Publications by authors named "Monica Mendoza"

13 Publications

  • Page 1 of 1

In vivo MRI evaluation of early postnatal development in normal and impaired rat eyes.

Sci Rep 2021 Jul 30;11(1):15513. Epub 2021 Jul 30.

Department of Ophthalmology, NYU Grossman School of Medicine, NYU Langone Health, New York University, New York, NY, USA.

This study employed in vivo 7-T magnetic resonance imaging (MRI) to evaluate the postnatal ocular growth patterns under normal development or neonatal impairments in Sprague-Dawley rats. Using T2-weighted imaging on healthy rats from postnatal day (P) 1 (newborn) to P60 (adult), the volumes of the anterior chamber and posterior chamber (ACPC), lens, and vitreous humor increased logistically with ACPC expanding by 33-fold and the others by fivefold. Intravitreal potassium dichromate injection at P1, P7, and P14 led to T1-weighted signal enhancement in the developing retina by 188-289%. Upon unilateral hypoxic-ischemic encephalopathy at P7, monocular deprivation at P15, and monocular enucleation at P1, T2-weighted imaging of the adult rats showed decreased ocular volumes to different extents. In summary, in vivo high-field MRI allows for non-invasive evaluation of early postnatal development in the normal and impaired rat eyes. Chromium-enhanced MRI appeared effective in examining the developing retina before natural eyelid opening at P14 with relevance to lipid metabolism. The reduced ocular volumes upon neonatal visual impairments provided evidence to the emerging problems of why some impaired visual outcomes cannot be solely predicted by neurological assessments and suggested the need to look into both the eye and the brain under such conditions.
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http://dx.doi.org/10.1038/s41598-021-93991-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8324881PMC
July 2021

The elongation factor eEF1A2 controls translation and actin dynamics in dendritic spines.

Sci Signal 2021 Jul 13;14(691). Epub 2021 Jul 13.

Molecular Biology Institute of Barcelona (IBMB), CSIC, Catalonia 08028, Spain.

Synaptic plasticity involves structural modifications in dendritic spines that are modulated by local protein synthesis and actin remodeling. Here, we investigated the molecular mechanisms that connect synaptic stimulation to these processes. We found that the phosphorylation of isoform-specific sites in eEF1A2-an essential translation elongation factor in neurons-is a key modulator of structural plasticity in dendritic spines. Expression of a nonphosphorylatable eEF1A2 mutant stimulated mRNA translation but reduced actin dynamics and spine density. By contrast, a phosphomimetic eEF1A2 mutant exhibited decreased association with F-actin and was inactive as a translation elongation factor. Activation of metabotropic glutamate receptor signaling triggered transient dissociation of eEF1A2 from its regulatory guanine exchange factor (GEF) protein in dendritic spines in a phosphorylation-dependent manner. We propose that eEF1A2 establishes a cross-talk mechanism that coordinates translation and actin dynamics during spine remodeling.
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http://dx.doi.org/10.1126/scisignal.abf5594DOI Listing
July 2021

Stress granules display bistable dynamics modulated by Cdk.

J Cell Biol 2021 03;220(3)

Molecular Biology Institute of Barcelona, Spanish National Research Council, Catalonia, Spain.

Stress granules (SGs) are conserved biomolecular condensates that originate in response to many stress conditions. These membraneless organelles contain nontranslating mRNAs and a diverse subproteome, but our knowledge of their regulation and functional relevance is still incipient. Here, we describe a mutual-inhibition interplay between SGs and Cdc28, the budding yeast Cdk. Among Cdc28 interactors acting as negative modulators of Start, we have identified Whi8, an RNA-binding protein that localizes to SGs and recruits the mRNA of CLN3, the most upstream G1 cyclin, for efficient translation inhibition and Cdk inactivation under stress. However, Whi8 also contributes to recruiting Cdc28 to SGs, where it acts to promote their dissolution. As predicted by a mutual-inhibition framework, the SG constitutes a bistable system that is modulated by Cdk. Since mammalian cells display a homologous mechanism, we propose that the opposing functions of specific mRNA-binding proteins and Cdk's subjugate SG dynamics to a conserved hysteretic switch.
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http://dx.doi.org/10.1083/jcb.202005102DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7836273PMC
March 2021

[Arsenic Intake: Impact in Human Nutrition and Health].

Rev Peru Med Exp Salud Publica 2018 Jan-Mar;35(1):93-102

Facultad de Ciencias de la Salud, Universidad Científica del Sur. Lima Perú.

Arsenic is an element that is widely distributed throughout the environment. Its compounds are mainly in the state of pentavalent and trivalent oxidation; and in inorganic and organic forms. Arsenical species vary in their degree of toxicity, with inorganic compounds being more toxic than organic and trivalent compounds more toxic than pentavalent compounds. There would be interconversion between the less toxic species and other more toxic species and the cooking and processing methods could affect it. Arsenic is a carcinogenic agent and causes multiple negative effects on human health in the short and long term. Non-occupational human exposure to arsenic occurs mainly through water and food. The regulation is variable for each country and is based on WHO standards, the Codex Alimentarius, and the European Union. Many studies focus on determining the total arsenic content but do not identify arsenical species in foods. Globally, fish and seafood, chicken, meat, rice, and seaweed have high levels of arsenic. In Peru, there are few studies on total arsenic content and arsenical species in food despite the fact that we have areas with high levels of environmental contamination. The objective of this review is to discuss exposure to arsenic through food and water intake, related regulations, toxicity, consequences on human health and main foods that contribute to its intake.
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http://dx.doi.org/10.17843/rpmesp.2018.351.3604DOI Listing
January 2019

[Genes associated to cancer].

Rev Med Inst Mex Seguro Soc 2015 ;53 Suppl 2:S178-87

Laboratorio de Oncología Genómica, Unidad de Investigación Médica en Enfermedades Oncológicas, Hospital de Oncología, Instituto Mexicano del Seguro Social, Distrito Federal, México.

In 2010, in a cancer genes census, 291 genes were enumerated. These represent near to the 1 % of the total genes, for which there is enough biological evidence that they belong to a new genes classification, known as the cancer genes. These have been defined as the causal genes for sporadic or familiar cancer, when they mutate. The mutation types for these genes includes amplifications, point mutations, deletions, genomic rearranges, amongst others, which lead to a protein over-expression, muting, production of chimeric proteins or a de novo expression. In conjunction these genomic alterations or those of the genetic expression, when they affect specific genes which contribute to the development of cancer, are denominated as cancer genes. It is possible that the list of these alterations will grow longer due to new strategies being developed, for example, the genomic analysis.
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January 2017

Human papillomavirus genotypes among females in Mexico: a study from the Mexican institute for social security.

Asian Pac J Cancer Prev 2014 ;15(23):10061-6

Unidad de Investigacion Medica en Enfermedades Oncologicas, Hospital de Oncologia, Centro Medico Nacional Siglo XXI, Instituto Mexicano del Seguro Social (Mexican Institute for Social Security; IMSS), Mexico E-mail :

Background: The aetiological relationship between human papillomavirus (HPV) infection and cervical cancer (CC) is widely accepted. Our goal was to determine the prevalence of HPV types in Mexican women attending at the Mexican Institute for Social Security from different areas of Mexico.

Materials And Methods: DNAs from 2,956 cervical samples were subjected to HPV genotyping: 1,020 samples with normal cytology, 931 with low-grade squamous intraepithelial lesions (LGSIL), 481 with high grade HGSIL and 524 CC.

Results: Overall HPV prevalence was 67.1%. A total of 40 HPV types were found; HPV16 was detected in 39.4% of the HPV-positive samples followed by HPV18 at 7.5%, HPV31 at 7.1%, HPV59 at 4.9%, and HPV58 at 3.2%. HPV16 presented the highest prevalence both in women with altered or normal cytology and HPV 18 presented a minor prevalence as reported worldwide. The prevalence ratio (PR) was calculated for the HPV types. The analysis of PR showed that HPV16 presents the highest association with CC, HPV 31, -33, -45, -52 and -58 also demonstrating a high association.

Conclusions: The most prevalent HPV types in cervical cancer samples were -16, -18, -31, but it is important to note that we obtained a minor prevalence of HPV18 as reported worldwide, and that HPV58 and -52 also were genotypes with an important prevalence in CC samples. Determination of HPV genotypes is very important in order to evaluate the impact of vaccine introduction and future cervical cancer prevention strategies.
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http://dx.doi.org/10.7314/apjcp.2014.15.23.10061DOI Listing
September 2015

The neurofibromin 1 type I isoform predominance characterises female population affected by sporadic breast cancer: preliminary data.

J Clin Pathol 2012 May 12;65(5):419-23. Epub 2012 Mar 12.

Laboratorio de Oncogenómica, Unidad de Investigación Médica en Enfermedades Oncológicas, Hospital de Oncología, CMN-SXXI, IMSS, Mexico, D.F.

Aims: Neurofibromin 1 (NF1) as a tumour suppressor gene can give rise to several transcripts by an alternative splicing event, generated at least for CELF cofactors. At present, the NF1 isoforms and CELF splicing transcripts in sporadic breast cancer are unknown. The aim of the authors was to detect NF1 gene expression, the NF1 isoform ratio and the CELF transcripts present in sporadic breast cancer.

Methods: Neurofibromin and RAS expression were analysed on tissue microarrays containing sporadic breast cancer (n=22), benign lesions (n=18, including six fibroadenomas, six fibrocystic changes and six ductal hyperplasias) and normal breast tissue (n=6) by immunohistochemistry assay. NF1 and CELF 3-6 RNA expression was performed by end point reverse transcription-PCR in the breast samples.

Results: NF1 and RAS expression in breast tissues showed no differential expression by immunohistochemistry results. Interestingly, the authors observed a shift transition in the isoform transcripts, from type II in normal breast tissue to type I isoform in breast carcinomas. CELF cofactor expression failed to be related with the shift transition of NF1 in breast tissues.

Conclusions: These data suggest that there is a tendency for an NF1 expression shift transition from type II to type I isoform, which could comprise a significant event in the development and progression of sporadic breast cancer. This shift transition may not be related with CELF cofactors.
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http://dx.doi.org/10.1136/jclinpath-2011-200569DOI Listing
May 2012

Low frequency of human papillomavirus infection in conjunctival squamous cell carcinoma of Mexican patients.

Infect Agent Cancer 2011 Nov 18;6:24. Epub 2011 Nov 18.

Laboratorio de Oncogenomica, UIMEO, Hospital de Oncología, CMN-SXXI, IMSS, Av Cuauhtemoc 330, Col, Doctores, 06720, Mexico DF, Mexico.

Background: The relationship between Human Papillomavirus (HPV) infection and conjunctiva cancer is controversial. HPV detection will provide more information about the role of this infectious agent in the biology of conjunctiva cancer. In the present study, DNA extracted and purified from 36 Conjunctival Squamous Cell Carcinomas (CSCC) was evaluated by PCR for HPV DNA sequences. The results were correlated with the clinical and histopathological variables.

Results: The results showed that HPV DNA was present in 8 CSCC samples (22%); HPV16 was the sole type detected. Significant association was found between HPV detection and the limbus tumor subtype (p = 0.03). All the samples were non-metastatic squamous cell carcinoma.

Conclusions: The HPV presence in CSCC from Mexican patients is not a common event.
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http://dx.doi.org/10.1186/1750-9378-6-24DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3226560PMC
November 2011

Correlation between expression of cellular retinol-binding protein 1 and its methylation status in larynx cancer.

J Clin Pathol 2012 Jan 2;65(1):46-50. Epub 2011 Nov 2.

Laboratorio de Oncogenomica, UIMEO, Hospital de Oncología, CMN-SXXI, IMSS, México, Distrito Federal, Mexico.

Aims: The authors have previously reported that cellular retinol-binding protein 1 (CRBP1) gene gain and its expression correlated significantly with survival in laryngeal carcinoma patients. The authors hypothesised that inactivation of the CRBP1 gene through CpG methylation is associated with patient status and gene expression. In this work, the authors determine the expression and methylation status of the CRBP1 gene and its correlation with clinical variables of laryngeal carcinoma patients.

Methods: The CRBP1 gene methylation promoter was assessed by methylation specific PCR analysis in tissue samples from larynx cancer specimens and its expression was assessed by immunohistochemistry on paraffin embedded tissue using tissue microarray. The results were then compared with the clinical pathological variables and outcome measures. The study included 46 samples from patients with non-metastatic squamous cell carcinoma of the larynx without any previous oncological treatments.

Results: Lack of CRBP1 expression was seen in 17 of the 46 laryngeal carcinoma samples, while the remaining 29 samples showed increased expression. Significant associations were found between CRBP1 expression and methylation and patient status. There was a tendency for association in all clinical stages of the disease. CRBP1 gene expression and its unmethylated promoter correlated significantly with survival (p<0.05).

Conclusions: An early event of larynx cancer could be CRBP1 expression related to unmethylation of the promoter region. These features could also be associated with good response and survival. The authors hypothesised that increased expression and unmethylated promoter of the CRBP1 gene could be considered as markers for larynx cancer.
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http://dx.doi.org/10.1136/jclinpath-2011-200304DOI Listing
January 2012

The Arabidopsis ABA-INSENSITIVE (ABI) 4 factor acts as a central transcription activator of the expression of its own gene, and for the induction of ABI5 and SBE2.2 genes during sugar signaling.

Plant J 2009 Aug 26;59(3):359-74. Epub 2009 Mar 26.

Departamento de Biología Molecular de Plantas, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Morelos, México.

The transcription factor ABA INSENSITIVE 4 (ABI4), discovered nearly 10 years ago, plays a central role in a variety of functions in plants, including sugar responses. However, not until very recently has its mechanism of action begun to be elucidated. Modulating gene expression is one of the primary mechanisms of sugar regulation in plants. Nevertheless, the transcription factors involved in regulating sugar responses and their role(s) during the signal transduction cascade remain poorly defined. In this paper we analyzed the participation of ABI4, as it is one of the main transcription factors implicated in glucose signaling during early seedling development. Our studies show that ABI4 is an essential activator of its own expression during development, in ABA signaling and in sugar responses. It is also important for the glucose-mediated expression of the genes ABI5 and SBE2.2. We demonstrate that ABI4 binds directly to the promoter region of all three genes and activates their expression in vivo through at CE1-like element. Previous studies found that ABI4 also functions as a transcriptional repressor of sugar-regulated genes, therefore this transcription factor is a versatile protein with dual functions for modulating gene expression.
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http://dx.doi.org/10.1111/j.1365-313X.2009.03877.xDOI Listing
August 2009

Kidney damage after renal ablation is worsened in endothelial nitric oxide synthase -/- mice and improved by combined administration of L-arginine and antioxidants.

Nephrology (Carlton) 2008 Jun;13(3):218-27

Escuela Superior de Medicina IPN, México City, Mexico.

Aim: Reduction in nitric oxide (NO) levels during kidney failure has been related to the reaction of NO with superoxide anions to yield peroxynitrite which possesses the biological activity responsible for renal damage. However, stimulation of the NO pathway ameliorates the progression of kidney failure. Thus, it is unclear whether NO prevents or acts as the compound responsible for the cytotoxicity observed during kidney failure.

Methods: We evaluated the development of kidney failure in animals that were wild type and deficient in endothelial NO synthase (eNOS -/-) and tested the effects of an antioxidant treatment and NO precursors on the generation of superoxide anion and kidney failure parameters.

Results: In wild-type mice, five-sixths nephrectomy increased proteinuria from 3.0 +/- 0.35 to 14.5 +/- 0.76 mg protein/24 h (P < 0.05), blood pressure from 83.1 +/- 1.8 to 126.6 +/- 1.7 mmHg (P < 0.05), and superoxide production from 1.4 +/- 0.6% to 74.3 +/- 0.8% (P < 0.05). The effects of five-sixths nephrectomy on the eNOS -/- mice were greater compared with wild-type mice. Proteinuria increased from 6.7 +/- 0.5 to 22.7 +/- 2.0 mg protein/24 h (P < 0.05), blood pressure increased from 93.3 +/- 0.9 to 151.2 +/- 3.4 mmHg (P < 0.05), and superoxide production increased from 12.9 +/- 0.5% to 99.8 +/- 1.3% (P < 0.05). The nitrotyrosine levels were lower in eNOS -/- mice as compared to wild-type mice. A combination of L-arginine and antioxidant treatment ameliorated renal damage. The effect was improved in wild-type animals.

Conclusion: Our data support the relevance of NO as an antagonist to superoxide in renal tissues and suggest that the loss of this mechanism promotes the progression of kidney failure.
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http://dx.doi.org/10.1111/j.1440-1797.2007.00897.xDOI Listing
June 2008

Nitric oxide-dependent neovascularization role in the lower extremity disease.

Curr Pharm Des 2007 ;13(35):3591-6

Escuela Superior de Medicina IPN, México DF, México.

Peripheral arterial occlusive disease (PAD) describes vascular disorders associated with ischemia and PAD affects about 8 million people in the United States. Moreover, PAD's prevalence can increase dramatically if cardiovascular disease is present. In healthy individuals reducing blood flow through the lower extremity is followed by a physiological process to limit ischemia in the distal tissue. This process is called revascularization and impairing revascularization results in PAD. Studies suggest nitric oxide (NO) maybe involved in the ischemia-dependent hindlimb revascularization process. NO is increased in the ischemic hindlimb and eliminating NO impairs the revascularization process. Moreover, restoring NO improves hindlimb revascularization. NO may be acting through its effects on vascular tone, cell migration, or extracellular matrix degradation. The present review illustrates nitric oxide's critical role in the ischemia-induced hindlimb revascularization. Thus, restoring normal NO levels in diseased arteries may represent a viable therapeutic avenue by supplementing exogenous NO or employing therapeutic strategies to either increase NO synthesis and its messengers or decrease NO catabolism.
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http://dx.doi.org/10.2174/138161207782794103DOI Listing
February 2008

WRINKLED1 specifies the regulatory action of LEAFY COTYLEDON2 towards fatty acid metabolism during seed maturation in Arabidopsis.

Plant J 2007 Jun 5;50(5):825-38. Epub 2007 Apr 5.

Laboratoire de Biologie des Semences, IJPB,UMR 204 INRA/AgroParis Tech, F-78026 Versailles, France.

The WRINKLED1 (WRI1) transcription factor has been shown to play a role of the utmost importance during oil accumulation in maturing seeds of Arabidopsis thaliana. However, little is known about the regulatory processes involved. In this paper, comprehensive functional analyses of three new mutants corresponding to null alleles of wri1 confirm that the induction of WRI1 is a prerequisite for fatty acid synthesis and is important for normal embryo development. The strong expression of WRI1 specifically detected at the onset of the maturation phase in oil-accumulating tissues of A. thaliana seeds is fully consistent with this function. Complementation experiments carried out with various seed-specific promoters emphasized the importance of a tight regulation of WRI1 expression for proper oil accumulation, raising the question of the factors controlling WRI1 transcription. Interestingly, molecular and genetic analyses using an inducible system demonstrated that WRI1 is a target of LEAFY COTYLEDON2 and is necessary for the regulatory action of LEC2 towards fatty acid metabolism. In addition to this, quantitative RT-PCR experiments suggested that several genes encoding enzymes of late glycolysis, the fatty acid synthesis pathway, and the biotin and lipoic acid biosynthetic pathways are targets of WRI1. Taken together, these results indicate new relationships in the regulatory model for the control of oil synthesis in maturing A. thaliana seeds. In addition, they exemplify how metabolic and developmental processes affecting the developing embryo can be coordinated at the molecular level.
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http://dx.doi.org/10.1111/j.1365-313X.2007.03092.xDOI Listing
June 2007
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