Extracellular vesicles-associated miRNAs in triple-negative breast cancer: from tumor biology to clinical relevance

Breast cancer (BC), a heterogeneous group of diseases, is the most frequent type and the leading cause of cancer-related death among women worldwide. Tumor heterogeneity directly impacts cancer progression and treatment, as evidenced by the patients´ diverse prognosis and treatment responses across the distinct molecular subtypes. Triple-negative breast cancer (TNBC), which accounts for 10-20% of all diagnosed BC cases, is an aggressive BC subtype with a challenging prognosis. Current treatment options include systemic chemotherapy and/or target therapies based on PARP and PD-L1 inhibitors for eligible patients. MicroRNAs (miRNAs) are important regulatory non-coding RNAs (ncRNAs) in TNBC tumorigenesis. These molecules are present both intracellularly and released into biofluids, packaged into extracellular vesicles (EVs). Emerging evidence indicates that EVs-associated miRNAs (EVs-miRNAs), transferred from parental to recipient cells, are key mediators of cell-to-cell communication. Considering their stability and abundance in several biofluids, these molecules may reflect the epigenomic composition of their tumors of origin and contribute to mediate tumorigenesis, similar to their intracellular counterparts. This review provides the current knowledge on EVs-miRNAs in the TNBC subtype, focusing on their role in regulating mRNA targets involved in tumor phenotypes and their clinical relevance as promising biomarkers in liquid biopsies.

Genetic Association and Differential RNA Expression of Histone (De)Acetylation-Related Genes in Pemphigus Foliaceus-A Possible Epigenetic Effect in the Autoimmune Response

Pemphigus foliaceus (PF) is an autoimmune skin blistering disease characterized by antidesmoglein-1 IgG production, with an endemic form (EPF) in Brazil. Genetic and epigenetic factors have been associated with EPF, but its etiology is still not fully understood. To evaluate the genetic association of histone (de)acetylation-related genes with EPF susceptibility, we evaluated 785 polymorphisms from 144 genes, for 227 EPF patients and 194 controls. Carriers of HDAC4_rs4852054*A were more susceptible (OR = 1.79, p = 0.0038), whereas those with GSE1_rs13339618*A (OR = 0.57, p = 0.0011) and homozygotes for PHF21A_rs4756055*A (OR = 0.39, p = 0.0006) were less susceptible to EPF. These variants were not associated with sporadic PF (SPF) in German samples of 75 SPF patients and 150 controls, possibly reflecting differences in SPF and EPF pathophysiology. We further evaluated the expression of histone (de)acetylation-related genes in CD4+ T lymphocytes, using RNAseq. In these cells, we found a higher expression of KAT2B, PHF20, and ZEB2 and lower expression of KAT14 and JAD1 in patients with active EPF without treatment compared to controls from endemic regions. The encoded proteins cause epigenetic modifications related to immune cell differentiation and cell death, possibly affecting the immune response in patients with PF.

The landscape of the immunoglobulin repertoire in endemic pemphigus foliaceus

Introduction

Primarily driven by autoreactive B cells, pemphigus foliaceus (PF) is an uncommon autoimmune blistering skin disease of sporadic occurrence worldwide. However, PF reaches a prevalence of 3% in the endemic areas of Brazil, the highest ever registered for any autoimmune disease, which indicates environmental factors influencing the immune response in susceptible individuals. We aimed to provide insights into the immune repertoire of patients with PF living in the endemic region of the disease, compared to healthy individuals from the endemic region and a non-endemic area.

Methods

We characterized the B-cell repertoire in i) nontreated patients (n=5); ii) patients under immunosuppressive treatment (n=5); iii) patients in remission without treatment (n=6); and two control groups iv) from the endemic (n=6) and v) non-endemic areas in Brazil (n=4). We used total RNA extracted from peripheral blood mononuclear cells and performed a comprehensive characterization of the variable region of immunoglobulin heavy chain (IGH) in IgG and IgM using next-generation sequencing.

Results

Compared to individuals from a different area, we observed remarkably lower clonotype diversity in the B-cell immune repertoire of patients and controls from the endemic area (p < 0.02), suggesting that the immune repertoire in the endemic area is under geographically specific and intense environmental pressure. Moreover, we observed longer CDR3 sequences in patients, and we identified differential disease-specific usage of IGHV segments, including increased IGHV3-30 and decreased IGHV3-23 in patients with active disease (p < 0.04). Finally, our robust network analysis discovered clusters of CDR3 sequences uniquely observed in patients with PF.

Discussion

Our results indicate that environmental factors, in addition to disease state, impact the characteristics of the repertoire. Our findings can be applied to further investigation of the environmental factors that trigger pemphigus and expand the knowledge for identifying new targeted and more effective therapies.

COVID-19: The question of genetic diversity and therapeutic intervention approaches

Coronavirus disease 2019 (COVID-19), caused by the Severe Acute Respiratory Syndrome Coronavirus type 2 (SARS-CoV-2), is the largest pandemic in modern history with very high infection rates and considerable mortality. The disease, which emerged in China's Wuhan province, had its first reported case on December 29, 2019, and spread rapidly worldwide. On March 11, 2020, the World Health Organization (WHO) declared the COVID-19 outbreak a pandemic and global health emergency. Since the outbreak, efforts to develop COVID-19 vaccines, engineer new drugs, and evaluate existing ones for drug repurposing have been intensively undertaken to find ways to control this pandemic. COVID-19 therapeutic strategies aim to impair molecular pathways involved in the virus entrance and replication or interfere in the patients' overreaction and immunopathology. Moreover, nanotechnology could be an approach to boost the activity of new drugs. Several COVID-19 vaccine candidates have received emergency-use or full authorization in one or more countries, and others are being developed and tested. This review assesses the different strategies currently proposed to control COVID-19 and the issues or limitations imposed on some approaches by the human and viral genetic variability.

Oncogenic Role of Exosomal Circular and Long Noncoding RNAs in Gastrointestinal Cancers

Circular RNAs (circRNAs) and long noncoding RNAs (lncRNAs) are differentially expressed in gastrointestinal cancers. These noncoding RNAs (ncRNAs) regulate a variety of cellular activities by physically interacting with microRNAs and proteins and altering their activity. It has also been suggested that exosomes encapsulate circRNAs and lncRNAs in cancer cells. Exosomes are then discharged into the extracellular environment, where they are taken up by other cells. As a result, exosomal ncRNA cargo is critical for cell-cell communication within the cancer microenvironment. Exosomal ncRNAs can regulate a range of events, such as angiogenesis, metastasis, immune evasion, drug resistance, and epithelial-to-mesenchymal transition. To set the groundwork for developing novel therapeutic strategies against gastrointestinal malignancies, a thorough understanding of circRNAs and lncRNAs is required. In this review, we discuss the function and intrinsic features of oncogenic circRNAs and lncRNAs that are enriched within exosomes.

Genome interaction of the virus and the host genes and non-coding RNAs in SARS-CoV-2 infection

In this review, we highlight the interaction of SARS-CoV-2 virus and host genomes, reporting the current studies on the sequence analysis of SARS-CoV-2 isolates and host genomes from diverse world populations. The main genetic variants that are present in both the virus and host genomes were particularly focused on the ACE2 and TMPRSS2 genes, and their impact on the patients' susceptibility to the virus infection and severity of the disease. Finally, the interaction of the virus and host non-coding RNAs is described in relation to their regulatory roles in target genes and/or signaling pathways critically associated with SARS-CoV-2 infection. Altogether, these studies provide a significant contribution to the knowledge of SARS-CoV-2 mechanisms of infection and COVID-19 pathogenesis. The described genetic variants and molecular factors involved in host/virus genome interactions have significantly contributed to defining patient risk groups, beyond those based on patients' age and comorbidities, and they are promising candidates to be potentially targeted in treatment strategies for COVID-19 and other viral infectious diseases.

Genetic association and differential expression of HLAComplexGroup lncRNAs in pemphigus

BACKGROUND

Pemphigus is a group of bullous diseases characterized by acantholysis and skin blisters. As for other autoimmune diseases, the strongest genetic associations found so far for pemphigus foliaceus (PF) and vulgaris (PV) are with alleles of HLA genes. However, apart from protein-coding genes, the MHC region includes a set of poorly explored long non-coding RNA (lncRNA) genes, the HLA complex group (HCG).

OBJECTIVES

To investigate if HCG lncRNA alleles are associated with pemphigus susceptibility.

METHODS AND RESULTS

We analyzed SNPs in 13 HCG lncRNA genes, both in PV (Germany: 241 patients; 1,188 controls) and endemic PF (Brazil: 227 patients; 194 controls), applying multivariate logistic regression. We found 55 associations with PV (p_corr < 0.01) and nine with endemic PF (p_corr < 0.05), the majority located in TSBP1-AS1 (which includes HCG23) and HCG27 lncRNA genes, independently of HLA alleles previously associated with pemphigus. The association of TSBP1-AS1 rs3129949*A allele was further replicated in sporadic PF (p = 0.027, OR = 0.054; 75 patients and 150 controls, all from Germany). Next, we evaluated the expression levels of TSBP1-AS1, TSBP1, HCG23, and HCG27 in blood mononuclear cells of Brazilian patients and controls. HCG27 was upregulated in endemic PF (p = 0.035, log₂ FC = 1.3), while TSBP1-AS1 was downregulated in PV (p = 0.029, log₂ FC = -1.29). The same expression patterns were also seen in cultured keratinocytes stimulated with IgG antibodies from patients and controls from Germany. TSBP1 mRNA levels were also decreased in endemic PF blood cells (p = 0.042, log₂ FC = -2.14). TSBP1-AS1 and HCG27 were also observed downregulated in CD19⁺ cells of endemic PF (p < 0.01, log₂ FC = -0.226 and -0.46 respectively).

CONCLUSIONS

HCG lncRNAs are associated with susceptibility to pemphigus, being TSBP1-AS1 and HCG27 also differentially expressed in distinct cell populations. These results suggest a role for HCG lncRNAs in pemphigus autoimmunity.

Comprehensive analysis of ceRNA networks in HPV16- and HPV18-mediated cervical cancers reveals XIST as a pivotal competing endogenous RNA

Cervical cancer (CC) is one of the most common cancers in women worldwide, being closely related to high-risk human papillomavirus (HR-HPVs). After a particular HR-HPV infects a cervical cell, transcriptional changes in the host cell are expected, including the regulation of lncRNAs, miRNAs, and mRNAs. Such transcripts may work independently or integrated in complex molecular networks - as in competing endogenous RNA (ceRNA) networks. In our research, we gathered transcriptome data from samples of HPV16/HPV18 cervical squamous cell carcinoma and endocervical adenocarcinoma (CESC), from The Cancer Genome Atlas (TCGA) project. Using GDCRNATools, we identified ceRNA networks that differentiate HPV16- from HPV18-mediated CESC. For HPV16-CESC, three lncRNA-mRNA co-expressed pairs were reported, all led by the X-inactive specific transcript (XIST): XIST | DLG5, XIST | LGR4, and XIST | ZNF81. The XIST | LGR4 and XIST | ZNF81 pairs shared 11 miRNAs, suggesting an increased impact on their final biological effect. XIST also stood out as an important lncRNA in HPV18-CESC, leading 35 of the 42 co-expressed pairs. Some mRNAs, such as ADAM9 and SLC38A2, emerged as important players in the ceRNA regulatory networks due to sharing a considerable amount of miRNAs with XIST. Furthermore, some XIST-associated axes, namely XIST | miR-23a-3p | LGR4 and XIST | miR-30b-5p or miR-30c-5p or miR-30e-5p I ADAM9, had a significant impact on the overall survival of HPV16- and HPV18-CESC patients, respectively. Together, these data suggest that XIST has an important role in HPV-mediated tumorigenesis, which may implicate different molecular signatures between HPV16 and HPV18-associated tumors.

Genetic variability of immune-related lncRNAs: polymorphisms in LINC-PINT and LY86-AS1 are associated with pemphigus foliaceus susceptibility

Pemphigus foliaceus (PF) is an autoimmune blistering disease of the skin, clinically characterized by erosions and, histopathologically, by acantholysis. PF is endemic in the Brazilian Central-Western region. Numerous single nucleotide polymorphisms (SNPs) have been shown to affect the susceptibility for PF, including SNPs at long non-coding RNA (lncRNA) genes, which are known to participate in many physiological and pathogenic processes, such as autoimmunity. Here, we investigated whether the genetic variation of immune-related lncRNA genes affects the risk for endemic and sporadic forms of PF. We analysed 692 novel SNPs for PF from 135 immune-related lncRNA genes in 227 endemic PF patients and 194 controls. The SNPs were genotyped by Illumina microarray and analysed by applying logistic regression at additive model, with correction for sex and population structure. Six associated SNPs were also evaluated in an independent German cohort of 76 sporadic PF patients and 150 controls. Further, we measured the expression levels of two associated lncRNA genes (LINC-PINT and LY86-AS1) by quantitative PCR, stratified by genotypes, in peripheral blood mononuclear cells of healthy subjects. We found 27 SNPs in 11 lncRNA genes associated with endemic PF (p < .05 without overlapping with protein-coding genes). Among them, the LINC-PINT SNP rs10228040*A (OR = 1.47, p = .012) was also associated with increased susceptibility for sporadic PF (OR = 2.28, p = .002). Moreover, the A+ carriers of LY86-AS1*rs12192707 mark lowest LY86-AS1 RNA levels, which might be associated with a decreasing autoimmune response. Our results suggest a critical role of lncRNA variants in immunopathogenesis of both PF endemic and sporadic forms.

Variation in genes implicated in B-cell development and antibody production affects susceptibility to pemphigus

Pemphigus foliaceus (PF) is an autoimmune blistering skin disease characterized by the presence of pathogenic autoantibodies against desmoglein 1, a component of intercellular desmosome junctions. PF occurs sporadically across the globe and is endemic in some Brazilian regions. Because PF is a B-cell-mediated disease, we aimed to study the impact of variants within genes encoding molecules involved in the different steps of B-cell development and antibody production on the susceptibility of endemic PF. We analysed 3,336 single nucleotide polymorphisms (SNPs) from 167 candidate genes genotyped with Illumina microarray in a cohort of 227 PF patients and 193 controls. After quality control and exclusion of non-informative and redundant SNPs, 607 variants in 149 genes remained in the logistic regression analysis, in which sex and ancestry were included as covariates. Our results revealed 10 SNPs within or nearby 11 genes that were associated with susceptibility to endemic PF (OR >1.56; p < 0.005): rs6657275*G (TGFB2); rs1818545*A (RAG1/RAG2/IFTAP);rs10781530*A (PAXX), rs10870140*G and rs10781522*A (TRAF2); rs535068*A (TNFRSF1B); rs324011*A (STAT6);rs6432018*C (YWHAQ); rs17149161*C (YWHAG); and rs2070729*C (IRF1). Interestingly, these SNPs have been previously associated with differential gene expression, mostly in peripheral blood, in publicly available databases. For the first time, we show that polymorphisms in genes involved in B-cell development and antibody production confer differential susceptibility to endemic PF, and therefore are candidates for possible functional studies to understand immunoglobulin gene rearrangement and its impact on diseases.

Natural killer cell receptor variants and chronic hepatitis B virus infection in the Vietnamese population

OBJECTIVES

Genes of host immunity play an important role in disease pathogenesis and are determinants of clinical courses of infections, including hepatitis B virus (HBV). Killer-cell immunoglobulin-like receptor (KIR), expressed on the surface of natural killer cells (NK), regulate NK cell cytotoxicity by interacting with human leukocyte antigen (HLA) class I molecules and are candidates for influencing the course of HBV. This study evaluated whether variations in KIR gene content and HLA-C ligands are associated with HBV and with the development of liver cirrhosis and hepatocellular carcinoma.

METHODS

A Vietnamese study cohort (HBV n = 511; controls n = 140) was genotyped using multiplex sequence-specific polymerase chain reaction (PCR-SSP) followed by melting curve analysis.

RESULTS

The presence of the functional allelic group of KIR2DS4 was associated with an increased risk of chronic HBV (OR = 1.86, p^corr = 0.02), while KIR2DL2+HLA-C1 (OR = 0.62, p^corr = 0.04) and KIR2DL3+HLA-C1 (OR = 0.48, p^corr = 0.04) were associated with a decreased risk. The pair KIR2DL3+HLA-C1 was associated with liver cirrhosis (OR = 0.40, p^corr = 0.01). The presence of five or more activating KIR variants was associated with hepatocellular carcinoma (OR = 0.53, p^corr = 0.04).

CONCLUSIONS

KIR gene content variation and combinations KIR-HLA influence the outcome of HBV infection.

HLA-E genotyping and its relevance in kidney transplantation outcome

HLA-E, a class I nonclassical HLA molecule, is expressed in all tissues and is involved in the regulation of both innate (by interaction with the CD94/NKG2 receptor expressed mainly in NK cells) and adaptive immunity (by interaction with T CD8+ cells), suggesting a possible role in the solid organ transplantation context. Transplanted patients with chronic kidney disease and their respective donors (N = 107 pairs) were genotyped for exons 2 and 3 of the HLA-E locus by sequence-based typing (SBT). Groups' genotype frequencies were compared regarding episodes of clinical rejection by global G test, and binary logistic regression was made to demonstrate the contribution of genetic variables vs epidemiological variables. Comparisons of donors' genotype frequencies showed significant differences (P = .0230), revealing a protective profile of E*01:01/*01:01 compared to the other genotypes (P = .0099; OR = 0.3088; CI [95%] = 0.1333-0.7157). The same happened when the aforementioned genotype was combined with the E*01:01/*01:01 recipients' genotype (P = .0065; OR = 0.1760; CI [95%] = 0.0517-0.5987). A binary logistic regression analysis was performed, and, of all variables considered, only two were included in the resulting model (P = .007; R2 Cox and Snell = 0.243; R2 Nagelkerke = 0.328)- "End-Stage Renal Disease" and "HLA class II Mismatches." A protective profile (E*01:01/*01:01) was observed between the recipients and donors, suggesting a possible impact of the HLA-E genotype in rejection episodes.

Identification of miRNAs Enriched in Extracellular Vesicles Derived from Serum Samples of Breast Cancer Patients

MicroRNAs derived from extracellular vesicles (EV-miRNAs) are circulating miRNAs considered as potential new diagnostic markers for cancer that can be easily detected in liquid biopsies. In this study, we performed RNA sequencing analysis as a screening strategy to identify EV-miRNAs derived from serum of clinically well-annotated breast cancer (BC) patients from the south of Brazil. EVs from three groups of samples (healthy controls (CT), luminal A (LA), and triple-negative (TNBC)) were isolated from serum using a precipitation method and analyzed by RNA-seq (screening phase). Subsequently, four EV-miRNAs (miR-142-5p, miR-150-5p, miR-320a, and miR-4433b-5p) were selected to be quantified by quantitative real-time PCR (RT-qPCR) in individual samples (test phase). A panel composed of miR-142-5p, miR-320a, and miR-4433b-5p distinguished BC patients from CT with an area under the curve (AUC) of 0.8387 (93.33% sensitivity, 68.75% specificity). The combination of miR-142-5p and miR-320a distinguished LA patients from CT with an AUC of 0.9410 (100% sensitivity, 93.80% specificity). Interestingly, decreased expression of miR-142-5p and miR-150-5p were significantly associated with more advanced tumor grades (grade III), while the decreased expression of miR-142-5p and miR-320a was associated with a larger tumor size. These results provide insights into the potential application of EVs-miRNAs from serum as novel specific markers for early diagnosis of BC.

Unveiling the Diversity of Immunoglobulin Heavy Constant Gamma (IGHG) Gene Segments in Brazilian Populations Reveals 28 Novel Alleles and Evidence of Gene Conversion and Natural Selection

Even though immunoglobulins are critical for immune responses and human survival, the diversity of the immunoglobulin heavy chain gene (IGH) is poorly known and mostly characterized only by serological methods. Moreover, this genomic region is not well-covered in genomic databases and genome-wide association studies due to particularities that impose technical difficulties for its analysis. Therefore, the IGH gene has never been systematically sequenced across populations. Here, we deliver an unprecedented and comprehensive characterization of the diversity of the IGHG1, IGHG2, and IGHG3 gene segments, which encode the constant region of the most abundant circulating immunoglobulins: IgG1, IgG2, and IgG3, respectively. We used Sanger sequencing to analyze 357 individuals from seven different Brazilian populations, including five Amerindian, one Japanese-descendant and one Euro-descendant population samples. We discovered 28 novel IGHG alleles and provided evidence that some of them may have been originated by gene conversion between common alleles of different gene segments. The rate of synonymous substitutions was significantly higher than the rate of the non-synonymous substitutions for IGHG1 and IGHG2 (p = 0.01 and 0.03, respectively), consistent with purifying selection. Fay and Wu's test showed significant negative values for most populations (p < 0.001), which indicates that positive selection in an adjacent position may be shaping IGHG variation by hitchhiking of variants in the vicinity, possibly the regions that encode the Ig variable regions. This study shows that the variation in the IGH gene is largely underestimated. Therefore, exploring its nucleotide diversity in populations may provide valuable information for comprehension of its evolution, its impact on diseases and vaccine research.

Screening the full leucocyte receptor complex genomic region revealed associations with pemphigus that might be explained by gene regulation

Pemphigus foliaceus (PF) is a blistering autoimmune skin disease rare in most of the world but endemic in certain regions of Brazil. PF is characterized by the detachment of epidermal cells and the presence of autoantibodies against desmoglein 1. In previous studies, we have shown that genetic polymorphisms and variable expression levels of certain leucocyte receptor complex (LRC) genes were associated with PF. However, the role of the LRC on PF susceptibility remained to be investigated. Here, we analysed 527 tag single nucleotide polymorphisms (SNPs) distributed within the 1·5 Mb LRC. After quality control, a total of 176 SNPs were analysed in 229 patients with PF and 194 controls. Three SNPs were associated with differential susceptibility to PF. The intergenic variant rs465169 [odds ratio (OR) = 1·50; P = 0·004] is located in a region that might regulate several immune-related genes, including VSTM1, LILRB1/2, LAIR1/2, LILRA3/4 and LENG8. The rs35336528 (OR = 3·44; P = 0·009) and rs1865097 (OR = 0·57; P = 0·005) SNPs in LENG8 and FCAR genes, respectively, were also associated with PF. Moreover, we found four haplotypes with SNPs within the KIR3DL2/3, LAIR2 and LILRB1 genes associated with PF (P < 0·05), which corroborate previously reported associations. Thus, our results confirm the importance of the LRC for differential susceptibility to PF and reveal new markers that might influence expression levels of several LRC genes, as well as candidates for further functional studies.

Extracellular vesicles from triple-negative breast cancer cells promote proliferation and drug resistance in non-tumorigenic breast cells

Purpose

Triple-negative breast cancer (TNBC), an aggressive breast cancer subtype, is genetically heterogeneous which challenges the identification of clinically effective molecular makers. Extracellular vesicles (EVs) are key players in the intercellular signaling communication and have been shown to be involved in tumorigenesis. The main goal of this study was to evaluate the role and mechanisms of EVs derived from TNBC cells in modulating proliferation and cytotoxicity to chemotherapeutic agents in non-tumorigenic breast cells (MCF10A).

Methods

EVs were isolated from TNBC cell lines and characterized by nanoparticle tracking analysis, Western blot, and transmission electron microscopy. MCF10A cells were treated with the isolated EVs and evaluated for cell proliferation and cytotoxicity to Docetaxel and Doxorubicin by the MTT and MTS assays, respectively. Gene and miRNA expression profiling was performed in the treated cells to determine expression changes that may be caused by EVs treatment.

Results

MCF10A cells treated with HCC1806-EVs (MCF10A/HCC1806-EVs) showed a significant increase in cell proliferation and resistance to the therapeutic agents tested. No significant effects were observed in the MCF10A cells treated with EVs derived from MDA-MB-231 cells. Gene and miRNA expression profiling revealed 138 genes and 70 miRNAs significantly differentially expressed among the MCF10A/HCC1806-EVs and the untreated MCF10A cells, affecting mostly the PI3K/AKT, MAPK, and HIF1A pathways.

Conclusion

EVs isolated from the HCC1806 TNBC cells are capable of inducing proliferation and drug resistance on the non-tumorigenic MCF10A breast cells, potentially mediated by changes in genes and miRNAs expression associated with cell proliferation, apoptosis, invasion, and migration.

Electronic supplementary material

The online version of this article (10.1007/s10549-018-4925-5) contains supplementary material, which is available to authorized users.

Besides Pathology: Long Non-Coding RNA in Cell and Tissue Homeostasis

A significant proportion of mammalian genomes corresponds to genes that transcribe long non-coding RNAs (lncRNAs). Throughout the last decade, the number of studies concerning the roles played by lncRNAs in different biological processes has increased considerably. This intense interest in lncRNAs has produced a major shift in our understanding of gene and genome regulation and structure. It became apparent that lncRNAs regulate gene expression through several mechanisms. These RNAs function as transcriptional or post-transcriptional regulators through binding to histone-modifying complexes, to DNA, to transcription factors and other DNA binding proteins, to RNA polymerase II, to mRNA, or through the modulation of microRNA or enzyme function. Often, the lncRNA transcription itself rather than the lncRNA product appears to be regulatory. In this review, we highlight studies identifying lncRNAs in the homeostasis of various cell and tissue types or demonstrating their effects in the expression of protein-coding or other non-coding RNA genes.

Pathologies related to depression in elderly patients

Introduction

The occurrence of chronic diseases, motor limitation, cognitive impairment and social isolation could be related to late life depression.

Objective

To describe the pathologies related to elderly patients with depression. To study possible relationship between depression and others pathologies in elderly patients.

Methods

This retrospective study included 124 geriatric patients enrolled in a private long-term care institution with mean age of 86.2 ± 6.5 years old, mean weight of 60.28 ± 2.00 kg and mean period of hospitalisation of 4.4 ± 2.3 years. For data analysis, double-entry tables and tests of proportion Qui-square were used.

Results

Cardiovascular, respiratory, endocrine metabolic, skeletal muscle, sense organs, hematological, digestive tract; neuropsychological and genitourinary, diseases were analyzed.

We observed a significant correlation between depression and endocrine-metabolic (P value of 0.0003), sense organs (P value of 9.298 E-5) and skeletal muscle pathologies (P value of 6.843 E-6)

Conclusions

We observed in that population that depression could be prevalent in elderly patients with endocrine-metabolic, sense organs and skeletal muscle pathologies.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Hypothyroidism in psychiatric patients

Introduction

Hypothyroidism psychocognitive key features may include melancholia, memory impairment, depression and dementia which could be misdiagnosed as a psychiatric disorder.

Objective

To study the incidence of hypothyroidism in psychiatric patients.

Methods

This retrospective study included 232 psychiatric patients with mean age of 43.39 ± 10 years old weight mean of 79.81 ± 19.07 kg, BIM of 29.55 ± 6.83, enrolled in a public mental health service.

Results

Twenty point twenty-one percent (39) patients presented hypothyroidism with thyroid-stimulating hormone (TSH) levels above 5 mIU/L and Free T4 levels below 0.7 ng/dl.

Comparing the incidence of hypothyroidism in Brazilian population estimated rate of until 10% [1] with this psychiatric patients population we observed a significant difference with p value of 2.28 E-6. Neuroleptics 92%(36), biperiden 62%(24) and benzodiazepines 38% (15) were the most frequent prescribed drugs for these hypothyroidism patients.

Conclusion

Significant difference in the incidence of hypothyroidism between general Brazilian population and the studied psychiatric patients was observed [2,3].

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Genome-wide gene expression profiling reveals unsuspected molecular alterations in pemphigus foliaceus

Pemphigus foliaceus (PF) is a complex autoimmune disease characterized by bullous skin lesions and the presence of antibodies against desmoglein 1. In this study we sought to contribute to a better understanding of the molecular processes in endemic PF, as the identification of factors that participate in the pathogenesis is a prerequisite for understanding its biological basis and may lead to novel therapeutic interventions. CD4+ T lymphocytes are central to the development of the disease. Therefore, we compared genome-wide gene expression profiles of peripheral CD4+ T cells of various PF patient subgroups with each other and with that of healthy individuals. The patient sample was subdivided into three groups: untreated patients with the generalized form of the disease, patients submitted to immunosuppressive treatment, and patients with the localized form of the disease. Comparisons between different subgroups resulted in 135, 54 and 64 genes differentially expressed. These genes are mainly related to lymphocyte adhesion and migration, apoptosis, cellular proliferation, cytotoxicity and antigen presentation. Several of these genes were differentially expressed when comparing lesional and uninvolved skin from the same patient. The chromosomal regions 19q13 and 12p13 concentrate differentially expressed genes and are candidate regions for PF susceptibility genes and disease markers. Our results reveal genes involved in disease severity, potential therapeutic targets and previously unsuspected processes involved in the pathogenesis. Besides, this study adds original information that will contribute to the understanding of PF's pathogenesis and of the still poorly defined in vivo functions of most of these genes.

COMPARATIVE ANALYSIS OF THE EFFECTS OF MELOXICAM AND FLUNIXIN MEGLUMINE ON RENAL FUNCTION OF WISTAR RATS

O presente trabalho avaliou a função renal de ratos Wistar submetidos ao tratamento com meloxicam (ME) e flunixin meglumine (FM). Foram utilizados 66 ratos Wistar distribuídos em três grupos (n=22). O grupo controle recebeu solução fisiológica, enquanto os grupos tratados com ME e FM receberam duas doses de 2 e 1,1 mg/Kg, respectivamente, da medicação por via subcutânea. Todos os animais foram submetidos à coleta de 2 mL de sangue no início e ao fim do estudo para posterior detecção dos níveis de ureia. A partir destes dados foi feita a aplicação do teste ANOVA-fator duplo. O nível de significância utilizado foi ≤0,05. Foi possível concluir que o uso de ambos os medicamentos nas dosagens terapêuticas provocaram alterações na função renal dos animais indicando que o uso destes medicamentos deve ser feito com cautela quando utilizados em roedores.

Renal transplantation in children younger than 6 years old

Herein we report our experience in renal transplantation in 38 children (40 transplants), ages 1 to 5 years, between 1989 and 2005. Demographics as well as patient and graft survivals are reported. Mean age at transplantation was 3.3 +/- 1.3 years, and mean weight was 14 kg (range, 5.7-25 kg); 92.5% were Caucasian, 7.5% African-Brazilian. The main etiology for end-stage renal disease (ESRD) was uropathic/vesicoureteral reflux (45%) followed by glomerulopathy (25%), congenital/hereditary diseases (10%), and hemolytic uremic syndrome (12.5%). Prior to transplantation, 5% were on hemodialysis, 85% on peritoneal dialysis, and 10% preemptive. All children were followed for at least 6 months posttransplantation, except 2 who died in the first month. In 75% of cases, kidneys were obtained from living-related donors, and in 25% from deceased donors. Thirty-nine kidneys were extraperitoneally placed. Primary immunosuppressant therapy consisted of cyclosporine (61%), tacrolimus (39%), mycophenolate (49%), and azathioprine (51%). A steroid-free protocol was used in 17% of patients. In the last 21 cases, basiliximab or daclizumab was added. There were 13 (32.5%) graft losses (4 artery/vein thromboses, 3 chronic rejections, 3 deaths, 3 other causes). The 5-year patient and graft survival rates were 89.6% and 72.2%. We have concluded that renal transplantation can be performed with good long-term results in children younger than 6 years old.

Plasmapheresis for Recurrent Posttransplant Focal Segmental Glomerulosclerosis

The high recurrence rate of focal segmental glomerulosclerosis (FSGS) in kidney transplant recipients suggests that such patients have a circulating factor that alters glomerular capillary permeability. Serum from patients with FSGS increases glomerular permeability to albumin. This permeability factor has been partially identified as a protein. The removal of this protein by plasmapheresis (PP) decreases proteinuria. In this study we report data on the therapeutic effects of PP in FSGS children with recurrence in the transplanted kidney. Three hundred pediatric (age <19 years) renal transplants were performed, including 21 patients (24 transplants) with FSGS as a cause of renal failure. Fourteen (58.3%) subjects experienced disease recurrence (proteinuria >1 g/m(2) per day) within 1 month after transplantation. Mean age patient was 12 +/- 4.3 years, including 83.3% Caucasians and 70.2% recipients of living donor grafts. Nine were treated with 10 cycles of PP (3 cycles/weekly), initiated immediately after recurrence (<48 hours). Immunosuppression included high doses of cyclosporine (C(2) levels of 1700-1800 ng/mL), mycophenolate sodium or mofetil, and prednisone. Thirteen patients were induced with anti-IL2 receptor monoclonal antibody (daclizumab/basiliximab). Among the patients who underwent PP, five (55.5%) achieved a complete remission and one (12%), a partial remission (1 g/24 hours). There were no cases of remission among the five patients who were not treated with PP. Those who achieved remission after PP experienced no recurrences during the 2.6 +/- 1.4 years follow-up. PP appears to be effective to treat recurrent FSGS following kidney transplantation. It should be started as soon as possible.

Conversion to Sirolimus in Pediatric Renal Transplantation Recipients

We retrospectively evaluated the efficacy and safety of sirolimus (SRL) in 16 pediatric renal transplant recipients, who were 9.4 +/- 4.1 years of age when they first received SRL. The indications for SRL therapy were rescue from steroid-resistant acute rejection (31.3%), neoplasia (31.3%), diabetes (12.5%), polyomavirus-associated nephropathy (6.3%), chronic allograft dysfunction (6.3%), calcineurin inhibitor nephrotoxicity (6.3%), and hemolytic uremic syndrome (6.3%). Mean follow-up after the switch to SRL was 17.7 +/- 15 months. The final immunosuppression was CNI + SRL + prednisone (PRED) in five patients, SRL + PRED in six, SRL + mycophenolate mofetil (MMF) + PRED in four, and SRL + MMF in one. The use of SRL in these selected pediatric renal recipients was successful, except when creatinine was high at the moment of conversion. Further studies are necessary to assess the beneficial outcomes versus adverse events among the pediatric transplant population receiving SRL for immunosuppression.

Pemphigus foliaceus and desmoglein 1 gene polymorphism: is there any relationship?

Transmembrane proteins of the cadherin superfamily, the desmogleins and desmocollins, mediate intercellular adhesion in desmosomes. Autoantibodies to desmoglein 1 (dsg1) are a hallmark of pemphigus foliaceus (PF), a disease characterized by skin blistering resulting from keratinocyte cell detachment. The etiology and pathogenesis of this disease remain poorly understood; however, genetic susceptibility is clearly involved. The aim of this study was to verify if genetic variants of dsg1 influence susceptibility/resistance to endemic PF (fogo selvagem). Two single nucleotide polymorphisms (SNPs) were analyzed: 809 (C,T), a synonymous variation, and 1660 (A,C), a tyrosine<-->serine variation in the fifth extracellular domain. Allelic, haplotypic and genotypic frequencies did not differ significantly between the patient (n=134) and the control (n=227) population samples. Moreover, there is no evidence of interaction between the DSG1 and the HLA-DRB1 and IL6 genes, whose alleles had been found associated with differential susceptibility to PF. The results of this study agree with the described and predicted B- and T-cell epitopes of the dsg1 molecule, which seemingly are not affected by the allelic variation. We conclude that genetic diversity of the autoantigen dsg1 is not a major factor for PF pathogenesis in the Brazilian population.

Renal transplantation in systemic lupus erythematosus. A case control study of 45 patients

BACKGROUND

Outcome and the issue of recurrence of disease in systemic lupus erythematosus (SLE) renal transplant recipients is still a matter of controversy. There is a lack of comparative studies with non-SLE patients. The aim of this paper is to compare renal transplantation in lupus patients with a similar matched non-SLE group.

METHODS

Forty-five patients with systemic lupus erythematosus subjected to 48 kidney transplants were studied. For comparative purposes, a case-control population was selected, matched for gender, race, type of donor, age, and time of transplantation. Patients with non-glomerulonephritis diseases were excluded.

RESULTS

No differences in acute episodes of rejection, causes of kidney loss or patient death were observed. General as well as infectious complications were similar. Pregnancy rates and outcomes were similar with no deleterious effect on patients or grafts. Actuarial 1- and 5-year patient survivals (97.7 and 91.1% for SLE and 95.4 and 87% for controls, respectively) and graft survivals (93.1 and 80.7% for SLE and 88.8 and 70.2% for controls, respectively) were similar. Long-term renal function expressed by serum creatinine was the same. No differences in immunosuppressive drug (azathioprine, prednisone, and cyclosporin) requirements were found. Clinical SLE recurrence was suspected only once (a patient with thrombocytopenia, hypocomplementaemia with low complement levels and positive antiplatelet antibodies). Two SLE patients showed mesangial proliferative glomerulonephritis compatible with recurrence. Both grafts were lost. Two further patients showed membranous glomerulonephritis with an immunofluorescence pattern compatible with recurrence. A fifth patient had necrotizing arteritis which recovered after treatment with cyclophosphamide and another patient showed focal and segmental glomerulosclerosis. Histology of biopsies from five patients in the control group showed signs compatible with recurrence of focal and segmental glomerulosclerosis and membranous glomerulonephritis. There was a wide variation in serum levels of antinuclear antibodies. A wide variation in complement levels was also observed, but with a tendency towards low C4 levels.

CONCLUSIONS

The safety of renal transplantation in SLE patients is equivalent to a matched case-control group with a similar rate of recurrence of disease.

[Long term results in 70 pediatric renal transplants after more than 10 years. Histological study]

A clinicopathologic study of 41 biopsy specimens from renal grafts transplanted at least ten years earlier showed normal findings or only mild tubulointerstitial lesions in 63% of cases. Results confirmed the good prognostic value of renal graft biopsy performed ten years after transplantation. A very close correlation was demonstrated between histologic evidence of chronic rejection (interstitial fibrosis, tubular atrophy, and fibrous endarteritis) and long-term graft outcome. Severity of interstitial fibrosis was apparently a more reliable indicator of prognosis than severity of fibrous endarteritis. Among 16 patients with a history of acute rejection, none had residual parenchymatous lesions. In contrast, among patients with major tubulointerstitial and/or vascular lesions, most had previously experienced one or several episodes of acute rejection. Evidence of allograft glomerulopathy was seen in approximately one case in four (11 patients). Among these patients, only eight had proteinuria and only four lost their graft. Among the four patients who developed recurrent membranoproliferative glomerulonephritis (type I in three cases and type II in one case), three lost the deposits previously detected by immunofluorescence, probably as a result of immunosuppressive therapy.