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1.
J Toxicol ; 2024: 3769933, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38633362

RESUMO

Although herbal drugs are often considered safe for consumption, there is increasing evidence that some can generate undesirable health effects. However, polyphenols found in certain plants have been shown to provide a range of benefits for human health. In previous work, a standardized and quantified extract (P2Et) obtained from Caesalpinia spinosa (Dividivi) plant showed promising antioxidant, immunomodulatory, and anti-inflammatory properties in animal models of cancer and COVID-19 patients. The extract has also been subjected to genotoxicity, mutagenicity, and 28-day oral chronic toxicity evaluations, demonstrating a good safety profile. To advance preclinical and clinical development, further acute and chronic toxicity evaluations of the P2Et extract were performed. Acute toxicity tests were performed orally in Wistar rats at a dose of 2000 mg/kg, indicating that the lethal dose 50% (LD50) value exceeded 2000 mg/kg and classifying the P2Et extract as category 5 according to the Globally Harmonized System of Classification (GHS). In this work, chronic toxicity tests were conducted for 180 days on Wistar rats and New Zealand rabbits at a dose of 1000 mg/kg under Good Laboratory Practice (GLP) conditions. No weight loss or alterations in biochemical and hematological parameters associated with treatment were observed in the animals, suggesting the absence of toxicity in the assessed parameters. These results indicate that the P2Et extract is safe for oral administration at doses up to 1000 mg/kg body weight over a six-month period.

2.
Am J Otolaryngol ; 45(4): 104278, 2024 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-38604100

RESUMO

BACKGROUND: Merkel cell carcinoma (MCC) is an aggressive and rare neuroendocrine tumor, accounting for less than 1% of skin cancers. Metastasis primarily manifests in the cervical lymph nodes but rarely affect the thyroid. METHODS: We report a case of primary head and neck cutaneous MCC with metastasis to the thyroid gland. A review of the literature of MCC with thyroid metastasis was conducted. RESULTS: We identified five cases of MCC with thyroid metastasis. Primary sites included the distal upper and lower extremities, axilla, buttock, and groin. Treatment courses varied including thyroidectomy, immunotherapy, and expectant palliative measures. Time from initial diagnosis to thyroid metastasis ranged from four months to four years. Tissue diagnosis was achieved in 5 of 6 cases. CONCLUSIONS: MCC with thyroid metastasis is rare and likely represents aggressive disease. Despite advances in treatment and surveillance, outcomes for MCC remain poor. Ongoing research may establish predictors for treatment response.

3.
ACS Chem Biol ; 19(2): 407-418, 2024 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-38301282

RESUMO

Mixed lineage kinase domain-like (MLKL) is a key signaling protein of necroptosis. Upon activation by phosphorylation, MLKL translocates to the plasma membrane and induces membrane permeabilization, which contributes to the necroptosis-associated inflammation. Membrane binding of MLKL is initially initiated by electrostatic interactions between the protein and membrane phospholipids. We previously showed that MLKL and its phosphorylated form (pMLKL) are S-acylated during necroptosis. Here, we characterize the acylation sites of MLKL and identify multiple cysteines that can undergo acylation with an interesting promiscuity at play. Our results show that MLKL and pMLKL undergo acylation at a single cysteine, with C184, C269, and C286 as possible acylation sites. Using all-atom molecular dynamic simulations, we identify differences that the acylation of MLKL causes at the protein and membrane levels. Through investigations of the S-palmitoyltransferases that might acylate pMLKL in necroptosis, we showed that zDHHC21 activity has the strongest effect on pMLKL acylation, inactivation of which profoundly reduced the pMLKL levels in cells and improved membrane integrity. These results suggest that blocking the acylation of pMLKL destabilizes the protein at the membrane interface and causes its degradation, ameliorating the necroptotic activity. At a broader level, our findings shed light on the effect of S-acylation on MLKL functioning in necroptosis and MLKL-membrane interactions mediated by its acylation.


Assuntos
Necroptose , Proteínas Quinases , Proteínas Quinases/metabolismo , Fosforilação , Membrana Celular/metabolismo , Apoptose
4.
Am J Physiol Endocrinol Metab ; 326(3): E207-E214, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38170165

RESUMO

Mitochondrial open reading frame of the 12S ribosomal RNA type-c (MOTS-c), a mitochondrial microprotein, has been described as a novel regulator of glucose and lipid metabolism. In addition to its role as a metabolic regulator, MOTS-c prevents skeletal muscle atrophy in high fat-fed mice. Here, we examined the preventive effect of MOTS-c on skeletal muscle mass, using an immobilization-induced muscle atrophy model, and explored its underlying mechanisms. Male C57BL/6J mice (10 wk old) were randomly assigned to one of the three experimental groups: nonimmobilization control group (sterilized water injection), immobilization control group (sterilized water injection), and immobilization and MOTS-c-treated group (15 mg/kg/day MOTS-c injection). We used casting tape for the immobilization experiment. After 8 days of the experimental period, skeletal muscle samples were collected and used for Western blotting, RNA sequencing, and lipid and collagen assays. Immobilization reduced ∼15% of muscle mass, whereas MOTS-c treatment attenuated muscle loss, with only a 5% reduction. MOTS-c treatment also normalized phospho-AKT, phospho-FOXO1, and phospho-FOXO3a expression levels and reduced circulating inflammatory cytokines, such as interleukin-1b (IL-1ß), interleukin-6 (IL-6), chemokine C-X-C motif ligand 1 (CXCL1), and monocyte chemoattractant protein 1 (MCP-1), in immobilized mice. Unbiased RNA sequencing and its downstream analyses demonstrated that MOTS-c modified adipogenesis-modulating gene expression within the peroxisome proliferator-activated receptor (PPAR) pathway. Supporting this observation, muscle fatty acid levels were lower in the MOTS-c-treated group than in the casted control mice. These results suggest that MOTS-c treatment inhibits skeletal muscle lipid infiltration by regulating adipogenesis-related genes and prevents immobilization-induced muscle atrophy.NEW & NOTEWORTHY MOTS-c, a mitochondrial microprotein, attenuates immobilization-induced skeletal muscle atrophy. MOTS-c treatment improves systemic inflammation and skeletal muscle AKT/FOXOs signaling pathways. Furthermore, unbiased RNA sequencing and subsequent assays revealed that MOTS-c prevents lipid infiltration in skeletal muscle. Since lipid accumulation is one of the common pathologies among other skeletal muscle atrophies induced by aging, obesity, cancer cachexia, and denervation, MOTS-c treatment could be effective in other muscle atrophy models as well.


Assuntos
60526 , Proteínas Proto-Oncogênicas c-akt , Masculino , Camundongos , Animais , Proteínas Proto-Oncogênicas c-akt/metabolismo , Camundongos Endogâmicos C57BL , Atrofia Muscular/etiologia , Atrofia Muscular/prevenção & controle , Músculo Esquelético/metabolismo , Fatores de Transcrição/metabolismo , Água , Lipídeos
5.
Mol Psychiatry ; 2024 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-38167865

RESUMO

Mitochondrial DNA single nucleotide polymorphisms (mtSNPs) have been associated with a reduced risk of developing Parkinson's disease (PD), yet the underlying mechanisms remain elusive. In this study, we investigate the functional role of a PD-associated mtSNP that impacts the mitochondrial-derived peptide (MDP) Small Humanin-like Peptide 2 (SHLP2). We identify m.2158 T > C, a mtSNP associated with reduced PD risk, within the small open reading frame encoding SHLP2. This mtSNP results in an alternative form of SHLP2 (lysine 4 replaced with arginine; K4R). Using targeted mass spectrometry, we detect specific tryptic fragments of SHLP2 in neuronal cells and demonstrate its binding to mitochondrial complex 1. Notably, we observe that the K4R variant, associated with reduced PD risk, exhibits increased stability compared to WT SHLP2. Additionally, both WT and K4R SHLP2 show enhanced protection against mitochondrial dysfunction in in vitro experiments and confer protection against a PD-inducing toxin, a mitochondrial complex 1 inhibitor, in a mouse model. This study sheds light on the functional consequences of the m.2158 T > C mtSNP on SHLP2 and provides insights into the potential mechanisms by which this mtSNP may reduce the risk of PD.

6.
Nat Commun ; 15(1): 267, 2024 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-38267429

RESUMO

Ultrafast photoinduced phase transitions at room temperature, driven by a single laser shot and persisting long after stimuli, represent emerging routes for ultrafast control over materials' properties. Time-resolved studies provide fundamental mechanistic insight into far-from-equilibrium electronic and structural dynamics. Here we study the photoinduced phase transformation of the Rb0.94Mn0.94Co0.06[Fe(CN)6]0.98 material, designed to exhibit a 75 K wide thermal hysteresis around room temperature between MnIIIFeII tetragonal and MnIIFeIII cubic phases. We developed a specific powder sample streaming technique to monitor by ultrafast X-ray diffraction the structural and symmetry changes. We show that the photoinduced polarons expand the lattice, while the tetragonal-to-cubic photoinduced phase transition occurs within 100 ps above threshold fluence. These results are rationalized within the framework of the Landau theory of phase transition as an elastically-driven and cooperative process. We foresee broad applications of the streaming powder technique to study non-reversible and ultrafast dynamics.

7.
Artigo em Inglês | MEDLINE | ID: mdl-38092990

RESUMO

Major depressive disorder (MDD) and type 2 diabetes (T2D) are complex disorders whose comorbidity can be due to hypercortisolism and may be explained by dysfunction of the corticotropin-releasing hormone receptor 1 (CRHR1) and cortisol feedback within the hypothalamic-pituitary-adrenal axis (HPA axis). To investigate the role of the CRHR1 gene in familial T2D, MDD, and MDD-T2D comorbidity, we tested 152 CRHR1 single-nucleotide-polymorphisms (SNPs), via 2-point parametric linkage and linkage disequilibrium (LD; i.e., association) analyses using 4 models, in 212 peninsular families with T2D and MDD. We detected linkage/LD/association to/with MDD and T2D with 122 (116 novel) SNPs. MDD and T2D had 4 and 3 disorder-specific novel risk LD blocks, respectively, whose risk variants reciprocally confirm one another. Comorbidity was conferred by 3 novel independent SNPs. In silico analyses reported novel functional changes, including the binding site of glucocorticoid receptor-alpha [GR-α] on CRHR1 for transcription regulation. This is the first report of CRHR1 pleiotropic linkage/LD/association with peninsular familial MDD and T2D. CRHR1 contribution to MDD is stronger than to T2D and may antecede T2D onset. Our findings suggest a new molecular-based clinical entity of MDD-T2D and should be replicated in other ethnic groups.

8.
J Clin Med ; 12(24)2023 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-38137584

RESUMO

The aim of this study was to assess the shear wave velocity by LUS elastography (SWE2D) for the evaluation of superficial lung stiffness after COVID-19 pneumonia, according to "fibrosis-like" signs found by Computed Tomography (CT), considering the respiratory function. Seventy-nine adults participated in the study 42 to 353 days from symptom onset. Paired evaluations (SWE2D and CT) were performed along with the assessment of arterial blood gases and spirometry, three times with 100 days in between. During the follow-up and within each evaluation, the SWE2D velocity changed over time (MANOVA, p < 0.05) according to the extent of "fibrosis-like" CT signs by lung lobe (ANOVA, p < 0.05). The variability of the SWE2D velocity was consistently related to the first-second forced expiratory volume and the forced vital capacity (MANCOVA, p < 0.05), which changed over time with no change in blood gases. Covariance was also observed with age and patients' body mass index, the time from symptom onset until hospital admission, and the history of diabetes in those who required intensive care during the acute phase (MANCOVA, p < 0.05). After COVID-19 pneumonia, SWE2D velocity can be related to the extent and regression of "fibrotic-like" involvement of the lung lobes, and it could be a complementary tool in the follow-up after COVID-19 pneumonia.

9.
J Homosex ; : 1-22, 2023 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-37976200

RESUMO

The representation of gays and lesbians on Chilean television has increased steadily over the last decades. This paper offers an analysis of the role these images had in the processes of sexual identification of a sample of 25 members of the audience who identify as gays or lesbians. Through a thematic analysis of semi-structured interviews, it is shown that the respondents believed that the televisual representations of homosexuality have contributed to further marginalize gay and lesbian lives. This strengthened damaging feelings that fed into a sense of shame that was originating from multiple institutions and texts, thus complicating their processes of self-recognition and self-acceptance during their childhood and adolescence. Taking examples of how participants described their relationship with these representations and the ways in which they circulated socially, it is argued that they could only articulate their identification as gays or lesbians by disassociating themselves from these images and establishing a clear difference in regard to them. This was in a process in which several other informational and experiential opportunities came into play, which allowed them to resignify the categories gay/lesbian and lead less conflictive processes of identification.

10.
bioRxiv ; 2023 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-37986949

RESUMO

FoxP3 is a transcription factor (TF) essential for development of regulatory T cells (Tregs), a branch of T cells that suppress excessive inflammation and autoimmunity 1-5 . Molecular mechanisms of FoxP3, however, remain elusive. We here show that FoxP3 utilizes the Forkhead domain--a DNA binding domain (DBD) that is commonly thought to function as a monomer or dimer--to form a higher-order multimer upon binding to T n G repeat microsatellites. A cryo-electron microscopy structure of FoxP3 in complex with T 3 G repeats reveals a ladder-like architecture, where two double-stranded DNA molecules form the two "side rails" bridged by five pairs of FoxP3 molecules, with each pair forming a "rung". Each FoxP3 subunit occupies TGTTTGT within the repeats in the manner indistinguishable from that of FoxP3 bound to the Forkhead consensus motif (FKHM; TGTTTAC). Mutations in the "intra-rung" interface impair T n G repeat recognition, DNA bridging and cellular functions of FoxP3, all without affecting FKHM binding. FoxP3 can tolerate variable "inter-rung" spacings, explaining its broad specificity for T n G repeat-like sequences in vivo and in vitro . Both FoxP3 orthologs and paralogs show similar T n G repeat recognition and DNA bridging. These findings thus reveal a new mode of DNA recognition that involves TF homo-multimerization and DNA bridging, and further implicates microsatellites in transcriptional regulation and diseases.

11.
Front Mol Biosci ; 10: 1235160, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38028534

RESUMO

Acute leukemias (AL) are aggressive neoplasms with high mortality rates. Metabolomics and oxidative status have emerged as important tools to identify new biomarkers with clinical utility. To identify the metabolic differences between healthy individuals (HI) and patients with AL, a multiplatform untargeted metabolomic and lipidomic approach was conducted using liquid and gas chromatography coupled with quadrupole-time-of-flight mass spectrometry (LC-QTOF-MS or GC-QTOF-MS). Additionally, the total antioxidant capacity (TAC) was measured. A total of 20 peripheral blood plasma samples were obtained from patients with AL and 18 samples from HI. Our analysis revealed 135 differentially altered metabolites in the patients belonging to 12 chemical classes; likewise, the metabolic pathways of glycerolipids and sphingolipids were the most affected in the patients. A decrease in the TAC of the patients with respect to the HI was evident. This study conducted with a cohort of Colombian patients is consistent with observations from other research studies that suggest dysregulation of lipid compounds. Furthermore, metabolic differences between patients and HI appear to be independent of lifestyle, race, or geographic location, providing valuable information for future advancements in understanding the disease and developing more global therapies.

12.
Front Physiol ; 14: 1286808, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38033343

RESUMO

CaVγ2 (Stargazin or TARPγ2) is a protein expressed in various types of neurons whose function was initially associated with a decrease in the functional expression of voltage-gated presynaptic Ca2+ channels (CaV) and which is now known to promote the trafficking of the postsynaptic α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors (AMPAR) towards the cell membrane. Alterations in CaVγ2 expression has been associated with several neurological disorders, such as absence epilepsy. However, its regulation at the transcriptional level has not been intensively addressed. It has been reported that the promoter of the Cacng2 gene, encoding the rat CaVγ2, is bidirectional and regulates the transcription of a long non-coding RNA (lncRNA) in the antisense direction. Here, we investigate the proximal promoter region of the human CACNG2 gene in the antisense direction and show that this region includes two functional cAMP response elements that regulate the expression of a lncRNA called CACNG2-DT. The activity of these sites is significantly enhanced by forskolin, an adenylate cyclase activator, and inhibited by H89, a protein kinase A (PKA) antagonist. Therefore, this regulatory mechanism implies the activation of G protein-coupled receptors and downstream phosphorylation. Interestingly, we also found that the expression of CACNG2-DT may increase the levels of the CaVγ2 subunit. Together, these data provide novel information on the organization of the human CACNG2-DT gene promoter, describe modulatory domains and mechanisms that can mediate various regulatory inputs, and provide initial information on the molecular mechanisms that regulate the functional expression of the CaVγ2 protein.

13.
Clin Cancer Res ; 2023 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-37939112

RESUMO

PURPOSE: To demonstrate lymphatic drainage fluid (lymph) has improved sensitivity in quantifying postoperative minimal residual disease (MRD) in locally advanced HPV-associated oropharyngeal squamous cell carcinoma (OPSCC) compared to plasma, which can be leveraged for patient risk stratification. EXPERIMENTAL DESIGN: We prospectively collected lymph samples from neck drains of 106 HPV (+) OPSCC patients, along with 67 matched plasma samples, 24 hours after surgery. PCR and next-generation sequencing were used to quantify cancer-associated cell-free HPV (cf-HPV) and tumor-informed variants in lymph and plasma. Next, lymph cf-HPV and variants were compared to TMN stage, extranodal extension (ENE), and composite definitions of high-risk pathology. We then created a machine learning model, informed by lymph MRD and clinicopathological features, to compare with progression-free survival (PFS). RESULTS: Postoperative lymph was enriched with cf-HPV compared to plasma (P < 0.0001) and correlated with pN2 stage (P = 0.003), ENE (P < 0.0001), and trial-defined pathological risk criteria (mean AUC = 0.78). Additionally, the lymph mutation number and variant allele frequency (VAF) were higher in pN2 ENE (+) necks than in pN1 ENE (+) (P = 0.03, P = 0.02) or pN0-N1 ENE (-) (P = 0.04, P = 0.03, respectively). The lymph MRD-informed risk model demonstrated inferior PFS in high-risk patients (AUC = 0.96, P < 0.0001). CONCLUSIONS: Variant and cf-HPV quantification, performed in 24-hour postoperative lymph samples, reflect single- and multi-feature high-risk pathological criteria. Incorporating lymphatic MRD and clinicopathological feature analysis can stratify PFS early after surgery in patients with HPV (+) head and neck cancer.

14.
Rev Med Inst Mex Seguro Soc ; 61(Suppl 3): S492-S496, 2023 Oct 02.
Artigo em Espanhol | MEDLINE | ID: mdl-37935013

RESUMO

Background: Fusarium infection in the central nervous system is a rare pathology generally reported in patients with hematological malignancies. Clincal case: A patient with Fusarium meningoencephalitis during the late postpartum period is presented. The patient's main symptom was holocranial headache with poor response to analgesics, adding dysarthria and blurred vision. Initially, it was classified as aseptic meningitis due to the absence of bacterial isolation, however, 8 weeks after the onset of the symptoms, Fusarium development was obtained in cerebrospinal fluid cultures. Targeted treatment with liposomal amphotericin and voriconazole was established, with partial improvement at first; however, at 16 weeks from the onset of the clinical picture, the patient presented sudden deterioration of alertness, an ischemic area was found in the occipital lobe by imaging study, which quickly led the patient to a fatal outcome. Conclusion: Despite the fact that in recent years Fusarium spp infection has been detected more frequently in the population, the treatment is still not well established, making management of the Central Nervous System a challenge.


Introducción: la infección por Fusarium en el sistema nervioso central es una patología rara, reportada generalmente en pacientes con neoplasias hematológicas. Caso clínico: se presenta una paciente con meningoencefalitis por Fusarium durante el periodo de puerperio tardío. El síntoma principal de la paciente fue cefalea holocraneana con baja respuesta a analgésicos, agregándose disartria y visión borrosa. De manera inicial, se catalogó como meningitis aséptica por ausencia de aislamiento bacteriano, no obstante, a las 8 semanas posterior al inicio del cuadro se obtuvo desarrollo de Fusarium en los cultivos de líquido cefalorraquídeo. Se estableció tratamiento dirigido con anfotericina liposomal y voriconazol, con mejoría parcial en un inicio; sin embargo, la paciente a las 16 semanas desde el inicio del cuadro clínico presentó deterioro súbito del estado de alerta, se evidenció zona isquémica en el lóbulo occipital por estudio de imagen, lo que rápidamente llevó a la paciente a un desenlace fatal. Conclusión: a pesar de que en los últimos años la infección por Fusarium spp se ha detectado con mayor frecuencia en la población, el tratamiento aún no se encuentra bien establecido ocasionando que sea un reto el manejo en Sistema Nervioso Central.


Assuntos
Fusarium , Meningoencefalite , Feminino , Humanos , Antifúngicos/uso terapêutico , Voriconazol/uso terapêutico , Meningoencefalite/diagnóstico , Meningoencefalite/tratamento farmacológico
15.
Toxicol Rep ; 11: 396-404, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37955035

RESUMO

The genus Passiflora (Passifloraceae) comprises about 500 species. The Passiflora edulis stands out because of its economic and medicinal importance. It is widely planted in tropical and subtropical regions worldwide, especially in South America, the Caribbean, South Africa, and Asia. The aqueous extract of Passiflora edulis Sims f. edulis (Gulupa) leaves is used in traditional medicine for its soothing and tranquilizing effects on the central nervous system. Therefore, evaluating its safety for human use is a fundamental requirement to continue the development of new therapies within the framework of regulatory, preclinical, and clinical guidelines. Here, the sub-acute toxicity study was conducted following the Organization for Economic Cooperation and Development (OECD) guideline 407 for 28 days in Wistar albino rats. The study showed that 1000 mg/kg/day of the aqueous extract in 10 adult Wistar rats (five males and five females) was well tolerated. The hematological results are at normal levels. However, monocytopenia and eosinopenia were observed with a significant difference (P < 0,05) for both male and female rats treated with the aqueous extract of Passiflora edulis. The results show that liver and kidney function profiles were conserved. However, an increase in ALT is observed with significant differences between male and female rats treated with the extract compared to the controls. Study findings were limited to non-adverse histopathological results of a slightly increased incidence of focal periportal lymphocytic infiltrate in the liver and focal corticomedullary nephrocalcinosis in the kidney compared to control. Therefore, the aqueous extract of Passiflora edulis has a good safety profile in oral administration, was well tolerated, and did not cause any lethality or adverse effects in the sub-acute toxicity study in male and female rats. The NOAEL (no observed adverse effect level) for the 28-day subacute toxicity study was considered to be 1000 mg/kg.

16.
Nature ; 624(7991): 433-441, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38030726

RESUMO

FOXP3 is a transcription factor that is essential for the development of regulatory T cells, a branch of T cells that suppress excessive inflammation and autoimmunity1-5. However, the molecular mechanisms of FOXP3 remain unclear. Here we here show that FOXP3 uses the forkhead domain-a DNA-binding domain that is commonly thought to function as a monomer or dimer-to form a higher-order multimer after binding to TnG repeat microsatellites. The cryo-electron microscopy structure of FOXP3 in a complex with T3G repeats reveals a ladder-like architecture, whereby two double-stranded DNA molecules form the two 'side rails' bridged by five pairs of FOXP3 molecules, with each pair forming a 'rung'. Each FOXP3 subunit occupies TGTTTGT within the repeats in a manner that is indistinguishable from that of FOXP3 bound to the forkhead consensus motif (TGTTTAC). Mutations in the intra-rung interface impair TnG repeat recognition, DNA bridging and the cellular functions of FOXP3, all without affecting binding to the forkhead consensus motif. FOXP3 can tolerate variable inter-rung spacings, explaining its broad specificity for TnG-repeat-like sequences in vivo and in vitro. Both FOXP3 orthologues and paralogues show similar TnG repeat recognition and DNA bridging. These findings therefore reveal a mode of DNA recognition that involves transcription factor homomultimerization and DNA bridging, and further implicates microsatellites in transcriptional regulation and diseases.


Assuntos
DNA , Fatores de Transcrição Forkhead , Repetições de Microssatélites , Sequência de Bases , Sequência Consenso , Microscopia Crioeletrônica , DNA/química , DNA/genética , DNA/metabolismo , DNA/ultraestrutura , Fatores de Transcrição Forkhead/química , Fatores de Transcrição Forkhead/metabolismo , Fatores de Transcrição Forkhead/ultraestrutura , Repetições de Microssatélites/genética , Mutação , Motivos de Nucleotídeos , Domínios Proteicos , Multimerização Proteica , Linfócitos T Reguladores/metabolismo
17.
BMC Complement Med Ther ; 23(1): 309, 2023 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-37670337

RESUMO

BACKGROUND: Chemotherapy in breast cancer is effective but can generate significant toxicity and lead to tumor resistance. Joint treatment with standardized plant extracts can be an alternative to improve the response and allow an effective activation of the antitumor immune response that favors recovery in the short and long term. The P2Et extract of Caesalpinia spinosa presents antitumor activity in cells and animal models of breast cancer, improves the tumor microenvironment, and induces activation of the specific immune response against the tumor and is synergistic when used together with anthracyclines, which makes it a good candidate for evaluation in patients. METHODS: Conducted at a single center, this phase II study is a randomized, double-blind, placebo-controlled trial aimed at assessing the safety and efficacy of P2Et extract in patients diagnosed with stage II and III breast cancer, who are eligible for neoadjuvant treatment. The study aims to determine the safety profile at the previously established optimal biological dose from phase I trial while investigating various efficacy outcomes. These outcomes include improvements in quality of life, immunomodulation, metabolic profile, microbiome, as well as clinical indicators such as tumor reduction, disease-free survival, and pathological response, assessed at different stages of the treatment regimen. DISCUSSION: Treatment with the P2Et extract in breast cancer patients is hypothesized to enhance overall well-being, positively influencing their quality of life, while also triggering an antitumor immune response and enhancing immune infiltration. These combined effects have the potential to contribute to improved long-term survival outcomes for patients receiving the phytomedicine alongside neoadjuvant chemotherapy treatment. TRIAL REGISTRATION: This trial was registered in the US National Library of Medicine with identifier NCT05007444. First Registered August 16th, 2021. Last Updated: August 9th, 2022.


Assuntos
Caesalpinia , Neoplasias , Estados Unidos , Animais , Qualidade de Vida , Óxidos S-Cíclicos , Morfolinas , Ensaios Clínicos Controlados Aleatórios como Assunto , Ensaios Clínicos Fase II como Assunto , Ensaios Clínicos Veterinários como Assunto
18.
Cell Rep ; 42(8): 113018, 2023 08 29.
Artigo em Inglês | MEDLINE | ID: mdl-37605532

RESUMO

Mutations of the transcription factor FoxP3 in patients with "IPEX" (immune dysregulation, polyendocrinopathy, enteropathy, X-linked syndrome) disrupt regulatory T cells (Treg), causing an array of multiorgan autoimmunity. To understand the functional impact of mutations across FoxP3 domains, without genetic and environmental confounders, six human FOXP3 missense mutations are engineered into mice. Two classes of mutations emerge from combined immunologic and genomic analyses. A mutation in the DNA-binding domain shows the same lymphoproliferation and multiorgan infiltration as complete FoxP3 knockouts but delayed by months. Tregs expressing this mutant FoxP3 are destabilized by normal Tregs in heterozygous females compared with hemizygous males. Mutations in other domains affect chromatin opening differently, involving different cofactors and provoking more specific autoimmune pathology (dermatitis, colitis, diabetes), unmasked by immunological challenges or incrossing NOD autoimmune-susceptibility alleles. This work establishes that IPEX disease heterogeneity results from the actual mutations, combined with genetic and environmental perturbations, explaining then the intra-familial variation in IPEX.


Assuntos
Fatores de Transcrição Forkhead , Linfócitos T Reguladores , Animais , Feminino , Humanos , Masculino , Camundongos , Alelos , Fatores de Transcrição Forkhead/genética , Camundongos Endogâmicos NOD , Mutação/genética
19.
Int J Mol Sci ; 24(16)2023 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-37629156

RESUMO

The poor response, adverse effects and drug resistance to treatment of acute myeloid leukemia (AML) have led to searching for safer and more effective therapeutic alternatives. We previously demonstrated that the alcoholic extract of Petiveria alliacea (Esperanza) has a significant in vitro antitumor effect on other tumor cells and also the ability to regulate energy metabolism. We evaluated the effect of the Esperanza extract in vitro and in vivo in a murine model of AML with DA-3/ER-GM cells. First, a chemical characterization of the extract was conducted through liquid and gas chromatography coupled with mass spectrometry. In vitro findings showed that the extract modulates tumor metabolism by decreasing glucose uptake and increasing reactive oxygen species, which leads to a reduction in cell proliferation. Then, to evaluate the effect of the extract in vivo, we standardized the mouse model by injecting DA-3/ER-GM cells intravenously. The animals treated with the extract showed a lower percentage of circulating blasts, higher values of hemoglobin, hematocrit, and platelets, less infiltration of blasts in the spleen, and greater production of cytokines compared to the control group. These results suggest that the antitumor activity of this extract on DA-3/ER-GM cells can be attributed to the decrease in glycolytic metabolism, its activity as a mitocan, and the possible immunomodulatory effect by reducing tumor proliferation and metastasis.


Assuntos
Leucemia Mieloide , Phytolaccaceae , Animais , Camundongos , Carga Tumoral , Cromatografia Gasosa-Espectrometria de Massas , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico
20.
bioRxiv ; 2023 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-37645912

RESUMO

Mixed lineage kinase domain-like (MLKL) is a key signaling protein of necroptosis. Upon activation by phosphorylation, MLKL translocates to the plasma membrane and induces membrane permeabilization which contributes to the necroptosis-associated inflammation. Membrane binding of MLKL is initially initiated by the electrostatic interactions between the protein and membrane phospholipids. We previously showed that MLKL and its phosphorylated form (pMLKL) are S-acylated during necroptosis. Here, we characterize acylation sites of MLKL and identify multiple cysteines that can undergo acylation with an interesting promiscuity at play. Our results show that MLKL and pMLKL undergo acylation at a single cysteine, C184, C269 and C286 are the possible acylation sites. Using all atom molecular dynamic simulations, we identify differences that the acylation of MLKL causes at the protein and membrane level. Through systematic investigations of the S-palmitoyltransferases that might acylate MLKL in necroptosis, we showed that zDHHC21 activity has the strongest effect on pMLKL acylation, inactivation of which profoundly reduced the pMLKL levels in cells and improved membrane integrity. These results suggest that blocking the acylation of pMLKL destabilizes the protein at the membrane interface and causes its degradation, ameliorating necroptotic activity. At a broader level, our findings shed light on the effect of S-acylation on MLKL functioning in necroptosis and MLKL-membrane interactions mediated by its acylation.

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