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1.
Molecules ; 29(11)2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38893570

RESUMO

Sigma receptors (SRs), including SR1 and SR2 subtypes, have attracted increasing interest in recent years due to their involvement in a wide range of activities, including the modulation of opioid analgesia, neuroprotection, and potential anticancer activity. In this context, haloperidol (HAL), a commonly used antipsychotic drug, also possesses SR activity and cytotoxic effects. Herein, we describe the identification of novel SR ligands, obtained by a chemical hybridization approach. There wereendowed with pan-affinity for both SR subtypes and evaluated their potential anticancer activity against SH-SY5Y and HUH-7 cancer cell lines. Through a chemical hybridization approach, we identified novel compounds (4d, 4e, 4g, and 4j) with dual affinity for SR1 and SR2 receptors. These compounds were subjected to cytotoxicity testing using a resazurin assay. The results revealed potent cytotoxic effects against both cancer cell lines, with IC50 values comparable to HAL. Interestingly, the cytotoxic potency of the novel compounds resembled that of the SR1 antagonist HAL rather than the SR2 agonist siramesine (SRM), indicating the potential role of SR1 antagonism in their mechanism of action. The further exploration of their structure-activity relationships and their evaluation in additional cancer cell lines will elucidate their therapeutic potential and may pave the way for the development of novel anticancer agents that target SRs.


Assuntos
Antineoplásicos , Desenho de Fármacos , Haloperidol , Receptores sigma , Receptores sigma/metabolismo , Receptores sigma/antagonistas & inibidores , Haloperidol/farmacologia , Haloperidol/análogos & derivados , Humanos , Antineoplásicos/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Linhagem Celular Tumoral , Relação Estrutura-Atividade , Estrutura Molecular , Sobrevivência Celular/efeitos dos fármacos , Ligantes , Proliferação de Células/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais
2.
J Biol Chem ; 298(8): 102252, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35835219

RESUMO

TAR DNA-binding protein 43 (TDP-43) is a nucleic acid-binding protein found in the nucleus that accumulates in the cytoplasm under pathological conditions, leading to proteinopathies, such as frontotemporal dementia and ALS. An emerging area of TDP-43 research is represented by the study of its post-translational modifications, the way they are connected to disease-associated mutations, and what this means for pathological processes. Recently, we described a novel mutation in TDP-43 in an early onset ALS case that was affecting a potential phosphorylation site in position 375 (S375G). A preliminary characterization showed that both the S375G mutation and its phosphomimetic variant, S375E, displayed altered nuclear-cytoplasmic distribution and cellular toxicity. To better investigate these effects, here we established cell lines expressing inducible WT, S375G, and S375E TDP-43 variants. Interestingly, we found that these mutants do not seem to affect well-studied aspects of TDP-43, such as RNA splicing or autoregulation, or protein conformation, dynamics, or aggregation, although they do display dysmorphic nuclear shape and cell cycle alterations. In addition, RNA-Seq analysis of these cell lines showed that although the disease-associated S375G mutation and its phosphomimetic S375E variant regulate distinct sets of genes, they have a common target in mitochondrial apoptotic genes. Taken together, our data strongly support the growing evidence that alterations in TDP-43 post-translational modifications can play a potentially important role in disease pathogenesis and provide a further link between TDP-43 pathology and mitochondrial health.


Assuntos
Mutação , Proteinopatias TDP-43 , Citoplasma/metabolismo , Humanos , Doenças Neurodegenerativas/genética , Doenças Neurodegenerativas/patologia , Proteinopatias TDP-43/genética , Proteinopatias TDP-43/patologia
3.
Ann Surg ; 277(4): 664-671, 2023 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-35766422

RESUMO

OBJECTIVE: To evaluate the effect of a liver transplantation (LT) program on the outcomes of resectable hepatocellular carcinoma (HCC). BACKGROUND: Surgical treatment of HCC includes both hepatic resection (HR) and LT. However, the presence of cirrhosis and the possibility of recurrence make the management of this disease complex and probably different according to the presence of a LT program. METHODS: Patients undergoing HR for HCC between January 2005 and December 2019 were identified from a national database of HCC. The main study outcomes were major surgical complications according to the Comprehensive Complication Index, posthepatectomy liver failure (PHLF), 90-day mortality, overall survival, and disease-free survival. Secondary outcomes were salvage liver transplantation (SLT) and postrecurrence survival. RESULTS: A total of 3202 patients were included from 25 hospitals over the study period. Three of 25 (12%) had an LT program. The presence of an LT program within a center was associated with a reduced probability of PHLF (odds ratio=0.38) but not with overall survival and disease-free survival. There was an increased probability of SLT when HR was performed in a transplant hospital (odds ratio=12.05). Among transplant-eligible patients, those who underwent LT had a significantly longer postrecurrence survival. CONCLUSIONS: This study showed that the presence of a LT program was associated with decreased PHLF rates and an increased probability to receive SLT in case of recurrence.


Assuntos
Carcinoma Hepatocelular , Falência Hepática , Neoplasias Hepáticas , Transplante de Fígado , Humanos , Carcinoma Hepatocelular/cirurgia , Cirrose Hepática/complicações , Falência Hepática/complicações , Recidiva Local de Neoplasia/epidemiologia , Estudos Retrospectivos
4.
Molecules ; 28(8)2023 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-37110664

RESUMO

Neurodegeneration is a slow and progressive loss of neuronal cells or their function in specific regions of the brain or in the peripheral system. Among several causes responsible for the most common neurodegenerative diseases (NDDs), cholinergic/dopaminergic pathways, but also some endogenous receptors, are often involved. In this context, sigma 1 receptor (S1R) modulators can be used as neuroprotective and antiamnesic agents. Herein, we describe the identification of novel S1R ligands endowed with antioxidant properties, potentially useful as neuroprotective agents. We also computationally assessed how the most promising compounds might interact with the S1R protein's binding sites. The in silico predicted ADME properties suggested that they could be able to cross the brain-blood-barrier (BBB), and to reach the targets. Finally, the observation that at least two novel ifenprodil analogues (5d and 5i) induce an increase of the mRNA levels of the antioxidant NRF2 and SOD1 genes in SH-SY5Y cells suggests that they might be effective agents for protecting neurons against oxidative damage.


Assuntos
Neuroblastoma , Fármacos Neuroprotetores , Receptores sigma , Humanos , Antioxidantes/farmacologia , Antioxidantes/química , Ligantes , Neuroproteção , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/química , Receptores sigma/metabolismo
5.
HPB (Oxford) ; 25(10): 1223-1234, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37357112

RESUMO

BACKGROUND: Despite second-line transplant(SLT) for recurrent hepatocellular carcinoma(rHCC) leads to the longest survival after recurrence(SAR), its real applicability has never been reported. The aim was to compare the SAR of SLT versus repeated hepatectomy and thermoablation(CUR group). METHODS: Patients were enrolled from the Italian register HE.RC.O.LE.S. between 2008 and 2021. Two groups were created: CUR versus SLT. A propensity score matching (PSM) was run to balance the groups. RESULTS: 743 patients were enrolled, CUR = 611 and SLT = 132. Median age at recurrence was 71(IQR 6575) years old and 60(IQR 53-64, p < 0.001) for CUR and SLT respectively. After PSM, median SAR for CUR was 43 months(95%CI = 37 - 93) and not reached for SLT(p < 0.001). SLT patients gained a survival benefit of 9.4 months if compared with CUR. MilanCriteria(MC)-In patients were 82.7% of the CUR group. SLT(HR 0.386, 95%CI = 0.23 - 0.63, p < 0.001) and the MELD score(HR 1.169, 95%CI = 1.07 - 1.27, p < 0.001) were the only predictors of mortality. In case of MC-Out, the only predictor of mortality was the number of nodules at recurrence(HR 1.45, 95%CI= 1.09 - 1.93, p = 0.011). CONCLUSION: It emerged an important transplant under referral in favour of repeated hepatectomy or thermoablation. In patients with MC-Out relapse, the benefit of SLT over CUR was not observed.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Transplante de Fígado , Humanos , Hepatectomia/efeitos adversos , Transplante de Fígado/efeitos adversos , Estudos Retrospectivos , Recidiva Local de Neoplasia , Terapia de Salvação
6.
Bioorg Med Chem Lett ; 72: 128860, 2022 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-35724925

RESUMO

In our continuing effort to develop novel sigma receptor (SR) ligands, we present the design, synthesis and binding studies of a small library of aminopropylcarboxamide derivatives, obtained from a deconstruction of the piperidine ring of previously synthesized piperidine-based compounds. The best results were achieved with benzofuran (5c, 5g) and quinoline (5a, 5e) derivatives. These compounds revealed the highest affinity for both receptor subtypes. In particular, the 3,4-dimethoxyphenyl derivatives 5e and 5g showed the highest selectivity profile for S2R, especially the quinoline derivative 5e exhibited a 35-fold higher affinity for S2R subtype. The cytotoxic activity of aforementioned compounds was evaluated against SKBR3 and MCF7 cell lines, widely used for breast cancer studies. Whereas the potency of 5g was similar that of Siramesine and Haloperidol in both cell lines, compounds 5a, 5c and 5e exhibited a potency at least comparable to that of Haloperidol in SKBR3 cells. A molecular modelling evaluation towards the S2R binding site, confirmed the strong interaction of compound 5e thus justifying its highest S2R affinity.


Assuntos
Quinolinas , Receptores sigma , Haloperidol , Ligantes , Piperidinas , Quinolinas/farmacologia , Receptores sigma/metabolismo , Relação Estrutura-Atividade
7.
Int J Mol Sci ; 23(23)2022 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-36499618

RESUMO

To extend our screening for novel antimycobacterial molecules, we have designed, synthesized, and biologically evaluated a library of 14 new hydrazide derivatives containing 1,3,4-oxadiazole core. A variety of mycobacterial strains, including some drug-resistant strains, were tested for antimycobacterial activity. Among the compounds tested, five showed high antimycobacterial activity (MIC values of 8 µg/mL) against M. tuberculosis H37Ra attenuated strain, and two derivatives were effective (MIC of 4 µg/mL) against pyrazinamide-resistant strains. Furthermore, the novel compounds were tested against the fungal C. albicans strain, showing no antimycotic activity, and thus demonstrating a good selectivity profile. Notably, they also exhibited low cytotoxicity against human SH-SY5Y cells. The molecular modeling carried out suggested a plausible mechanism of action towards the active site of the InhA enzyme, which confirmed our hypothesis. In conclusion, the active compounds were predicted in silico for ADME properties, and all proved to be potentially orally absorbed in humans.


Assuntos
Mycobacterium tuberculosis , Neuroblastoma , Humanos , Antituberculosos/química , Hidrazinas/farmacologia , Testes de Sensibilidade Microbiana , Neuroblastoma/tratamento farmacológico , Fungos , Relação Estrutura-Atividade , Simulação de Acoplamento Molecular
8.
HPB (Oxford) ; 24(8): 1291-1304, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35125292

RESUMO

BACKGROUND: We aimed to evaluate, in a large Western cohort, perioperative and long-term oncological outcomes of salvage hepatectomy (SH) for recurrent hepatocellular carcinoma (rHCC) after primary hepatectomy (PH) or locoregional treatments. METHODS: Data were collected from the Hepatocarcinoma Recurrence on the Liver Study Group (He.RC.O.Le.S.) Italian Registry. After 1:1 propensity score-matched analysis (PSM), two groups were compared: the PH group (patients submitted to resection for a first HCC) and the SH group (patients resected for intrahepatic rHCC after previous HCC-related treatments). RESULTS: 2689 patients were enrolled. PH included 2339 patients, SH 350. After PSM, 263 patients were selected in each group with major resected nodule median size, intraoperative blood loss and minimally invasive approach significantly lower in the SH group. Long-term outcomes were compared, with no difference in OS and DFS. Univariate and multivariate analyses revealed only microvascular invasion as an independent prognostic factor for OS. CONCLUSION: SH proved to be equivalent to PH in terms of safety, feasibility and long-term outcomes, consistent with data gathered from East Asia. In the awaiting of reliable treatment-allocating algorithms for rHCC, SH appears to be a suitable alternative in patients fit for surgery, regardless of the previous therapeutic modality implemented.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Carcinoma Hepatocelular/patologia , Hepatectomia/efeitos adversos , Humanos , Neoplasias Hepáticas/patologia , Recidiva Local de Neoplasia/patologia , Pontuação de Propensão , Estudos Retrospectivos , Resultado do Tratamento
9.
HPB (Oxford) ; 24(8): 1365-1375, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35293320

RESUMO

BACKGROUND: Benchmark analysis for open liver surgery for cirrhotic patients with hepatocellular carcinoma (HCC) is still undefined. METHODS: Patients were identified from the Italian national registry HE.RC.O.LE.S. The Achievable Benchmark of Care (ABC) method was employed to identify the benchmarks. The outcomes assessed were the rate of complications, major comorbidities, post-operative ascites (POA), post-hepatectomy liver failure (PHLF), 90-day mortality. Benchmarking was stratified for surgical complexity (CP1, CP2 and CP3). RESULTS: A total of 978 of 2698 patients fulfilled the inclusion criteria. 431 (44.1%) patients were treated with CP1 procedures, 239 (24.4%) with CP2 and 308 (31.5%) with CP3 procedures. Patients submitted to CP1 had a worse underlying liver function, while the tumor burden was more severe in CP3 cases. The ABC for complications (13.1%, 19.2% and 28.1% for CP1, CP2 and CP3 respectively), major complications (7.6%, 11.1%, 12.5%) and 90-day mortality (0%, 3.3%, 3.6%) increased with the surgical difficulty, but not POA (4.4%, 3.3% and 2.6% respectively) and PHLF (0% for all groups). CONCLUSION: We propose benchmarks for open liver resections in HCC cirrhotic patients, stratified for surgical complexity. The difference between the benchmark values and the results obtained during everyday practice reflects the room for potential growth, with the aim to encourage constant improvement among liver surgeons.


Assuntos
Carcinoma Hepatocelular , Falência Hepática , Neoplasias Hepáticas , Benchmarking , Hepatectomia/efeitos adversos , Hepatectomia/métodos , Humanos , Cirrose Hepática/complicações , Cirrose Hepática/patologia , Cirrose Hepática/cirurgia , Falência Hepática/etiologia , Neoplasias Hepáticas/complicações , Neoplasias Hepáticas/cirurgia , Complicações Pós-Operatórias , Estudos Retrospectivos
10.
Nucleic Acids Res ; 45(13): 8026-8045, 2017 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-28575377

RESUMO

Nuclear factor TDP-43 is known to play an important role in several neurodegenerative pathologies. In general, TDP-43 is an abundant protein within the eukaryotic nucleus that binds to many coding and non-coding RNAs and influence their processing. Using Drosophila, we have performed a functional screening to establish the ability of major hnRNP proteins to affect TDP-43 overexpression/depletion phenotypes. Interestingly, we observed that lowering hnRNP and TDP-43 expression has a generally harmful effect on flies locomotor abilities. In parallel, our study has also identified a distinct set of hnRNPs that is capable of powerfully rescuing TDP-43 toxicity in the fly eye (Hrb27c, CG42458, Glo and Syp). Most importantly, removing the human orthologs of Hrb27c (DAZAP1) in human neuronal cell lines can correct several pre-mRNA splicing events altered by TDP-43 depletion. Moreover, using RNA sequencing analysis we show that DAZAP1 and TDP-43 can co-regulate an extensive number of biological processes and molecular functions potentially important for the neuron/motor neuron pathophysiology. Our results suggest that changes in hnRNP expression levels can significantly modulate TDP-43 functions and affect pathological outcomes.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Proteínas de Drosophila/metabolismo , Ribonucleoproteínas Nucleares Heterogêneas/metabolismo , Neurônios/metabolismo , Esclerose Lateral Amiotrófica/genética , Esclerose Lateral Amiotrófica/metabolismo , Animais , Animais Geneticamente Modificados , Linhagem Celular , Proteínas de Ligação a DNA/antagonistas & inibidores , Proteínas de Ligação a DNA/genética , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Drosophila melanogaster/crescimento & desenvolvimento , Drosophila melanogaster/metabolismo , Olho/crescimento & desenvolvimento , Olho/metabolismo , Técnicas de Silenciamento de Genes , Células HeLa , Ribonucleoproteínas Nucleares Heterogêneas/genética , Humanos , Splicing de RNA , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo
11.
Bioorg Med Chem Lett ; 28(19): 3206-3209, 2018 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-30143421

RESUMO

The sigma receptor (σR) family has been considered mysterious for a long time. In fact, the σ2R subtype has been cloned only recently, revealing its identity as TMEM97, a NPC1-binding protein involved in cholesterol biosynthesis and implicated in the pathogenesis of cancer and neurologic disorders. With the aim of developing new chemical entities gifted with σR affinity, herein we report the design and synthesis of new piperidine-based alkylacetamide derivatives with mixed affinity towards both σ1 and σ2R subtypes.


Assuntos
Piperidinas/química , Receptores sigma/efeitos dos fármacos , Linhagem Celular Tumoral , Humanos , Ligantes , Piperidinas/síntese química , Piperidinas/farmacologia
12.
Nucleic Acids Res ; 43(18): 8990-9005, 2015 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-26261209

RESUMO

In recent times, high-throughput screening analyses have broadly defined the RNA cellular targets of TDP-43, a nuclear factor involved in neurodegeneration. A common outcome of all these studies is that changing the expression levels of this protein can alter the expression of several hundred RNAs within cells. What still remains to be clarified is which changes represent direct cellular targets of TDP-43 or just secondary variations due to the general role played by this protein in RNA metabolism. Using an HTS-based splicing junction analysis we identified at least six bona fide splicing events that are consistent with being controlled by TDP-43. Validation of the data, both in neuronal and non-neuronal cell lines demonstrated that TDP-43 substantially alters the levels of isoform expression in four genes potentially important for neuropathology: MADD/IG20, STAG2, FNIP1 and BRD8. For MADD/IG20 and STAG2, these changes could also be confirmed at the protein level. These alterations were also observed in a cellular model that successfully mimics TDP-43 loss of function effects following its aggregation. Most importantly, our study demonstrates that cell cycle alterations induced by TDP-43 knockdown can be recovered by restoring the STAG2, an important component of the cohesin complex, normal splicing profile.


Assuntos
Processamento Alternativo , Antígenos Nucleares/genética , Proteínas de Ligação a DNA/metabolismo , Proteínas Adaptadoras de Sinalização de Receptores de Domínio de Morte/genética , Fatores de Troca do Nucleotídeo Guanina/genética , Antígenos Nucleares/metabolismo , Apoptose , Sítios de Ligação , Ciclo Celular , Proteínas de Ciclo Celular , Linhagem Celular Tumoral , Proteínas de Ligação a DNA/genética , Proteínas Adaptadoras de Sinalização de Receptores de Domínio de Morte/metabolismo , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Células HEK293 , Humanos , Mitose , Isoformas de Proteínas/genética
13.
J Cell Physiol ; 231(4): 768-76, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26357947

RESUMO

Cholangiocarcinoma (CCAs) may be defined as tumors that derived from the biliary tree with the differentiation in the biliary epithelial cells. This tumor is malignant, extremely aggressive with a poor prognosis. It can be treated surgically and its pathogenesis is poorly understood. The tumor microenvironment (TME) is a very important factor in the regulation of tumor angiogenesis, invasion, and metastasis. Besides cancer stem cells (CSCs) can modulate tumor growth, stroma formation, and migratory capability. The initial stage of tumorigenesis is characterized by genetic mutations and epigenetic alterations due to intrinsic factors which lead to the generation of oncogenes thus inducing tumorigenesis. CSCs may result from precancerous stem cells, cell de-differentiation, normal stem cells, or an epithelial-mesenchymal transition (EMT). CSCs have been found in the cancer niche, and EMT may occur early within the tumor microenvironment. Previous studies have demonstrated evidence of cholangiocarcinoma stem cells (CD133, CD24, EpCAM, CD44, and others) and the presence of these markers has been associated with malignant potential. The interaction between TME and cholangiocarcinoma stem cells via signaling mediators may create an environment that accommodates tumor growth, yielding resistance to cytotoxic insults (chemotherarapeutic). While progress has been made in the understanding of the mechanisms, the interactions in the tumorigenic process still remain a major challenge. Our review, addresses recent concepts of TME-CSCs interaction and will emphasize the importance of early detection with the use of novel diagnostic mechanisms such as CCA-CSC biomarkers and the importance of tumor stroma to define new treatments. J. Cell. Physiol. 231: 768-776, 2016. © 2015 Wiley Periodicals, Inc.


Assuntos
Colangiocarcinoma/patologia , Células-Tronco Neoplásicas/patologia , Microambiente Tumoral , Biomarcadores Tumorais/metabolismo , Humanos , Modelos Biológicos , Transdução de Sinais
14.
Bioorg Med Chem Lett ; 26(14): 3287-3290, 2016 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-27241693

RESUMO

N(1)-[1-[1-aryl-3-[4-(1H-imidazol-1-yl)phenyl]-3-oxo]propyl]-pyridine-2-carboxamidrazone derivatives were design, synthesized and tested for their in vitro antimycobacterial activity. The new compounds showed a moderate antimycobacterial activity against the tested strain of Mycobacterium tuberculosis H37Ra and a significant antimycobacterial activity against several mycobacteria other than tuberculosis strains.


Assuntos
Antibacterianos/farmacologia , Antifúngicos/farmacologia , Bactérias/efeitos dos fármacos , Fungos/efeitos dos fármacos , Imidazóis/farmacologia , Piridinas/farmacologia , Antibacterianos/síntese química , Antibacterianos/química , Antifúngicos/síntese química , Antifúngicos/química , Relação Dose-Resposta a Droga , Imidazóis/síntese química , Imidazóis/química , Testes de Sensibilidade Microbiana , Estrutura Molecular , Piridinas/síntese química , Piridinas/química , Relação Estrutura-Atividade
15.
J Biol Chem ; 289(10): 7121-7130, 2014 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-24492607

RESUMO

Human TDP-43 represents the main component of neuronal inclusions found in patients with neurodegenerative diseases, especially frontotemporal lobar degeneration and amyotrophic lateral sclerosis. In vitro and in vivo studies have shown that the TAR DNA-binding protein 43 (TDP-43) Drosophila ortholog (TBPH) can biochemically and functionally overlap the properties of the human factor. The recent direct implication of the human heterogeneous nuclear ribonucleoproteins (hnRNPs) A2B1 and A1, known TDP-43 partners, in the pathogenesis of multisystem proteinopathy and amyotrophic lateral sclerosis supports the hypothesis that the physical and functional interplay between TDP-43 and hnRNP A/B orthologs might play a crucial role in the pathogenesis of neurodegenerative diseases. To test this hypothesis and further validate the fly system as a useful model to study this type of diseases, we have now characterized human TDP-43 and Drosophila TBPH similarity in terms of protein-protein interaction pathways. In this work we show that TDP-43 and TBPH share the ability to associate in vitro with Hrp38/Hrb98DE/CG9983, the fruit fly ortholog of the human hnRNP A1/A2 factors. Interestingly, the protein regions of TDP-43 and Hrp38 responsible for reciprocal interactions are conserved through evolution. Functionally, experiments in HeLa cells demonstrate that TDP-43 is necessary for the inhibitory activity of Hrp38 on splicing. Finally, Drosophila in vivo studies show that Hrp38 deficiency produces locomotive defects and life span shortening in TDP-43 with and without animals. These results suggest that hnRNP protein levels can play a modulatory role on TDP-43 functions.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/fisiologia , Ribonucleoproteínas Nucleares Heterogêneas Grupo A-B/metabolismo , Ribonucleoproteínas Nucleares Heterogêneas/metabolismo , Ribonucleoproteínas/metabolismo , Sequência de Aminoácidos , Animais , Apolipoproteína A-II/química , Sequência Conservada , Proteínas de Ligação a DNA/genética , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Evolução Molecular , Éxons/genética , Humanos , Imunoprecipitação , Locomoção/genética , Longevidade/genética , Dados de Sequência Molecular , Splicing de RNA
16.
EMBO J ; 30(2): 277-88, 2011 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-21131904

RESUMO

TAR DNA-binding protein (TDP-43) is an evolutionarily conserved heterogeneous nuclear ribonucleoprotein (hnRNP) involved in RNA processing, whose abnormal cellular distribution and post-translational modification are key markers of certain neurodegenerative diseases, such as amyotrophic lateral sclerosis and frontotemporal lobar degeneration. We generated human cell lines expressing tagged forms of wild-type and mutant TDP-43 and observed that TDP-43 controls its own expression through a negative feedback loop. The RNA-binding properties of TDP-43 are essential for the autoregulatory activity through binding to 3' UTR sequences in its own mRNA. Our analysis indicated that the C-terminal region of TDP-43, which mediates TDP-43-hnRNP interactions, is also required for self-regulation. TDP-43 binding to its 3' UTR does not significantly change the pre-mRNA splicing pattern but promotes RNA instability. Moreover, blocking exosome-mediated degradation partially recovers TDP-43 levels. Our findings demonstrate that cellular TDP-43 levels are under tight control and it is likely that disease-associated TDP-43 aggregates disrupt TDP-43 self-regulation, thus contributing to pathogenesis.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Retroalimentação Fisiológica/fisiologia , Regulação da Expressão Gênica/genética , Processamento Pós-Transcricional do RNA/genética , RNA Mensageiro/metabolismo , Sequência de Bases , Northern Blotting , Linhagem Celular , Proteínas de Ligação a DNA/genética , Biblioteca Gênica , Humanos , Immunoblotting , Imunoprecipitação , Dados de Sequência Molecular , Plasmídeos/genética , Reação em Cadeia da Polimerase , Interferência de RNA , Análise de Sequência de DNA
17.
Mol Cell Neurosci ; 56: 465-74, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23500590

RESUMO

Dysfunctions in RNA processing and in particular the aberrant regulation of RNA binding proteins (RBPs) have recently been shown to play a fundamental role in the pathogenesis of neurodegenerative diseases. Understanding the pathogenic mechanisms involved will require the elucidation of the role(s) played by these RBPs in the general cell metabolism and neuronal survival in particular. In the past, the preferred approach has been to determine first of all the functional properties of the factor(s) of interest and then use this knowledge to determine targets in biologically relevant events. More recently, novel experimental approaches such as microarrays, RNA-seq and CLIP-seq have also become very popular to study RBPs. The advantage of these approaches, collectively known as high throughput screening (HTS), is their ability to determine gene expression changes or RNA/protein targets at a global cellular level. In theory, HTS strategies should be ideal for uncovering novel functional roles/targets of any RBP inside the cell. In practice, however, there are still difficulties in getting a coherent picture from all the huge amount of data they generate, frequently not validated experimentally and thus of unknown value. They may even act unfavorably towards a specific increase of knowledge of RBP functions, as the incomplete results are taken as solid data. In this work we will illustrate as an example the use of the HTS methodologies to characterize the interactions of a specific RBP: TDP-43. The multiple functions of this protein in RNA processing and its involvement in the pathogenesis of several forms of amyotrophic lateral sclerosis, frontotemporal lobar degeneration and other neurodegenerative diseases make it an excellent substrate for our analysis of the various advantages and limitations of different HTS experimental approaches.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Proteinopatias TDP-43/metabolismo , Humanos , Ligação Proteica , Sensibilidade e Especificidade
18.
Prog Transplant ; 24(2): 142-5, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24919730

RESUMO

Liver transplant is the preferred treatment for hepatocellular carcinoma in patients with cirrhosis, as both neoplastic and cirrhotic liver tissue can be removed. Treatment of recurring neoplasms is a difficult issue, especially in long-term survivors of liver transplant. No consensus has been reached on the treatment of recurrent hepatocellular carcinoma. Although patients with extrahepatic metastases are generally not candidates for local therapy, successful multimodal salvage therapy including resection or ablation can be achieved in liver transplant recipients with local recurrence of hepatocellular carcinoma. Microwave ablation is safe and effective for treating unresectable hepatocellular carcinoma, achieving excellent results in local disease down-staging or as a "bridge" to liver transplant, with no significant differences in local recurrence and complications compared with the more commonly used radiofrequency ablation. A patient with local recurrence of hepatocellular carcinoma 36 months after liver transplant for multifocal hepatocellular carcinoma and cirrhosis due to hepatitis C was successfully treated with laparoscopic microwave ablation without any postoperative complications. The patient is disease free 24 months after microwave ablation.


Assuntos
Técnicas de Ablação , Carcinoma Hepatocelular/terapia , Neoplasias Hepáticas/terapia , Transplante de Fígado , Micro-Ondas/uso terapêutico , Recidiva Local de Neoplasia/terapia , Humanos , Laparoscopia , Masculino , Pessoa de Meia-Idade
19.
Gene ; 905: 148212, 2024 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-38281673

RESUMO

Fusarium oxysporum f.sp. cepae (FOC), as basal rot fungus, is the most detrimental pathogen causing a serious threat to onion productivity in the world. In this study, we first determined FOC tolerance in seven Iranian onion cultivars, two known international onions (Texas Early Grano and Sweet Yellow Spanish), and an Allium species related to the onion (Allium asarence) based on the infection severity. Then, a transcriptional screen was performed by comparing the transcript levels of some pathogen-responsive genes (ERF1, COI1, and TIR1) and their predicted miRNAs in the sensitive (Ghermeze Azarshahr Cv.) and the resistant (A. asarence) onions to determine key genes and their miRNAs involved in the defense responses of onions to FOC. From our results, a difference was found in the COI1 and ERF1 expression 48 h after inoculation with FOC as compared to the respective 24 and 72 h. It can be explained by either special mechanisms involved in raising energy consumption efficiency or the interactive effects of other genes in the jasmonic acid (JA) and ethylene (ET) signaling pathways. Moreover, expression analysis of the pathogen-responsive genes and their targeting miRNAs identified the miR-5629, which targets the COI1 gene as a likely key factor in conferring resistance in the FOC-resistant onion, i.e., A. asarence. However, exploring the function of the miRNA/target pair is highly recommended to deeply understand the effect of the miRNA/target pair-associated pathway in the control of A. asarense-FOC interaction.


Assuntos
Fusarium , MicroRNAs , Cebolas/genética , Fusarium/genética , MicroRNAs/genética , Irã (Geográfico) , Doenças das Plantas/genética , Doenças das Plantas/microbiologia
20.
Cells ; 13(10)2024 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-38786046

RESUMO

Our study focused on assessing the effects of three newly identified BRCA1 exon 11 variants (c.1019T>C, c.2363T>G, and c.3192T>C) on breast cancer susceptibility. Using computational predictions and experimental splicing assays, we evaluated their potential as pathogenic mutations. Our in silico analyses suggested that the c.2363T>G and c.3192T>C variants could impact both splicing and protein function, resulting in the V340A and V788G mutations, respectively. We further examined their splicing effects using minigene assays in MCF7 and SKBR3 breast cancer cell lines. Interestingly, we found that the c.2363T>G variant significantly altered splicing patterns in MCF7 cells but not in SKBR3 cells. This finding suggests a potential influence of cellular context on the variant's effects. While attempts to correlate in silico predictions with RNA binding factors were inconclusive, this observation underscores the complexity of splicing regulation. Splicing is governed by various factors, including cellular contexts and protein interactions, making it challenging to predict outcomes accurately. Further research is needed to fully understand the functional consequences of the c.2363T>G variant in breast cancer pathogenesis. Integrating computational predictions with experimental data will provide valuable insights into the role of alternative splicing regulation in different breast cancer types and stages.


Assuntos
Proteína BRCA1 , Neoplasias da Mama , Éxons , Precursores de RNA , Splicing de RNA , Humanos , Éxons/genética , Proteína BRCA1/genética , Proteína BRCA1/metabolismo , Precursores de RNA/genética , Precursores de RNA/metabolismo , Splicing de RNA/genética , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Feminino , Linhagem Celular Tumoral , Mutação/genética , Células MCF-7 , Processamento Alternativo/genética , Predisposição Genética para Doença
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