tunnel after tunnel widening. The tunnel location which shifted nonanatomically were relatively anterior and distal position. CONCLUSIONS: Tunnel widening shifts the tunnel position to the anterior and distal direction, which could change the initial tunnel position. Nevertheless, the majority of tunnel positions remained in the anatomical position after tunnel widening and shifting. LEVEL OF EVIDENCE: Level III, retrospective cohort study.


Assuntos
Reconstrução do Ligamento Cruzado Anterior , Ligamento Cruzado Anterior , Ligamento Cruzado Anterior/cirurgia , Autoenxertos , Estudos de Coortes , Fêmur/diagnóstico por imagem , Fêmur/cirurgia , Humanos , Imageamento Tridimensional , Estudos Retrospectivos , Tíbia/cirurgia , Tomografia Computadorizada por Raios X
16.
Exp Mol Med ; 53(3): 369-383, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33654220

RESUMO

Unc-51-like autophagy activating kinase 1 (ULK1), a mammalian homolog of the yeast kinase Atg1, has an essential role in autophagy induction. In nutrient and growth factor signaling, ULK1 activity is regulated by various posttranslational modifications, including phosphorylation, acetylation, and ubiquitination. We previously identified glycogen synthase kinase 3 beta (GSK3B) as an upstream regulator of insulin withdrawal-induced autophagy in adult hippocampal neural stem cells. Here, we report that following insulin withdrawal, GSK3B directly interacted with and activated ULK1 via phosphorylation of S405 and S415 within the GABARAP-interacting region. Phosphorylation of these residues facilitated the interaction of ULK1 with MAP1LC3B and GABARAPL1, while phosphorylation-defective mutants of ULK1 failed to do so and could not induce autophagy flux. Furthermore, high phosphorylation levels of ULK1 at S405 and S415 were observed in human pancreatic cancer cell lines, all of which are known to exhibit high levels of autophagy. Our results reveal the importance of GSK3B-mediated phosphorylation for ULK1 regulation and autophagy induction and potentially for tumorigenesis.


Assuntos
Proteína Homóloga à Proteína-1 Relacionada à Autofagia/metabolismo , Autofagia , Glicogênio Sintase Quinase 3 beta/metabolismo , Hipocampo/patologia , Células-Tronco Neurais/patologia , Processamento de Proteína Pós-Traducional , Animais , Proteína Homóloga à Proteína-1 Relacionada à Autofagia/genética , Glicogênio Sintase Quinase 3 beta/genética , Hipocampo/metabolismo , Células-Tronco Neurais/metabolismo , Fosforilação , Ratos , Ratos Sprague-Dawley , Transdução de Sinais
17.
Knee Surg Relat Res ; 33(1): 4, 2021 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-33431062

RESUMO

BACKGROUND: The alignment correction after high tibial osteotomy (HTO) is made both by bony correction and soft-tissue correction around the knee. Change of the joint-line convergence angle (JLCA) represents the soft-tissue correction after HTO, which is the angle made by a tangential line between the femoral condyles and the tibial plateau. We described the patterns of JLCA change and related factors after HTO and investigated the appropriate preoperative planning method. METHODS: Eighty patients who underwent HTO between 2013 and 2016 were included for this retrospective study. Standing, whole-limb radiograph, supine knee anteroposterior (AP) and lateral were measured on the preoperative and postoperative radiographs. The patterns of JLCA changes and related factors were analyzed. RESULTS: JLCA decreased by a mean of 0.9° ± 1.2° (P < 0.001) after HTO. Sixteen patients (20%, group II) showed a greater JLCA decrease ≥ 2°, while 64 (80%, group I) patients remained in a narrow range of JLCA change < 2°. Group II showed more varus deformity (varus 8.1° vs. varus 4.7° in the mechanical femorotibial angle, P < 0.001), greater JLCA on standing (4.9° vs. 2.1°, P < 0.001), and the difference of JLCA in the standing and supine positions (2.8° vs. 0.7°, P < 0.001) preoperatively compared to group I. The risk of a greater JLCA decrease ≥ 2° was associated with greater preoperative JLCA in the standing position and the difference between the JLCA in the standing and supine positions. Postoperative JLCA correlated better with preoperative JLCA in the supine position than those in the standing position. A preoperative JLCA ≥ 4° or the difference of preoperative JLCA in the standing and supine positions ≥ 1.7° was the cut-off value to predict a large JLCA decrease ≥ 2° after HTO in the receiver operating characteristic (ROC) curve analysis. CONCLUSIONS: Surgeons should consider the effect of the JLCA change during the preoperative planning and intraoperative procedure to avoid unintended overcorrection.

18.
Taehan Yongsang Uihakhoe Chi ; 82(3): 743-748, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-36238778

RESUMO

Various anomalous origins of the vertebral arteries (VAs) have been reported. However, anomalous origins of the bilateral VAs arising directly from the aortic arch are extremely rare. We encountered a 60-year-old male who developed sudden-onset right hemiparesis with an incidentally discovered rare origins of the bilateral VAs from aortic arch. CT angiography demonstrated the right VA originating from the aortic arch distal to the left subclavian artery and left VA originating from the aortic arch between the left common carotid artery and the left subclavian artery. The possible embryological mechanism of this variant was also reviewed. If the VA can not be found in the usual position during the procedure, a rare variant of the VA with anomalous origin should be considered. Understanding these variations is important to avoid unexpected events during endovascular procedures or surgery.

19.
Radiol Case Rep ; 15(5): 628-632, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32256924

RESUMO

Tertiary hyperparathyroidism is defined as a state of excessive secretion of parathyroid hormone after long-standing secondary hyperparathyroidism, which typically occurs in patients with chronic kidney disease. Tertiary hyperparathyroidism is typically characterized by marked parathyroid hyperplasia or parathyroid adenomas. Here we present a case of multiple parathyroid adenomas in a 23-year-old woman with tertiary hyperparathyroidism due to chronic kidney disease and describe the ultrasonography and computed tomography findings. To our knowledge, this is the first case of four parathyroid adenomas showing variable radiological features in a patient with tertiary hyperparathyroidism.

20.
Knee ; 27(2): 436-443, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32014410

RESUMO

PURPOSE: Hydroxyapatite (HA) does not fully degrade, which raises concerns about poor remodeling and incorporation into the bone after open-wedge high tibial osteotomy (HTO). The purpose of this study was to compare the results between gap filling with allogenous chip bone and HA chip after open-wedge HTO using propensity score matching and to analyze the radiological unabsorbed area of opening gaps histologically in HA using patients. METHODS: The matched variables were age, body mass index, sex, correction angle, and smoking status. After matching, the allogenous group and HA group included 33 patients each with two years of follow-up. The range of motion (ROM), International Knee Documentation Committee (IKDC) subjective score, Knee Injury and Osteoarthritis Outcome Score (KOOS), mechanical axis (MA), tibial slope, osteoconductivity, and absorbability were evaluated and compared between both groups. Among the HA group, 20 patients underwent bone biopsy and histologically analyzed of the radiological unabsorbed area. RESULTS: The postoperative ROM, IKDC subjective score, and KOOS were similar in both groups. The osteoconductivities did not differ significantly. The absorbability in the HA group was significantly lower than allogenous group (59.6% vs. 22.6%, P < .001). The histological sections of the radiological unabsorbed area showed mature lamelliform bone tissues were significantly greater than structurally degraded remnant HA (30.4% and 4.2%, P < .001). CONCLUSION: The HA chips showed an inferior absorbability, however, a mature lamelliform bone was observed in significantly larger amounts than remnant HA in the radiological unabsorbed area. The allogenous bone chips and HA chips showed similar clinical and radiological results after open-wedge HTO.


Assuntos
Materiais Biocompatíveis , Durapatita , Osteotomia/métodos , Tíbia/cirurgia , Osso Esponjoso/transplante , Feminino , Seguimentos , Humanos , Masculino , Análise por Pareamento , Pessoa de Meia-Idade , Osteogênese , Porosidade , Transplante Homólogo
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