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1.
Eur J Radiol ; 178: 111523, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-39013270

RESUMO

BACKGROUND: Neck computed tomography (NCT) is essential for diagnosing suspected neck tumors and abscesses, but radiation exposure can be an issue. In conventional reconstruction techniques, limiting radiation dose comes at the cost of diminished diagnostic accuracy. Therefore, this study aimed to evaluate the effects of an AI-based denoising post-processing software solution in low-dose neck computer tomography. MATERIALS AND METHODS: From 01 September 2023 to 01 December 2023, we retrospectively included patients with clinically suspected neck tumors from the same single-source scanner. The scans were reconstructed using Advanced Modeled Iterative Reconstruction (Original) at 100% and simulated 50% and 25% radiation doses. Each dataset was post-processed using a novel denoising software solution (Denoising). Three radiologists with varying experience levels subjectively rated image quality, diagnostic confidence, sharpness, and contrast for all pairwise combinations of radiation dose and reconstruction mode in a randomized, blinded forced-choice setup. Objective image quality was assessed using ROI measurements of mean CT numbers, noise, and a contrast-to-noise ratio (CNR). An adequately corrected mixed-effects analysis was used to compare objective and subjective image quality. RESULTS: At each radiation dose level, pairwise comparisons showed significantly lower image noise and higher CNR for Denoising than for Original (p < 0.001). In subjective analysis, image quality, diagnostic confidence, sharpness, and contrast were significantly higher for Denoising than for Original at 100 and 50 % (p < 0.001). However, there were no significant differences in the subjective ratings between Original 100 % and Denoising 25 % (p = 0.906). CONCLUSIONS: The investigated denoising algorithm enables diagnostic-quality neck CT images with radiation doses reduced to 25% of conventional levels, significantly minimizing patient exposure.

2.
Sci Adv ; 10(23): eadm7273, 2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38848365

RESUMO

By analyzing 15,000 samples from 348 mammalian species, we derive DNA methylation (DNAm) predictors of maximum life span (R = 0.89), gestation time (R = 0.96), and age at sexual maturity (R = 0.85). Our maximum life-span predictor indicates a potential innate longevity advantage for females over males in 17 mammalian species including humans. The DNAm maximum life-span predictions are not affected by caloric restriction or partial reprogramming. Genetic disruptions in the somatotropic axis such as growth hormone receptors have an impact on DNAm maximum life span only in select tissues. Cancer mortality rates show no correlation with our epigenetic estimates of life-history traits. The DNAm maximum life-span predictor does not detect variation in life span between individuals of the same species, such as between the breeds of dogs. Maximum life span is determined in part by an epigenetic signature that is an intrinsic species property and is distinct from the signatures that relate to individual mortality risk.


Assuntos
Metilação de DNA , Epigênese Genética , Longevidade , Mamíferos , Animais , Longevidade/genética , Mamíferos/genética , Feminino , Humanos , Masculino , Características de História de Vida , Especificidade da Espécie
3.
Nat Commun ; 15(1): 4083, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38744825

RESUMO

Energetic stress compels cells to evolve adaptive mechanisms to adjust their metabolism. Inhibition of mTOR kinase complex 1 (mTORC1) is essential for cell survival during glucose starvation. How mTORC1 controls cell viability during glucose starvation is not well understood. Here we show that the mTORC1 effectors eukaryotic initiation factor 4E binding proteins 1/2 (4EBP1/2) confer protection to mammalian cells and budding yeast under glucose starvation. Mechanistically, 4EBP1/2 promote NADPH homeostasis by preventing NADPH-consuming fatty acid synthesis via translational repression of Acetyl-CoA Carboxylase 1 (ACC1), thereby mitigating oxidative stress. This has important relevance for cancer, as oncogene-transformed cells and glioma cells exploit the 4EBP1/2 regulation of ACC1 expression and redox balance to combat energetic stress, thereby supporting transformation and tumorigenicity in vitro and in vivo. Clinically, high EIF4EBP1 expression is associated with poor outcomes in several cancer types. Our data reveal that the mTORC1-4EBP1/2 axis provokes a metabolic switch essential for survival during glucose starvation which is exploited by transformed and tumor cells.


Assuntos
Acetil-CoA Carboxilase , Proteínas Adaptadoras de Transdução de Sinal , Proteínas de Ciclo Celular , Sobrevivência Celular , Ácidos Graxos , Glucose , Alvo Mecanístico do Complexo 1 de Rapamicina , Animais , Humanos , Camundongos , Acetil-CoA Carboxilase/metabolismo , Acetil-CoA Carboxilase/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/genética , Linhagem Celular Tumoral , Fatores de Iniciação em Eucariotos/metabolismo , Fatores de Iniciação em Eucariotos/genética , Ácidos Graxos/metabolismo , Glucose/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/genética , NADP/metabolismo , Estresse Oxidativo , Fosfoproteínas/metabolismo , Fosfoproteínas/genética , Biossíntese de Proteínas
4.
Plant J ; 119(1): 153-175, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38593295

RESUMO

Plant acclimation to an ever-changing environment is decisive for growth, reproduction, and survival. Light availability limits biomass production on both ends of the intensity spectrum. Therefore, the adjustment of plant metabolism is central to high-light (HL) acclimation, and the accumulation of photoprotective anthocyanins is commonly observed. However, mechanisms and factors regulating the HL acclimation response are less clear. Two Arabidopsis mutants of spliceosome components exhibiting a pronounced anthocyanin overaccumulation in HL were isolated from a forward genetic screen for new factors crucial for plant acclimation. Time-resolved physiological, transcriptome, and metabolome analysis revealed a vital function of the spliceosome components for rapidly adjusting gene expression and metabolism. Deficiency of INCREASED LEVEL OF POLYPLOIDY1 (ILP1), NTC-RELATED PROTEIN1 (NTR1), and PLEIOTROPIC REGULATORY LOCUS1 (PRL1) resulted in a marked overaccumulation of carbohydrates and strongly diminished amino acid biosynthesis in HL. While not generally limited in N-assimilation, ilp1, ntr1, and prl1 showed higher glutamate levels and reduced amino acid biosynthesis in HL. The comprehensive analysis reveals a function of the spliceosome components in the conditional regulation of the carbon:nitrogen balance and the accumulation of anthocyanins during HL acclimation. The importance of gene expression, metabolic regulation, and re-direction of carbon towards anthocyanin biosynthesis for HL acclimation are discussed.


Assuntos
Aclimatação , Proteínas de Arabidopsis , Arabidopsis , Carbono , Regulação da Expressão Gênica de Plantas , Luz , Nitrogênio , Spliceossomos , Arabidopsis/genética , Arabidopsis/fisiologia , Arabidopsis/metabolismo , Arabidopsis/efeitos da radiação , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Spliceossomos/metabolismo , Spliceossomos/genética , Carbono/metabolismo , Nitrogênio/metabolismo , Antocianinas/metabolismo
5.
PLoS One ; 19(4): e0302017, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38603731

RESUMO

In Neurofibromatosis type 1 (NF1), peripheral nerve sheaths tumors are common, with cutaneous neurofibromas resulting in significant aesthetic, painful and functional problems requiring surgical removal. To date, determination of adequate surgical resection margins-complete tumor removal while attempting to preserve viable tissue-remains largely subjective. Thus, residual tumor extension beyond surgical margins or recurrence of the disease may frequently be observed. Here, we introduce Shifted-Excitation Raman Spectroscopy in combination with deep neural networks for the future perspective of objective, real-time diagnosis, and guided surgical ablation. The obtained results are validated through established histological methods. In this study, we evaluated the discrimination between cutaneous neurofibroma (n = 9) and adjacent physiological tissues (n = 25) in 34 surgical pathological specimens ex vivo at a total of 82 distinct measurement loci. Based on a convolutional neural network (U-Net), the mean raw Raman spectra (n = 8,200) were processed and refined, and afterwards the spectral peaks were assigned to their respective molecular origin. Principal component and linear discriminant analysis was used to discriminate cutaneous neurofibromas from physiological tissues with a sensitivity of 100%, specificity of 97.3%, and overall classification accuracy of 97.6%. The results enable the presented optical, non-invasive technique in combination with artificial intelligence as a promising candidate to ameliorate both, diagnosis and treatment of patients affected by cutaneous neurofibroma and NF1.


Assuntos
Neurofibroma , Neurofibromatose 1 , Neuroma , Neoplasias Cutâneas , Humanos , Análise Espectral Raman/métodos , Inteligência Artificial , Neurofibroma/diagnóstico , Neurofibroma/genética , Neurofibroma/patologia , Neurofibromatose 1/diagnóstico , Neurofibromatose 1/genética , Neurofibromatose 1/patologia , Neoplasias Cutâneas/diagnóstico , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/patologia , Redes Neurais de Computação
6.
Acta Biomater ; 177: 148-156, 2024 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-38325708

RESUMO

Bone morphogenic protein 2 (BMP2) is known to induce osteogenesis and is applied clinically to enhance spinal fusion despite adverse effects. BMP2 needs to be used in high doses to be effective due to the presence of BMP2 inhibitors. L51P is a BMP2 analogue that acts by inhibition of BMP2 inhibitors. Here, we hypothesized that mixtures of BMP2 and L51P could achieve better spinal fusion outcomes regarding ossification. To test whether mixtures of both cytokines are sufficient to improve ossification, 45 elderly Wistar rats (of which 21 were males) were assigned to seven experimental groups, all which received spinal fusion surgery, including discectomy at the caudal 4-5 level using an external fixator and a porous ß-tricalcium phosphate (ßTCP) carrier. These ßTCP carriers were coated with varying concentrations of BMP2 and L51P. X-rays were taken immediately after surgery and again six and twelve weeks post-operatively. Histological sections and µCT were analyzed after twelve weeks. Spinal fusion was assessed using X-ray, µCT and histology according to the Bridwell scale by voxel-based quantification and a semi-quantitative histological score, respectively. The results were congruent across modalities and revealed high ossification for high-dose BMP2 (10 µg), while PBS induced no ossification. Low-dose BMP2 (1 µg) or 10 µg L51P alone did not induce relevant bone formation. However, all combinations of low-dose BMP2 with L51P (1 µg + 1/5/10 µg) were able to induce similar ossificationas high-dose BMP2. These results are of high clinical relevance, as they indicate L51P is sufficient to increase the efficacy of BMP2 and thus lower the required dose for spinal fusion. STATEMENT OF SIGNIFICANCE: Spinal fusion surgery is frequently applied to treat spinal pathologies. Bone Morphogenic Protein-2 (BMP2) has been approved by the U .S. Food and Drug Administration (FDA-) and by the "Conformité Européenne" (CE)-label. However, its application is expensive and high concentrations cause side-effects. This research targets the improvement of the efficacy of BMP2 in spinal fusion surgery.


Assuntos
Proteína Morfogenética Óssea 2 , Fusão Vertebral , Humanos , Masculino , Ratos , Animais , Idoso , Feminino , Proteína Morfogenética Óssea 2/farmacologia , Ratos Wistar , Fusão Vertebral/métodos , Cauda , Osteogênese , Fator de Crescimento Transformador beta/farmacologia
7.
J Clin Endocrinol Metab ; 109(8): e1652-e1664, 2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-38366650

RESUMO

CONTEXT: Prolactin (PRL) is a highly versatile, multifunctional hormone synthesized and secreted by lactotroph cells of the anterior pituitary. Its metabolic role has been extensively studied even in normoprolactinemic populations. Recently, a wealth of observational data have outlined the potential prognostic value of PRL in various clinical settings. OBJECTIVE: This systematic review aims to systematically evaluate and quantitatively synthesize the association between serum PRL levels and risk of mortality in adults without prolactinoma. METHODS: A systematic literature search was conducted up to June 10, 2023, to identify studies reporting the association of serum PRL levels with clinical outcomes of adults without prolactinoma. A random-effects meta-analysis was conducted to quantify the adjusted hazard ratios [(a)HRs] for all-cause and cardiovascular death (CVD) during follow-up. RESULTS: Twenty-eight studies were deemed eligible reporting the outcomes of adults without prolactinoma, in whom serum PRL levels were measured for risk-stratification. Fourteen studies reported appropriate data for meta-analysis encompassing a total of 23 596 individuals. Each unit of PRL increase was independently associated with increased risk of all-cause (pooled aHR = 1.17 [1.08-1.27]; I2 = 48%) and CV mortality (pooled aHR = 1.54 [1.14-2.09]; I2 = 89%). Individuals belonging to the highest PRL category had significantly higher risk for all-cause (pooled aHR = 1.81 [1.43-2.30]; I2 = 65%) and CV (pooled aHR = 1.59 [1.04-2.42]; I2 = 82%) mortality compared to their lowest-PRL category counterparts. The association between PRL levels and in-hospital death did not reach statistical significance. CONCLUSION: PRL levels seem to be an independent predictor for mortality. Further validation is warranted before its role as a risk-stratification tool can be delineated in clinical practice.


Assuntos
Prolactina , Humanos , Prolactina/sangue , Adulto , Prolactinoma/sangue , Prolactinoma/mortalidade , Prognóstico , Doenças Cardiovasculares/mortalidade , Doenças Cardiovasculares/sangue , Mortalidade , Neoplasias Hipofisárias/sangue , Neoplasias Hipofisárias/mortalidade
8.
Unfallchirurgie (Heidelb) ; 127(5): 374-380, 2024 May.
Artigo em Alemão | MEDLINE | ID: mdl-38300253

RESUMO

BACKGROUND: Time is a scarce resource for physicians. One medical task is the request for radiological diagnostics. This process is characterized by high administrative complexity and sometimes considerable time consumption. Measures that lead to an administrative relief in favor of patient care have so far been lacking. AIM OF THE STUDY: Process optimization of the request for radiological diagnostics. As a proof of concept the request for radiological diagnostics was conducted using a mobile, smartphone and tablet-based application with dedicated voice recognition software in the Department of Trauma Surgery at the University Hospital of Würzburg (UKW). MATERIAL AND METHODS: In a prospective study, time differences and efficiency of the mobile app-based method (ukw.mobile based Application = UMBA) compared to the PC-based method (PC-based application = PCBA) for requesting radiological services were analyzed. The time from the indications to the completed request and the time required to create the request on the device were documented and assessed. Due to the non-normal distribution of the data, a Mann-Whitney U test was performed. RESULTS: The time from the indications to the completed request was significantly (p < 0.05) reduced using UMBA compared to PCBA (PCBA: mean ± standard difference [SD] 19.57 ± 33.24 min, median 3.00 min, interquartile range [IQR] 1.00-30.00 min vs. UMBA: 9.33 ± 13.94 min, median 1.00 min, IQR 0.00-20.00 min). The time to complete the request on the device was also significantly reduced using UMBA (PCBA: mean ± SD 63.77 ± 37.98 s, median 51.96 s, IQR 41.68-68.93 s vs. UMBA: 25.21 ± 11.18 s, median 20.00 s, IQR 17.27-29.00 s). CONCLUSION: The mobile, voice-assisted request process leads to a considerable time reduction in daily clinical routine and illustrates the potential of user-oriented, targeted digitalization in healthcare. In future, the process will be supported by artificial intelligence.


Assuntos
Aplicativos Móveis , Humanos , Ferimentos e Lesões/diagnóstico por imagem , Ferimentos e Lesões/cirurgia , Alemanha , Estudos Prospectivos , Computadores de Mão , Smartphone , Traumatologia , Interface para o Reconhecimento da Fala , Telerradiologia/instrumentação , Telerradiologia/métodos , Cirurgia de Cuidados Críticos
9.
Biomedicines ; 12(2)2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38397978

RESUMO

Low back pain (LBP) is associated with the degeneration of human intervertebral discs (IVDs). Despite progress in the treatment of LBP through spinal fusion, some cases still end in non-fusion after the removal of the affected IVD tissue. In this study, we investigated the hypothesis that the remaining IVD cells secrete BMP inhibitors that are sufficient to inhibit osteogenesis in autologous osteoblasts (OBs) and bone marrow mesenchymal stem cells (MSCs). A conditioned medium (CM) from primary human IVD cells in 3D alginate culture was co-cultured with seven donor-matched OB and MSCs. After ten days, osteogenesis was quantified at the transcript level using qPCR to measure the expression of bone-related genes and BMP antagonists, and at the protein level by alkaline phosphatase (ALP) activity. Additionally, cells were evaluated histologically using alizarin red (ALZR) staining on Day 21. For judging ALP activity and osteogenesis, the Noggin expression in samples was investigated to uncover the potential causes. The results after culture with the CM showed significantly decreased ALP activity and the inhibition of the calcium deposit formation in alizarin red staining. Interestingly, no significant changes were found among most bone-related genes and BMP antagonists in OBs and MSCs. Noteworthy, Noggin was relatively expressed higher in human IVD cells than in autologous OBs or MSCs (relative to autologous OB, the average fold change was in 6.9, 10.0, and 6.3 in AFC, CEPC, and NPC, respectively; and relative to autologous MSC, the average fold change was 2.3, 3.4, and 3.2, in AFC, CEPC, and NPC, respectively). The upregulation of Noggin in residual human IVDs could potentially inhibit the osteogenesis of autologous OB and MSC, thus inhibiting the postoperative spinal fusion after discectomy surgery.

10.
Life Sci Alliance ; 7(2)2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-37957016

RESUMO

Cristae membranes have been recently shown to undergo intramitochondrial merging and splitting events. Yet, the metabolic and bioenergetic factors regulating them are unclear. Here, we investigated whether and how cristae morphology and dynamics are dependent on oxidative phosphorylation (OXPHOS) complexes, the mitochondrial membrane potential (ΔΨm), and the ADP/ATP nucleotide translocator. Advanced live-cell STED nanoscopy combined with in-depth quantification were employed to analyse cristae morphology and dynamics after treatment of mammalian cells with rotenone, antimycin A, oligomycin A, and CCCP. This led to formation of enlarged mitochondria along with reduced cristae density but did not impair cristae dynamics. CCCP treatment leading to ΔΨm abrogation even enhanced cristae dynamics showing its ΔΨm-independent nature. Inhibition of OXPHOS complexes was accompanied by reduced ATP levels but did not affect cristae dynamics. However, inhibition of ADP/ATP exchange led to aberrant cristae morphology and impaired cristae dynamics in a mitochondrial subset. In sum, we provide quantitative data of cristae membrane remodelling under different conditions supporting an important interplay between OXPHOS, metabolite exchange, and cristae membrane dynamics.


Assuntos
Mitocôndrias , Membranas Mitocondriais , Animais , Carbonil Cianeto m-Clorofenil Hidrazona/metabolismo , Mitocôndrias/metabolismo , Membranas Mitocondriais/metabolismo , Fosforilação Oxidativa , Trifosfato de Adenosina/metabolismo , Mamíferos/metabolismo
11.
Acad Radiol ; 2023 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-37989681

RESUMO

OBJECTIVES: In interventional bronchial artery embolization (BAE), periprocedural cone beam CT (CBCT) improves guiding and localization. However, a trade-off exists between 6-second runs (high radiation dose and motion artifacts, but low noise) and 3-second runs (vice versa). This study aimed to determine the efficacy of an advanced deep learning denoising (DLD) technique in mitigating the trade-offs related to radiation dose and image quality during interventional BAE CBCT. MATERIALS AND METHODS: This study included BMI-matched patients undergoing 6-second and 3-second BAE CBCT scans. The dose-area product values (DAP) were obtained. All datasets were reconstructed using standard weighted filtered back projection (OR) and a novel DLD software. Objective image metrics were derived from place-consistent regions of interest, including CT numbers of the Aorta and lung, noise, and contrast-to-noise ratio. Three blinded radiologists performed subjective assessments regarding image quality, sharpness, contrast, and motion artifacts on all dataset combinations in a forced-choice setup (-1 = inferior, 0 = equal; 1 = superior). The points were averaged per item for a total score. Statistical analysis ensued using a properly corrected mixed-effects model with post hoc pairwise comparisons. RESULTS: Sixty patients were assessed in 30 matched pairs (age 64 ± 15 years; 10 female). The mean DAP for the 6 s and 3 s runs was 2199 ± 185 µGym² and 1227 ± 90 µGym², respectively. Neither low-dose imaging nor the reconstruction method introduced a significant HU shift (p ≥ 0.127). The 3 s-DLD presented the least noise and superior contrast-to-noise ratio (CNR) (p < 0.001). While subjective evaluation revealed no noticeable distinction between 6 s-DLD and 3 s-DLD in terms of quality (p ≥ 0.996), both outperformed the OR variants (p < 0.001). The 3 s datasets exhibited fewer motion artifacts than the 6 s datasets (p < 0.001). CONCLUSIONS: DLD effectively mitigates the trade-off between radiation dose, image noise, and motion artifact burden in regular reconstructed BAE CBCT by enabling diagnostic scans with low radiation exposure and inherently low motion artifact burden at short examination times.

12.
Diagnostics (Basel) ; 13(20)2023 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-37892061

RESUMO

PET/CT scanners with a long axial field-of-view (LAFOV) provide increased sensitivity, enabling the adjustment of imaging parameters by reducing the injected activity or shortening the acquisition time. This study aimed to evaluate the limitations of reduced [18F]FDG activity doses on image quality, lesion detectability, and the quantification of lesion uptake in the Biograph Vision Quadra, as well as to assess the benefits of the recently introduced ultra-high sensitivity mode in a clinical setting. A number of 26 patients who underwent [18F]FDG-PET/CT (3.0 MBq/kg, 5 min scan time) were included in this analysis. The PET raw data was rebinned for shorter frame durations to simulate 5 min scans with lower activities in the high sensitivity (HS) and ultra-high sensitivity (UHS) modes. Image quality, noise, and lesion detectability (n = 82) were assessed using a 5-point Likert scale. The coefficient of variation (CoV), signal-to-noise ratio (SNR), tumor-to-background ratio (TBR), and standardized uptake values (SUV) including SUVmean, SUVmax, and SUVpeak were evaluated. Subjective image ratings were generally superior in UHS compared to the HS mode. At 0.5 MBq/kg, lesion detectability decreased to 95% (HS) and to 98% (UHS). SNR was comparable at 1.0 MBq/kg in HS (5.7 ± 0.6) and 0.5 MBq/kg in UHS (5.5 ± 0.5). With lower doses, there were negligible reductions in SUVmean and SUVpeak, whereas SUVmax increased steadily. Reducing the [18F]FDG activity to 1.0 MBq/kg (HS/UHS) in a LAFOV PET/CT provides diagnostic image quality without statistically significant changes in the uptake parameters. The UHS mode improves image quality, noise, and lesion detectability compared to the HS mode.

13.
Nat Commun ; 14(1): 6245, 2023 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-37803001

RESUMO

Genomic and proteomic screens have identified numerous host factors of SARS-CoV-2, but efficient delineation of their molecular roles during infection remains a challenge. Here we use Perturb-seq, combining genetic perturbations with a single-cell readout, to investigate how inactivation of host factors changes the course of SARS-CoV-2 infection and the host response in human lung epithelial cells. Our high-dimensional data resolve complex phenotypes such as shifts in the stages of infection and modulations of the interferon response. However, only a small percentage of host factors showed such phenotypes upon perturbation. We further identified the NF-κB inhibitor IκBα (NFKBIA), as well as the translation factors EIF4E2 and EIF4H as strong host dependency factors acting early in infection. Overall, our study provides massively parallel functional characterization of host factors of SARS-CoV-2 and quantitatively defines their roles both in virus-infected and bystander cells.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , COVID-19/genética , Proteômica , Pulmão , Células Epiteliais
14.
Sci Rep ; 13(1): 17832, 2023 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-37857740

RESUMO

Calorie restriction (CR), which is a reduction in calorie intake without malnutrition, usually extends lifespan and improves tissue integrity. This report focuses on the relationship between nuclear genomic instability and dietary-restriction and its effect on cell survival. We demonstrate that the cell survival rates of the genomic instability yeast mutant rrm3 change under metabolic restricted conditions. Rrm3 is a DNA helicase, chromosomal replication slows (and potentially stalls) in its absence with increased rates at over 1400 natural pause sites including sites within ribosomal DNA and tRNA genes. Whereas rrm3 mutant cells have lower cell death rates compared to wild type (WT) in growth medium containing normal glucose levels (i.e., 2%), under CR growth conditions cell death rates increase in the rrm3 mutant to levels, which are higher than WT. The silent-information-regulatory (Sir) protein complex and mitochondrial oxidative stress are required for the increase in cell death rates in the rrm3 mutant when cells are transferred from growth medium containing 2% glucose to CR-medium. The Rad53 checkpoint protein is highly phosphorylated in the rrm3 mutant in response to genomic instability in growth medium containing 2% glucose. Under CR, Rad53 phosphorylation is largely reduced in the rrm3 mutant in a Sir-complex dependent manner. Since CR is an adjuvant treatment during chemotherapy, which may target genomic instability in cancer cells, our studies may gain further insight into how these therapy strategies can be improved.


Assuntos
Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Restrição Calórica , DNA Helicases/genética , Instabilidade Genômica , Glucose/metabolismo , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Fatores de Transcrição/metabolismo
15.
Cells ; 12(17)2023 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-37681928

RESUMO

With a global increase in chronic kidney disease patients, alternatives to dialysis and organ transplantation are needed. Stem cell-based therapies could be one possibility to treat chronic kidney disease. Here, we used multipotent urine-derived renal progenitor cells (UdRPCs) to study nephrogenesis. UdRPCs treated with the JNK inhibitor-AEG3482 displayed decreased proliferation and downregulated transcription of cell cycle-associated genes as well as the kidney progenitor markers-SIX2, SALL1 and VCAM1. In addition, levels of activated SMAD2/3, which is associated with the maintenance of self-renewal in UdRPCs, were decreased. JNK inhibition resulted in less efficient oxidative phosphorylation and more lipid peroxidation via ferroptosis, an iron-dependent non-apoptotic cell death pathway linked to various forms of kidney disease. Our study is the first to describe the importance of JNK signalling as a link between maintenance of self-renewal and protection against ferroptosis in SIX2-positive renal progenitor cells.


Assuntos
Ferroptose , Sistema de Sinalização das MAP Quinases , Insuficiência Renal Crônica , Humanos , Rim , Diálise Renal , Células-Tronco
16.
Biomedicines ; 11(9)2023 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-37760834

RESUMO

Despite great efforts to develop new therapeutic strategies to combat melanoma, the prognosis remains rather poor. Artesunate (ART) is an antimalarial drug displaying anti-cancer effects in vitro and in vivo. In this in vitro study, we investigated the selectivity of ART on melanoma cells. Furthermore, we aimed to further elucidate the mechanism of the drug with a focus on the role of iron, the induction of oxidative stress and the implication of the enzyme heme oxygenase 1 (HO-1). ART treatment decreased the cell viability of A375 melanoma cells while it did not affect the viability of normal human dermal fibroblasts, used as a model for normal (healthy) cells. ART's toxicity was shown to be dependent on intracellular iron and the drug induced high levels of oxidative stress as well as upregulation of HO-1. Melanoma cells deficient in HO-1 or treated with a HO-1 inhibitor were less sensitive towards ART. Taken together, our study demonstrates that ART induces oxidative stress resulting in the upregulation of HO-1 in melanoma cells, which subsequently triggers the effect of ART's own toxicity. This new finding that HO-1 is involved in ART-mediated toxicity may open up new perspectives in cancer therapy.

17.
Evolution ; 77(10): 2314-2325, 2023 10 03.
Artigo em Inglês | MEDLINE | ID: mdl-37638607

RESUMO

Chromosome number change is a driver of speciation in eukaryotic organisms. Carnivorous sundews in the plant genus Drosera L. exhibit single chromosome number variation both among and within species, especially in the Australian Drosera subg. Ergaleium D.C., potentially linked to atypical centromeres that span much of the length of the chromosomes. We critically reviewed the literature on chromosome counts in Drosera, verified the taxonomy and quality of the original counts, and reconstructed dated phylogenies. We used the BiChrom model to test whether rates of single chromosome number increase and decrease, and chromosome number doubling differed between D. subg. Ergaleium and the other subgenera and between self-compatible and self-incompatible lineages. The best model for chromosome evolution among subgenera had equal rates of chromosome number doubling but higher rates of single chromosome number change in D. subg. Ergaleium than in the other subgenera. Contrary to expectation, self-incompatible lineages had a significantly higher rate of single chromosome loss than self-compatible lineages. We found no evidence for an association between differences in single chromosome number changes and diploidization after polyploidy or centromere type. This study presents an exemplar for critically examining published cytological data and rigorously testing factors that may impact the rates of chromosome number evolution.


Assuntos
Drosera , Droseraceae , Drosera/genética , Droseraceae/genética , Austrália , Cromossomos , Filogenia
18.
Urologie ; 62(9): 879-888, 2023 Sep.
Artigo em Alemão | MEDLINE | ID: mdl-37526710

RESUMO

Spectacular advances have been made in personalized medicine , which has rapidly revolutionized our traditional understanding of disease diagnosis and treatment. Molecular testing of tissue and liquid samples using next generation sequencing has developed into a key technology in this scenario. It can be used for both the determination of biomarkers for diagnostic, prognostic and predictive purposes, as well as the possible improvement of treatment outcome through the use of targeted therapies and the avoidance of therapies in the event of special resistance situations. In addition to drugs that have already been approved, which among other things intervene in cellular DNA repair, many new drugs have been developed and are in clinical testing. Furthermore, new possibilities in molecular imaging have dramatically expanded our understanding of tumor spread and created new approaches for targeted therapies.


Assuntos
Neoplasias , Medicina de Precisão , Humanos , Medicina de Precisão/métodos , Biomarcadores Tumorais/genética , Neoplasias/diagnóstico , Prognóstico , Resultado do Tratamento
19.
Hellenic J Cardiol ; 74: 65-73, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37414144

RESUMO

AIMS: Atrial fibrillation (AF) and cancer often co-exist. Each has been associated with an increased risk of morbidity and mortality. The aim of this meta-analysis was to synthesize available data regarding the incidence of arterial thromboembolism (TE), bleeding, and all-cause mortality in patients with AF with or without cancer. METHODS: Literature search was conducted in PubMed, Ovid MEDLINE, WebOfScience, Scopus, CENTRAL, OpenGrey, and EThOS databases to identify studies that included patients with AF and accounted for cancer status with the incidence of TE (ischemic stroke, transient ischemic attack, or arterial thrombosis), major or clinically relevant non-major bleeding, and all-cause mortality. A random-effects meta-analysis was used. RESULTS: Overall, 17 studies were included (3,149,547 patients). The risk of TE was similar in patients with AF with comorbid cancer compared with that in AF alone (pooled odds ratio [pOR] 0.97, 95% Confidence Interval [CI] 0.85-1.11, I2 = 87%). Major or clinically relevant non-major bleeding (pOR 1.65, 95% CI 1.35-2.02, I2 = 98%) and all-cause death (pOR 2.17, 95% CI 1.83-2.56, I2 = 98%) were significantly higher in patients with AF with cancer than in patients with AF only. The history of TE and hypertension and mean age were significant moderators of TE risk. CONCLUSION: In patients with AF, the presence of cancer is associated with a similar risk of TE as well as an increased risk of bleeding and all-cause death compared with the absence of cancer.


Assuntos
Fibrilação Atrial , Neoplasias , Acidente Vascular Cerebral , Tromboembolia , Humanos , Fibrilação Atrial/complicações , Fibrilação Atrial/epidemiologia , Acidente Vascular Cerebral/etiologia , Anticoagulantes , Hemorragia/epidemiologia , Hemorragia/induzido quimicamente , Tromboembolia/epidemiologia , Tromboembolia/etiologia , Neoplasias/complicações , Neoplasias/epidemiologia , Fatores de Risco
20.
Toxicol In Vitro ; 91: 105625, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37268255

RESUMO

Neuroblastoma is the most common extracranial malignant tumor in childhood. Approximately 60% of all patients are classified as high-risk and require intensive treatment including non-selective chemotherapeutic agents leading to severe side effects. Recently, phytochemicals like the natural chalcone cardamonin (CD) have gained attention in cancer research. For the first time, we investigated the selective anti-cancer effects of CD in SH-SY5Y human neuroblastoma cells compared to healthy (normal) fibroblasts (NHDF). Our study revealed selective and dose-dependent cytotoxicity of CD in SH-SY5Y. The natural chalcone CD specifically altered the mitochondrial membrane potential (ΔΨm), as an early marker of apoptosis, in human neuroblastoma cells. Caspase activity was also selectively induced and the amount of cleaved caspase substrates such as PARP was thus increased in human neuroblastoma cells. CD-mediated apoptotic cell death was rescued by pan caspase inhibitor Z-VAD-FMK. The natural chalcone CD selectively induced apoptosis, the programmed cell death, in SH-SY5Y human neuroblastoma cells whereas NHDF being a model for normal (healthy) cells were unaffected. Our data indicates a clinical potential of CD in the more selective and less harmful treatment of neuroblastoma.


Assuntos
Chalcona , Chalconas , Neuroblastoma , Humanos , Chalconas/farmacologia , Neuroblastoma/metabolismo , Chalcona/farmacologia , Linhagem Celular Tumoral , Apoptose , Caspases/metabolismo , Caspase 3/metabolismo
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