Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 418
Filtrar
1.
Biochem Biophys Res Commun ; 699: 149499, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38281328

RESUMO

In yeast, ras-like small G proteins, Gtr1p and Gtr2p, form heterodimers that affect cell division, detect amino acids, and regulate the activity of TORC1, a protein complex that integrates various signals, including those related to nutrient availability, growth factors, and stress signals. To explore novel roles of Gtr2p, yeast two-hybrid screening was performed using gtr2S23Np, an active form of Gtr2p, which identified Rps31p and Rpl12p as Gtr2p-interacting proteins. In the present study, we found that Gtr2p, but not Gtr1p, interacts with Rps31p, a 40S ribosomal subunit, and a component of the ubiquitin fusion protein Ubi3p, which is essential for the initiation and elongation of translation. In yeast cells expressing gtr2Q66Lp, an inactive form of Gtr2p, the interaction between Rps31p and gtr2Q66Lp, as well as the level of exogenous expression of Rps31p, was reduced. However, the level of exogenous expression of Rpl12p was unaffected. Introducing a mutation in ubiquitin target lysine residues to arginine (rps31-K5R) restored the level of exogenously expressed Rps31p and rescued the rapamycin and caffeine sensitivity of gtr2Q66L cells. Sucrose density gradient centrifugation of yeast cell lysate expressing Rps31p and gtr2Q66Lp revealed that exogenously expressed Rps31p was poorly incorporated, whereas rps31-K5Rp was efficiently incorporated, into ribosomes. These results suggest that Gtr2p influences incorporation of Rps31p into ribosomes and contributes to drug resistance through its interaction with Rps31p.


Assuntos
Proteínas Monoméricas de Ligação ao GTP , Proteínas de Saccharomyces cerevisiae , Proteínas Monoméricas de Ligação ao GTP/metabolismo , Proteínas Ribossômicas/genética , Proteínas Ribossômicas/metabolismo , Ribossomos/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Ubiquitinas/metabolismo
2.
J Neurooncol ; 168(1): 49-56, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38520571

RESUMO

BACKGROUND: The optimal management strategy for recurrent glioblastoma (rGBM) remains uncertain, and the impact of re-irradiation (Re-RT) on overall survival (OS) is still a matter of debate. This study included patients who achieved gross total resection (GTR) after a second surgery after recurrence, following the GlioCave criteria. METHODS: Inclusion criteria include being 18 years or older, having histologically confirmed locally recurrent IDHwt or IDH unknown GBM, achieving MRI-proven GTR after the second surgery, having a Karnofsky performance status of at least 60% after the second surgery, having a minimum interval of 6 months between the first radiotherapy and the second surgery, and a maximum of 8 weeks from second surgery to the start of Re-RT. RESULTS: A total of 44 patients have met the inclusion criteria. The median OS after the second surgery was 14 months. All patients underwent standard treatment after initial diagnosis, including maximum safe resection, adjuvant radiochemotherapy and adjuvant chemotherapy. Re-RT did not significantly impact OS. However, MGMT promoter methylation status and a longer interval (> 12 months) between treatments were associated with better OS. Multivariate analysis revealed the MGMT status as the only significant predictor of OS. CONCLUSION: Factors such as MGMT promoter methylation status and treatment interval play crucial roles in determining patient outcomes after second surgery. Personalized treatment strategies should consider these factors to optimize the management of rGBM. Prospective research is needed to define the value of re-RT after second surgery and to inform decision making in this situation.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Recidiva Local de Neoplasia , Reirradiação , Humanos , Glioblastoma/radioterapia , Glioblastoma/cirurgia , Glioblastoma/mortalidade , Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/cirurgia , Neoplasias Encefálicas/mortalidade , Masculino , Feminino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/patologia , Idoso , Adulto , Reirradiação/métodos , Estudos de Coortes , Radioterapia Adjuvante , Centros de Atenção Terciária , Metilases de Modificação do DNA/genética , Metilases de Modificação do DNA/metabolismo , Enzimas Reparadoras do DNA/genética , Enzimas Reparadoras do DNA/metabolismo , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismo
3.
BMC Med Imaging ; 24(1): 142, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38862900

RESUMO

BACKGROUND: To investigate whether the intraoperative superb microvascular imaging(SMI) technique helps evaluate lesion boundaries compared with conventional grayscale ultrasound in brain tumor surgery and to explore factors that may be associated with complete radiographic resection. METHODS: This study enrolled 57 consecutive brain tumor patients undergoing surgery. During the operation, B-mode and SMI ultrasound evaluated the boundaries of brain tumors. MRI before and within 48h after surgery was used as the gold standard to evaluate gross-total resection(GTR). The ultrasound findings and GTR results were analyzed to determine the imaging factors related to GTR. RESULTS: A total of 57 patients were enrolled in the study, including 32 males and 25 females, with an average age of 53.4 ± 14.1 years old(range 19 ~ 80). According to the assessment criteria of MRI, before and within 48 h after the operation, 37(63.9%) cases were classified as GTR, and 20(35.1%) cases were classified as GTR. In comparing tumor interface definition between B-mode and SMI mode, SMI improved HGG boundary recognition in 5 cases(P = 0.033). The results showed that the tumor size ≥ 5 cm and unclear ultrasonic boundary were independent risk factors for nGTR (OR>1, P<0.05). CONCLUSIONS: As an innovative intraoperative doppler technique in neurosurgery, SMI can effectively demarcate the tumor's boundary and help achieve GTR as much as possible.


Assuntos
Neoplasias Encefálicas , Imageamento por Ressonância Magnética , Humanos , Feminino , Pessoa de Meia-Idade , Masculino , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/cirurgia , Adulto , Idoso , Imageamento por Ressonância Magnética/métodos , Idoso de 80 Anos ou mais , Microvasos/diagnóstico por imagem , Adulto Jovem , Ultrassonografia/métodos
4.
Neuropathology ; 2024 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-38409890

RESUMO

Astroblastoma is an uncommon circumscribed glial tumor mostly involving the cerebral hemisphere. The characteristic molecular alteration is meningioma (disrupted in balanced translocation) 1 (MN1) rearrangement. No definite World Health Organization grade has been assigned as both low- and high-grade tumors are known to occur. Tumors in the spine are extremely rare; to date only three cases have been reported in the literature. A vigilant microscopy and ancillary testing aid in diagnosis when the tumors present in unusual locations, as in our case. The prompt differentiation of this tumor from its mimickers is a mandate as modalities of management are different and not clearly established.

5.
Adv Tech Stand Neurosurg ; 52: 207-227, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39017796

RESUMO

Pineal lesions represent less than 1% of all brain tumors (Villani et al., Clin Neurol Neurosurg 109:1-6, 2007). The abysmal location and critical neurovascular structures remain a surgical challenge, despite the advent of microneurosurgery. The classical wide surgical suboccipital craniotomy with the supracerebellar infratentorial approach, described by Sir Victor Horsley (Victor, Proc R Soc Med 3:77-78, 1910), is infamous for its considerable surgical morbidity and mortality. This was later upgraded microneurosurgically by Stein to improve surgical outcomes (Stein, J Neurosurg 35:197-202, 1971).Ruge et al. reported the first purely endoscopic fenestration of quadrigeminal arachnoid cysts via this corridor (Ruge et al., Neurosurgery 38:830-7, 1996). A cadaver-based anatomical study by Cardia et al. demonstrated the viability for endoscope-assisted techniques (Cardia et al., J Neurosurg 2006;104(6 Suppl):409-14). However, the first purely endoscopic supracerebellar infratentorial (eSCIT) approach to a pineal cyst was performed in 2008 by Gore et al. (Gore PA et al., Neurosurgery 62:108-9, 2008).Unlike transventricular endoscopy, eSCIT approach poses no mechanical risk to the fornices and can be utilized irrespective of ventricular size. More vascular control and resultant reduction in uncontrolled hemorrhage improve the feasibility of attaining complete resection, especially around corners (Zaidi et al,, World Neurosurg 84, 2015). Gravity-dependent positioning and cerebrospinal fluid (CSF) diversion aid cerebellar relaxation, creating the ideal anatomical pathway. Also, angle of the straight sinus, tentorium, and tectal adherence can often influence the choice of approach; thus direct endoscopic visualization not only counteracts access to the engorged Galenic complex but also encourages sharp dissection of the arachnoid (Cardia et al., J Neurosurg 104:409-14, 2006). These tactics help provide excellent illumination with magnification, making it less fatiguing for the surgeon (Broggi et al., Neurosurgery 67:159-65, 2010).The purely endoscopic approach thwarts the dreaded risk of air embolisms, via simple copious irrigation from a small burr hole (Shahinian and Ra, J Neurol Surg B Skull Base 74:114-7, 2013). The tiny opening and closure are rapid to create, and the smaller wound decreases postoperative pain and morbidity. Recent literature supports its numerous advantages and favorable outcomes, making it a tough contender to traditional open methods.


Assuntos
Glândula Pineal , Criança , Humanos , Neoplasias Encefálicas/cirurgia , Cerebelo/cirurgia , Endoscopia/métodos , Neuroendoscopia/métodos , Procedimentos Neurocirúrgicos/métodos , Glândula Pineal/cirurgia , Pinealoma/cirurgia
6.
Cell Tissue Bank ; 25(1): 295-303, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36627541

RESUMO

Managing furcation defects constitutes a problem in successful periodontal therapy. Guided tissue regeneration (GTR) is the mainstay for the management of such defects but is expensive. This study makes use of indigenously prepared demineralized freeze-dried bone allograft (DFDBA) and amniotic membrane (AM) as a cost-effective alternative. The purpose of the study was to compare the clinical outcome of grade II and III furcation defects with and without using indigenous DFDBA and AM prepared at Central Tissue Bank, MAIDS. 18 systemically healthy patients with chronic periodontitis displaying either grade II or III furcation defects were treated with open flap debridement (OFD) + intramarrow penetration (IMP) (control group) and OFD + IMP + DFDBA + AM (test group). The clinical and radiographic parameters were recorded at 3 and 6 months postoperatively. All parameters were statistically analyzed. Both treatment modalities resulted in improvement in all clinical variables evaluated. Radiographic dimensions evaluating bone fill showed a statistically significant difference in the test group compared to the control group. Within the limitations of this study, data suggest GTR using indigenously prepared DFDBA and amniotic membrane to be an economical and viable option for treating furcation defects.


Assuntos
Periodontite Crônica , Defeitos da Furca , Humanos , Defeitos da Furca/diagnóstico por imagem , Defeitos da Furca/cirurgia , Âmnio/transplante , Periodontite Crônica/cirurgia , Regeneração Tecidual Guiada Periodontal/métodos , Transplante Ósseo/métodos , Resultado do Tratamento , Perda da Inserção Periodontal/cirurgia
7.
J Neurooncol ; 164(2): 397-404, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37650954

RESUMO

OBJECTIVE: Primary intracranial angiosarcomas (PIAs) are exceedingly uncommon, with the literature predominantly comprising case reports. The clinical characteristics and prognosis of this condition remain elusive. Our objective is to describe the clinical characteristics and surgical prognosis of this rare disease while offering insights into the most effective contemporary treatment strategy. METHODS: The authors of this article incorporated a cohort of 28 cases of PIAs, consisting of 3 from our institution and 25 from previously documented literature sources. Subsequently, we conducted both Cox univariate and multivariate analyses to assess the potential risk factors influencing overall survival (OS). RESULTS: The cohort include 19 males and 9 females with a mean age of 39.6 ± 23.5 years (range: 0.03-73 years). Radiologically, 24 cases were located at supratentorial area, while only 4 cases were located at infratentorial area. 17 cases underwent gross total resection (GTR), and 11 cases underwent Non-GTR. Postoperative radiotherapy was administered to 17 cases, and postoperative chemotherapy was administered to 6 cases. After a mean follow-up time of 21.5 ± 26.4 months, 19 (67.9%) patients died. The 1-year, 2-year, 5-year OS is 55.3%, 50.7% and 24.6%, respectively. Univariate and multivariate Cox regression analysis showed that Non-GTR was the sole factor predicting a shorter OS (p = 0.004). CONCLUSION: In this study, we found that PIAs have a higher incidence in males than in females, and most cases show evidence of old hemorrhage on preoperative MRI. Through our statistical analysis, GTR plays a crucial role in for treating this rare disease. Further clinical data are needed to validate our conclusions.


Assuntos
Hemangiossarcoma , Masculino , Feminino , Humanos , Adolescente , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Hemangiossarcoma/cirurgia , Doenças Raras , Resultado do Tratamento , Prognóstico , Fatores de Risco , Estudos Retrospectivos
8.
Periodontol 2000 ; 93(1): 254-269, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37845802

RESUMO

In the past decades, personalized regenerative medicine has gained increased attention. Autologous platelet concentrates (APCs) such as PRP, PRGF, and L-PRF, all serving as a source of a large variety of cells and growth factors that participate in hard and soft tissue healing and regeneration, could play a significant role in regenerative periodontal procedures. This narrative review evaluated the relative impact of APCs in alveolar ridge preservation, sinus floor augmentation, and the regeneration of bony craters around teeth, both as a single substitute or in combination with a xenograft. L-PRF has a significant beneficial effect on alveolar ridge preservation (bone quality). The data for PRGF are less convincing, and PRP is controversial. L-PRF can successfully be used as a single substitute during transcrestal (≥3.5 mm bone gain) as well as 1-stage lateral window sinus floor elevation (>5 mm bone gain). For PRGF and especially PRP the data are very scarce. In the treatment of bony craters around teeth, during open flap debridement, L-PRF as a single substitute showed significant adjunctive benefits (e.g., >PPD reduction, >CAL gain, >crater depth reduction). The data for PRP and PRGF were non-conclusive. Adding PRP or L-PRF to a xenograft during OFD resulted in additional improvements (>PPD reduction, >CAL gain, >bone fill), for PRGF no data were found. Autologous platelet concentrates demonstrated to enhance bone and soft tissue healing in periodontal regenerative procedures. The data for L-PRF were most convincing. L-PRF also has the advantage of a greater simplicity of production, and its 100% autologous character.


Assuntos
Perda do Osso Alveolar , Fibrina Rica em Plaquetas , Levantamento do Assoalho do Seio Maxilar , Humanos , Regeneração Óssea , Perda do Osso Alveolar/terapia , Regeneração Tecidual Guiada Periodontal/métodos
9.
BMC Endocr Disord ; 23(1): 176, 2023 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-37587420

RESUMO

BACKGROUND: To prevent thyroid storm and ensure surgical safety, it is imperative to regulate excessive thyroid hormone levels in patients with thyrotropin-secreting pituitary adenomas (TSHoma) prior to surgery. Somatostatin analogues (SSAs), such as octreotide, have showed efficacy in shrinking tumors, which may facilitate surgical resection. This retrospective study aimed to investigate the effect of shortterm preoperative octreotide treatment on the surgical outcome of TSHoma. METHODS: A total of 65 TSHoma patients from January 2010 to July 2019 were included in the study. Of these,41 patients received short-term preoperative octreotide (Sandostatin, intermittent subcutaneous injection) treatment and all patients subsequently underwent surgery. The following data were recorded: clinical manifestations, laboratory examinations, sellar region MRI, postoperative pathological and electron microscopy data, intraoperative situation, and follow-up (> 3 months) regarding hormone levels and tumor recurrence. RESULTS: There was no significant difference in the consistency and blood supply of the tumor between patients who received short-term preoperative octreotide treatment and those who did not. Additionally, preoperative short-term octreotide treatment (median of 10 days with a range of 6-18 days) did not significantly improve the rates of gross total resection (GTR) or biochemical remission. Moreover, electron microscopy revealed subcellular level impairments and cell apoptotic in the octreotide treated TSHoma specimens. CONCLUSION: Preoperative octreotide treatment for the purpose of reducing excessive thyroid hormones may not enhance surgical outcomes, and the duration of octreotide treatment needs to be extended to fully benefit from the tumor-shrinking effects of SSAs.


Assuntos
Octreotida , Neoplasias Hipofisárias , Humanos , Octreotida/uso terapêutico , Neoplasias Hipofisárias/tratamento farmacológico , Neoplasias Hipofisárias/cirurgia , Estudos Retrospectivos , Somatostatina/uso terapêutico , Tireotropina
10.
Mar Drugs ; 21(11)2023 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-37999389

RESUMO

Periodontitis is a microbially-induced inflammation of the periodontium that is characterized by the destruction of the periodontal ligament (PDL) and alveolar bone and constitutes the principal cause of teeth loss in adults. Periodontal tissue regeneration can be achieved through guided tissue/bone regeneration (GTR/GBR) membranes that act as a physical barrier preventing epithelial infiltration and providing adequate time and space for PDL cells and osteoblasts to proliferate into the affected area. Electrospun nanofibrous scaffolds, simulating the natural architecture of the extracellular matrix (ECM), have attracted increasing attention in periodontal tissue engineering. Carrageenans are ideal candidates for the development of novel nanofibrous GTR/GBR membranes, since previous studies have highlighted the potential of carrageenans for bone regeneration by promoting the attachment and proliferation of osteoblasts. Herein, we report the development of bi- and tri-layer nanofibrous GTR/GBR membranes based on carrageenans and other biocompatible polymers for the regeneration of periodontal tissue. The fabricated membranes were morphologically characterized, and their thermal and mechanical properties were determined. Their periodontal tissue regeneration potential was investigated through the evaluation of cell attachment, biocompatibility, and osteogenic differentiation of human PDL cells seeded on the prepared membranes.


Assuntos
Nanofibras , Osteogênese , Adulto , Humanos , Carragenina/farmacologia , Sulfatos , Membranas Artificiais , Periodonto , Regeneração Óssea
11.
Int Endod J ; 56(8): 910-921, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37212140

RESUMO

BACKGROUND: Endodontic-periodontal lesions may need surgical approach and the application of guided tissue regeneration (GTR) to be treated by a combined approach. OBJECTIVES: The aim of the present study was to evaluate the effects of GTR on the success (clinical and radiological healing) of teeth with endodontic-periodontal lesions treated by modern surgical endodontic treatment, by means of a systematic review of the literature. METHODS: An exhaustive electronic (Medline, Embase and Scopus searched from inception to August 2020) and manual literature search combined with strict inclusion and exclusion criteria was undertaken to identify any clinical (prospective case series or comparative trials) studies that assessed the added benefit of GTR in modern surgical endodontic treatment of teeth with endodontic-periodontal lesions. The success of the treatment was assessed based on radiographic healing and clinical evaluations. The risk of bias of the identified studies was evaluated using the Cochrane's collaboration RoB 2.0 tool and the Joanna Briggs Institute (JBI) critical appraisal tools. RESULTS: A systematic literature search for eligible reports retrieved three randomized controlled trials (RCTs) and one prospective single arm study with a total of 125 teeth in 125 subjects. One of the RCTs has a low risk of bias, while the other two raised some concerns, using the RoB 2.0 tool. Due to the heterogeneity of the results, it was not possible to perform a comparative meta-analysis and the results are presented in a narrative manner and by calculating pooled outcomes. Pooling together the data from all the included studies, the reported outcome was of complete healing in 58.4% of all cases, of scar tissue formation/incomplete healing in 24% of cases, of uncertain healing in 12.8% of cases, and of failure in 4.8% of all analysed teeth, with a follow-up ranging from 12 to 60 months. DISCUSSION: The scientific evidence about the use of GTR in modern surgical endodontic treatment of endodontic-periodontal lesion is sparse, and the available results are derived from very heterogeneous studies, thus not permitting to clarify which is the most effective treatment option in these cases. CONCLUSIONS: There is an absence of studies comparing GTR versus no GTR. REGISTRATION: The protocol for this review was registered in the PROSPERO database with the registration ID number CRD42022300470.


Assuntos
Regeneração Tecidual Guiada Periodontal , Cicatrização , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto
12.
Int J Mol Sci ; 24(2)2023 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-36674437

RESUMO

The glucosinolate transporters 1/2/3 (GTR1/2/3) from the Nitrate and Peptide transporter Family (NPF) play an essential role in the transport, accumulation, and distribution of the specialized plant metabolite glucosinolates. Due to representing both antinutritional and health-promoting compounds, there is increasing interest in characterizing GTRs from various plant species. We generated seven artificial glucosinolates (either aliphatic or benzenic) bearing different fluorophores (Fluorescein, BODIPY, Rhodamine, Dansylamide, and NBD) and investigated the ability of GTR1/2/3 from Arabidopsis thaliana to import the fluorescent glucosinolates (F-GSLs) into oocytes from Xenopus laevis. Five out of the seven F-GSLs synthesized were imported by at least one of the GTRs. GTR1 and GTR2 were able to import three F-GSLs actively above external concentration, while GTR3 imported only one actively. Competition assays indicate that the F-GSLs are transported by the same mechanism as non-tagged natural glucosinolates. The GTR-mediated F-GSL uptake is detected via a rapid and sensitive assay only requiring simple fluorescence measurements on a standard plate reader. This is highly useful in investigations of glucosinolate transport function and provides a critical prerequisite for elucidating the relationship between structure and function through high-throughput screening of GTR mutant libraries. The F-GSL themselves may also be suitable for future studies on glucosinolate transport in vivo.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Glucosinolatos/metabolismo , Arabidopsis/metabolismo , Transporte Biológico , Proteínas de Membrana Transportadoras/metabolismo
13.
J Cell Sci ; 133(17)2020 09 09.
Artigo em Inglês | MEDLINE | ID: mdl-32801125

RESUMO

Mechanical stresses, including high hydrostatic pressure, elicit diverse physiological effects on organisms. Gtr1, Gtr2, Ego1 (also known as Meh1) and Ego3 (also known as Slm4), central regulators of the TOR complex 1 (TORC1) nutrient signaling pathway, are required for the growth of Saccharomyces cerevisiae cells under high pressure. Here, we showed that a pressure of 25 MPa (∼250 kg/cm2) stimulates TORC1 to promote phosphorylation of Sch9, which depends on the EGO complex (EGOC) and Pib2. Incubation of cells at this pressure aberrantly increased glutamine and alanine levels in the ego1Δ, gtr1Δ, tor1Δ and pib2Δ mutants, whereas the polysome profiles were unaffected. Moreover, we found that glutamine levels were reduced by combined deletions of EGO1, GTR1, TOR1 and PIB2 with GLN3 These results suggest that high pressure leads to the intracellular accumulation of amino acids. Subsequently, Pib2 loaded with glutamine stimulates the EGOC-TORC1 complex to inactivate Gln3, downregulating glutamine synthesis. Our findings illustrate the regulatory circuit that maintains intracellular amino acid homeostasis and suggest critical roles for the EGOC-TORC1 and Pib2-TORC1 complexes in the growth of yeast under high hydrostatic pressure.


Assuntos
Proteínas Monoméricas de Ligação ao GTP , Proteínas de Saccharomyces cerevisiae , Aminoácidos , Homeostase , Pressão Hidrostática , Alvo Mecanístico do Complexo 1 de Rapamicina , Proteínas Monoméricas de Ligação ao GTP/metabolismo , Proteínas Serina-Treonina Quinases , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
14.
Biochem Biophys Res Commun ; 598: 107-112, 2022 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-35158208

RESUMO

Yeast Gtr1p is a GTPase that forms a heterodimer with Gtr2p, another GTPase; it is involved in regulating TORC1 activity in nutrient signaling, including amino acid availability and growth control. Gtr1p is a positive regulator of TORC1, a kinase that regulates various cellular functions (e.g., protein synthesis and autophagy) under specific nutrient and environmental conditions, including oxidative stress. In this study, we examined the roles of Gtr1p in oxidative stress responses. We found that yeast cells expressing guanosine diphosphatase (GDP)-bound Gtr1p (Gtr1-S20Lp) were resistant to hydrogen peroxide (H2O2), whereas guanosine triphosphate (GTP)-bound Gtr1p (Gtr1-Q65Lp) was sensitive to H2O2 compared with the wild type. Consistent with these findings, yeast cells lacking Iml1p, a component of the GTPase-activating protein complex for Gtr1p, exhibited the H2O2-sensitive phenotype. In gtr1S20L cells, autophagy was highly induced under oxidative stress. gtr1Q65L cells showed decreased expression of the SNQ2 gene, which encodes a multidrug transporter involved in resistance to oxidative stress, and the overexpression of SNQ2 rescued the oxidative stress sensitivity of gtr1Q65L cells. These results suggest that Gtr1p is involved in oxidative stress responses through mechanisms that include autophagy and SNQ2 expression.


Assuntos
Proteínas Monoméricas de Ligação ao GTP/metabolismo , Estresse Oxidativo/fisiologia , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/fisiologia , Transportadores de Cassetes de Ligação de ATP/genética , Transportadores de Cassetes de Ligação de ATP/metabolismo , Autofagia , Regulação Fúngica da Expressão Gênica , Peróxido de Hidrogênio/farmacologia , Proteínas Monoméricas de Ligação ao GTP/genética , Estresse Oxidativo/efeitos dos fármacos , Saccharomyces cerevisiae/efeitos dos fármacos , Proteínas de Saccharomyces cerevisiae/genética
15.
Plant Biotechnol J ; 20(1): 211-225, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34525252

RESUMO

A high content of seed glucosinolates and their degradation products imposes anti-nutritional effects on livestock; therefore, persistent efforts are made to reduce the seed GSL content to increase the commercial value of rapeseed meal. Here, we dissected the genetic structure of SGC by genome-wide association studies (GWAS) combined with transcriptome-wide association studies (TWAS). Fifteen reliable quantitative trait loci (QTLs) were identified to be associated with the reduced SGC in modern B. napus cultivars by GWAS. Analysis of the selection strength and haplotypes at these QTLs revealed that low SGC was predominantly generated by the co-selection of qGSL.A02.2, qGSL.C02.1, qGSL.A09.2, and qGSL.C09.1. Integration of the results from TWAS, comprehensive bioinformatics, and POCKET algorithm analyses indicated that BnaC02.GTR2 (BnaC02g42260D) is a candidate gene underlying qGSL.C02.1. Using CRISPR/Cas9-derived Bna.gtr2s knockout mutants, we experimentally verified that both BnaC02.GTR2 and its three paralogs positively regulate seed GSL accumulation but negatively regulated vegetative tissue GSL contents. In addition, we observed smaller seeds with higher seed oil content in these Bna.gtr2 mutants. Furthermore, both RNA-seq and correlation analyses suggested that Bna.GTR2s might play a comprehensive role in seed development, such as amino acid accumulation, GSL synthesis, sugar assimilation, and oil accumulation. This study unravels the breeding selection history of low-SGC improvement and provides new insights into the molecular function of Bna.GTR2s in both seed GSL accumulation and seed development in B. napus.


Assuntos
Brassica napus , Brassica napus/genética , Brassica napus/metabolismo , Estudo de Associação Genômica Ampla/métodos , Glucosinolatos/metabolismo , Melhoramento Vegetal/métodos , Sementes , Transcriptoma/genética
16.
J Periodontal Res ; 57(3): 510-518, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35212414

RESUMO

BACKGROUND AND OBJECTIVE: The clinical outcomes of guided tissue regeneration (GTR) or guided bone regeneration (GBR) procedures can be impaired if a bacterial infection develops at the surgical site. Membrane exposure is one of the causes of the onset of bacterial infection. Previously, we have fabricated a poly(lactic acid/caprolactone) (PLCL) bilayer membrane composed of a porous layer and a compact layer. The compact layer acts as a barrier against connective tissue and epithelial cells, and we hypothesized that it could also be an effective barrier against bacterial cells. The objective of this study was to evaluate the ability of the PLCL bilayer membrane to block bacterial cell penetration, which would be useful for preventing postoperative infections. METHODS: Porphyromonas gingivalis, Streptococcus mutans, and multispecies bacteria collected from human saliva were used in this study. Bacteria were seeded directly on the compact layer of a PLCL bilayer membrane, and bacterial adhesion to the membrane, as well as penetration into the membrane's structure, were assessed. Bacterial adhesion was evaluated by the number of colonies formed at 6, 24, and 72 h, and penetration was observed using a scanning electron microscope at 24 and 72 h. Commercially available membranes, composed of poly(lactic-co-glycolic acid) or type I collagen, were used as controls. RESULTS: P. gingivalis, S. mutans, and the multispecies bacteria obtained from human saliva adhered onto all the membranes after only 6 h of incubation. However, fewer adherent cells were observed for the PLCL bilayer membrane compared with the controls for all experimental periods. The PLCL membrane was capable of blocking bacterial penetration, and no bacterial cells were observed in the structure. In contrast, bacteria penetrated both the control membranes and were observed at depths of up to 80 µm after 72 h of incubation. CONCLUSION: Membrane characteristics may influence how bacterial colonization occurs. The PLCL membrane had reduced bacterial adhesion and blocked bacterial penetration, and these characteristics could contribute to a favorable outcome for regenerative treatments. In the event of membrane exposure at GTR/GBR surgical sites, membranes with an efficient barrier function, such as the PLCL bilayer membrane, could simplify the management of GTR/GBR complications.


Assuntos
Regeneração Óssea , Caproatos , Bactérias , Humanos , Ácido Láctico/farmacologia , Lactonas , Membranas Artificiais
17.
World J Surg Oncol ; 20(1): 137, 2022 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-35488347

RESUMO

BACKGROUND: Glioblastoma (GBM) is the most frequent and lethal brain tumor, which possesses highly malignant characteristics and predominates in elder patients. Systemic inflammatory response index (SIRI) is a novel prognostic marker from peripheral blood, which is defined as neutrophil count × monocyte count/lymphocyte count. In the current research, we aim to explore the relationship between SIRI and newly diagnosed GBM underwent gross total resection (GTR). METHODS: A retrospective analysis was conducted on consecutive newly diagnosed GBM patients underwent operation at West China Hospital from March 2015 to January 2019. X-tile software was used to determine the optimal cut-off values of SIRI, and neutrophil to lymphocyte ratio (NLR). All statistical analyses were performed using SPSS software and R software. Propensity score matching (PSM) was conducted to adjust for imbalance of all potential confounding covariates. RESULTS: The current research included a total of 291 consecutive newly diagnosed GBM patients underwent gross total resection. Among them, 186 were male patients and 105 were female patients. In original cohort, only gender was evidently related to SIRI level. SIRI and NLR were independent prognostic indicators both in original cohort and PSM cohort. Prognostic models based on the independent prognostic factors were established, and prognostic capacity of Model SIRI was superior to Model NLR. CONCLUSION: In the current research, SIRI was determined to be an independent prognostic indicator for GBM. And the prognostic predictive ability of SIRI was stronger than NLR.


Assuntos
Glioblastoma , Idoso , Feminino , Glioblastoma/patologia , Glioblastoma/cirurgia , Humanos , Inflamação/patologia , Masculino , Prognóstico , Pontuação de Propensão , Estudos Retrospectivos
18.
Int J Mol Sci ; 23(15)2022 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-35955500

RESUMO

The Gtr1 protein was a member of the RagA subfamily of the Ras-like small GTPase superfamily and involved in phosphate acquisition, ribosome biogenesis and epigenetic control of gene expression in yeast. However, Gtr1 regulation sexual or asexual development in filamentous fungi is barely accepted. In the study, SeGtr1, identified from Stemphylium eturmiunum, could manipulate mycelial growth, nuclear distribution of mycelium and the morphology of conidia in Segtr1 silenced strains compared with its overexpression transformants, while the sexual activity of Segtr1 silenced strains were unchanged. SeASF1, a H3/H4 chaperone, participated in nucleosome assembly/disassembly, DNA replication and transcriptional regulation. Our experiments showed that deletion Seasf1 mutants produced the hyphal fusion and abnormal conidia. Notably, we characterized that Segtr1 was down-regulated in Se∆asf1 mutants and Seasf1 was also down-regulated in SiSegtr1 strains. We further confirmed that SeGtr1 interacted with SeASF1 or SeH4 in vivo and vitro, respectively. Thus, SeGtr1 can cooperate with SeASF1 to modulate asexual development in Stemphylium eturmiunum.


Assuntos
Ascomicetos , Proteínas de Saccharomyces cerevisiae , Ascomicetos/metabolismo , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ligação ao GTP/metabolismo , Chaperonas Moleculares/metabolismo , Ligação Proteica , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo
19.
Int J Mol Sci ; 23(16)2022 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-36012530

RESUMO

Immune checkpoint inhibitors (ICIs) are widely used in cancer immunotherapy, requiring effective methods for response monitoring. This study evaluated changes in 18F-2-fluoro-2-deoxy-D-glucose (FDG) and 18F-fluorothymidine (FLT) uptake by tumors following ICI treatment as potential imaging biomarkers in mice. Tumor uptakes of 18F-FDG and 18F-FLT were measured and compared between the ICI treatment and control groups. A combined imaging index of glucose-thymidine uptake ratio (GTR) was defined and compared between groups. In the ICI treatment group, tumor growth was effectively inhibited, and higher proportions of immune cells were observed. In the early phase, 18F-FDG uptake was higher in the treatment group, whereas 18F-FLT uptake was not different. There was no difference in 18F-FDG uptake between the two groups in the late phase. However, 18F-FLT uptake of the control group was markedly increased compared with the ICI treatment group. GTR was consistently higher in the ICI treatment group in the early and late phases. After ICI treatment, changes in tumor cell proliferation were observed with 18F-FLT, whereas 18F-FDG showed altered metabolism in both tumor and immune cells. A combination of 18F-FLT and 18F-FDG PET, such as GTR, is expected to serve as a potentially effective imaging biomarker for monitoring ICI treatment.


Assuntos
Fluordesoxiglucose F18 , Neoplasias , Animais , Biomarcadores , Didesoxinucleosídeos , Fluordesoxiglucose F18/uso terapêutico , Glucose/uso terapêutico , Inibidores de Checkpoint Imunológico/farmacologia , Inibidores de Checkpoint Imunológico/uso terapêutico , Camundongos , Neoplasias/diagnóstico por imagem , Neoplasias/tratamento farmacológico , Tomografia por Emissão de Pósitrons/métodos , Compostos Radiofarmacêuticos/uso terapêutico , Timidina/farmacologia
20.
BMC Plant Biol ; 21(1): 394, 2021 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-34418959

RESUMO

BACKGROUND: To understand the mechanism of glucosinolates (GSs) accumulation in the specific organs, combined analysis of physiological change and transcriptome sequencing were applied in the current study. Taking Chinese kale as material, seeds and silique walls were divided into different stages based on the development of the embryo in seeds and then subjected to GS analysis and transcriptome sequencing. RESULTS: The main GS in seeds of Chinese kale were glucoiberin and gluconapin and their content changed with the development of the seed. During the transition of the embryo from torpedo- to the early cotyledonary-embryo stage, the accumulation of GS in the seed was accompanied by the salient decline of GS in the corresponding silique wall. Thus, the seed and corresponding silique wall at these two stages were subjected to transcriptomic sequencing analysis. 135 genes related to GS metabolism were identified, of which 24 genes were transcription factors, 81 genes were related to biosynthetic pathway, 25 genes encoded catabolic enzymes, and 5 genes matched with transporters. The expression of GS biosynthetic genes was detected both in seeds and silique walls. The high expression of FMOGS-OX and AOP2, which is related to the production of gluconapin by side modification, was noted in seeds at both stages. Interestingly, the expression of GS biosynthetic genes was higher in the silique wall compared with that in the seed albeit lower content of GS existed in the silique wall than in the seed. Combined with the higher expression of transporter genes GTRs in silique walls than in seeds, it was proposed that the transportation of GS from the silique wall to the seed is an important source for seed GS accumulation. In addition, genes related to GS degradation expressed abundantly in the seed at the early cotyledonary-embryo stage indicating its potential role in balancing seed GS content. CONCLUSIONS: Two stages including the torpedo-embryo and the early cotyledonary-embryo stage were identified as crucial in GS accumulation during seed development. Moreover, we confirmed the transportation of GS from the silique wall to the seed and proposed possible sidechain modification of GS biosynthesis may exist during seed formation.


Assuntos
Brassica/genética , Brassica/metabolismo , Glucosinolatos/genética , Glucosinolatos/metabolismo , Sementes/crescimento & desenvolvimento , Sementes/genética , Sementes/metabolismo , Parede Celular/genética , Parede Celular/metabolismo , Produtos Agrícolas/genética , Produtos Agrícolas/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Variação Genética , Genótipo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA