The Implications of Aging Couples’ Linked Lives: Dyadic Associations in Health and Well-Being

Older adults age in the context of their intimate partnerships. Partners’ lives—their emotions, behaviors, and health—are intricately linked as they navigate the challenges associated with aging. This symposium presents research that illuminates ways partners influence one another later in life. The talks are diverse with regard to their timescale (e.g., years vs. hours) and context (e.g., dementia vs. pain). Dr. Martire will examine associations between declines in one spouse’s physical health over 5 years and the other’s mental health. This talk will further consider whether discussing health concerns exclusively with one’s spouse intensifies such associations. Ms. Nah will show how the pain of both partners (care providers and recipients) contributes to escalating marital conflict over 2 years. Dr. Wilson will demonstrate that emotional reactivity to spousal distress in the lab is associated with increased proinflammatory gene expression up to 80 minutes later, a risky pattern for health if repeated over time. Dr. Monin will examine actor and partner associations of affect and depressive symptoms among people with early-stage dementia and their spouses; the absence of partner associations suggests that emotional spillover may operate differently in early-stage dementia dyads. Dr. Novak will identify correlates of four latent profiles derived from couples’ physical, psychological, and relationship well-being: happy, healthy couples; unhappy, unhealthy couples; and two groups with blissful marriages despite individual problems. Dr. Amy Rauer, an internationally recognized scholar of relationships and health, will discuss ways in which this research advances our understanding of couples’ linked lives.

Expression of Emotions and Genes: Proinflammatory Gene Expression Rises With Spousal Distress

Marital quality shares ties to inflammation-related conditions like cardiovascular disease and diabetes. Lab-based studies implicate hostility during marital conflict as a mechanism via inflammatory reactivity. However, developmental theories suggest that conflict declines with age. Spousal distress is an important but overlooked context for aging couples as networks shrink and assistance needs increase. To examine the effects of spousal distress on changes in proinflammatory gene expression, 38 adults ages 40-81 witnessed their spouse relive an upsetting personal memory aloud, rated their mood before and after, and provided blood samples at baseline and twice post-task. Those whose negative mood increased more in response to spousal disclosure showed larger elevations in proinflammatory gene expression 40 (p=.022) and 80 minutes (p<.0001) after the task. Effects were robust to race, gender, age, alcohol, smoking, and body mass index. These novel findings identify spousal distress as a key marital context that may escalate inflammation-related health risks.

Deficiency of Myeloid Pfkfb3 Protects Mice From Lung Edema and Cardiac Dysfunction in LPS-Induced Endotoxemia

Sepsis, a pathology resulting from excessive inflammatory response that leads to multiple organ failure, is a major cause of mortality in intensive care units. Macrophages play an important role in the pathophysiology of sepsis. Accumulating evidence has suggested an upregulated rate of aerobic glycolysis as a key common feature of activated proinflammatory macrophages. Here, we identified a crucial role of myeloid 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 3 (Pfkfb3), a glycolytic activator in lipopolysaccharide (LPS)-induced endotoxemia in mice. Pfkfb3 expression is substantially increased in bone marrow derived macrophages (BMDMs) treated with LPS in vitro and in lung macrophages of mice challenged with LPS in vivo. Myeloid-specific knockout of Pfkfb3 in mice protects against LPS-induced lung edema, cardiac dysfunction and hypotension, which were associated with decreased expression of interleukin 1 beta (Il1b), interleukin 6 (Il6) and nitric oxide synthase 2 (Nos2), as well as reduced infiltration of neutrophils and macrophages in lung tissue. Pfkfb3 ablation in cultured macrophages attenuated LPS-induced glycolytic flux, resulting in a decrease in proinflammatory gene expression. Mechanistically, Pfkfb3 ablation or inhibition with a Pfkfb3 inhibitor AZ26 suppresses LPS-induced proinflammatory gene expression via the NF-κB signaling pathway. In summary, our study reveals the critical role of Pfkfb3 in LPS-induced sepsis via reprogramming macrophage metabolism and regulating proinflammatory gene expression. Therefore, PFKFB3 is a potential target for the prevention and treatment of inflammatory diseases such as sepsis.

Tracheal aspirate RNA sequencing identifies distinct immunological features of COVID-19 ARDS

The immunological features that distinguish COVID-19-associated acute respiratory distress syndrome (ARDS) from other causes of ARDS are incompletely understood. Here, we report the results of comparative lower respiratory tract transcriptional profiling of tracheal aspirate from 52 critically ill patients with ARDS from COVID-19 or from other etiologies, as well as controls without ARDS. In contrast to a “cytokine storm,” we observe reduced proinflammatory gene expression in COVID-19 ARDS when compared to ARDS due to other causes. COVID-19 ARDS is characterized by a dysregulated host response with increased PTEN signaling and elevated expression of genes with non-canonical roles in inflammation and immunity. In silico analysis of gene expression identifies several candidate drugs that may modulate gene expression in COVID-19 ARDS, including dexamethasone and granulocyte colony stimulating factor. Compared to ARDS due to other types of viral pneumonia, COVID-19 is characterized by impaired interferon-stimulated gene (ISG) expression. The relationship between SARS-CoV-2 viral load and expression of ISGs is decoupled in patients with COVID-19 ARDS when compared to patients with mild COVID-19. In summary, assessment of host gene expression in the lower airways of patients reveals distinct immunological features of COVID-19 ARDS.

Endothelin receptors in renal interstitial cells do not contribute to the development of fibrosis during experimental kidney disease

Renal interstitial fibrosis is characterized by the development of myofibroblasts, originating from resident renal and immigrating cells. Myofibroblast formation and extracellular matrix production during kidney damage are triggered by various factors. Among these, endothelins have been discussed as potential modulators of renal fibrosis. Utilizing mouse models of adenine nephropathy (AN) and unilateral ureter occlusion (UUO), this study aimed to investigate the contribution of endothelin signaling in stromal mesenchymal resident renal interstitial cells. We found in controls that adenine feeding and UUO caused marked upregulations of endothelin-1 (ET-1) gene expression in endothelial and in tubular cells and a strong upregulation of ETA-receptor (ETA-R) gene expression in interstitial and mesangial cells, while the gene expression of ETB-receptor (ETB-R) did not change. Conditional deletion of ETA-R and ETB-R gene expression in the FoxD1 stromal cell compartment which includes interstitial cells significantly reduced renal ETA-R gene expression and moderately lowered renal ETB-R gene expression. ET receptor (ET-R) deletion exerted no apparent effects on kidney development nor on kidney function. Adenine feeding and UUO led to similar increases in profibrotic and proinflammatory gene expression in control as well as in ETAflflETBflfl FoxD1Cre+ mice (ET-Ko). In summary, our findings suggest that adenine feeding and UUO activate endothelin signaling in interstitial cells which is due to upregulated ETA-R expression and enhanced renal ET-1 production Our data also suggest that the activation of endothelin signaling in interstitial cells has less impact for the development of experimentally induced fibrosis.

THRAP3 depletion reduces PPARγ mRNA and anti-inflammatory action in 3T3-L1 adipocytes

Peroxisome proliferator-activated receptor γ (PPARγ) is the master transcriptional regulator of adipocytes and the cellular target of thiazolidinedione (TZD) drugs. Suppression of proinflammatory actions, including proinflammatory gene expression and lipolysis in adipocytes, contributes to PPARγ-mediated anti-diabetic effects of TZDs. However, adverse side effects largely limited the clinical use of TZDs, despite their potent insulin-sensitizing effects. Therefore, it is important to understand how PPARγ is regulated. Thyroid hormone receptor-associated protein 3 (THRAP3) was previously reported to promote diabetic gene expression by acting as a transcriptional coregulator of PPARγ in adipocytes. Therefore, we tested if THRAP3 modulated anti-inflammatory functions of PPARγ in 3T3-L1 adipocytes. THRAP3 depletion increased basal and tumor necrosis factor α (TNFα)-induced lipolysis, proinflammatory gene expression, and phosphorylation of extracellular signal-regulated kinases (ERKs), suggesting elevated proinflammatory response after THRAP3 depletion in adipocytes. Moreover, TZD-mediated suppression of TNFα-induced lipolysis, proinflammatory gene expression, and ERK phosphorylation were attenuated or alleviated after THRAP3 depletion. Interestingly, the mRNA and protein levels of PPARγ were greatly reduced in THRAP3-depleted adipocytes. Actinomycin D treatment revealed that the stability of PPARγ mRNA was greatly reduced by THRAP3 depletion in adipocytes. Thus, in addition to modulating PPARγ function, THRAP3 may directly regulate the transcript of PPARγ in differentiated adipocytes.

miR-335 Targets LRRK2 and Mitigates Inflammation in Parkinson’s Disease

Parkinson’s disease (PD) is mainly driven by dopaminergic neuronal degeneration in the substantia nigra pars compacta accompanied by chronic neuroinflammation. Despite being mainly sporadic, approximately 10% of all cases are defined as heritable forms of PD, with mutations in the leucine-rich repeat kinase (LRRK2) gene being the most frequent known cause of familial PD. MicroRNAs (miRNAs or miRs), including miR-335, are frequently deregulated in neurodegenerative diseases, such as PD. Here, we aimed to dissect the protective role of miR-335 during inflammation and/or neurodegenerative events in experimental models of PD. Our results showed that miR-335 is significantly downregulated in different PD-mimicking conditions, including BV2 microglia cells stimulated with lipopolysaccharide (LPS) and/or overexpressing wild-type LRRK2. Importantly, these results were confirmed in serum of mice injected with 1-methyl-1-4-phenyl-1,2,3,6-tetrahydripyridine hydrochloride (MPTP), and further validated in patients with idiopathic PD (iPD) and those harboring mutations in LRRK2 (LRRK2-PD), thus corroborating potential clinical relevance. Mechanistically, miR-335 directly targeted LRRK2 mRNA. In the BV2 and N9 microglia cell lines, miR-335 strongly counteracted LPS-induced proinflammatory gene expression, and downregulated receptor interacting protein 1 (RIP1) and RIP3, two important players of necroptotic and inflammatory signaling pathways. Further, miR-335 inhibited LPS-mediated ERK1/2 activation. LRRK2-Wt-induced proinflammatory gene expression was also significantly reduced by miR-335 overexpression. Finally, in SH-SY5Y neuroblastoma cells, miR-335 decreased the expression of pro-inflammatory genes triggered by α-synuclein. In conclusion, we revealed novel roles for miR-335 in both microglia and neuronal cells that strongly halt the effects of classical inflammatory stimuli or LRRK2-Wt overexpression, thus attenuating chronic neuroinflammation.

TRIM25 and ZAP target the Ebola virus ribonucleoprotein complex to mediate interferon-induced restriction

Ebola virus (EBOV) causes highly pathogenic disease in primates. Through screening a library of human interferon-stimulated genes (ISGs), we identified TRIM25 as a potent inhibitor of EBOV transcription-and-replication-competent virus-like particle (trVLP) propagation. TRIM25 overexpression inhibited the accumulation of viral genomic and messenger RNAs independently of the RNA sensor RIG-I or secondary proinflammatory gene expression. Deletion of TRIM25 strongly attenuated the sensitivity of trVLPs to inhibition by type-I interferon. The antiviral activity of TRIM25 required ZAP and the effect of type-I interferon was modulated by the CpG dinucleotide content of the viral genome. We find that TRIM25 interacts with the EBOV vRNP, resulting in its autoubiquitination and ubiquitination of the viral nucleoprotein (NP). TRIM25 is recruited to incoming vRNPs shortly after cell entry, and leads to dissociation of NP from the vRNA. We propose that TRIM25 targets the EBOV vRNP, exposing CpG-rich viral RNA species to restriction by ZAP.

AB0056 TNFR2 PROMOTES INFLAMMATORY PROGRAMS IN FIBROBLAST-LIKE SYNOVIOCYTES

Background:TNF-mediated fibroblast-like synoviocyte (FLS) activation is important for inflammation and joint destruction in rheumatoid arthritis (RA). The role of TNF-receptor 1 (TNFR1) in FLS activation has thoroughly been characterized. The functions of TNFR2 are, however, largely unknown.Objectives:To investigate the contribution of TNFR2 to the TNF-mediated activation of FLS.Methods:RA-FLS were transfected with TNFR2-targeting siRNA pools and transcriptional changes were determined by RNA-seq. QPCR, ELISA and immunoblotting were used to confirm the RNA-seq results and to gain insights into the pathways that regulate TNFR2-mediated changes in FLS.Results:TNF stimulation of FLS resulted in a strong upregulation of proinflammatory cytokines, chemokines, tissue-degrading enzymes and other genes that are associated with synovial inflammation in RA. Silencing of TNFR2 markedly diminished the TNF-response of RA-FLS. Especially, “interferon”-stimulated-genes (ISGs) including putative master regulators of joint inflammation, such as the CXCR3 chemokines CXCL9, CXCL10 and CXCL11 were affected by the knockdown of TNFR2. Consistently, immunoblots showed that TNFR2 was required for the TNF-induced phosphorylation of the transcription factor STAT1, which is known to mediate the transcription of ISGs, such as CXCR3 chemokines.Conclusion:TNFR2 regulates proinflammatory gene expression in RA-FLS via STAT1 and thereby contributes to the detrimental effects of TNF in synovial joint inflammation.Disclosure of Interests:None declared