LncRNA MALAT1 in Keratinocyte function: A review of recent advances.

Keratinocytes, the principal epidermal cells, play a vital role in maintaining the structural integrity and functionality of the skin. Beyond their protective role, keratinocytes are key contributors to the process of wound healing, as they migrate to injury sites, proliferate, and generate new layers of epidermis, facilitating tissue repair and remodeling. Moreover, keratinocytes actively participate in the skin's immune responses, expressing pattern recognition receptors (PRRs) to detect microbial components and interact with immune cells to influence adaptive immunity. Keratinocytes express a diverse repertoire of signaling pathways, transcription factors, and epigenetic regulators to regulate their growth, differentiation, and response to environmental cues. Among these regulatory elements, long non-coding RNAs (lncRNAs) have emerged as essential players in keratinocyte biology. LncRNAs, including MALAT1, play diverse roles in gene regulation and cellular processes, influencing keratinocyte proliferation, differentiation, migration, and response to environmental stimuli. Dysregulation of specific lncRNAs such as MALAT1 can disrupt keratinocyte homeostasis, leading to impaired differentiation, compromised barrier integrity, and contributing to the pathogenesis of various skin disorders. Understanding the intricate interplay between lncRNAs and keratinocytes offers promising insights into the molecular underpinnings of skin health and disease, with potential implications for targeted therapies and advancements in dermatological research. Hence, our objective is to provide a comprehensive summary of the available knowledge concerning keratinocytes and their intricate relationship with MALAT1.

Mononuclear cells from patients with rhupus are influenced by TNF in their production of gp130/sIL-6Rb and APRIL.

OBJECTIVE: Rhupus is a rare disease that shares characteristics of systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). While several studies have explored the clinical and immunological profiles of patients with rhupus, the underlying cause of the disease remains unknown due to its complex pathogenesis. The objective of this study was to investigate the role of tumour necrosis factor (TNF) in the production of inflammatory molecules by peripheral blood mononuclear cells (PBMCs) from patients with rhupus. METHODS: The study involved five healthy controls, seven patients with rhupus and seven patients with SLE. PBMCs were obtained from each participant and stimulated with recombinant human TNF for 24 hours. The levels of various molecules secreted by the cells, such as cytokines and chemokines, were measured using immunobead-based assays on xMAP technology. RESULTS: The production levels of some molecules were higher in TNF-stimulated PBMCs from patients with rhupus and SLE than in unstimulated cells. In addition, the levels of certain molecules, including gp130/sIL-6Rb, a proliferation-inducing ligand (APRIL), interferon-ß, matrix metalloproteinase-3 and interleukin (IL)-12, were higher in PBMCs from patients with rhupus even without TNF stimulation. Similarly, the levels of gp130/sIL-6Rb and APRIL were higher in TNF-stimulated PBMCs from patients with rhupus than in healthy controls. These results were further validated against patients with RA using enzyme-linked immunosorbent assay. CONCLUSIONS: These findings suggest that the spontaneous production of molecules by cells from patients with rhupus may contribute to the development of the disease, and that TNF may play a role in this process by regulating the secretion of gp130/sIL-6Rb and APRIL.

Diagnostic Performance of Serum MicroRNAs for ST-Segment Elevation Myocardial Infarction in the Emergency Department.

Prompt diagnosis of ST-segment elevation myocardial infarction (STEMI) is essential for initiating timely treatment. MicroRNAs have recently emerged as biomarkers in cardiovascular diseases. This study aimed to evaluate the discriminatory capacity of serum microRNAs in identifying an ischemic origin in patients presenting with chest discomfort to the Emergency Department. The study included 98 participants (78 with STEMI and 20 with nonischemic chest discomfort). Significant differences in the expression levels of miR-133b, miR-126, and miR-155 (but not miR-1, miR-208, and miR-208b) were observed between groups. miR-133b and miR-155 exhibited 97% and 93% sensitivity in identifying STEMI patients, respectively. miR-126 demonstrated a specificity of 90% in identifying STEMI patients. No significant associations were found between microRNAs and occurrence of major adverse cardiovascular events (MACE). However, patients with MACE had higher levels of interleukin (IL)-15, IL-21, IFN-γ-induced protein-10, and N-terminal pro B-type natriuretic peptide compared to non-MACE patients. Overall, there were significant associations among the expression levels of microRNAs. However, microRNAs did not demonstrate associations with either inflammatory markers or cardiovascular risk scores. This study highlights the potential of microRNAs, particularly miR-133b and miR-126, as diagnostic biomarkers for distinguishing patients with STEMI from those presenting with nonischemic chest discomfort to the Emergency Department.

lncRNAs dysregulation in monocytes from primary antiphospholipid syndrome patients: a bioinformatic and an experimental proof-of-concept approach.

BACKGROUND: Antiphospholipid syndrome (APS) is the main cause of acquired thrombophilia where peripheral circulating cells such as monocytes have a key role. Currently, several studies have linked long non-coding RNAs (lncRNAs) in different inflammatory and autoimmune processes, including lupus. However, the role of lncRNAs in antiphospholipid syndrome is unknown, therefore, we aimed to select and measure expression levels of three lncRNAs based on its abundance in monocytes from APS patients. METHODS: Selection of lncRNAs candidates were carried out based on its abundance in monocytes and their relationship with Perez-Sanchez miRNA signature by using miRNet 2.0 bioinformatic tool, then lncRNAs expression levels was measured in monocytes by RT-qPCR. RESULTS: This is the first study to report that lncRNAs: FGD5-AS1, OIP5-AS1 and GAS5 are promising candidates for play a role on APS monocytes and they are expressed differently between patients and controls. CONCLUSIONS: OIP5-AS1, FGD5-AS1 and GAS5 are downregulated on monocytes from APS patients.

Interferon-alpha regulates expression of lncRNA MALAT1 and interferon-stimulated genes, as well as chemokine production, in primary Sjögren's syndrome.

OBJECTIVES: This study aimed to explore the contribution of interferon-alpha (IFN-α) to MALAT1 expression in primary Sjögren's syndrome (pSS). METHODS: Peripheral blood mononuclear cells (PBMC) from pSS patients and healthy blood donors were stimulated with recombinant human IFN-α, and the expression levels of MALAT1 and several interferon-stimulated genes (ISGs) were measured by RT-PCR, while supernatant levels of interferon-regulated chemokines were measured using multiplex cytokine immunobead assay. RESULTS: In this work, we found that MALAT1 expression levels were increased in IFN-α-stimulated PBMC from pSS patients and healthy controls. As expected, ISG expression levels and interferon-regulated chemokine secretion levels were higher after IFN-α stimulation. However, the fold-change values for ISG15, Ly6E, OAS1, and OASL expression levels were higher in cells from pSS patients than in controls. Similarly, PBMC from pSS patients produced higher concentrations of chemokines than those from healthy controls after IFN-α stimulation. CONCLUSIONS: Our data provide insights into the abnormal IFN-α-mediated regulation of the lncRNA MALAT1 in pSS. Based on an unusually high capacity of PBMC to express ISG and to produce interferon-responsive chemokines, it is likely that targeted therapies to block these molecules may be of benefit to patients with pSS.

The prognostic importance of the angiotensin II/angiotensin-(1-7) ratio in patients with SARS-CoV-2 infection.

BACKGROUND: Information about angiotensin II (Ang II), angiotensin-converting enzyme 2 (ACE2), and Ang-(1-7) levels in patients with COVID-19 is scarce. OBJECTIVE: To characterize the Ang II-ACE2-Ang-(1-7) axis in patients with SARS-CoV-2 infection to understand its role in pathogenesis and prognosis. METHODS: Patients greater than 18 years diagnosed with COVID-19, based on clinical findings and positive RT-PCR test, who required hospitalization and treatment were included. We compared Ang II, aldosterone, Ang-(1-7), and Ang-(1-9) concentrations and ACE2 concentration and activity between COVID-19 patients and historic controls. We compared baseline demographics, laboratory results (enzyme, peptide, and inflammatory marker levels), and outcome (patients who survived versus those who died). RESULTS: Serum from 74 patients [age: 58 (48-67.2) years; 68% men] with moderate (20%) or severe (80%) COVID-19 were analyzed. During 13 (10-21) days of hospitalization, 25 patients died from COVID-19 and 49 patients survived. Compared with controls, Ang II concentration was higher and Ang-(1-7) concentration was lower, despite significantly higher ACE2 activity in patients. Ang II concentration was higher and Ang-(1-7) concentration was lower in patients who died. The Ang II/Ang-(1-7) ratio was significantly higher in patients who died. In multivariate analysis, Ang II/Ang-(1-7) ratio greater than 3.45 (OR = 5.87) and lymphocyte count ⩽0.65 × 103/µl (OR = 8.43) were independent predictors of mortality from COVID-19. CONCLUSION: In patients with severe SARS-CoV-2 infection, imbalance in the Ang II-ACE2-Ang-(1-7) axis may reflect deleterious effects of Ang II and may indicate a worse outcome.

Elevated Levels of Soluble CD147 are Associated with Hyperinflammation and Disease Severity in COVID-19: A Proof-of-Concept Clinical Study.

To evaluate soluble CD147 levels in COVID-19 and identify whether these are associated with hyperinflammation and disease severity. One-hundred and nine COVID-19 patients and 72 healthy blood donors were studied. Levels of CD147, matrix metalloproteases (MMP) and inflammatory markers were measured on hospital arrival, while the need for mechanical ventilation and the occurrence of death during hospitalization were recorded. CD147 levels were higher in COVID-19 (1.6, 1.0-2.3 vs 1.3, 1.0-1.6 ng/ml; P = 0.003) than controls. MMP-2 (9.2, 4.5-12.9 vs 4.2, 3.7-4.6 ng/ml; P < 0.001), MMP-3 (1.1, 0.9-1.3 vs 0.9, 0.7-1.0 ng/ml; P < 0.001) and MMP-9 (0.9, 0.5-1.2 vs 0.4, 0.2-0.6 ng/ml; P < 0.001) were also higher in COVID-19, while MMP-1 (0.6, 0-1.4 vs 0.6, 0.3-0.7 ng/ml; P = 0.711) was not different. Significant correlations were found between CD147 and MMP-2 (ρ = 0.34), MMP-3 (ρ = 0.21), interleukin 6 (ρ = 0.21), and the neutrophil/lymphocyte ratio (ρ = 0.26). Furthermore, CD147 levels were higher in patients who required mechanical ventilation (1.8, 1.4-2.4 vs 1.2, 0.8-1.9 ng/ml; P < 0.001) and in those who ultimately died (1.9, 1.4-2.7 vs 1.4, 0.9-1.9 ng/ml; P = 0.009). CD147 is elevated in COVID-19 and appears to contribute to hyperinflammation and disease severity.

Usefulness of Easy-to-Use Risk Scoring Systems Rated in the Emergency Department to Predict Major Adverse Outcomes in Hospitalized COVID-19 Patients.

BACKGROUND: Several easy-to-use risk scoring systems have been built to identify patients at risk of developing complications associated with COVID-19. However, information about the ability of each score to early predict major adverse outcomes during hospitalization of severe COVID-19 patients is still scarce. METHODS: Eight risk scoring systems were rated upon arrival at the Emergency Department, and the occurrence of thrombosis, need for mechanical ventilation, death, and a composite that included all major adverse outcomes were assessed during the hospital stay. The clinical performance of each risk scoring system was evaluated to predict each major outcome. Finally, the diagnostic characteristics of the risk scoring system that showed the best performance for each major outcome were obtained. RESULTS: One hundred and fifty-seven adult patients (55 ± 12 years, 66% men) were assessed at admission to the Emergency Department and included in the study. A total of 96 patients (61%) had at least one major outcome during hospitalization; 32 had thrombosis (20%), 80 required mechanical ventilation (50%), and 52 eventually died (33%). Of all the scores, Obesity and Diabetes (based on a history of comorbid conditions) showed the best performance for predicting mechanical ventilation (area under the ROC curve (AUC), 0.96; positive likelihood ratio (LR+), 23.7), death (AUC, 0.86; LR+, 4.6), and the composite outcome (AUC, 0.89; LR+, 15.6). Meanwhile, the inflammation-based risk scoring system (including leukocyte count, albumin, and C-reactive protein levels) was the best at predicting thrombosis (AUC, 0.63; LR+, 2.0). CONCLUSIONS: Both the Obesity and Diabetes score and the inflammation-based risk scoring system appeared to be efficient enough to be integrated into the evaluation of COVID-19 patients upon arrival at the Emergency Department.

Interferon Lambda 3/4 (IFNλ3/4) rs12979860 Polymorphisms Is Not Associated With Susceptibility to Systemic Lupus Erythematosus, Although It Regulates OASL Expression in Patients With SLE.

Systemic lupus erythematosus (SLE) is an autoimmune disease with a complex etiology. Various genetic factors are associated with susceptibility to developing SLE and contribute to its onset and progression. Different single-nucleotide polymorphisms (SNPs) have been associated with SLE in several populations. The rs12979860 SNP in interferon lambda 3/4 (IFNλ3/4) is significantly associated with SLE susceptibility in patients negative for nephritis in Taiwanese people, and interferon-stimulated genes (ISGs) are differentially expressed in normal liver by the rs12979860 genotype. This study aimed to investigate whether rs12979860 is associated with the presence of SLE and lupus nephritis in Mexican individuals as well as with the expression of several ISGs in SLE patients. In total, 439 SLE patients and 358 healthy donors were genotyped for rs12979860 using real-time PCR, and allelic discrimination plots were constructed. Additionally, peripheral blood mononuclear cells (PBMCs) were isolated from the venous blood of SLE patients by centrifugation (n = 78). The mRNA levels of 2'-5'-oligoadenylate synthetase like (OASL), myxovirus resistance 1 (MX1), 2'5'-oligoadenylate synthetase 1 (OAS1), interferon-stimulated gene 15 (ISG15) and lymphocyte antigen 6 complex, locus E (LY6E) were determined using real-time PCR. The distributions of rs12979860 genotypes and allele frequencies were compared between SLE patients and healthy donors; case-control analysis revealed that rs12979860 was not associated with SLE susceptibility (OR 1.18, 95% CI 0.97-1.45, p = 0.08) or with the risk for lupus nephritis (OR 0.913, 95% CI 0.590-1.411, p = 0.682). However, OASL expression levels in PBMCs were significantly different between rs12979860 genotypes in SLE patients: median OASL mRNA levels were significantly higher in patients carrying the CC genotype (197.10, IQR 71.10-411.17) than in those with CT/TT genotypes (173.75, IQR 58.80-278.75, p = 0.016). Our results suggest that the SNP rs12979860 does not play a relevant role in susceptibility to SLE in Mexican individuals. However, IFNλ3/4 genotypes appear to be associated with OASL expression in PBMCs from patients with SLE.

High fructose exposure modifies the amount of adipocyte-secreted microRNAs into extracellular vesicles in supernatants and plasma.

BACKGROUND: High fructose exposure induces metabolic and endocrine responses in adipose tissue. Recent evidence suggests that microRNAs in extracellular vesicles are endocrine signals secreted by adipocytes. Fructose exposure on the secretion of microRNA by tissues and cells is poorly studied. Thus, the aim of this study was to evaluate the effect of fructose exposure on the secretion of selected microRNAs in extracellular vesicles from 3T3-L1 cells and plasma from Wistar rats. METHODS: 3T3-L1 cells were exposed to 550 µM of fructose or standard media for four days, microRNAs levels were determined in extracellular vesicles of supernatants and cells by RT-qPCR. Wistar rats were exposed to either 20% fructose drink or tap water for eight weeks, microRNAs levels were determined in extracellular vesicles of plasma and adipose tissue by RT-qPCR. RESULTS: This study showed that fructose exposure increased the total number of extracellular vesicles released by 3T3-L1 cells (p = 0.0001). The levels of miR-143-5p were increased in extracellular vesicles of 3T3-L1 cells exposed to fructose (p = 0.0286), whereas miR-223-3p levels were reduced (p = 0.0286). Moreover, in plasma-derived extracellular vesicles, miR-143-5p was higher in fructose-fed rats (p = 0.001), whereas miR-223-3p (p = 0.022), miR-342-3p (p = 0.0011), miR-140-5p (p = 0.0129) and miR-146b-5p (p = 0.0245) were lower. CONCLUSION: Fructose exposure modifies the levels of microRNAs in extracellular vesicles in vitro and in vivo. In particular, fructose exposure increases miR-143-5p, while decreases miR-223-3p and miR-342-3p.

Activation Status of NLRP3 Inflammasome in Peripheral Blood Mononuclear Cells From Patients With Gout Flare.

BACKGROUND/OBJECTIVE: Although gout flares are featured by systemic signs of inflammation, cellular sources of inflammatory mediators are not yet properly characterized. Our objective was to evaluate serum levels and gene expression in peripheral blood mononuclear cells (PBMCs) of several molecules associated with the activation of NLRP3 inflammasome. METHODS: Fifteen patients with gout flare and 15 individuals with asymptomatic hyperuricemia were cross-sectionally studied. Serum levels of interleukin 1ß (IL-1ß), IL-18, monocyte chemoattractant protein 1/chemokine (C-C motif) ligand 2 (CCL2), and vascular cell adhesion molecule 1 were measured as a reflection of systemic inflammation, whereas the expression of NLRP3, CASP1, IL18, and CCL2 genes was measured to assess the inflammatory characteristics of PBMCs. RESULTS: Serum levels of IL-1ß (1.27 [0.07-1.99] pg/mL vs. 0 [0-0.82] pg/mL, p = 0.032) and vascular cell adhesion molecule 1 (606 [435-748] pg/mL vs. 349 [305-422] pg/mL, p = 0.014) were significantly higher in patients with gout flare than in individuals with asymptomatic hyperuricemia, whereas differences in IL-18 and monocyte chemoattractant protein 1/CCL2 were not found. Notably, no differences were observed in the expression of NLRP3, CASP1, IL18, or CCL2 in PBMCs from individuals of one or another group. CONCLUSIONS: Systemic inflammation during gout flares does not appear to be associated with NLRP3 inflammasome activation in PBMCs, suggesting that it may represent the systemic spread of local (synovial) inflammation to monosodium urate crystals, which provides a rationale for redirecting anti-inflammatory therapy from a systemic approach to one centered on the inflamed joint.

Plasma let-7i, miR-16, and miR-221 levels as candidate biomarkers for the assessment of ankylosing spondylitis in Mexican patients naïve to anti-TNF therapy.

Novel biomarkers are needed for the diagnosis and clinical assessment of ankylosing spondylitis (AS). Our objective was to investigate plasma microRNAs differentially expressed between AS patients and controls and to evaluate their potential as biomarkers in Mexican subjects. A cross-sectional study including 15 AS patients naïve to anti-TNF therapy and 13 controls was performed. Disease activity, physical function, and global well-being were evaluated by the AS Disease Activity Score (ASDAS-CRP), the Bath AS Disease Activity Index (BASDAI), the Bath AS Functional Index (BASFI), and the AS Quality of Life Questionnaire (ASQoL), respectively. Total RNA was isolated from plasma of participants and relative expression of let-7i, miR-16, and miR-221 was evaluated. Serum levels of C-reactive protein (CRP), matrix metalloproteinase-1 (MMP-1), MMP-9, and intercellular adhesion molecule-1 (ICAM-1) were also measured. Expression of let-7i was higher in patients than in controls (1.8, 0.9 to 3.4 versus 0.6, 0.4 to 1.2; P = 0.033) with an AUC/ROC of 0.74 (0.54 to 0.93; P = 0.032). Levels of miR-16 and miR-221 were unable to discriminate between patients and controls. Notably, plasma miR-16 levels were inversely correlated with the ASDAS-CRP score (rho - 64, - 0.87 to - 0.18; P = 0.011), the BASFI score (rho - 0.78, - 0.93 to - 0.43; P = 0.001), and serum MMP-1 levels (rho - 0.59, - 0.85 to - 0.09; P = 0.022). No other associations were found. Plasma let-7i levels may serve as a biomarker for the diagnosis of AS in Mexican individuals. Additionally, plasma miR-16 levels are associated with disease activity and physical functionality in patients naïve to anti-TNF therapy.

Functional polymorphisms in pre-miR146a and pre-miR499 are associated with systemic lupus erythematosus but not with rheumatoid arthritis or Graves' disease in Mexican patients.

Recently, different microRNA (miRNA) gene polymorphisms have been evaluated in patients with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and Graves' disease (GD). In the present study, we examined three single-nucleotide polymorphisms (SNPs) located in the pre-miR-146a (rs2910164G/C), pre-miR-196a-2 (rs11614913C/T), and pre-miR-499 (rs3746444A/G) genes. Our study population included 900 Mexican patients with RA, SLE, or GD, as well as 486 healthy control individuals with no family history of inflammatory or autoimmune diseases. Genotyping was performed using TaqMan probes and a 5' exonuclease assay. None of the investigated SNPs were associated with RA or GD susceptibility under any genetic model (co-dominant, recessive, or dominant). Genotype and allele frequencies of the miR-196a-2 rs11614913C/T polymorphism were similar between SLE cases and controls. In contrast, the miR-146a rs2910164G/C and miR-499 rs3746444A/G polymorphisms were associated with SLE susceptibility. These SNPs were not associated with lupus nephritis (LN). Our results suggest that polymorphisms in miR-146a, miR-196a-2, and miR-499 are not associated with RA or GD susceptibility. This is the first report documenting that the miR-146a rs2910164G/C and miR-499 rs3746444 polymorphisms are associated with SLE susceptibility but not with LN.

The PTPN22 R263Q polymorphism confers protection against systemic lupus erythematosus and rheumatoid arthritis, while PTPN22 R620W confers susceptibility to Graves' disease in a Mexican population.

OBJECTIVE: The functional PTPN22 R620W polymorphism (rs2476601) is clearly associated with susceptibility to several autoimmune diseases (ADs). However, the PTPN22 R263Q polymorphism (rs33996649) has been scarcely explored in different ADs. Here we aimed to examine the associations of the PTPN22 R620W and R263Q polymorphisms with susceptibility to or protection against rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and Graves' disease (GD) among Mexican patients. METHODS: We conducted a case-control study including 876 patients (405 with SLE, 388 with RA, and 83 with GD) and 336 healthy control individuals. PTPN22 genotypes were determined using the TaqMan 5' allele discrimination assay. RESULTS: PTPN22 R620W was associated with GD susceptibility (OR 4.3, p = 0.004), but was not associated with SLE (OR 1.8, p = 0.19). We previously demonstrated that this polymorphism is associated with RA susceptibility (OR 4.17, p = 0.00036). Moreover, PTPN22 R263Q was associated with protection against SLE (OR 0.09, p = 004) and RA (OR 0.28, p = 0.045), but was not associated with GD. CONCLUSIONS: Our data provide the first demonstration that PTPN22 R620W confers GD susceptibility among Latin-American patients. Moreover, this is the second report documenting the association of PTPN22 R263Q with protection against SLE and RA.

Inflammation Related MicroRNAs Are Modulated in Total Plasma and in Extracellular Vesicles from Rats with Chronic Ingestion of Sucrose.

Circulating microRNAs (miRNAs) and the functional implications of miRNAs contained in extracellular vesicles (EVs) have gained attention in the last decade. Little is known about the regulation of the abundance of plasma miRNAs in response to chronic ingestion of carbohydrates. Therefore, we explored the circulating levels of miR-21, miR-146a, miR-155, and miR-223 in rats consuming sucrose in drinking water. Weanling Wistar rats were 25 weeks with 30% sucrose in drinking water, and miRNAs expression was determined in total plasma and in microvesicles, by RT-qPCR with TaqMan probe based assays for miR-21, miR-146a, miR-155, and miR-223, using cel-miR-39 (as spike in control and reference). Endotoxemia was also measured. Sucrose-fed animals showed higher body weight and retroperitoneal adipose tissue as well as higher glucose and triglyceride plasma levels than controls. Plasma endotoxin levels were low and not different among groups. Plasma miR-21 and miR-223 were higher in the sucrose group (p < 0.05), whereas miR-155 tended to be lower (p = 0.0661), and miR-146a did not show significant differences. In the plasma EVs the same trend was found except for miR-146a that showed significantly higher levels (p < 0.05). Overall, our results show that high carbohydrate ingestion modulates circulating miRNAs levels related to an inflammatory response.