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1.
Biomed Pharmacother ; 178: 117177, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39053423

RESUMEN

Cytokines regulate immune responses essential for maintaining immune homeostasis, as deregulated cytokine signaling can lead to detrimental outcomes, including inflammatory disorders. The antioxidants emerge as promising therapeutic agents because they mitigate oxidative stress and modulate inflammatory pathways. Antioxidants can potentially ameliorate inflammation-related disorders by counteracting excessive cytokine-mediated inflammatory responses. A comprehensive understanding of cytokine-mediated inflammatory pathways and the interplay with antioxidants is paramount for developing natural therapeutic agents targeting inflammation-related disorders and helping to improve clinical outcomes and enhance the quality of life for patients. Among these antioxidants, curcumin, vitamin C, vitamin D, propolis, allicin, and cinnamaldehyde have garnered attention for their anti-inflammatory properties and potential therapeutic benefits. This review highlights the interrelationship between cytokines-mediated disorders in various diseases and therapeutic approaches involving antioxidants.


Asunto(s)
Antiinflamatorios , Antioxidantes , Citocinas , Inflamación , Antioxidantes/uso terapéutico , Antioxidantes/farmacología , Humanos , Citocinas/metabolismo , Inflamación/tratamiento farmacológico , Animales , Antiinflamatorios/uso terapéutico , Antiinflamatorios/farmacología , Estrés Oxidativo/efectos de los fármacos , Transducción de Señal/efectos de los fármacos
2.
J Maxillofac Oral Surg ; 23(3): 688-691, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38911413

RESUMEN

Primary hyperparathyroidism is an endocrine disorder occurring due to increased secretion of parathormone resulting in clinical, anatomical, and biochemical alterations. On the other hand, excision of a parathyroid adenoma can normalize the metabolic status. Brown tumors represent the terminal stage of the remodeling processes during primary or secondary hyperparathyroidism. They are erosive bony lesions caused by rapid osteolysis and peritrabecular fibrosis, resulting in a local destructive phenomenon. Facial skeleton is involved in about 2% of all cases of which the mandible is frequently affected. We report a case series of four patients who presented with brown tumor of both maxilla and mandible. A complete assessment of the medical history, blood investigations and radiological findings combined with biopsy results is necessary for a correct diagnosis. The standard treatment of the Brown tumors is not a surgical resection, but the treatment of the cause of the tumor, which in this case is hyperparathyroidism. However in our case, the extent of the lesion and the non resolution after the parathyroidectomy necessitated a surgical approach in two of our patients however two responded well to medical management alone.

3.
Microb Cell Fact ; 22(1): 201, 2023 Oct 06.
Artículo en Inglés | MEDLINE | ID: mdl-37803395

RESUMEN

BACKGROUND: Xylitol has a wide range of applications in the pharmaceuticals, cosmetic, food and beverage industry. Microbial xylitol production reduces the risk of contamination and is considered as environment friendly and sustainable compared to the chemical method. In this study, random mutagenesis and genetic engineering approaches were employed to develop Candida tropicalis strains with reduced xylitol dehydrogenase (XDH) activity to eliminate co-substrate requirement for corn cob-based xylitol-ethanol biorefinery. RESULTS: The results suggest that when pure xylose (10% w/v) was fermented in bioreactor, the Ethyl methane sulfonate (EMS) mutated strain (C. tropicalis K2M) showed 9.2% and XYL2 heterozygous (XYL2/xyl2Δ::FRT) strain (C. tropicalis K21D) showed 16% improvement in xylitol production compared to parental strain (C. tropicalis K2). Furthermore, 1.5-fold improvement (88.62 g/L to 132 g/L) in xylitol production was achieved by C. tropicalis K21D after Response Surface Methodology (RSM) and one factor at a time (OFAT) applied for media component optimization. Finally, corncob hydrolysate was tested for xylitol production in biorefinery mode, which leads to the production of 32.6 g/L xylitol from hemicellulosic fraction, 32.0 g/L ethanol from cellulosic fraction and 13.0 g/L animal feed. CONCLUSIONS: This work, for the first time, illustrates the potential of C. tropicalis K21D as a microbial cell factory for efficient production of xylitol and ethanol via an integrated biorefinery framework by utilising lignocellulosic biomass with minimum waste generation.


Asunto(s)
Candida tropicalis , Xilitol , Candida tropicalis/genética , Zea mays , Fermentación , Etanol , Hidrólisis , Xilosa
4.
Philos Trans R Soc Lond B Biol Sci ; 378(1890): 20220236, 2023 11 20.
Artículo en Inglés | MEDLINE | ID: mdl-37778387

RESUMEN

During mammalian embryo development, pluripotent epiblast cells diversify into the three primary germ layers, which will later give rise to all fetal and adult tissues. These processes involve profound transcriptional and epigenetic changes that require precise coordination. Peptidylarginine deiminase IV (PADI4) is a transcriptional regulator that is strongly associated with inflammation and carcinogenesis but whose physiological roles are less well understood. We previously found that Padi4 expression is associated with pluripotency. Here, we examined the role of PADI4 in maintaining the multi-lineage differentiation potential of mouse embryonic stem (ES) cells. Using bulk and single-cell transcriptomic analyses of embryoid bodies (EBs) derived from Padi4 knock-out (Padi4-KO) mouse ES cells, we find that PADI4 loss impairs mesoderm diversification and differentiation of cardimyocytes and endothelial cells. Additionally, Padi4 deletion leads to concerted downregulation of genes associated with polarized growth, sterol metabolism and the extracellular matrix (ECM). This study indicates a requirement for Padi4 in the specification of the mesodermal lineage and reports the Padi4 associated transcriptome, providing a platform for understanding the physiological functions of Padi4 in development and homeostasis. This article is part of the Theo Murphy meeting issue 'The virtues and vices of protein citrullination'.


Asunto(s)
Células Endoteliales , Arginina Deiminasa Proteína-Tipo 4 , Transcriptoma , Animales , Ratones , Diferenciación Celular , Células Madre Embrionarias , Arginina Deiminasa Proteína-Tipo 4/genética
5.
J Craniofac Surg ; 34(1): e46-e52, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36008879

RESUMEN

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has posed another serious threat, mucormycosis infection, affecting the maxilla and orbitocerebral region. This condition has not spared world population from its merciless claws. This article addresses the challenges faced by the maxillofacial surgeons in setting the protocols from preoperative diagnosis, surgical management to postoperative care, including short-term and long-term rehabilitation. To manage this relentlessly progressing condition, a multispecialty team approach is to be activated in diagnosing, managing, and rehabilitating the patients. PURPOSE: The purpose of this clinical study is to document and analyze the clinical and demographic data, presentation of the lesion, the diagnostic methods followed for early clinical detection, and management of post COVID-19 midface mucormycosis. The article also discusses postoperative medical management and prosthetic rehabilitation. RESULTS: Most of the mucormycosis cases reporting to our center were treated and recovered patients of Severe Acute Respiratory Syndrome Coronavirus 2 infection. Thirty-four (n=34) case were operated for post COVID-19 midface mucormycosis between October 2020 and December 2021. Male to Female ratio is 1:42. The average age of the patients was 57.5 years. Maximum patients were in fifth and sixth decade of life. Maxilla was the involved bone. Treatment was primarily surgical debridement to extended or radical maxillectomy. All patients were treated with Liposomal Amphotericin B and tab posaconazole for 3 to 4 weeks depending upon the age, weight, and physiological state of the patients to attain an optimal cumulative load. Three patients succumbed to illness postoperatively (n=3, 1.02%). Average duration of hospital stay was 47 days. The average review period was 5.1 months.


Asunto(s)
COVID-19 , Mucormicosis , Humanos , Femenino , Masculino , Persona de Mediana Edad , Mucormicosis/diagnóstico , Mucormicosis/cirugía , Cara , Cuidados Posoperatorios , Antifúngicos/uso terapéutico
6.
Ann Maxillofac Surg ; 13(2): 240-243, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38405571

RESUMEN

Rationale: Congenital orofacial swellings in neonates are mainly limited to vascular malformations and neuroectodermal benign tumours. Congenital granular cell tumour (CGCT) is a rare condition affecting neonates with a prevalence rate of 6 in 1 million. Our report provides a brief review of diagnosis and management. Patient Concern: A 4-day-old female neonate was brought in with the chief complaint of a single, lobulated mass protruding from the right side of the oral cavity. The inability to achieve lip seal and suckling resulting in feeding problems was the primary concern. Diagnosis and Treatment: Surgical excision of the lesion was carried out under general anaesthesia. Resected mass was confirmed to be a CGCT upon histopathological evaluation. Outcome: One-year follow-up showed satisfactory healing with no evidence of recurrence. Take-away Lesson: Ultrasonography and other imaging modalities help in differentiating it from vascular malformations. Simple surgical excision suffices to treat the condition.

7.
Proc Natl Acad Sci U S A ; 119(50): e2217542119, 2022 12 13.
Artículo en Inglés | MEDLINE | ID: mdl-36490315

RESUMEN

R-loops, or RNA:DNA hybrids, can induce DNA damage, which requires DNA repair factors including breast cancer type 1 susceptibility protein (BRCA1) to restore genomic integrity. To date, several pathogenic mutations have been found within the tandem BRCA1 carboxyl-terminal (BRCT) domains that mediate BRCA1 interactions with proteins and DNA in response to DNA damage. Here, we describe a nonrepair role of BRCA1 BRCT in suppressing ribosomal R-loops via two mechanisms. Through its RNA binding and annealing activities, BRCA1 BRCT facilitates the formation of double-stranded RNA between ribosomal RNA (rRNA) and antisense-rRNA (as-rRNA), hereby minimizing rRNA hybridization to ribosomal DNA to form R-loops. BRCA1 BRCT also promotes RNA polymerase I-dependent transcription of as-rRNA to enhance double-stranded rRNA (ds-rRNA) formation. In addition, BRCA1 BRCT-mediated as-rRNA production restricts rRNA maturation in unperturbed cells. Hence, impairing as-rRNA transcription and ds-rRNA formation due to BRCA1 BRCT deficiency deregulates rRNA processing and increases ribosomal R-loops and DNA breaks. Our results link ribosomal biogenesis dysfunction to BRCA1-associated genomic instability.


Asunto(s)
Proteína BRCA1 , ARN Bicatenario , Proteína BRCA1/metabolismo , ARN sin Sentido , Reparación del ADN , Daño del ADN , ADN
8.
Nat Commun ; 13(1): 7344, 2022 11 29.
Artículo en Inglés | MEDLINE | ID: mdl-36446780

RESUMEN

Triple-Negative Breast Cancer (TNBC) has a poor prognosis and adverse clinical outcomes among all breast cancer subtypes as there is no available targeted therapy. Overexpression of Enhancer of zeste homolog 2 (EZH2) has been shown to correlate with TNBC's poor prognosis, but the contribution of EZH2 catalytic (H3K27me3) versus non-catalytic EZH2 (NC-EZH2) function in TNBC progression remains elusive. We reveal that selective hyper-activation of functional EZH2 (H3K27me3) over NC-EZH2 alters TNBC metastatic landscape and fosters its peritoneal metastasis, particularly splenic. Instead of H3K27me3-mediated repression of gene expression; here, it promotes KRT14 transcription by attenuating binding of repressor SP1 to its promoter. Further, KRT14 loss significantly reduces TNBC migration, invasion, and peritoneal metastasis. Consistently, human TNBC metastasis displays positive correlation between H3K27me3 and KRT14 levels. Finally, EZH2 knockdown or H3K27me3 inhibition by EPZ6438 reduces TNBC peritoneal metastasis. Altogether, our preclinical findings suggest a rationale for targeting TNBC with EZH2 inhibitors.


Asunto(s)
Neoplasias Peritoneales , Neoplasias de la Mama Triple Negativas , Humanos , Proteína Potenciadora del Homólogo Zeste 2/genética , Histonas/genética , Queratina-14/genética , Neoplasias Peritoneales/genética , Neoplasias Peritoneales/secundario , Neoplasias de la Mama Triple Negativas/genética , Neoplasias de la Mama Triple Negativas/patología , Regulación hacia Arriba
9.
Ann Maxillofac Surg ; 12(1): 91-94, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36199457

RESUMEN

Rationale: Melanotic neuroectodermal tumour of infancy (MNTI) is universally described as a rare, benign, pigmented lesion which most frequently involves the maxilla. Its origin is well established to be in the neural crest cells. Due to the high recurrence rate and aggressive behaviour mimicking malignancy, it poses a great challenge in their diagnosis, treatment planning, and prognosis. Patient Concern: Two-year-old female with no known comorbidities was brought in with the chief complaint of a growing swelling in the upper lip region. Diagnosis and Treatment: She was taken up for resection of the tumour under general anaesthesia. The specimen was subjected to histological and immunological examination confirming the diagnosis of MNTI. Outcome: The postoperative period was uneventful. After regular follow-up, the patient showed satisfactory healing with no signs of recurrence. Take-Away Lessons: Based on our experience, we feel that the diagnosis of MNTI is mainly clinical. Early conservative surgical excision and regular follow-up provide an excellent result with good prognosis.

10.
Environ Technol ; : 1-15, 2022 Jul 06.
Artículo en Inglés | MEDLINE | ID: mdl-35762251

RESUMEN

HIGHLIGHTSCandia tropicalis K2 isolate was screened from natural sites of biomass degradation and characterized for xylitol production.Non-detoxified Albizia pod and corncob hydrolysates were explored for xylitol production using selected C. tropicalis K2 isolate.A maximum of 0.90 g/g yield and 1.07 g/L.h xylitol productivity was achieved with pure xylose.A >10% increase in xylitol yield was achieved using glycerol as a co-substrate.

11.
Med J Armed Forces India ; 78(3): 360-364, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35368449

RESUMEN

COVID-19 (Coronavirus Disease 2019), illness with associated comorbidities and corticosteroid therapy makes the host immunocompromised and prone to opportunistic microbial infections. As the world continues to struggle with the pandemic of COVID-19, an increase in cases of opportunistic fungal infections have been reported from all over the world during the second wave of COVID-19 like aspergillosis, mucormycosis, and candidiasis. Scedosporium apiospermum is an emerging pathogen that is usually associated with mycetoma, pulmonary infection, and central nervous infections. It has been rarely associated with fungal rhinosinusitis (FRS). In this study, a rare case of FRS caused by S.apiospermum in an immunocompromised post-Covid-19 diabetic woman is reported.

12.
Curr Microbiol ; 78(8): 3258-3267, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-34230990

RESUMEN

Rapid industrialization and intensive agriculture activities have led to a rise in heavy metal contamination all over the world. Chhattisgarh (India) being an industrial state, the soil and water are thickly contaminated with heavy metals, especially from arsenic (As). In the present study, we isolated 108 arsenic-resistant bacteria (both from soil and water) from different arsenic-contaminated industrial and mining sites of Chhattisgarh to explore the bacterial gene pool. Further, we screened 24 potential isolates out of 108 for their ability to tolerate a high level of arsenic. The sequencing of the 16S rRNA gene of bacterial isolates revealed that all these samples belong to different diverse genera including Bacillus, Enterobacter, Klebsiella, Pantoea, Acinetobacter, Cronobacter, Pseudomonas and Agrobacterium. The metal tolerance ability was determined by amplification of arsB (arsenite efflux gene) and arsC (arsenate reductase gene) from chromosomal DNA of isolated RnASA11, which was identified as Klebsiella pneumoniae through in silico analysis. The bacterial strains RpSWA2 and RnASA11 were found to tolerate 600 mM As (V) and 30 mM As (III) but the growth of strain RpSWA2 was slower than RnASA11. Furthermore, atomic absorption spectroscopy (AAS) of the sample obtained from bioremediation assay revealed that Klebsiella pneumoniae RnASA11 was able to reduce the arsenic concentration significantly in the presence of arsenate (44%) and arsenite (38.8%) as compared to control.


Asunto(s)
Arsénico , Contaminantes del Suelo , Biodegradación Ambiental , Farmacorresistencia Bacteriana , India , Klebsiella pneumoniae/genética , Filogenia , ARN Ribosómico 16S/genética , Suelo , Agua
13.
Viruses ; 13(2)2021 01 29.
Artículo en Inglés | MEDLINE | ID: mdl-33573085

RESUMEN

Viruses require a host for replication and survival and hence are subjected to host immunological pressures. The complement system, a crucial first response of the host immune system, is effective in targeting viruses and virus-infected cells, and boosting the antiviral innate and acquired immune responses. Thus, the system imposes a strong selection pressure on viruses. Consequently, viruses have evolved multiple countermeasures against host complement. A major mechanism employed by viruses to subvert the complement system is encoding proteins that target complement. Since viruses have limited genome size, most of these proteins are multifunctional in nature. In this review, we provide up to date information on the structure and complement regulatory functions of various viral proteins.


Asunto(s)
Proteínas del Sistema Complemento/inmunología , Proteínas Virales/inmunología , Virus/inmunología , Animales , Activación de Complemento , Humanos , Evasión Inmune , Inmunidad Innata , Virosis/inmunología , Virosis/virología , Virus/clasificación
14.
Folia Microbiol (Praha) ; 66(2): 189-196, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33131029

RESUMEN

In the present study, bacterial isolates were screened for arsenic resistance efficiency. Environmental isolates were isolated from arsenic-rich soil samples (i.e., from Rajnandgaon district of Chhattisgarh state, India). Amplification and sequencing of 16S rRNA gene revealed that the isolates were of Bacillus firmus RSN1, Brevibacterium senegalense RSN2, Enterobacter cloacae RSN3, Stenotrophomonas pavanii RSN6, Achromobacter mucicolens RSN7, and Ochrobactrum intermedium RSN10. Arsenite efflux gene (arsB) was successfully amplified in E. cloacae RSN3. Atomic absorption spectroscopy (AAS) analysis showed an absorption of 32.22% arsenic by the RSN3 strain. Furthermore, results of scanning electron microscopy (SEM) for morphological variations revealed an initial increase in the cell size at 1 mM sodium arsenate; however, it was decreased at 10 mM concentration in comparison to control. This change of the cell size in different metal concentrations was due to the uptake and expulsion of the metal from the cell, which also confirmed the arsenite efflux system.


Asunto(s)
Arsénico , Contaminantes del Suelo , Achromobacter , Brevibacterium , Enterobacter cloacae/genética , Ochrobactrum , ARN Ribosómico 16S/genética , Suelo , Stenotrophomonas
15.
Epigenetics ; 16(2): 144-161, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-32635858

RESUMEN

Drug resistance is one of the trademark features of Cancer Stem Cells (CSCs). We and others have recently shown that paucity of functional death receptors (DR4/5) on the cell surface of tumour cells is one of the major reasons for drug resistance, but their involvement in the context of in CSCs is poorly understood. By harnessing CSC specific cytotoxic function of salinomycin, we discovered a critical role of epigenetic modulator EZH2 in regulating the expression of DRs in colon CSCs. Our unbiased proteome profiler array approach followed by ChIP analysis of salinomycin treated cells indicated that the expression of DRs, especially DR4 is epigenetically repressed in colon CSCs. Concurrently, EZH2 knockdown demonstrated increased expression of DR4/DR5, significant reduction of CSC phenotypes such as spheroid formation in-vitro and tumorigenic potential in-vivo in colon cancer. TCGA data analysis of human colon cancer clinical samples shows strong inverse correlation between EZH2 and DR4. Taken together, this study provides an insight about epigenetic regulation of DR4 in colon CSCs and advocates that drug-resistant colon cancer can be therapeutically targeted by combining TRAIL and small molecule EZH2 inhibitors.


Asunto(s)
Neoplasias del Colon , Proteína Potenciadora del Homólogo Zeste 2/antagonistas & inhibidores , Células Madre Neoplásicas , Piranos/farmacología , Receptores del Ligando Inductor de Apoptosis Relacionado con TNF/metabolismo , Apoptosis , Línea Celular Tumoral , Neoplasias del Colon/metabolismo , Metilación de ADN , Epigénesis Genética , Humanos , Células Madre Neoplásicas/metabolismo , Receptores del Ligando Inductor de Apoptosis Relacionado con TNF/genética
16.
Trends Cancer ; 6(7): 559-568, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32336659

RESUMEN

Despite their ubiquitous expression, the inheritance of monoallelic germline mutations in breast cancer susceptibility gene type 1 or 2 (BRCA1/2) poses tissue-specific variations in cancer risks and primarily associate with familial breast and ovarian cancers. The molecular basis of this tissue-specific tumor incidence remains unknown and intriguing to cancer researchers. A plethora of recent reports support the idea that several nongenetic factors present in the tissue microenvironment could induce tumors in the mutant BRCA1/2 background. This Opinion article summarizes the recent advances on tissue-specific carcinogens and their complex crosstalk with the compromised DNA repair machinery of BRCA1/2-mutant cells. Finally, we present our perspective on the therapeutic and chemopreventive interpretations of these developments.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Carcinógenos/metabolismo , Síndrome de Cáncer de Mama y Ovario Hereditario/patología , Neoplasias de la Próstata/patología , Microambiente Tumoral/efectos de los fármacos , Aldehídos/metabolismo , Andrógenos/metabolismo , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Antioxidantes/farmacología , Antioxidantes/uso terapéutico , Proteína BRCA1/genética , Proteína BRCA1/metabolismo , Proteína BRCA2/genética , Proteína BRCA2/metabolismo , Bicarbonatos/metabolismo , Mama/patología , Carcinogénesis/genética , Carcinogénesis/patología , Roturas del ADN de Doble Cadena , Reparación del ADN/efectos de los fármacos , Estrógenos/metabolismo , Femenino , Predisposición Genética a la Enfermedad , Síndrome de Cáncer de Mama y Ovario Hereditario/tratamiento farmacológico , Síndrome de Cáncer de Mama y Ovario Hereditario/genética , Síndrome de Cáncer de Mama y Ovario Hereditario/prevención & control , Humanos , Masculino , Mutación , Ovario/patología , Inhibidores de Poli(ADP-Ribosa) Polimerasas/farmacología , Inhibidores de Poli(ADP-Ribosa) Polimerasas/uso terapéutico , Próstata/patología , Neoplasias de la Próstata/tratamiento farmacológico , Neoplasias de la Próstata/genética , Neoplasias de la Próstata/prevención & control , Especies de Nitrógeno Reactivo/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Microambiente Tumoral/genética
17.
Proc Natl Acad Sci U S A ; 117(7): 3621-3626, 2020 02 18.
Artículo en Inglés | MEDLINE | ID: mdl-32024762

RESUMEN

Ten-eleven translocation (TET) family enzymes (TET1, TET2, and TET3) oxidize 5-methylcytosine (5mC) and generate 5-hydroxymethylcytosine (5hmC) marks on the genome. Each TET protein also interacts with specific binding partners and partly plays their role independent of catalytic activity. Although the basic role of TET enzymes is well established now, the molecular mechanism and specific contribution of their catalytic and noncatalytic domains remain elusive. Here, by combining in silico and biochemical screening strategy, we have identified a small molecule compound, C35, as a first-in-class TET inhibitor that specifically blocks their catalytic activities. Using this inhibitor, we explored the enzymatic function of TET proteins during somatic cell reprogramming. Interestingly, we found that C35-mediated TET inactivation increased the efficiency of somatic cell programming without affecting TET complexes. Using high-throughput mRNA sequencing, we found that by targeting 5hmC repressive marks in the promoter regions, C35-mediated TET inhibition activates the transcription of the BMP-SMAD-ID signaling pathway, which may be responsible for promoting somatic cell reprogramming. These results suggest that C35 is an important tool for inducing somatic cell reprogramming, as well as for dissecting the other biological functions of TET enzymatic activities without affecting their other nonenzymatic roles.


Asunto(s)
Reprogramación Celular , Proteínas de Unión al ADN/antagonistas & inhibidores , Dioxigenasas/antagonistas & inhibidores , Inhibidores Enzimáticos/química , Proteínas Proto-Oncogénicas/antagonistas & inhibidores , 5-Metilcitosina/análogos & derivados , 5-Metilcitosina/metabolismo , Dominio Catalítico , Línea Celular , Reprogramación Celular/efectos de los fármacos , Proteínas de Unión al ADN/química , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Dioxigenasas/química , Dioxigenasas/genética , Dioxigenasas/metabolismo , Humanos , Oxigenasas de Función Mixta/antagonistas & inhibidores , Oxigenasas de Función Mixta/química , Oxigenasas de Función Mixta/genética , Oxigenasas de Función Mixta/metabolismo , Proteínas Proto-Oncogénicas/química , Proteínas Proto-Oncogénicas/genética , Proteínas Proto-Oncogénicas/metabolismo
18.
Nucleic Acids Res ; 48(6): 3001-3013, 2020 04 06.
Artículo en Inglés | MEDLINE | ID: mdl-31965183

RESUMEN

Nucleosomal histones are barriers to the DNA repair process particularly at DNA double-strand breaks (DSBs). However, the molecular mechanism by which these histone barriers are removed from the sites of DNA damage remains elusive. Here, we have generated a single specific inducible DSB in the cells and systematically examined the histone removal process at the DNA lesion. We found that histone removal occurred immediately following DNA damage and could extend up to a range of few kilobases from the lesion. To examine the molecular mechanism underlying DNA damage-induced histone removal, we screened histone modifications and found that histone ADP-ribosylation was associated with histone removal at DNA lesions. PARP inhibitor treatment suppressed the immediate histone eviction at DNA lesions. Moreover, we examined histone chaperones and found that the FACT complex recognized ADP-ribosylated histones and mediated the removal of histones in response to DNA damage. Taken together, our results reveal a pathway that regulates early histone barrier removal at DNA lesions. It may also explain the mechanism by which PARP inhibitor regulates early DNA damage repair.


Asunto(s)
Daño del ADN/genética , Reparación del ADN/genética , Histonas/genética , Poli ADP Ribosilación/genética , ADP-Ribosilación/genética , Núcleo Celular/genética , Cromatina/genética , Cromosomas Humanos X/genética , Roturas del ADN de Doble Cadena/efectos de los fármacos , Reparación del ADN/efectos de los fármacos , Células HCT116 , Humanos , Chaperonas Moleculares/genética , Nucleosomas/genética , Inhibidores de Poli(ADP-Ribosa) Polimerasas/farmacología
19.
J Biol Chem ; 293(33): 12770-12780, 2018 08 17.
Artículo en Inglés | MEDLINE | ID: mdl-29959229

RESUMEN

Set7/9 (also known as Set7, Set9, Setd7, and Kmt7) is a lysine methyltransferase that catalyzes the methylation of multiple substrates, including histone H3 and non-histone proteins. Although not essential for normal development and physiology, Set7/9-mediated methylation events play important roles in regulating cellular pathways involved in various human diseases, making Set7/9 a promising therapeutic target. Multiple Set7/9 inhibitors have been developed, which exhibit varying degrees of potency and selectivity in vitro However, validation of these compounds in vivo has been hampered by the lack of a reliable cellular biomarker for Set7/9 activity. Here, we report the identification of Rpl29, a ribosomal protein abundantly expressed in all cell types, as a major substrate of Set7/9. We show that Rpl29 lysine 5 (Rpl29K5) is methylated exclusively by Set7/9 and can be demethylated by Lsd1 (also known as Kdm1a). Rpl29 is not a core component of the ribosome translational machinery and plays a regulatory role in translation efficiency. Our results indicate that Rpl29 methylation has no effect on global protein synthesis but affects Rpl29 subcellular localization. Using an Rpl29 methylation-specific antibody, we demonstrate that Rpl29K5 methylation is present ubiquitously and validate that (R)-PFI-2, a Set7/9 inhibitor, efficiently reduces Rpl29K5 methylation in cell lines. Thus, Rpl29 methylation can serve as a specific cellular biomarker for measuring Set7/9 activity.


Asunto(s)
Factores de Coagulación Sanguínea/genética , Metilación de ADN , Regulación de la Expresión Génica , N-Metiltransferasa de Histona-Lisina/metabolismo , Histonas/metabolismo , Lisina/química , Proteínas Ribosómicas/fisiología , Animales , Factores de Coagulación Sanguínea/metabolismo , Células Cultivadas , Células Madre Embrionarias/citología , Células Madre Embrionarias/metabolismo , Fibroblastos/citología , Fibroblastos/metabolismo , N-Metiltransferasa de Histona-Lisina/genética , Humanos , Masculino , Ratones Noqueados , Procesamiento Proteico-Postraduccional , Proteínas de Unión al ARN , Transcripción Genética
20.
Langmuir ; 33(46): 13401-13406, 2017 11 21.
Artículo en Inglés | MEDLINE | ID: mdl-29087204

RESUMEN

Rylene imides (RIs) self-assemble into various nanostructures. Often, the synthesis of unsymmetrical RIs (URIs) is required to achieve nanostructures. However, the synthesis of URIs is nontrivial. Thus, a structurally similar alternative is desirable. iso-Indigo (i-indigo) has a π core and lactam rings that are structurally similar to the RIs. Unsymmetrical iso-indigo (i-indigo) can be easily synthesized by condensing oxindole and isatin. We have synthesized a series of unsymmetrical i-indigo molecules. In these molecules, the π-π interaction, hydrogen bonding, and van der Waals interactions are in operation. Because of these, the molecules self-assemble into spheres, fibers, and dahlia flower morphologies. If the hydrogen bonding interaction is disrupted, then all of them form fibers. Control experiments indicate that the complete absence of hydrogen bonding is deleterious to self-assembly. We also show that the lower analogs of i-indigo are not sufficient to form self-assembled nanostructures.

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