RESUMEN
Autosomal dominant polycystic kidney disease is caused by mutations in the membrane receptor PKD1 or the cation channel PKD2. TACAN (also termed TMEM120A), recently reported as an ion channel in neurons for mechanosensing and pain sensing, is also distributed in diverse non-neuronal tissues, such as kidney, heart and intestine, suggesting its involvement in other functions. In this study, we found that TACAN is in a complex with PKD2 in native renal cell lines. Using the two-electrode voltage clamp in Xenopus oocytes, we found that TACAN inhibits the channel activity of PKD2 gain-of-function mutant F604P. TACAN fragments containing the first and last transmembrane domains interacted with the PKD2 C- and N-terminal fragments, respectively. The TACAN N-terminus acted as a blocking peptide, and TACAN inhibited the function of PKD2 by the binding of PKD2 with TACAN. By patch clamping in mammalian cells, we found that TACAN inhibits both the single-channel conductance and the open probability of PKD2 and mutant F604P. PKD2 co-expressed with TACAN, but not PKD2 alone, exhibited pressure sensitivity. Furthermore, we found that TACAN aggravates PKD2-dependent tail curvature and pronephric cysts in larval zebrafish. In summary, this study revealed that TACAN acts as a PKD2 inhibitor and mediates mechanosensitivity of the PKD2-TACAN channel complex. KEY POINTS: TACAN inhibits the function of PKD2 in vitro and in vivo. TACAN N-terminal S1-containing fragment T160X interacts with the PKD2 C-terminal fragment N580-L700, and its C-terminal S6-containing fragment L296-D343 interacts with the PKD2 N-terminal A594X. TACAN inhibits the function of the PKD2 channel by physical interaction. The complex of PKD2 with TACAN, but not PKD2 alone, confers mechanosensitivity.
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Riñón Poliquístico Autosómico Dominante , Pez Cebra , Animales , Canales Catiónicos TRPP/genética , Canales Catiónicos TRPP/metabolismo , Canales Iónicos/genética , Riñón Poliquístico Autosómico Dominante/genética , Riñón Poliquístico Autosómico Dominante/metabolismo , Riñón/metabolismo , Mamíferos/metabolismoRESUMEN
BACKGROUND: Most commonly, cyst excision and Roux-en-Y hepaticojejunostomy reconstruction are the optimal treatment for choledochal cysts (CC). Robotic surgery (RS) is being conducted with increasing frequency to treat CC. It is unclear whether RS can overcome the limitations of laparoscopic surgery (LS) and improve the prognosis of patients. In terms of efficacy, evidence concerning which minimally invasive surgery is preferred is, however, sparse. Our objective is to further compare the efficacy of RS and LS in children with CC and draw a useful clinical conclusion. METHODS: Studies meeting inclusion criteria were identified from a series of databases, consisting of PubMed, Embase, Scopus, Web of Science, the Cochrane Library and their reference list of articles up to May 2022. Eligible articles comprised at least five objects that were younger than 18 years of age and the language was limited to English. Two authors independently evaluated selected studies and extracted data for analysis. RESULTS: Forty studies were selected for analysis, with thirty-six reporting data on LS and eight containing data on RS. The pooled conversion rate and pooled postoperative complication rate of RS were lower than those of LS, but none of them was statistically significant. Moreover, comparisons of the following detailed postoperative complication rates were not statistically significant, such as intestinal obstruction or ileus, anastomotic bleeding, anastomotic or bile leakage, and anastomotic stenosis. However, the intraoperative blood loss and the postoperative hospital stay in RS group were significantly lower than those in LS group. CONCLUSIONS: RS is a safe and feasible option for children with CC. Further studies with more cases, long-term efficacy and health economics analysis are needed to confirm whether RS is more advantageous.
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Quiste del Colédoco , Obstrucción Intestinal , Laparoscopía , Procedimientos Quirúrgicos Robotizados , Niño , Humanos , Anastomosis en-Y de Roux , Quiste del Colédoco/cirugía , Obstrucción Intestinal/cirugía , Laparoscopía/efectos adversos , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/cirugía , Estudios Retrospectivos , Procedimientos Quirúrgicos Robotizados/efectos adversos , Resultado del TratamientoRESUMEN
BACKGROUND: Robotic-assisted surgery (RAS) is being increasingly used in pediatric choledochal cysts (CCs), but is most commonly performed in older children and adolescents. The outcomes in young infants remain to be explored. The purpose of this study is to compare outcomes in infants aged ≤ 1 year with an older cohort. METHODS: From July 2015 to January 2020, a retrospective study was conducted to evaluate the RAS in patients with CCs at our institution. Patients were divided into two groups (group A ≤ 1 year old and group B > 1 year old). Demographics, intraoperative details, complications, and outcomes were analyzed. RESULTS: A total of 79 patients were included in the study (28 patients in group A and 51patients in group B). The median age of patients at the surgery in group A was 4.9 months (IQR: 3.1-9.1), compared with 46.8 months (IQR: 28.5-86.5) in group B. Three patients in group A were neonates. No conversion to open surgery was required. No significant differences were found between the two groups including sex, Todani type, or diameter of the cysts. The diameter of the common hepatic duct was smaller in group A (6.0 ± 1.7 vs. 9.0 ± 3.0 mm; p < 0.001). Group A had the longer hepaticojejunostomy time [51(44-58) vs. 42(38-53) min; p = 0.013], while Group B had the longer cyst excision time [43(41-59) vs. 50(43-60) min; p = 0.005]. However, their total operative time and console time were similar. There were no statistical differences in length of hospital stay and complications between the two groups. CONCLUSIONS: Robot-assisted cyst resection and hepaticojejunostomy are feasible and safe in infants ≤ 1 year old. Age cannot be considered an absolute contraindication for robotic surgery in patients with CCs.
Asunto(s)
Quiste del Colédoco , Laparoscopía , Procedimientos Quirúrgicos Robotizados , Lactante , Recién Nacido , Adolescente , Niño , Humanos , Quiste del Colédoco/cirugía , Estudios Retrospectivos , Anastomosis en-Y de Roux/efectos adversos , Hígado/cirugía , Resultado del TratamientoRESUMEN
PURPOSE: There are only a few case reports of laparoscopic lateral duodenojejunostomy (LLDJ) in children with Wilkie's syndrome, also known as superior mesenteric artery compression syndrome (SMAS). We aimed to describe our laparoscopic technique and evaluate its outcomes for SMAS in children. METHODS: From January 2013 to May 2021, SMAS children who received LLDJ were included. The procedure was carried out utilizing the four-trocar technique. The elevation of the transverse colon allows good exposure of the dilated and bulging second and third sections of the duodenum. Using a linear stapler, we established a lateral anastomosis connecting the proximal jejunum with the third part of the duodenum. Following that, a running suture was used to intracorporeally close the common enterotomy. Clinical data on patients was collected for analysis. The demographics, diagnostic findings, and postoperative outcomes were analyzed retrospectively. RESULTS: We retrospectively analyzed 9 SMAS patients (6 females and 3 males) who underwent LLDJ, aged between 7 and 17 years old. The mean operative time was 118.4 ± 16.5 min and the mean estimated blood loss was 5.6 ± 1.4 ml. There were no conversion, intraoperative complications or immediate postoperative complications. The mean postoperative hospital stay was 6.8 ± 1.9 days and the mean follow-up time was 5.4 ± 3.0 years. During follow-up, seven patients (77.8%) experienced complete recovery of symptoms prior to surgery. One patient (11.1%) still had mild vomiting, which resolved with medication. Another patient (11.1%) developed psychological-induced nausea, which significantly improved after treatment with education, training and diet management. CONCLUSIONS: LLDJ represents a feasible and safe treatment option for SMAS in well-selected children. Further evaluation with more cases and case-control studies is required for the real benefits.
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Laparoscopía , Síndrome de la Arteria Mesentérica Superior , Masculino , Femenino , Humanos , Niño , Adolescente , Estudios Retrospectivos , Arteria Mesentérica Superior/cirugía , Síndrome de la Arteria Mesentérica Superior/cirugía , Síndrome de la Arteria Mesentérica Superior/diagnóstico , Laparoscopía/métodos , Anastomosis Quirúrgica/métodosRESUMEN
Cellulosic ethanol is regarded as a perfect additive for petrol fuels for global carbon neutralization. As bioethanol conversion requires strong biomass pretreatment and overpriced enzymatic hydrolysis, it is increasingly considered in the exploration of biomass processes with fewer chemicals for cost-effective biofuels and value-added bioproducts. In this study, we performed optimal liquid-hot-water pretreatment (190 °C for 10 min) co-supplied with 4% FeCl3 to achieve the near-complete biomass enzymatic saccharification of desirable corn stalk for high bioethanol production, and all the enzyme-undigestible lignocellulose residues were then examined as active biosorbents for high Cd adsorption. Furthermore, by incubating Trichoderma reesei with the desired corn stalk co-supplied with 0.05% FeCl3 for the secretion of lignocellulose-degradation enzymes in vivo, we examined five secreted enzyme activities elevated by 1.3-3.0-fold in vitro, compared to the control without FeCl3 supplementation. After further supplying 1:2 (w/w) FeCl3 into the T. reesei-undigested lignocellulose residue for the thermal-carbonization process, we generated highly porous carbon with specific electroconductivity raised by 3-12-fold for the supercapacitor. Therefore, this work demonstrates that FeCl3 can act as a universal catalyst for the full-chain enhancement of biological, biochemical, and chemical conversions of lignocellulose substrates, providing a green-like strategy for low-cost biofuels and high-value bioproducts.
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Celulasa , Celulasa/metabolismo , Zea mays/química , Etanol/metabolismo , Biocombustibles , Lignina/metabolismo , Carbono , Hidrólisis , Biomasa , FermentaciónRESUMEN
Fast excitatory synaptic transmission in the CNS is mediated by the neurotransmitter glutamate, binding to and activating AMPA receptors (AMPARs). AMPARs are known to interact with auxiliary proteins that modulate their behavior. One such family of proteins is the transmembrane AMPAR-related proteins, known as TARPs. Little is known about the role of TARPs during development or about their function in nonmammalian organisms. Here, we report on the presence of TARP γ-4 in developing zebrafish. We find that zebrafish express 2 forms of TARP γ-4: γ-4a and γ-4b as early as 12 h post-fertilization. Sequence analysis shows that both γ-4a and γ-4b shows great level of variation particularly in the intracellular C-terminal domain compared to rat, mouse, and human γ-4. RT-qPCR showed a gradual increase in the expression of γ-4a throughout the first 5 days of development, whereas γ-4b levels were constant until day 5 when levels increased significantly. Knockdown of TARP γ-4a and γ-4b via either splice-blocking morpholinos or translation-blocking morpholinos resulted in embryos that exhibited deficits in C-start escape responses, showing reduced C-bend angles. Morphant larvae displayed reduced bouts of swimming. Whole-cell patch-clamp recordings of AMPAR-mediated currents from Mauthner cells showed a reduction in the frequency of mEPCs but no change in amplitude or kinetics. Together, these results suggest that γ-4a and γ-4b are required for proper neuronal development.
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Proteínas de la Membrana , Receptores AMPA , Transmisión Sináptica , Proteínas de Pez Cebra , Pez Cebra , Animales , Proteínas de la Membrana/metabolismo , Morfolinos , Proteínas Nucleares/metabolismo , Receptores AMPA/química , Receptores AMPA/metabolismo , Transmisión Sináptica/fisiología , Pez Cebra/embriología , Pez Cebra/metabolismo , Proteínas de Pez Cebra/metabolismoRESUMEN
Transient receptor potential melastatin member 8 (TRPM8), a Ca2+ -permeable nonselective cation channel activated by cold and cooling agents, mediates allodynia. Dysfunction or abnormal expression of TRPM8 has been found in several human cancers. The role of ubiquitination in the regulation of TRPM8 function remains poorly understood. Here, we identified the ubiquitin (Ub)-ligase E3, tripartite motif-containing 4 (TRIM4), as a novel interaction partner of TRPM8 and confirmed that the TRIM4-TRPM8 interaction was mediated through the SPRY domain of TRIM4. Patch-clamp assays showed that TRIM4 negatively regulates TRPM8-mediated currents in HEK293 cells. Moreover, TRIM4 reduced the expression of TRPM8 on the cell surface by promoting the K63-linked ubiquitination of TRPM8. Further analyses revealed that the TRPM8 N-terminal lysine residue at 423 was the major ubiquitination site that mediates its functional regulation by TRIM4. A Ub-activating enzyme E1, Ub-like modifier-activating enzyme 1 (UBA1), was also found to interact with TRPM8, thereby regulating its channel function and ubiquitination. In addition, knockdown of UBA1 impaired the regulation of TRPM8 ubiquitination and function by TRIM4. Thus, this study demonstrates that TRIM4 downregulates TRPM8 via K423-mediated TRPM8 ubiquitination and requires UBA1 to regulate TRPM8.
Asunto(s)
Lisina/metabolismo , Canales Catiónicos TRPM/metabolismo , Proteínas de Motivos Tripartitos/metabolismo , Ubiquitinación , Secuencia de Aminoácidos , Animales , Células HEK293 , Humanos , Células MCF-7 , Unión Proteica , Dominios Proteicos , Ratas , Eliminación de Secuencia , Proteínas de Motivos Tripartitos/química , Enzimas Activadoras de Ubiquitina/química , Enzimas Activadoras de Ubiquitina/metabolismoRESUMEN
We previously showed that calnexin (Canx)-deficient mice are desensitized to experimental autoimmune encephalomyelitis (EAE) induction, a model that is frequently used to study inflammatory demyelinating diseases, due to increased resistance of the blood-brain barrier to immune cell transmigration. We also discovered that Fabp5, an abundant cytoplasmic lipid-binding protein found in brain endothelial cells, makes protein-protein contact with the cytoplasmic C-tail domain of Canx. Remarkably, both Canx-deficient and Fabp5-deficient mice commonly manifest resistance to EAE induction. Here, we evaluated the importance of Fabp5/Canx interactions on EAE pathogenesis and on the patency of a model blood-brain barrier to T-cell transcellular migration. The results demonstrate that formation of a complex comprised of Fabp5 and the C-tail domain of Canx dictates the permeability of the model blood-brain barrier to immune cells and is also a prerequisite for EAE pathogenesis.
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Calnexina/metabolismo , Encefalomielitis Autoinmune Experimental/metabolismo , Proteínas de Unión a Ácidos Grasos/metabolismo , Proteínas de Neoplasias/metabolismo , Animales , Transporte Biológico/fisiología , Barrera Hematoencefálica/metabolismo , Encéfalo/metabolismo , Línea Celular , Movimiento Celular/fisiología , Modelos Animales de Enfermedad , Células Endoteliales/metabolismo , Femenino , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , PermeabilidadRESUMEN
BACKGROUND: Pancreatic cancer is one of the most lethal malignancies and has an extremely poor diagnosis and prognosis. The development of resistance to gemcitabine is still a major challenge. The long noncoding RNA PVT1 was reported to be involved in carcinogenesis and chemoresistance; however, the mechanism by which PVT1 regulates the sensitivity of pancreatic cancer to gemcitabine remains poorly understood. METHODS: The viability of pancreatic cancer cells was assessed by MTT assay in vitro and xenograft tumor formation assay in vivo. The expression levels of PVT1 and miR-619-5p were detected by quantitative real-time polymerase chain reaction (qRT-PCR). Western blotting analysis and qRT-PCR were performed to assess the protein and mRNA levels of Pygo2 and ATG14, respectively. Autophagy was explored via autophagic flux detection under confocal microscopy and autophagic vacuole investigation under transmission electron microscopy (TEM). The functional role and mechanism of PVT1 were further investigated by gain- and loss-of-function assays in vitro. RESULTS: In the present study, we demonstrated that PVT1 was up-regulated in gemcitabine-resistant pancreatic cancer cell lines. Gain- and loss-of-function assays revealed that PVT1 impaired sensitivity to gemcitabine in vitro and in vivo. We further found that PVT1 up-regulated the expression of both Pygo2 and ATG14 and thus regulated Wnt/ß-catenin signaling and autophagic activity to overcome gemcitabine resistance through sponging miR-619-5p. Moreover, we discovered three TCF/LEF binding elements (TBEs) in the promoter region of PVT1, and activation of Wnt/ß-catenin signaling mediated by the up-regulation of Pygo2 increased PVT1 expression by direct binding to the TBE region. Furthermore, PVT1 was discovered to interact with ATG14, thus promoting assembly of the autophagy specific complex I (PtdIns3K-C1) and ATG14-dependent class III PtdIns3K activity. CONCLUSIONS: These data indicate that PVT1 plays a critical role in the sensitivity of pancreatic cancer to gemcitabine and highlight its potential as a valuable target for pancreatic cancer therapy.
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Proteínas Adaptadoras del Transporte Vesicular/genética , Proteínas Relacionadas con la Autofagia/genética , Autofagia/genética , Resistencia a Antineoplásicos/genética , Péptidos y Proteínas de Señalización Intracelular/genética , MicroARNs/genética , Neoplasias Pancreáticas/genética , ARN Largo no Codificante/genética , Vía de Señalización Wnt , Animales , Sitios de Unión , Línea Celular Tumoral , Proliferación Celular , Supervivencia Celular/genética , Desoxicitidina/análogos & derivados , Desoxicitidina/farmacología , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Regulación Neoplásica de la Expresión Génica , Humanos , Ratones , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patología , Unión Proteica , Interferencia de ARN , Ensayos Antitumor por Modelo de Xenoinjerto , GemcitabinaRESUMEN
The endoplasmic reticulum (ER) plays a central role in cellular stress responses via mobilization of ER stress coping responses, such as the unfolded protein response (UPR). The inositol-requiring 1α (IRE1α) is an ER stress sensor and component of the UPR. Muscle cells also have a well-developed and highly subspecialized membrane network of smooth ER called the sarcoplasmic reticulum (SR) surrounding myofibrils and specialized for Ca2+ storage, release, and uptake to control muscle excitation-contraction coupling. Here, we describe 2 distinct pools of IRE1α in cardiac and skeletal muscle cells, one localized at the perinuclear ER and the other at the junctional SR. We discovered that, at the junctional SR, calsequestrin binds to the ER luminal domain of IRE1α, inhibiting its dimerization. This novel interaction of IRE1α with calsequestrin, one of the highly abundant Ca2+ handling proteins at the junctional SR, provides new insights into the regulation of stress coping responses in muscle cells.-Wang, Q., Groenendyk, J., Paskevicius, T., Qin, W., Kor, K. C., Liu, Y., Hiess, F., Knollmann, B. C., Chen, S. R. W., Tang, J., Chen, X.-Z., Agellon, L. B., Michalak, M. Two pools of IRE1α in cardiac and skeletal muscle cells.
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Endorribonucleasas/metabolismo , Fibras Musculares Esqueléticas/metabolismo , Miocitos Cardíacos/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Animales , Sitios de Unión , Células COS , Señalización del Calcio , Calsecuestrina/metabolismo , Células Cultivadas , Chlorocebus aethiops , Endorribonucleasas/química , Ratones , Unión Proteica , Proteínas Serina-Treonina Quinasas/química , Conejos , Retículo Sarcoplasmático/metabolismoRESUMEN
Transient receptor potential (TRP) channels, subdivided into 6 subfamilies in mammals, have essential roles in sensory physiology. They respond to remarkably diverse stimuli, comprising thermal, chemical, and mechanical modalities, through opening or closing of channel gates. In this study, we systematically substituted the hydrophobic residues within the distal fragment of pore-lining helix S6 with hydrophilic residues and, based on Xenopus oocyte and mammalian cell electrophysiology and a hydrophobic gate theory, identified hydrophobic gates in TRPV6/V5/V4/C4/M8. We found that channel activity drastically increased when TRPV6Ala616 or Met617 or TRPV5Ala576 or Met577, but not any of their adjacent residues, was substituted with hydrophilic residues. Channel activity strongly correlated with the hydrophilicity of the residues at those sites, suggesting that consecutive hydrophobic residues TRPV6Ala616-Met617 and TRPV5Ala576-Met577 form a double-residue gate in each channel. By the same strategy, we identified a hydrophobic single-residue gate in TRPV4Iso715, TRPC4Iso617, and TRPM8Val976. In support of the hydrophobic gate theory, hydrophilic substitution at the gate site, which removes the hydrophobic gate seal, substantially increased the activity of TRP channels in low-activity states but had little effect on the function of activated channels. The double-residue gate channels were more sensitive to small changes in the gate's hydrophobicity or size than single-residue gate channels. The unconventional double-reside gating mechanism in TRP channels may have been evolved to respond especially to physiologic stimuli that trigger relatively small gate conformational changes.-Zheng, W., Hu, R., Cai, R., Hofmann, L., Hu, Q., Fatehi, M., Long, W., Kong, T., Tang, J., Light, P., Flockerzi, V., Cao, Y., Chen, X.-Z. Identification and characterization of hydrophobic gate residues in TRP channels.
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Activación del Canal Iónico , Modelos Moleculares , Canales de Potencial de Receptor Transitorio/química , Canales de Potencial de Receptor Transitorio/metabolismo , Animales , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Canales de Potencial de Receptor Transitorio/genética , Xenopus laevisRESUMEN
BACKGROUND: Breast cancer is a life-threatening disease in females and the leading cause of mortality among the female population, presenting huge challenges for prognosis and treatment. ITM2A is a member of the BRICHOS superfamily, which are thought to have a chaperone function. ITM2A has been identified to related to ovarian cancer progress recently. However, the biological role of ITM2A in breast cancer remains largely unclear. METHODS: Quantitative real-time polymerase chain reaction (qRT-PCR), western blotting assay and immunohistochemistry staining were used to analyzed the expression level of ITM2A. The patient overall survival versus ITM2A expression level was evaluated by Kaplan-Meier analysis. MTT assay, EdU incorporation assay and colony formation assay were used to evaluated the role of ITM2A on breast cancer cell proliferation. Autophagy was explored through autophagic flux detection using a confocal microscope and autophagic vacuoles investigation under a transmission electron microscopy (TEM). In vitro kinase assay was used to investigated the phosphorylation modification of ITM2A by HUNK. RESULTS: Our data showed that the expression of integral membrane protein 2A (ITM2A) was significantly down-regulated in human breast cancer tissues and cell lines. Kaplan-Meier analysis indicated that patients presenting with reduced ITM2A expression exhibited poor overall survival, and expression significantly correlated with age, progesterone receptor status, TNM classification and tumor stage. ITM2A overexpression significantly inhibited the proliferation of breast cancer cells. By studying several autophagic markers and events in human breast cancer SKBR-3 cells, we further demonstrated that ITM2A is a novel positive regulator of autophagy through an mTOR-dependent manner. Moreover, we found that ITM2A was phosphorylated at T35 by HUNK, a serine/threonine kinase significantly correlated with human breast cancer overall survival and HER2-induced mammary tumorigenesis. CONCLUSION: Our study provided evidence that ITM2A functions as a novel prognostic marker and represents a potential therapeutic target.
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Apoptosis , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Proteínas de la Membrana/metabolismo , Proliferación Celular , Células Cultivadas , Femenino , Humanos , Proteínas Serina-Treonina Quinasas/metabolismo , Transducción de Señal , Serina-Treonina Quinasas TOR/metabolismoRESUMEN
Transient receptor potential polycystin-3 (TRPP3) is a cation channel activated by calcium and proton and is involved in hedgehog signaling, intestinal development, and sour tasting. How TRPP3 channel function is regulated remains poorly understood. By N-terminal truncation mutations, electrophysiology, and Xenopus oocyte expression, we first identified fragment Asp-21-Ser-42 to be functionally important. We then found that deletion mutant Δ1-36 (TRPP3 missing fragment Met-1-Arg-36) has a similar function as wild-type TRPP3, whereas Δ1-38 is functionally dead, suggesting the importance of Val-37 or Cys-38. Further studies found that Cys-38, but not Val-37, is functionally critical. Cys-38 is a predicted site of palmitoylation, and indeed TRPP3 channel activity was inhibited by palmitoylation inhibitor 2-bromopalmitate and rescued by palmitoylation substrate palmitic acid. The TRPP3 N terminus (TRPP3NT, Met-1-Leu-95) localized along the plasma membrane of HEK293 cells but stayed in the cytoplasm with 2-bromopalmitate treatment or C38A mutation, indicating that TRPP3NT anchors to the surface membrane through palmitoylation at Cys-38. By acyl-biotin exchange assays, we showed that TRPP3, but not mutant C38A, is indeed palmitoylated. When putative phosphorylation sites near Cys-38 were mutated to Asp or Glu to mimic phosphorylation, only T39D and T39E reduced TRPP3 function. Furthermore, TRPP3NT displayed double bands in which the upper band was abolished by λ phosphatase treatment or T39A mutation. However, palmitoylation at Cys-38 and phosphorylation at Thr-39 independently regulated TRPP3 channel function, in contrast to previous reports about correlated palmitoylation with a proximate phosphorylation. Palmitoylation at Cys-38 represents a novel mechanism of functional regulation for TRPP3.
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Canales de Calcio/metabolismo , Lipoilación/fisiología , Receptores de Superficie Celular/metabolismo , Secuencia de Aminoácidos , Sustitución de Aminoácidos , Animales , Canales de Calcio/genética , Células HEK293 , Humanos , Mutación Missense , Fosforilación/fisiología , Dominios Proteicos , Receptores de Superficie Celular/genética , Eliminación de Secuencia , Xenopus laevisRESUMEN
Autosomal dominant polycystic kidney disease pathogenesis can be recapitulated in animal models by gene mutations in or dosage alterations of polycystic kidney disease 1 (PKD1) or PKD2, demonstrating that too much and too little PKD1/PKD2 are both pathogenic. Gene dosage manipulation has become an appealing approach by which to compensate for loss or gain of gene function, but the mechanisms controlling PKD2 expression remain incompletely characterized. In this study, using cultured mammalian cells and dual-luciferase assays, we found that the 3' untranslated region (3'UTR) of PKD2 mRNA inhibits luciferase protein expression. We then identified nucleotides 691-1044, which we called 3FI, as the 3'UTR fragment necessary for repressing the expression of luciferase or PKD2 in this system. Using a pull-down assay and mass spectrometry we identified far upstream element-binding protein 1 (FUBP1) as a 3FI-binding protein. In vitro overexpression of FUBP1 inhibited the expression of PKD2 protein but not mRNA. In embryonic zebrafish, FUBP1 knockdown (KD) by morpholino injection increased PKD2 expression and alleviated fish tail curling caused by morpholino-mediated KD of PKD2. Conversely, FUBP1 overexpression by mRNA injection significantly increased pronephric cyst occurrence and tail curling in zebrafish embryos. Furthermore, FUBP1 binds directly to eukaryotic translation initiation factor 4E-binding protein 1, indicating a link to the translation initiation complex. These results show that FUBP1 binds 3FI in the PKD2 3'UTR to inhibit PKD2 translation, regulating zebrafish disease phenotypes associated with PKD2 KD.
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Regiones no Traducidas 3'/fisiología , ADN Helicasas/metabolismo , Proteínas de Unión al ADN/metabolismo , Biosíntesis de Proteínas , Canales Catiónicos TRPP/genética , Animales , Células Cultivadas , Proteínas de Unión al ARN , Pez CebraRESUMEN
Mutations in polycystin-1, polycystin-2, or fibrocystin account for autosomal dominant or recessive polycystic kidney disease. Renal cystogenesis is linked to abnormal localization and function of these cystoproteins in renal primary cilia. They are also expressed in extrarenal tissues in which their functions are unclear. Here we found that human type-II alveolar epithelial A549, airway submucosal Calu-3 cells, and rat bronchioles contain primary or multiple cilia in which we detected these cystoproteins. At sub-confluency, polycystin-1 was expressed on plasma membrane, while polycystin-2 was localized to the ER of resting cells. Both polycystins were detected on the spindle and mid-body of mitotic cells, while fibrocystin was on centrosome throughout cell cycle. Polycystins and fibrocystin may participate in regulating mucociliary sensing and transport within pulmonary airways.
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Regulación de la Expresión Génica/fisiología , Pulmón/metabolismo , Receptores de Superficie Celular/biosíntesis , Canales Catiónicos TRPP/biosíntesis , Animales , Ciclo Celular/fisiología , Línea Celular Tumoral , Centrosoma/metabolismo , Cilios/genética , Cilios/metabolismo , Cricetinae , Humanos , Pulmón/citología , Ratas , Receptores de Superficie Celular/genética , Canales Catiónicos TRPP/genéticaRESUMEN
Macroautophagy/autophagy is an essential pro-survival mechanism activated in response to nutrient deficiency. The proper fusion between autophagosomes and lysosomes is a critical step for autophagic degradation. We recently reported that RUNDC1 (RUN domain containing 1) inhibits autolysosome formation via clasping the ATG14-STX17-SNAP29 complex to hinder VAMP8 binding. We showed that RUNDC1 colocalizes with LC3 and associates with mature autophagosomes in cell lines and the zebrafish model. We utilized liposome fusion and in vitro autophagosome-lysosome fusion assays to demonstrate that RUNDC1 inhibits autolysosome formation. Moreover, we found that RUNDC1 clasps the ATG14-STX17-SNAP29 complex via stimulating ATG14 homo-oligomerization to inhibit ATG14 dissociation, which in turn prevents VAMP8 from binding to STX17-SNAP29. Our results demonstrate that RUNDC1 is a negative regulator of autophagy that restricts autophagosome fusion with lysosomes and is crucial for zebrafish survival in nutrient-deficient conditions. Here, we summarize our findings and discuss their implications for our understanding of autophagy regulation.
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Autofagosomas , Autofagia , Animales , Autofagosomas/metabolismo , Autofagia/fisiología , Pez Cebra/metabolismo , Factores de Transcripción/metabolismo , Lisosomas/metabolismo , Fusión de Membrana/fisiología , Proteínas SNARE/metabolismoRESUMEN
Pancreatic cancer is a malignancy with high mortality. In addition to the few symptoms until the disease reaches an advanced stage, the high fatality rate is attributed to its rapid development, drug resistance and lack of appropriate treatment. In the selection and research of therapeutic drugs, gemcitabine is the first-line drug for pancreatic cancer. Solving the problem of gemcitabine resistance in pancreatic cancer will contribute to the progress of pancreatic cancer treatment. Long non coding RNAs (lncRNAs), which are RNA transcripts longer than 200 nucleotides, play vital roles in cellular physiological metabolic activities. Currently, our group and others have found that some lncRNAs are aberrantly expressed in pancreatic cancer cells, which can regulate the process of cancer through autophagy and Wnt/ß-catenin pathways simultaneously and affect the sensitivity of cancer cells to therapeutic drugs. This review presents an overview of the recent evidence concerning the node of lncRNA for the cross-talk between autophagy and Wnt/ß-catenin signaling in pancreatic cancer, together with the practicability of lncRNAs and the core regulatory factors as targets in therapeutic resistance.
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Autofagia , Resistencia a Antineoplásicos , Neoplasias Pancreáticas , ARN Largo no Codificante , Vía de Señalización Wnt , ARN Largo no Codificante/metabolismo , ARN Largo no Codificante/genética , Humanos , Autofagia/efectos de los fármacos , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/tratamiento farmacológico , Neoplasias Pancreáticas/genética , Resistencia a Antineoplásicos/genética , AnimalesRESUMEN
tRNA is the RNA type that undergoes the most modifications among known RNA, and in recent years, tRNA methylation has emerged as a crucial process in regulating gene translation. Dysregulation of tRNA abundance occurs in cancer cells, along with increased expression and activity of tRNA methyltransferases to raise the level of tRNA modification and stability. This leads to hijacking of translation and synthesis of multiple proteins associated with tumor proliferation, metastasis, invasion, autophagy, chemotherapy resistance, and metabolic reprogramming. In this review, we provide an overview of current research on tRNA methylation in cancer to clarify its involvement in human malignancies and establish a theoretical framework for future therapeutic interventions targeting tRNA methylation processes.
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Ferroptosis is a non-apoptotic mode of cell death driven by membrane lipid peroxidation and is characterized by elevated intracellular levels of Fe2+, ROS, and lipid peroxidation. Studies have shown that ferroptosis is related to the development of multiple diseases, such as cancer, neurodegenerative diseases, and acute myeloid leukemia. Ferroptosis plays a dual role in the occurrence and development of these diseases. Ferroptosis mainly involves iron metabolism, ROS, and lipid metabolism. Various mechanisms, including epigenetic regulation, have been reported to be deeply involved in ferroptosis. Abnormal epigenetic modifications have been reported to promote tumor onset or other diseases and resistance to chemotherapy drugs. In recent years, diversified studies have shown that epigenetic modification is involved in ferroptosis. In this review, we reviewed the current resistance system of ferroptosis and the research progress of epigenetic modification, such as DNA methylation, RNA methylation, non-coding RNAs, and histone modification in cancer and other diseases by regulating ferroptosis.
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Transient receptor potential vanilloid-6 (TRPV6) is a cation channel belonging to the TRP superfamily, specifically the vanilloid subfamily, and is the sixth member of this subfamily. Its presence in the body is primarily limited to the skin, ovaries, kidney, testes, and digestive tract epithelium. The body maintains calcium homeostasis using the TRPV6 channel, which has a greater calcium selectivity than the other TRP channels. Several pieces of evidence suggest that it is upregulated in the advanced stages of thyroid, ovarian, breast, colon, and prostate cancers. The function of TRPV6 in regulating calcium signaling in cancer will be covered in this review, along with its potential applications as a cancer treatment target.