hsa-miR-424-5p and hsa-miR-513c-3p dysregulation mediated by IFN-γ is associated with salivary gland dysfunction in Sjögren's syndrome patients

Salivary secretory dysfunction in SS-patients is associated with altered proteostasis, upregulation of ATF6α and components of the ERAD complex, such as SEL1L, and downregulation of XBP-1s and GRP78. Hsa-miR-424-5p is downregulated and hsa-miR-513c-3p is overexpressed in salivary glands from SS-patients. These miRNAs emerged as candidates that could regulate ATF6/SEL1L and XBP-1s/GRP78 levels, respectively. This study aimed to evaluate the effect of IFN-γ on hsa-miR-424-5p and hsa-miR-513c-3p expression and how these miRNAs regulate their targets. In labial salivary glands (LSG) biopsies from 9 SS-patients and 7 control subjects and IFN-γ-stimulated 3D-acini were analyzed. hsa-miR-424-5p and hsa-miR-513c-3p levels were measured by TaqMan assays and their localization by ISH. mRNA, protein levels, and localization of ATF6, SEL1L, HERP, XBP-1s and GRP78 were determined by qPCR, Western blot, or immunofluorescence. Functional and interaction assays were also performed. In LSGs from SS-patients and IFN-γ-stimulated 3D-acini, hsa-miR-424-5p was downregulated and ATF6α and SEL1L were upregulated. ATF6α and SEL1L were decreased after hsa-miR-424-5p overexpression, while ATF6α, SEL1L and HERP increased after hsa-miR-424-5p silencing. Interaction assays revealed that hsa-miR-424-5p targets ATF6α directly. hsa-miR-513c-3p was upregulated and XBP-1s and GRP78 were downregulated. XBP-1s and GRP78 were decreased after hsa-miR-513c-3p overexpression, while increases in XBP-1s and GRP78 were observed after hsa-miR-513c-3p silencing. Furthermore, we determined that hsa-miR-513c-3p targets XBP-1s directly. Significant correlations were found between both miRNA levels and clinical parameters. In conclusion, IFN-γ-dependent hsa-miR-424-5p and hsa-miR-513c-3p levels affect the expression of important factors involved in cellular proteostasis that control secretory function in LSG from SS-patients.

The integrated stress response is activated in the salivary glands of Sjögren's syndrome patients

Introduction

Primary Sjögren's syndrome (SS) is an autoimmune exocrinopathy that affects the structure and function of salivary and lachrymal glands. Labial salivary gland (LSG) acinar cells from SS patients lose cellular homeostasis and experience endoplasmic reticulum and oxidative stress. The integrated cellular stress response (ISR) is an adaptive pathway essential for restoring homeostasis against various stress-inducing factors, including pro-inflammatory cytokines, and endoplasmic reticulum and oxidative stress. ISR activation leads eIF2α phosphorylation, which transiently blocks protein synthesis while allowing the ATF4 expression, which induces a gene expression program that seeks to optimize cellular recovery. PKR, HRI, GCN2, and PERK are the four sentinel stress kinases that control eIF2α phosphorylation. Dysregulation and chronic activation of ISR signaling have pathologic consequences associated with inflammation.

Methods

Here, we analyzed the activation of the ISR in LSGs of SS-patients and non-SS sicca controls, determining the mRNA, protein, and phosphorylated-protein levels of key ISR components, as well as the expression of some of ATF4 targets. Moreover, we performed a qualitative characterization of the distribution of ISR components in LSGs from both groups and evaluated if their levels correlate with clinical parameters.

Results

We observed that the four ISR sensors are expressed in LSGs of both groups. However, only PKR and PERK showed increased expression and/or activation in LSGs from SS-patients. eIF2α and p-eIF2α protein levels significantly increased in SS-patients; meanwhile components of the PP1c complex responsible for eIF2α dephosphorylation decreased. ATF4 mRNA levels were decreased in LSGs from SS-patients along with hypermethylation of the ATF4 promoter. Despite low mRNA levels, SS-patients showed increased levels of ATF4 protein and ATF4-target genes involved in the antioxidant response. The acinar cells of SS-patients showed increased staining intensity for PKR, p-PKR, p-PERK, p-eIF2α, ATF4, xCT, CHOP, and NRF2. Autoantibodies, focus score, and ESSDAI were correlated with p-PERK/PERK ratio and ATF4 protein levels.

Discussion

In summary, the results showed an increased ISR activation in LSGs of SS-patients. The increased protein levels of ATF4 and ATF4-target genes involved in the redox homeostasis could be part of a rescue response against the various stressful conditions to which the LSGs of SS-patients are subjected and promote cell survival.

POS0100 ACTIVATION OF THE CELLULAR INTEGRATED STRESS RESPONSE IN LABIAL SALIVARY GLANDS FROM SJÖGREN’S SYNDROME PATIENTS

Background

Sjögren’s syndrome (SS) is a chronic autoimmune disease characterized by inflammation of the exocrine glands and severe symptoms of eye and mouth dryness. Disorders in the saliva secretion process have been associated with oxidative and endoplasmic reticulum (ER) stress in combination with inflammatory responses. The integrated stress response (ISR) is a mechanism that allows cells to modify their gene expression program to restore homeostasis and promote their survival against various extrinsic and intrinsic stress signals, such as hypoxia, nutrient deprivation, viral infections, inflammatory factors (cytokines, chemokines, inflammasomes), and accumulation of unfolded proteins in the ER, among others (1). The ISR is regulated by four kinases: PERK, PKR, HRI and GCN2, that dimerize and autophosphorylate to become active and each one responds to different stress stimuli. The signaling pathways that are activated in response to stress factors stimulate the phosphorylation of eIF2α, which causes a transient inhibition of global protein synthesis and induction of synthesis of some specific genes like ATF4 and NRF2. ATF4 induces the transcription of genes involved in metabolism and nutrient uptake, redox status, and regulation of apoptosis. Dephosphorylation of eIF2α is the ISR termination signal to restore protein synthesis and is mediated by the PP1 complex, which recruits the catalytic subunit PP1c and one of its two regulatory subunits: GADD34 or CREP.

Objectives

To evaluate the presence and functional state (phosphorylation) of the ISR sensing kinases: PERK, PKR, HRI and GCN2; the levels of eIF2α /p-eIF2α and the key ISR transcription factors ATF4 and NRF2, as well as subunits of the complex involved in the ISR termination: PP1c, GADD34 and CREP in labial salivary glands (LSG) of SS-patients.

Methods

Biopsies of LSG from 12 SS-patients and 11 control subjects were studied. The levels of mRNA, protein and phospho (p)-protein of the ISR components were determined by RT-qPCR and Western blotting.

Results

Our results show increased levels of p-PERK/PERK ratio (11/11), PKR (7/11), p-PKR (7/11), p-PKR/PKR ratio (7/11), eIF2α (5/11), p-eIF2α (5/11) and ATF4 (11/11) in LSG from SS-patients compared to control subjects. No significant changes were found in mRNA levels of HRI, GCN2, and GADD34 between LSG from SS-patients and control subjects. Decreased protein levels of HRI (8/12), p-GCN2 (6/11), eIF2α (6/11), p-eIF2α (6/11), NRF2 (11/12), and p-NRF2 (12/12) were found in LSG showing scarce parenchyma and high fibrosis and fat infiltration. On the other hand, PP1c and CREP showed decreased mRNA and protein levels in all SS-patients LSG. Interestingly, Ro autoantibodies and focus score were negatively correlated with PP1c and NRF2 mRNA and protein levels whereas positively correlated with PKR mRNA levels.

Conclusion

The overexpression and activation of some ISR kinases together with the decrease in the PP1c/CREP phosphatase complex suggests a continuous activation of ISR, resulting in p-eIF2α to remain activated in LSG from SS-patients. This would explain the high protein levels of ATF4 and of target genes involved in the antioxidant response in LSG from SS patients suggesting that ISR activation plays a key role in pro-survival response to cellular stress.

References

[1]Pakos-Zebrucka K, Koryga I, Mnich K, Ljujic M, Samali A, Gorman AM. The integrated stress response. EMBO Rep. 2016;17(10):1374-95.

Acknowledgements

This work was supported by Fondecyt-Chile 1210055; Enlace-VID Universidad de Chile [ENL04/20 to MJG]; Fondecyt Iniciacion 11201058 and PhD fellowship Conicyt Chile.

Disclosure of Interests

None declared

POS0455 TOFACITINIB DECREASES INFLAMMATORY MARKERS AND MITOCHONDRIAL MORPHOLOGICAL DAMAGE IN SALIVARY GLANDS OF A MURINE MODEL OF SJÖGREN’S SYNDROME

Background

Altered homeostasis of salivary gland (SG) epithelial cells in Sjögren’s syndrome (SS) patients could be the initiating factor that leads to inflammation, as well as secretory dysfunction. Mitochondria are important organelles involved in cellular metabolism and their dysfunction can induce a loss of homeostasis and inflammation. Altered mitochondrion can release mitochondrial components that can act as damage-associated molecular patterns (DAMPs) and induce an inflammatory response via pattern recognition receptors (PRRs) such as the NLRP3 inflammasome, TLR9, cGAS/STING, and ZBP1 (1). Previously we determined that SG from SS patients showed and altered autophagy, which is associated to an increased pro-inflammatory cytokines expression. Interestingly, increased expression of pro-inflammatory markers such as IL-6, was reversed by JAK inhibitor tofacitinib in three-dimensional (3D)-acini deficient in autophagy (2). It is not clear whether the alterations in autophagy found in SG patients include alterations in mitochondrial clearance (mitophagy) that may lead to the accumulation of damaged mitochondria and enhanced inflammation. In this context, recent results of our laboratory showed, for the first time, severe ultrastructural alterations of mitochondria in SG cells from SS patients (1). However, it remains to be determined if these alterations are related to inflammation and if an anti-inflammatory agent could regulate these processes.

Objectives

To analyze the effect of tofacitinib on the mitochondrial ultrastructure in submandibular glands of a murine model of SS. In addition, to evaluate the effect of tofacitinib on the expression and activation of some PRRs involved in the recognition of mitochondrial DAMPs in the same murine model.

Methods

Six-month-old female NOD.B10Sn-H2b/J mice (Jackson Laboratories, USA) were used with 4-5 mice per group. Procedures were approved by the Universidad de Chile Animal Care and Use Committee. 30 mg/kg/day tofacitinib citrate was administered by oral gavage. After 28 days of tofacitinib or vehicle administration, their submandibular glands were obtained, which were processed to evaluate the mitochondrial ultrastructure by electron microscopy or lysed in RIPA buffer to obtain proteins. The protein levels of PRRs: NLRP3, TLR9, ZBP-1, and cGAs, as well as molecules activated downstream of cGAS and ZBP-1 such as TBK1, pTBK1, pSTING, and STING were determined by Western blotting.

Results

The results show that the mitochondria of the glandular epithelial cells of NOD.B10Sn-H2b/J mice treated with vehicle (control) present alterations such as swelling, disruption of membranes and crest disorganization that previously were reported in patients with SS (1). Interestingly, tofacitinib treatment improves the architecture of mitochondria. On the other hand, the protein levels of PRRs such as NLRP3 and cGAS decreased in mice treated with tofacitinib, as well as pTBK1.

Conclusion

The altered morphology of mitochondria together with the increased protein levels of PRRs and downstream markers of these PRRs suggests release of mitochondrial DAMPs in submandibular glands of NOD.B10Sn-H2b/J mice. The improvement in mitochondrial morphology as well as the decrease in PRRs activation under tofacitinib treatment suggest a potential use of this anti-inflammatory agent in mitochondrial alterations associated with inflammation. Many questions remain to be addressed, such as determining which mitochondrial DAMP might be being released and whether this is associated with impaired mitochondrial function in SS.

References

[1]Barrera, M. J., et al (2021). Dysfunctional mitochondria as critical players in the inflammation of autoimmune diseases: Potential role in Sjögren’s syndrome. Autoimmunity reviews, 20(8), 102867.

[2]Barrera, M. J., et al (2021). Tofacitinib counteracts IL-6 overexpression induced by deficient autophagy: implications in Sjögren’s syndrome. Rheumatology (Oxford, England), 60(4), 1951–1962.

Acknowledgements

This work was supported by Fondecyt Iniciación 11201058 and Fondecyt-Chile 1210055.

Disclosure of Interests

None declared.

Small RNA Expression Profiling Reveals hsa-miR-181d-5p Downregulation Associated With TNF-α Overexpression in Sjögren’s Syndrome Patients

MicroRNAs (miRNAs) are small non-coding RNAs (sRNA), that alter gene expression by binding to target messenger RNAs (mRNAs) and repressing translation. Dysregulated miRNA expression has been implicated in the pathogenesis of autoimmune diseases such as Sjögren’s syndrome (SS). The aim of this study was to characterize the global profile of sRNAs in labial salivary glands (LSG) from SS-patients and to validate potential miRNA candidates implicated in glandular inflammation. LSG from 21 SS-patients and 9 sicca controls were analyzed. A global next generation sequencing (NGS)-based sRNA profiling approach was employed to identify direct targets whereby differentially expressed miRNAs were predicted using bioinformatics tools. miRNA levels were validated by TaqMan and target mRNA levels were determined by quantitative real-time PCR. We also performed in vitro assays using recombinant TNF-α. NGS shows that ~30% of sRNAs were miRNAs. In comparison with samples from sicca controls, four miRNAs were found differentially expressed in LSG from SS-patients with low focus score (LFS) and 18 from SS-patients with high focus score (HFS). The miRNA with the most significant changes identified by NGS was hsa-miR-181d-5p and downregulation was confirmed by TaqMan analysis. Levels of TNF-α mRNA, a direct target of hsa-miR-181d-5p, were significantly increased and negatively correlated with hsa-miR-181d-5p presence. Moreover, positive correlations between TNF-α transcript levels, focus score, ESSDAI, and autoantibody levels were also detected. Furthermore, TNF-α stimulation decreased hsa-miR-181d-5p levels in vitro. Downregulation of hsa-miR-181d-5p in LSG from SS-patients could contribute to the glandular pro-inflammatory environment by deregulation of its direct target TNF-α. Further dissection of the pathophysiological mechanisms underlying the hsa-miR-181d-5p-mediated action in inflammatory conditions could be useful to evaluate the benefits of increasing hsa-miR-181d-5p levels for restoration of salivary gland epithelial cell architecture and function.

[Chilean consensus on diagnosis and management of pancreatic cystic neoplasms]

Pancreatic cystic neoplasms (PCN) are frequently detected on abdominal images performed for non-pancreatic indications. Their prevalence in asymptomatic population ranges from 2.7 to 24.8%, and increases with age. There are several types of pancreatic cysts. Some may contain cancer or have malignant potential, such as mucinous cystic neoplasms, including mucinous cystadenoma (MCN) and intraductal papillary mucinous neoplasms (IPMN). In contrast, others are benign, such as serous cystadenoma (SCA). However, even those cysts with malignant potential rarely progress to cancer. Currently, the only treatment for pancreatic cysts is surgery, which is associated with high morbidity and occasional mortality. The Board of the Chilean Pancreas Club of the Chilean Gastroenterology Society developed the first Chilean multidisciplinary consensus for diagnosis, management, and surveillance of PCN. Thirty experts were invited and answered 21 statements with five possible alternatives: 1) fully agree; 2) partially agree; 3) undecided; 4) disagree and 5) strongly disagree. A consensus was adopted when at least 80% of the sum of the answers "fully agree" and "partially agree" was reached. The consensus was approved by the Board of Directors of the Chilean Pancreas Club for publication.

Tofacitinib counteracts IL-6 overexpression induced by deficient autophagy: implications in Sjögren's syndrome

OBJECTIVE

Altered homeostasis of salivary gland (SG) epithelial cells in Sjögren's syndrome (SS) could be the initiating factor that leads to inflammation, secretory dysfunction and autoimmunity. Autophagy is an important homeostatic mechanism, whose deficiency is associated with inflammation and accumulation of Janus kinase (JAK)-signal transducer and activator of transcription (STAT) components. We aimed to evaluate whether autophagy is altered in labial SG (LSG) epithelial cells from primary SS (pSS) patients and whether this contributes to inflammation through the JAK-STAT pathway. Furthermore, we investigated the anti-inflammatory effect of the JAK inhibitor tofacitinib in autophagy-deficient (ATG5 knockdown) three-dimensional (3D)-acini.

METHODS

We analysed LSG biopsies from 12 pSS patients with low focus score and 10 controls. ATG5-deficient 3D-acini were generated and incubated with IL-6 in the presence or absence of tofacitinib. Autophagy markers, pro-inflammatory cytokine expression, and JAK-STAT pathway activation were evaluated by PCR or western blot, along with correlation analyses between the evaluated markers and clinical parameters.

RESULTS

LSG from pSS patients showed increased p62 and decreased ATG5 expression, correlating negatively with increased activation of JAK-STAT pathway components (pSTAT1 and pSTAT3). Increased expression of STAT1 and IL-6 correlated with EULAR Sjögren's syndrome disease activity index and the presence of anti-Ro antibodies. ATG5-deficient 3D-acini reproduced the findings observed in LSG from pSS patients, showing increased expression of pro-inflammatory markers such as IL-6, which was reversed by tofacitinib.

CONCLUSION

Decreased expression of ATG5 in LSG epithelial cells from pSS patients possibly contributes to increased inflammation associated with JAK-STAT pathway activation, as evidenced in ATG5-deficient 3D-acini. Interestingly, these results suggest that tofacitinib could be used as an anti-inflammatory agent in pSS patients.

Dysfunctional mitochondria as critical players in the inflammation of autoimmune diseases: Potential role in Sjögren's syndrome

Relevant reviews highlight the association between dysfunctional mitochondria and inflammation, but few studies address the contribution of mitochondria and mitochondria-endoplasmic reticulum (ER) contact sites (MERCs) to cellular homeostasis and inflammatory signaling. The present review outlines the important role of mitochondria in cellular homeostasis and how dysfunctional mitochondrion can release and misplace mitochondrial components (cardiolipin, mitochondrial DNA (mtDNA), and mitochondrial formylated peptides) through multiple mechanisms. These components can act as damage-associated molecular patterns (DAMPs) and induce an inflammatory response via pattern recognition receptors (PRRs). Accumulation of damaged ROS-generating mitochondria, accompanied by the release of mitochondrial DAMPs, can activate PRRs such as the NLRP3 inflammasome, TLR9, cGAS/STING, and ZBP1. This process would explain the chronic inflammation that is observed in autoimmune diseases such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), type I diabetes (T1D), and Sjögren's syndrome. This review also provides a comprehensive overview of the importance of MERCs to mitochondrial function and morphology, cellular homeostasis, and the inflammatory response. MERCs play an important role in calcium homeostasis by mediating the transfer of calcium from the ER to the mitochondria and thereby facilitating the production of ATP. They also contribute to the synthesis and transfer of phospholipids, protein folding in the ER, mitochondrial fission, mitochondrial fusion, initiation of autophagosome formation, regulation of cell death/survival signaling, and regulation of immune responses. Therefore, alterations within MERCs could increase inflammatory signaling, modulate ER stress responses, cell homeostasis, and ultimately, the cell fate. This study shows severe ultrastructural alterations of mitochondria in salivary gland cells from Sjögren's syndrome patients for the first time, which could trigger alterations in cellular bioenergetics. This finding could explain symptoms such as fatigue and malfunction of the salivary glands in Sjögren's syndrome patients, which would contribute to the chronic inflammatory pathology of the disease. However, this is only a first step in solving this complex puzzle, and several other important factors such as changes in mitochondrial morphology, functionality, and their important contacts with other organelles require further in-depth study. Future work should focus on detecting the key milestones that are related to inflammation in patients with autoimmune diseases, such as Sjögren´s syndrome.

Type I Interferon Dependent hsa-miR-145-5p Downregulation Modulates MUC1 and TLR4 Overexpression in Salivary Glands From Sjögren's Syndrome Patients

Sjögren’s syndrome (SS) is an autoimmune disease that mainly affects salivary glands (SG) and is characterized by overactivation of the type I interferon (IFN) pathway. Type I IFNs can decrease the levels of hsa-miR-145-5p, a miRNA with anti-inflammatory roles that is downregulated in SG from SS-patients. Two relevant targets of hsa-miR-145-5p, mucin 1 (MUC1) and toll-like receptor 4 (TLR4) are overexpressed in SS-patients and contribute to SG inflammation and dysfunction. This study aimed to evaluate if hsa-miR-145-5p modulates MUC1 and TLR4 overexpression in SG from SS-patients in a type I IFN dependent manner. Labial SG (LSG) biopsies from 9 SS-patients and 6 controls were analyzed. We determined hsa-miR-145-5p levels by TaqMan assays and the mRNA levels of MUC1, TLR4, IFN-α, IFN-β, and IFN-stimulated genes (MX1, IFIT1, IFI44, and IFI44L) by real time-PCR. We also performed in vitro assays using type I IFNs and chemically synthesized hsa-miR-145-5p mimics and inhibitors. We validated the decreased hsa-miR-145-5p levels in LSG from SS-patients, which inversely correlated with the type I IFN score, mRNA levels of IFN-β, MUC1, TLR4, and clinical parameters of SS-patients (Ro/La autoantibodies and focus score). IFN-α or IFN-β stimulation downregulated hsa-miR-145-5p and increased MUC1 and TLR4 mRNA levels. Hsa-miR-145-5p overexpression decreased MUC1 and TLR4 mRNA levels, while transfection with a hsa-miR-145-5p inhibitor increased mRNA levels. Our findings show that type I IFNs decrease hsa-miR-145-5p expression leading to upregulation of MUC1 and TLR4. Together, this suggests that type I interferon-dependent hsa-miR-145-5p downregulation contributes to the perpetuation of inflammation in LSG from SS-patients.

POS0180 TYPE I INTERFERON DEPENDENT HSA-MIR-145-5P DOWNREGULATION MODULATES MUC1 AND TLR4 OVEREXPRESSION IN SALIVARY GLANDS FROM PRIMARY SJÖGREN’S SYNDROME PATIENTS

Background:

Primary Sjögren’s syndrome (pSS) is an autoimmune and inflammatory disease that mainly affects the salivary glands (SG) and is characterized by an overactivation of the type I interferon pathway (IFNs I). IFNs I are known to regulate the levels of microRNAs (miRNAs), non-coding RNAs whose levels are altered in pSS. IFNs I can decrease the levels of miR-145-5p, a miRNA with anti-inflammatory roles that has been reported downregulated in SG of from pSS patients [1]. This miRNA has TLR4 and MUC1 transcripts as predicted targets. MUC1 and TLR4 are two proteins overexpressed in SG of pSS patients that contribute, through various mechanisms, to the inflammatory state and glandular dysfunction [2-3]. Thus, we propose that IFNs I may contribute to a self-perpetuating inflammation loop through a hsa-miR-145-5p dependent MUC1 and TLR4 overexpression in the SG of pSS patients.

Objectives:

to evaluate whether mRNA levels of MUC1 and TLR4 are modulated by hsa-miR-145-5p in a IFNs I dependent manner.

Methods:

13 pSS patients and 9 controls SG biopsies were analyzed. hsa-miR-145-5p levels were determined by TaqMan assays and MUC1, TLR4, IFN-α and IFN-β mRNA levels by RT-qPCR. Additionally, in vitro assays using type I IFNs and chemically synthesized hsa-miR-145-5p mimics and inhibitors were performed to study its effect on MUC1 and TLR4 expression. JAK1 and STAT1 mRNA levels were also measured.

Results:

By Taqman assays we validated the decreased hsa-miR-145-5p levels (p=0.0001) in SG of pSS patients compared to controls. The decreased hsa-miR-145-5p levels correlated inversely with the increased mRNA levels of IFN-β (p=0.0192) in SG of pSS-patients. The hsa-miR-145-5p downregulation also correlated inversely with the overexpression of its predicted targets MUC1 (p=0.010) and TLR4 (p=0.0004). In vitro assays showed that IFN-β induces the overexpression of JAK1 (<p=0.0001) and STAT1 (p=<0.0001) leading to the downregulation of hsa-mir-145-5p (p=<0.0001) and increased MUC1 (p=<0.0001) and TLR4 mRNA levels (p=<0.0001). Functional assays suggest a regulation of hsa-miR-145-5p on MUC1 and TLR4 expression as MUC1 and TLR4 mRNA levels were decreased in HSG cells transfected with hsa-miR-513c-3p mimic and increased in HSG cells transfected with the miRNA inhibitor.

Conclusion:

Our findings suggest that IFNs I could induce the downregulation of hsa-miR-145-5p leading to the overexpression of MUC1 and TLR4 in SG from pSS patients. TLR4 is activated by ectopic mucins in the SG extracellular matrix from pSS patients which induces pro-inflammatory cytokines secretion [3]. Furthermore, the high levels of the MUC1-SEC and MUC1-Y isoforms observed in SG from pSS patients may favor cytokine synthesis through the immuno-enhancing peptide of MUC1-SEC or through the formation of a MUC1-SEC/MUC1-Y complex [4]. Therefore, IFNs I may contribute to the development of SS through amplification and perpetuation of inflammation due to a hsa-miR-145-5p dependent MUC1 and TLR4 overexpression.

References:

[1]I. Alevizos, et al,. Arthritis Rheum, 2011;63:535-44.

[2]HH. Sung, et al,. Oral Dis. 2015;21(6):730-8.

[3]MJ. Barrera, et al,. Rheumatology (Oxford). 2015;54(8):1518-27

[4]LM. Herbert, et al,. Cancer Res. 2004;64(21):8077-84.

Acknowledgements:

Fondecyt 1210055, Fondecyt 1160015, Fondecyt Iniciación 11170049, Fondecyt Iniciación 11201058, CONICYT fellowship (DJ, PC)

Disclosure of Interests:

None declared

Paisaje de la Protesta en Plaza Dignidad de Santiago, Chile

Esta investigación explora el paisaje de la protesta a través de las intervenciones gráficas realizadas durante las manifestaciones del estallido social de octubre del 2019 en Plaza Baquedano, Santiago. A partir de técnicas proporcionadas por la arqueología y la etnografía, se registran los grafitis que los manifestantes plasmaron, entre enero y marzo del 2020, sobre los muros y monumentos. La investigación permitió identificar los cambios materiales, sus características y patrones, y correlacionar dichas materialidades con su escena. Se concluye que por sobre la ira, la violencia y la destrucción de monumentos e inmuebles del espacio público, las intervenciones visuales apelan a una narrativa que como un mosaico anuncian las acciones de resistencia al modelo social imperante, pero, sobre todo, celebran los principios morales del respeto y sentido de justicia social. Finalmente, se señala que, en esta celebración y ejercicio performativo, surge un paisaje de la protesta cuyo colorido y estética juvenil se impone por sobre la monocromía de las ruinas y escombros de los edificios y monumentos patrimoniales.

THU0229 HSA-MIR-513C-3P OVEREXPRESSION DECREASES XBP-1S CORRELATING WITH INCREASED INFLAMMATION AND AUTOANTIBODIES IN SALIVARY GLANDS FROM SJÖGREN’S SYNDROME PATIENTS

Background:

Endoplasmic reticulum (ER) stress and the Unfolded Protein Response (UPR) are linked to inflammation in a variety of human pathologies including autoimmune diseases. Salivary glands (SG) from Sjögren’s syndrome (SS) patients have high levels of IFN-gamma among other cytokines, which trigger or exacerbate protein unfolding or misfolding, inducing ER stress. In this study, we focused on the IRE1α/XBP-1 pathway of the UPR, whose transcription factor is XBP-1s, which induces genes linked to regulation of the secretory pathway. We recently found that SG of SS patients have reduced levels of XBP-1s transcripts associated with an increased DNA methylation of XBP-1 promoter [1]. We postulate that other epigenetic mechanisms, such as miRNAs, could coexist with promoter DNA hyper-methylation to regulate XBP-1s expression.

Objectives:

Due to hsa-miR-513c-3p overexpression has been reported in SG from SS patients [2] and that XBP-1 is a predicted target of hsa-miR-513c-3p, the aim of this study was to evaluate whether mRNA levels of XBP-1s is modulated by hsa-miR-513c-3p and also if IFN-gamma modify the expression hsa-miR-513c-3p and XBP-1s.

Methods:

SG biopsies from 16 SS-patients with low and high focus score and 5 controls were analyzed. hsa-miR-513c-3p levels were measured by Taqman miRNA assays, whereas XBP-1s mRNA levels were determined by qRT-PCR. Additionally,in vitroassays using IFN-gamma and chemically synthesized hsa-miR-513c-3p mimics and inhibitors were performed to study its effect on XBP-1s expression.

Results:

By Taqman assays we validated the overexpression of hsa-miR-513c-3p in SG from 8 SS patients with low (p=0.03) and 8 SS-patients with high (p=0.003) focus score, compared with SG from 5 controls. In the same samples, a decrease of XBP-1s transcript levels was observed in SG from SS-patients with low (p=0.002) and high (p=0.026) focus score. XBP1s transcript levels were negatively correlated with hsa-miR-513c-3p (r=-0.47, p=0.014), Ro (r=-0.73, p=0.0009), ANA (r=-0.7, p=0.0033) and focus score (r=-0.72, p=0.001). Stimulation of 3D-acini with 1 ng/mL IFN-gamma increase the hsa-miR-513c-3p levels (p=0.014) and decrease the XBP-1s transcript levels (p=0.027). A negative correlation was found between hsa-miR-513c-3p and XBP-1s transcript levels in 3D-acini stimulated with IFN-gamma (r=-0.87, p=0.0001). The XBP-1s transcript levels were decreased in HSG cells transfected with hsa-miR-513c-3p mimic and increased in HSG cells transfected with the miRNA inhibitor.

Conclusion:

IFN-gamma-induced upregulation of hsa-miR-513c-3p is consistent with the presence of STAT1-binding elements in its promoter region. Our findings suggest that the combined action of miRNAs and DNA methylation modulated by IFN-gamma could explain the altered expression of XBP-1s, a key transcription factor involved in cellular proteostasis, affecting secretory function in LSG from SS-patients. Our results confirm previous correlations found between XBP-1s protein levels and clinical parameters of SS-patients, suggesting an association of XBP-1s with inflammation and impaired SG function.

References:

[1]D. Sepúlveda,et al, Rheumatology (Oxford), 2018;57:1021-32.

[2]I. Alevizos,et al,. Arthritis Rheum, 2011;63:535-44.

Acknowledgments :

Fondecyt 1160015, Fondecyt Iniciación 11170049, Fondecyt Postdoctorado 3170023, CONICYT fellowship (PC, DJ).

Disclosure of Interests: :

None declared

Aberrant MUC1 accumulation in salivary glands of Sjögren’s syndrome patients is reversed by TUDCA in vitro

Objectives

Xerostomia in SS patients has been associated with low quality and quantity of salivary mucins, which are fundamental for the hydration and protection of the oral mucosa. The aim of this study was to evaluate if cytokines induce aberrant mucin expression and whether tauroursodeoxycholic acid (TUDCA) is able to counteract such an anomaly.

Methods

Labial salivary glands from 16 SS patients and 15 control subjects, as well as 3D acini or human submandibular gland cells stimulated with TNF-α or IFN-γ and co-incubated with TUDCA, were analysed. mRNA and protein levels of Mucin 1 (MUC1) and MUC7 were determined by RT-qPCR and western blot, respectively. Co-immunoprecipitation and immunofluorescence assays for mucins and GRP78 [an endoplasmic reticulum (ER)-resident protein] were also performed. mRNA levels of RelA/p65 (nuclear factor-κB subunit), TNF-α, IL-1β, IL-6, SEL1L and EDEM1 were determined by RT-qPCR, and RelA/p65 localization was evaluated by immunofluorescence.

Results

MUC1 is overexpressed and accumulated in the ER of labial salivary gland from SS patients, while MUC7 accumulates throughout the cytoplasm of acinar cells; however, MUC1, but not MUC7, co-precipitated with GRP78. TUDCA diminished the overexpression and aberrant accumulation of MUC1 induced by TNF-α and IFN-γ, as well as the nuclear translocation of RelA/p65, together with the expression of inflammatory and ER stress markers in 3D acini.

Conclusion

Chronic inflammation alters the secretory process of MUC1, inducing ER stress and affecting the quality of saliva in SS patients. TUDCA showed anti-inflammatory properties decreasing aberrant MUC1 accumulation. Further studies are necessary to evaluate the potential therapeutic effect of TUDCA in restoring glandular homeostasis in SS patients.

[Syphilitic hepatitis. Report of three cases]

Liver involvement occurs in 0.2 to 3% of patients with syphilis. We report three patients with liver involvement in syphilis. A 52-year-old male presenting with erythema and malaise. Laboratory showed a gamma glutamyl transpeptidase (GGT) of 853 u/l, alkaline phosphatases of 1,010 U/L and VDRL was positive. Treatment with penicillin resolved the skin problem and normalized liver enzymes. A HIV positive 30-year-old male in peritoneal dialysis presenting with itching, malaise and markedly elevated GGT and alkaline phosphatases. VDRL was positive. He was treated with penicillin with remission of symptoms and enzyme normalization. A 43-year-old male presenting with erythema, malaise, arthralgias and elevated GGT and alkaline phosphatases. VDRL was positive and treatment with penicillin reverted symptoms and laboratory abnormalities.

Association of high 5-hydroxymethylcytosine levels with Ten Eleven Translocation 2 overexpression and inflammation in Sjögren's syndrome patients

Here, we determined the 5-hydroxymethylcytosine (5hmC), 5-methylcytosine (5mC), Ten Eleven Translocation (TETs), and DNA methyltransferases (DNMTs) levels in epithelial and inflammatory cells of labial salivary glands (LSG) from Sjögren's syndrome (SS)-patients and the effect of cytokines on HSG cells. LSG from SS-patients, controls and HSG cells incubated with cytokines were analysed. Levels of 5mC, 5hmC, DNMTs, TET2 and MeCP2 were assessed by immunofluorescence. In epithelial cells from SS-patients, an increase in TET2, 5hmC and a decrease in 5mC and MeCP2 were observed, additionally, high levels of 5mC and DNMTs and low levels of 5hmC were detected in inflammatory cells. Cytokines increased TET2 and 5hmC and decreased 5mC levels. Considering that the TET2 gene.promoter contains response elements for transcription factors activated by cytokines, together to in vitro results suggest that changes in DNA hydroxymethylation, resulting from altered levels of TET2 are likely to be relevant in the Sjögren's syndrome etiopathogenesis.

Cerebral large vessel vasculitis in systemic lupus erythematosus

Neuropsychiatric systemic lupus erythematosus (NPSLE) is defined by involvement of the central nervous system in systemic lupus erythematosus (SLE), with a wide range of both neurological and psychiatric manifestations. Although its aetiopathogenesis is not fully elucidated, NPSLE seems to be a consequence of cerebral vascular pathology including thromboembolism, small-vessel vasculopathy and, in rare cases, true vasculitis. Cerebral vasculitis is rare, and cerebral large-vessel vasculitis in SLE is even more unusual. We report the case of a female patient with the diagnosis of SLE. She presented with stroke-like symptoms, headache and vertigo, and palpable purpura on her legs. Further investigations revealed that she suffered from both vasculitis of the cerebral large vessels and coexisting cutaneous small-vessel vasculitis.

Is the Menopause Rating Scale accurate for diagnosing sexual dysfunction among climacteric women?

BACKGROUND

Although several tools have been designed to assess quality of life (QoL) among middle-aged women their capacity to specifically assess sexual dysfunction (SD) remains uncertain. Moreover, if SD impairs QoL within this population, then sexual assessment becomes a key issue.

OBJECTIVES

To evaluate the accuracy of the Menopause Rating Scale (MRS) in diagnosing SD among climacteric women.

METHODS

In this cross-sectional study 370 women aged 40-59 years filled out the MRS and the Female Sexual Functioning Index (FSFI) simultaneously. SD among surveyed women was defined as those obtaining a total FSFI score of <or=26.55. A receiver-operator curve (ROC) was used to plot and measure the diagnostic accuracy of one MRS item (item 8, assessing sexual problems) using the FSFI total score as a gold standard.

RESULTS

Mean age of surveyed women was 49.3+/-5.8 years. A 56.5% of them were married, 44.3% were postmenopausal, 66.8% were sexually active and 57% had SD (FSFI total score <or=26.55). ROC curve determined a score >or=1 in the MRS item 8 as a cut-off value for discriminating women with SD (78% sensitivity and 62% specificity with an area below the curve of 0.70 Swett).

CONCLUSIONS

The MRS was moderately accurate for diagnosing SD among climacteric women. More research is warranted in this regard.

[Assessment of quality of life using the Menopause Rating Scale in women aged 40 to 59 years]

BACKGROUND

Climacteric symptoms have a direct relationship with biological and sociocultural factors and significantly impair the quality of life of women.

AIM

To assess quality of life and factors affecting it in women aged 40 to 59 years.

MATERIAL AND METHODS

The Menopause Rating Scale (MRS) was applied to 370 healthy women aged 49 +/- 6 years, that accompanied patients to public hospitals in Santiago.

RESULTS

Forty four percent of women were postmenopausal and 6% used hormone replacement therapy. Half of the group had less than 12 years of formal education and 67% had a couple. The mean number of children was 2.8 +/- 1.5. Total MRS score was 16.2 +/- 8.5. The higher score was given by the psychological domain (7.7 + 4.4), followed by the somatic domain (5.8 +/- 3.5). The urogenital domain had the lowest score (2.7 +/- 2.9). Eighty percent of women had moderate to severe climacteric symptoms. A logistic regression analysis showed that the postmenopausal condition was the factor that caused the greatest derangement in quality of life, followed by her parity. Formal education had the lowest impact.

CONCLUSIONS

In this sample of women, menopause significantly deteriorated quality of life and sociocultural factors such as the parity also had an impact.