Inflammaging and age-associated diseases

Neutrophil-Lymphocyte Ratio as a Predictor of Persistent Type 2 Endoleak after Endovascular Aneurysm Repair

Objectives: One of the important postoperative complications of endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA) is type 2 endoleak (T2EL). However, there is no well-established biomarker. We aimed to evaluate the validity of the neutrophil-lymphocyte ratio (NLR) as a predictor of T2EL. Methods: Data were retrospectively collected from 146 patients who underwent EVAR for AAA at our institution between April 1, 2008 and March 31, 2021. Within 90 days before surgery, preoperative NLR was calculated from the same blood sample. The receiver operating characteristic curve (ROC) was used to determine the cutoff NLR values for persistent T2EL. Univariate and multivariate analyses were performed. Results: Compared with patients without persistent T2EL, those who had persistent T2EL had lower preoperative NLR (P = 0.041), based on a cutoff value of 1.918, and the entire group was then divided into two groups based on these values for comparison. Univariate analysis showed significant differences in NLR, the white blood cell (WBC) count, the percentage of mural thrombus of aneurysm, history of the hypertension, follow-up term, and aneurysm diameter at final follow-up. Multivariate analysis showed that NLR and AAA diameter on the last follow-up were significantly associated with T2EL persistence. Conclusions: Preoperative low NLR can be a useful predictor of postoperative persistent T2EL.

Development of an Inflamed High Throughput Stem-cell-based Gut Epithelium Model to Assess the Impact of Annexin A1

OBJECTIVE AND DESIGN

Annexin A1 (ANXA1) plays a role in maintaining intestinal hemostasis, especially following mucosal inflammation. The published data about ANXA1 was derived from experimental animal models where there is an overlapping between epithelial and immune cells. There is no in vitro gut epithelial model that can assess the direct effect of ANXA1 on the gut epithelium.

METHODS

We developed high-throughput stem-cell-based murine epithelial cells and bacterial lipopolysaccharides (LPS) were used to induce inflammation. The impact of ANXA1 and its functional part (Ac2-26) was evaluated in the inflamed model. Intestinal integrity was assessed by the transepithelial electrical resistance (TEER), and FITC-Dextran permeability. Epithelial junction proteins were assessed using confocal microscopy and RT-qPCR. Inflammatory cytokines were evaluated by RT-qPCR and ELISA.

RESULTS

LPS challenge mediated a damage in the epithelial cells as shown by a drop in the TEER and an increase in FITC-dextran permeability; reduced the expression of epithelial junctional proteins (Occludin, ZO-1, and Cadherin) and increased the expression of the gut leaky protein, Claudin - 2. ANXA1 and Ac2-26 treatment reduced the previous damaging effects. In addition, ANXA1 and Ac2-26 inhibited the inflammatory responses mediated by the LPS and increased the transcription of the anti-inflammatory cytokine, IL-10.

CONCLUSION

ANXA1 and Ac2-26 directly protect the epithelial integrity by affecting the expression of epithelial junction and inflammatory markers. The inflamed gut model is a reliable tool to study intestinal inflammatory diseases, and to evaluate the efficacy of potential anti-inflammatory drugs and the screening of new drugs that could be candidates for inflammatory bowel disease.

Characterization of Osteoarthritis in a Medial Meniscectomy-Induced Animal Model Using Contrast-Enhanced X-ray Microtomography

The aim of this study was to clarify degradation characteristics in each tissue of the knee complex of a medial meniscectomy (MMx)-induced knee osteoarthritis (KOA) animal model using classical methods and an alternative comprehensive evaluation method called contrast-enhanced X-ray micro-computed tomography (CEX-μCT), which was developed in the study. Surgical MMx was performed in the right knee joints of five male Wistar rats to induce KOA. At four weeks post-surgery, the synovitis was evaluated using quantitative polymerase chain reaction (qPCR). Degradations of the articular cartilage of the tibial plateau were evaluated using classical methods and CEX-μCT. Evaluation of the synovitis demonstrated significantly increased expression levels of inflammation-associated marker genes in MMx-treated knees compared with those in sham-treated knees. Evaluation of the articular cartilage using classical methods showed that MMx fully induced degradation of the cartilage. Evaluation using CEX-μCT showed that local areas of the medial cartilage of the tibial plateau were significantly reduced in MMx-treated knees compared with those in sham-treated knees. On the other hand, total cartilage volumes were significantly increased in MMx-treated knees. On the basis of the findings of this study, the method could be relevant to study new treatments in KOA research.

The stress polarity signaling (SPS) pathway serves as a marker and a target in the leaky gut barrier: implications in aging and cancer

The gut barrier separates trillions of microbes from the largest immune system in the body; when compromised, a "leaky" gut barrier fuels systemic inflammation, which hastens the progression of chronic diseases. Strategies to detect and repair the leaky gut barrier remain urgent and unmet needs. Recently, a stress-polarity signaling (SPS) pathway has been described in which the metabolic sensor, AMP-kinase acts via its effector, GIV (also known as Girdin) to augment epithelial polarity exclusively under energetic stress and suppresses tumor formation. Using murine and human colon-derived organoids, and enteroid-derived monolayers (EDMs) that are exposed to stressors, we reveal that the SPS-pathway is active in the intestinal epithelium and requires a catalytically active AMP-kinase. Its pharmacologic augmentation resists stress-induced collapse of the epithelium when challenged with microbes or microbial products. In addition, the SPS-pathway is suppressed in the aging gut, and its reactivation in enteroid-derived monolayers reverses aging-associated inflammation and loss of barrier function. It is also silenced during progression of colorectal cancers. These findings reveal the importance of the SPS-pathway in the gut and highlights its therapeutic potential for treating gut barrier dysfunction in aging, cancer, and dysbiosis.

Effect of tranexamic acid in improving the lifespan of naturally aging mice

An effective method to improve lifespan is not known. Therefore, in this study, we examined the lifespan-extending effect of tranexamic acid in normal mice. We bred hairless mice without exposure to ultraviolet radiation and psychical stress until they died naturally. During the study period, the mice were orally administered tranexamic acid (12 mg/kg/day) three times weekly. An increase in the lifespan of mice was observed by tranexamic acid administration. Furthermore, age-related diseases of the skin were ameliorated by tranexamic acid administration. Moreover, the blood level of tumor necrosis factor-α, interleukin-6, reactive oxygen species (ROS), and matrix metalloproteinase (MMP)-9 was decreased by tranexamic acid administration. These results indicate that tranexamic acid suppresses the secretion of inflammatory cytokines, MMP-9, and ROS induced by natural aging, ameliorating age-related diseases, and, consequently, extending the lifespan.