Many scientists are interested in anti-aging interventions and seek to identify anti-aging medicines. In our previous study, we reported that an antitussive drug, tipepidine (TIP), activates AMP-activated protein kinase (AMPK) and improves glucose intolerance in high-fat diet-induced obese mice. Activation of AMPK has been reported to extend lifespan in various experimental organisms, including Caenorhabditis elegans. In this study, we examined whether TIP extends lifespan in C. elegans via AMPK activation. TIP treatment (50-100 μM) extended the median lifespan of wild-type C. elegans (N2), but not that of the AMPK catalytic subunit mutant aak-2(rr48). These results suggest that TIP extends lifespan in C. elegans in an AMPK-dependent manner.
Plasminogen activator inhibitor-1 (PAI-1) is a serine protease inhibitor that controls trophoblast invasion by inhibiting fibrinolysis at the feto-maternal interface. This study aimed to compare PAI-1 expression patterns in decidual cells between different abortion types and investigate the role of PAI-1 in early pregnancy. Missed abortion (n = 22) and incomplete abortion (n = 16) cases were compared with induced abortion serving as normal pregnancy control (n = 16). PAI-1 localization and expression levels were evaluated using immunohistochemistry. PAI-1 was distributed in the cytoplasm of decidual cells. In addition, many PAI-1-positive cells were observed in the decidua basalis just under the Nitabuch fibrinoid layer, where many extravillous trophoblasts (EVTs) invaded. The percentage of PAI-1-positive decidual cells was not reduced in missed abortion (49.7 ± 29.6%) but was significantly reduced in incomplete abortion (11.6 ± 12.6%) compared to induced abortion as control (44.4 ± 10.9%). The significant reduction of PAI-1-positive decidual cells in incomplete abortion, which is characterized by bleeding, suggests that PAI-1 deficiency may cause excessive fibrinolysis leading to this clinical outcome.
Despite advances in oral cancer treatment, therapeutic resistance remains a major challenge. Cancer-associated fibroblasts (CAFs) play a pivotal role in shaping the tumor microenvironment. Building on our previous findings on immune responses in gingival fibroblasts, we investigated the immune characteristics of CAFs. Myofibroblast CAF-like cells (myCAF-like) were established using a co-culture system and compared with gingival fibroblast-derived myofibroblasts. MyCAF-like cells exhibited markedly reduced expression of TLR3 and TLR4, whereas RIG-I, COX-2, IL-1β, IL-6, and IL-8 were significantly upregulated. Activation of p38 MAPK signaling contributed to the increased expression of COX-2 and pro-inflammatory cytokines, and TGF-β was involved in the phenotypic transformation of gingival fibroblasts into myCAF-like cells. Microarray analysis revealed upregulation of IL-1α, IL-1β, CXCL8, PTGS2, and CXCL5, alongside downregulation of OMD, COL15A1, and ASPN in myCAF-like cells. Collectively, these findings demonstrate that CAFs acquire a distinct inflammatory signature that differs from gingival fibroblasts and promotes tumor invasion and progression. Targeting CAF-associated inflammatory and signaling pathways may represent a promising strategy to overcome tumor infiltration and treatment resistance in oral cancer.
Ultrastructural analysis has declined in diagnostic pathology since the advent of immunohistochemistry for formalin-fixed paraffin-embedded tissues. To reevaluate the utility of ultrastructural analysis, we adopted the osmium maceration method for scanning electron microscopy (SEM) of formalin-fixed surgical specimens: renal oncocytoma, chromophobe renal cell carcinoma (ChRCC), and tumors categorized as other oncocytic tumors of the kidney (OOT). Light microscopy and immunohistochemistry have revealed that these tumors have overlapping features. SEM observation of the formalin-fixed tumors highlighted distinct morphological features: The oncocytomas contained large mitochondria with vesicular cristae; ChRCCs harbored small mitochondria with microvesicles, and OOTs showed abundant but small mitochondria with lamellar cristae. Quantitative morphometry confirmed that the number of mitochondria in oncocytomas and OOTs exceeded that of non-neoplastic lesions, whereas ChRCCs contained fewer mitochondria. In addition, mitochondria in ChRCCs and OOTs were smaller than those of non-neoplastic lesions, whereas mitochondria in oncocytomas were larger. Thus, SEM of formalin-fixed tissues, optimized by osmium maceration, can provide diagnostically valuable information beyond conventional histology and immunohistochemistry that may help to clarify the biology of challenging oncocytic and chromophobe renal tumors.
This study aimed to elucidate the relationship between the spatiotemporal behavior of macrophages during exercise and axonal regeneration following peripheral nerve injury. A sciatic nerve crush model was created using male C57BL/6J mice, which were divided into sedentary and exercise groups. The exercise group performed low-intensity treadmill running (10 m/min, 60 min/day, 5 days/week) starting 3 days post-injury. Immunohistochemical analyses of Neurofilament 200 kDa (NF200), Growth Associated Protein-43 (GAP-43), F4/80, and arginase-1 (Arg-1), a representative marker of M2 macrophages and a downstream effector of the JAK-STAT6 signaling pathway, were conducted in the proximal and distal regions of the injured nerves. Functional recovery was assessed using the sciatic functional index (SFI) and compound muscle action potential (CMAP). At 7 and 14 days post-injury, the exercised group exhibited a significant increase in axonal number and Arg-1-positive area, specifically in the distal region. SFI and CMAP analyses also demonstrated enhanced functional recovery in the exercise group. These findings suggest that low-intensity treadmill exercise may enhance axonal regeneration, potentially through transient activation and local accumulation of M2-polarized macrophages. Therefore, exercise-induced regulation of macrophage dynamics may represent a novel therapeutic strategy for peripheral nerve repair.
