RESUMO
Abnormal cold sensitivity is a common feature of a range of neuropathies. In the murine somatosensory system, multiple aspects of cold sensitivity are dependent on TRPM8, both short term and in response to peripheral nerve injury. The specialized nature of cold-sensitive afferents and the restricted expression of TRPM8 render it an attractive target for the treatment of cold hypersensitivity. This current study examines the effect of a novel TRPM8 antagonist (M8-An) in naive and spinal nerve-ligated rats through behavioral and in vivo electrophysiological approaches. In vitro, M8-An inhibited icilin-evoked Ca(2+) currents in HEK293 cells stably expressing human TRPM8 with an IC(50) of 10.9 nM. In vivo, systemic M8-An transiently decreased core body temperature. Deep dorsal horn recordings were made in vivo from neurons innervating the hind paw. M8-An inhibited neuronal responses to innocuous and noxious cooling of the receptive field in spinal nerve-ligated rats but not in naive rats. No effect on neuronal responses to mechanical and heat stimulation was observed. In addition, M8-An also attenuated behavioral responses to cold but not mechanical stimulation after nerve ligation without affecting the uninjured contralateral response. The data presented here support a contribution of TRPM8 to the pathophysiology of cold hypersensitivity in this model and highlight the potential of the pharmacological block of TRPM8 in alleviating the associated symptoms.
Assuntos
Síndromes Periódicas Associadas à Criopirina/prevenção & controle , Ácidos Nicotínicos/uso terapêutico , Traumatismos dos Nervos Periféricos/complicações , Canais de Cátion TRPM/antagonistas & inibidores , Animais , Comportamento Animal/efeitos dos fármacos , Cálcio/metabolismo , Síndromes Periódicas Associadas à Criopirina/etiologia , Síndromes Periódicas Associadas à Criopirina/metabolismo , Modelos Animais de Doenças , Fenômenos Eletrofisiológicos , Células HEK293 , Humanos , Masculino , Ácidos Nicotínicos/administração & dosagem , Ácidos Nicotínicos/farmacologia , Traumatismos dos Nervos Periféricos/metabolismo , Traumatismos dos Nervos Periféricos/psicologia , Ratos , Ratos Sprague-DawleyRESUMO
Platinum-based chemotherapy remains one of the major choices for treatment of ovarian cancer (OC). However, primary or acquired drug resistance severely impairs their efficiency, thereby causing chemotherapy failure and poor prognosis. SH3 domain containing ring finger 2 (SH3RF2) has been linked to the development of cancer. Here we find higher levels of SH3RF2 in the tumor tissues from cisplatin-resistant OC patients when compared to those from cisplatin-sensitive patients. Similarly, cisplatin-resistant OC cells also express higher levels of SH3RF2 than normal OC cells. Through in vitro and in vivo loss-of-function experiments, SH3RF2 is identified as a driver of cisplatin resistance, as evidenced by increases in cisplatin-induced cell apoptosis and DNA damage and decreases in cell proliferation induced by SH3RF2 depletion. Mechanistically, SH3RF2 can directly bind to the RNA-binding protein mRNA processing factor (RBPMS). RBPMS has been reported as an inhibitor of cisplatin resistance in OC. As a E3 ligase, SH3RF2 promotes the K48-linked ubiquitination of RBPMS to increase its proteasomal degradation and activator protein 1 (AP-1) transactivation. Impairments in RBPMS function reverse the inhibitory effect of SH3RF2 depletion on cisplatin resistance. Collectively, the SH3RF2-RBPMS-AP-1 axis is an important regulator in cisplatin resistance and inhibition of SH3RF2 may be a potential target in preventing cisplatin resistance.
Assuntos
Cisplatino , Neoplasias Ovarianas , Humanos , Feminino , Cisplatino/farmacologia , Fator de Transcrição AP-1 , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/genética , Platina , Proteínas de Ligação a RNA/genética , Proteínas de Transporte , Proteínas OncogênicasRESUMO
Tuberculosis (TB) remains one of the major infectious diseases in the world with a high incidence rate. Drug-resistant tuberculosis (DR-TB) is a key and difficult challenge in the prevention and treatment of TB. Early, rapid, and accurate diagnosis of DR-TB is essential for selecting appropriate and personalized treatment and is an important means of reducing disease transmission and mortality. In recent years, imaging diagnosis of DR-TB has developed rapidly, but there is a lack of consistent understanding. To this end, the Infectious Disease Imaging Group, Infectious Disease Branch, Chinese Research Hospital Association; Infectious Diseases Group of Chinese Medical Association of Radiology; Digital Health Committee of China Association for the Promotion of Science and Technology Industrialization, and other organizations, formed a group of TB experts across China. The conglomerate then considered the Chinese and international diagnosis and treatment status of DR-TB, China's clinical practice, and evidence-based medicine on the methodological requirements of guidelines and standards. After repeated discussion, the expert consensus of imaging diagnosis of DR-PB was proposed. This consensus includes clinical diagnosis and classification of DR-TB, selection of etiology and imaging examination [mainly X-ray and computed tomography (CT)], imaging manifestations, diagnosis, and differential diagnosis. This expert consensus is expected to improve the understanding of the imaging changes of DR-TB, as a starting point for timely detection of suspected DR-TB patients, and can effectively improve the efficiency of clinical diagnosis and achieve the purpose of early diagnosis and treatment of DR-TB.
RESUMO
The envelope (E) protein from coronaviruses is a small polypeptide that contains at least one alpha-helical transmembrane domain. Absence, or inactivation, of E protein results in attenuated viruses, due to alterations in either virion morphology or tropism. Apart from its morphogenetic properties, protein E has been reported to have membrane permeabilizing activity. Further, the drug hexamethylene amiloride (HMA), but not amiloride, inhibited in vitro ion channel activity of some synthetic coronavirus E proteins, and also viral replication. We have previously shown for the coronavirus species responsible for severe acute respiratory syndrome (SARS-CoV) that the transmembrane domain of E protein (ETM) forms pentameric alpha-helical bundles that are likely responsible for the observed channel activity. Herein, using solution NMR in dodecylphosphatidylcholine micelles and energy minimization, we have obtained a model of this channel which features regular alpha-helices that form a pentameric left-handed parallel bundle. The drug HMA was found to bind inside the lumen of the channel, at both the C-terminal and the N-terminal openings, and, in contrast to amiloride, induced additional chemical shifts in ETM. Full length SARS-CoV E displayed channel activity when transiently expressed in human embryonic kidney 293 (HEK-293) cells in a whole-cell patch clamp set-up. This activity was significantly reduced by hexamethylene amiloride (HMA), but not by amiloride. The channel structure presented herein provides a possible rationale for inhibition, and a platform for future structure-based drug design of this potential pharmacological target.
Assuntos
Canais Iônicos/antagonistas & inibidores , Canais Iônicos/química , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/química , Proteínas do Envelope Viral/antagonistas & inibidores , Proteínas do Envelope Viral/química , Amilorida/análogos & derivados , Amilorida/metabolismo , Amilorida/farmacologia , Linhagem Celular , Humanos , Canais Iônicos/metabolismo , Modelos Moleculares , Ressonância Magnética Nuclear Biomolecular , Técnicas de Patch-Clamp , Ligação Proteica , Conformação Proteica , Estabilidade Proteica , Estrutura Terciária de Proteína , Reprodutibilidade dos Testes , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/metabolismo , Proteínas do Envelope Viral/metabolismoRESUMO
Cav1.2 L-type calcium channels are essential in heart and smooth muscle contraction. Rat Cav1.2 gene contains 11 alternatively spliced exons (1a, 1, 8a, 8, 9*, 21, 22, 31, 32, 32-6nt and 33) which can be assorted to generate a large number of functionally distinct splice variants. Until now, it is unknown whether the utilization of these alternatively spliced exons is altered in the hypertrophied hearts of hypertensive rats. By comparing the assortments of these 11 exons in full-length Cav1.2 transcripts derived from Spontaneously Hypertensive Rats (SHRs) and Wistar Kyoto Rats (WKYs) hearts, we found that the inclusion of Cav1.2 alternative exons was significantly different between the two rats both at individual loci and in combinatorial arrangements. Functional characterizations of three Cav1.2 channel splice variants that were identified to be significantly altered in SHR hypertrophied cardiomyocytes demonstrated distinct whole-cell electrophysiological properties when expressed in HEK 293 cells. Interestingly, aberrant splice variants which included or excluded both mutually exclusive exons 21/22 or exons 31/32 were found to be increased in hypertensive rats. Two aberrant splice variants that included both exons 21 and 22 were found to be unable to conduct currents even though they expressed proteins with the predicted molecular mass. Characterization of one of the aberrant splice variants showed that it exerted a dominant negative effect on the functional Cav1.2 channels when co-expressed in HEK293 cells. The altered combinatorial splicing profiles of Cav1.2 transcripts identified in SHR hearts provide a different and new perspective in understanding the possible role of molecular remodeling of Cav1.2 channels in cardiac hypertrophy as a consequence of hypertension.
Assuntos
Canais de Cálcio Tipo L/genética , Canais de Cálcio Tipo L/metabolismo , Miocárdio/metabolismo , Splicing de RNA/genética , Animais , Pressão Sanguínea , Linhagem Celular , DNA Complementar/genética , Eletrofisiologia , Éxons/genética , Regulação da Expressão Gênica , Humanos , Hipertensão/genética , Hipertensão/metabolismo , Hipertensão/fisiopatologia , Tamanho do Órgão , Técnicas de Patch-Clamp , Subunidades Proteicas/genética , Subunidades Proteicas/metabolismo , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY , Transcrição Gênica/genéticaRESUMO
BACKGROUND: Surgical-site infections after primary total joint arthroplasty (TJA) are a significant issue. Antibiotic-impregnated bone cement (AIBC) has been widely used for the treatment of infected joints, but routine use of AIBC in primary TJA remains controversial. In this systematic review, we evaluated the efficacy of AIBC in reducing surgical-site infections after primary TJA. METHODS: We systematically searched Pubmed, EMbase, Cochrane Library, CMB, CNKI, and WanFang Data for studies (published until June 1, 2019) evaluating AIBC use in reducing infection rates. Two reviewers independently screened the literature according to inclusion and exclusion criteria, extracted data, and assessed the methodological quality of included studies. Meta-analysis was performed using Review Manager 5.3 software. The registration number is CRD42017078341 in PROSPERO. RESULTS: In total, 10 studies were included, resulting in a sample size of 13,909 arthroplasty cases. The overall pooled data demonstrated that, compared with systemic antibiotics, AIBC was more effective in decreasing deep infection rates (odds ratio [OR]â=â0.35, 95% confidence interval [CI]â=â0.14-0.89, Pâ=â.030), although there were higher superficial infection rates with AIBC (ORâ=â1.53, 95% CIâ=â1.11-2.11, Pâ=â.010). Compared to systemic antibiotics alone, AIBC with systemic antibiotics significantly decreased deep infection rates (ORâ=â0.55, 95% CIâ=â0.41-0.75, Pâ=â.0001) but there was no difference in superficial infection rates (ORâ=â1.43, 95% CIâ=â0.81-2.54, Pâ=â.220). In the subgroup analysis, both randomized controlled trials and cohort studies had reduced deep infection rates after primary TJA (ORâ=â0.61, 95% CIâ=â0.37-0.99, Pâ=â.050 and ORâ=â0.49, 95% CIâ=â0.34-0.70, Pâ=â.0001, respectively). AIBC decreased deep infection rates in both total hip and knee arthroplasty (ORâ=â0.25, 95% CIâ=â0.12-0.52, Pâ=â.0002 and ORâ=â0.62, 95% CIâ=â0.45-0.87, Pâ=â.005, respectively). Deep infection rates were significantly decreased by AIBC with gentamicin (ORâ=â0.31, 95% CIâ=â0.20-0.49, Pâ<â.00001) but unaffected by AIBC with cefuroxime (ORâ=â0.35, 95% CIâ=â0.10-1.20, Pâ=â.100). Deep infection rates in the AIBC and control groups were similar when laminar airflow was applied to the operating room (ORâ=â0.90, 95% CIâ=â0.60-1.35, Pâ=â.620); however, without laminar airflow, the efficacy of AIBC in decreasing deep infection rates was significantly higher than that of control group (ORâ=â0.21, 95% CIâ=â0.08-0.59, Pâ=â.003). CONCLUSIONS: AIBC may significantly decrease deep infection rates after primary total hip and knee arthroplasty, with or without systemic antibiotics.
Assuntos
Antibacterianos/administração & dosagem , Antibioticoprofilaxia/métodos , Artroplastia de Quadril/métodos , Artroplastia do Joelho/métodos , Cimentos Ósseos/química , Infecções Relacionadas à Prótese/prevenção & controle , Administração Oral , Antibacterianos/uso terapêutico , Humanos , Razão de Chances , Infecção da Ferida Cirúrgica/prevenção & controleRESUMO
PURPOSE: We sought to investigate the anticonvulsive and neuroprotective effect of a selective metabotropic glutamate receptor 8 (mGluR8) agonist (S)-3,4-dicarboxyphenylglycines (S-3,4-DCPG) on pilocarpine-induced status epilepticus (PISE) and subsequent loss of hilar neurons in the dentate gyrus after systemic (intravenous) or local (intracerebroventricular) administration. We compared the difference in granular cell responses after paired-pulse stimulation of the perforant pathway and the sensitivity to local injection of S-3,4-DCPG into the stratum granulosum in the control and mice at 2 months after PISE. METHODS: We used intravenous, intracerebroventricular, or intrahippocampal administration of S-3,4-DCPG to mice with status epilepticus or temporal lobe epilepsy and neurophysiologic recording of somatic field excitatory postsynaptic potential (sfEPSP) and population spike (PS) of granular cells in response to perforant-pathway stimulation or S-3,4-DCPG treatment. RESULTS: Intracerebroventricular (1.91 micromol) but not systemic administration of S-3,4-DCPG (at doses of 12.5, 50, 100, 200, 400, 800, and 1,200 mg/kg) could control PISE with no neuroprotective effect. In epileptic mice, mGluR8-mediated inhibition of fEPSPs was reduced significantly in granular cell bodies. CONCLUSIONS: At doses ranging from 12.5 to 1,200 mg/kg, intravenous administration of S-3,4-DCPG may not be effective in controlling status epilepticus. Down-regulation of mGluR8 may be related to reduced S-3,4-DCPG-mediated inhibition and the subsequent occurrence of spontaneously recurrent seizures.
Assuntos
Anticonvulsivantes/farmacologia , Benzoatos/farmacologia , Glicina/análogos & derivados , Receptores de Glutamato Metabotrópico/agonistas , Estado Epiléptico/induzido quimicamente , Estado Epiléptico/prevenção & controle , Animais , Anticonvulsivantes/administração & dosagem , Giro Denteado/efeitos dos fármacos , Giro Denteado/patologia , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Estimulação Elétrica , Epilepsia do Lobo Temporal/patologia , Epilepsia do Lobo Temporal/prevenção & controle , Potenciais Pós-Sinápticos Excitadores/efeitos dos fármacos , Potenciais Pós-Sinápticos Excitadores/fisiologia , Glicina/farmacologia , Hipocampo/efeitos dos fármacos , Hipocampo/patologia , Injeções Intravenosas , Injeções Intraventriculares , Camundongos , Inibição Neural/efeitos dos fármacos , Inibição Neural/fisiologia , Neurônios/efeitos dos fármacos , Neurônios/patologia , Via Perfurante/efeitos dos fármacos , Via Perfurante/fisiologia , Pilocarpina , Estado Epiléptico/patologiaRESUMO
We showed that when CA3 pyramidal neurons in the caudal 80% of the dorsal hippocampus had almost disappeared completely, the efferent pathway of CA3 was rarely detectable. We used the mouse pilocarpine model of temporal lobe epilepsy (TLE), and injected iontophoretically the anterograde tracer phaseolus vulgaris leucoagglutinin (PHA-L) into gliotic CA3, medial septum and the nucleus of diagonal band of Broca, median raphe, and lateral supramammillary nuclei, or the retrograde tracer cholera toxin B subunit (CTB) into gliotic CA3 area of hippocampus. In the afferent pathway, the number of neurons projecting to CA3 from medial septum and the nucleus of diagonal band of Broca, median raphe, and lateral supramammillary nuclei increased significantly. In the hippocampus, where CA3 pyramidal neurons were partially lost, calbindin, calretinin, parvalbumin immunopositive back-projection neurons from CA1-CA3 area were observed. Sprouting of Schaffer collaterals with increased number of large boutons in both sides of CA1 area, particularly in the stratum pyramidale, was found. When CA3 pyramidal neurons in caudal 80% of the dorsal hippocampus have almost disappeared completely, surviving CA3 neurons in the rostral 20% of the dorsal hippocampus may play an important role in transmitting hyperactivity of granule cells to surviving CA1 neurons or to dorsal part of the lateral septum. We concluded that reorganization of CA3 area with its downstream or upstream nuclei may be involved in the occurrence of epilepsy.