BACKGROUND/AIM:Despite advances in therapy, lung cancer remains the leading cause of cancer-related mortality. R-spondin (RSPO) 3 and its receptor, leucine-rich repeat-containing G protein-coupled receptor 4 (LGR4), drive tumor progression in a subset of lung adenocarcinomas by potentiating Wnt signaling. In addition to RSPO3, LGR4 is also a receptor for receptor activator of nuclear factor-кB ligand (RANKL). Here, we investigated whether MHP1-AcN, our previously developed RANKL-derived peptide, acts on LGR4 and examined its effects on RSPO3-LGR4 signaling in A549 lung cancer cells. MATERIALS AND METHODS:An A549 xenograft model was established by subcutaneous inoculation in BALB/c nude mice, followed by daily intraperitoneal administration of MHP1-AcN. Tumor growth was assessed by volume and weight. In vitro, the effect of MHP1-AcN on A549 cell proliferation, cytotoxicity, migration, and invasion were evaluated. Molecular interactions and signaling pathways were analyzed using immunoprecipitation and immunoblotting. RESULTS:Intraperitoneal administration of MHP1-AcN significantly reduced tumor volume and weight in the subcutaneous A549 xenograft model. Mechanistically, MHP1-AcN directly interacted with LGR4 and disrupted RSPO3-induced LGR4-IQ motif-containing GTPase activating protein 1 complex formation. MHP1-AcN inhibited A549 cell proliferation without inducing cytotoxicity and suppressed RSPO3-enhaced phosphorylation of LRP6 and accumulation of β-catenin. Furthermore, MHP1-AcN dose-dependently inhibited A549 cell migration and invasion by reducing focal adhesion kinase phosphorylation and disrupting F-actin organization. CONCLUSION:These findings demonstrate MHP1-AcN as a novel LGR4 antagonist that inhibits RSPO3-LGR4-Wnt signaling, tumor growth, and metastatic potential in lung adenocarcinoma, highlighting its potential as a therapeutic agent targeting this pathway.

We investigated whether a peptide vaccine (FPP003) composed of B cell epitope for IL-17A and T cell epitope (AJP001) with innate immune activation could induce the antibody production without adjuvants. The safety and immune response of FPP003 were evaluated in a double-blind trial. Twenty healthy participants received either a low or high dose of FPP003 (n = 8, respectively) or placebo (n = 4) in three doses. Regarding safety, while mild to moderate adverse events were observed, no severe or serious adverse events occurred in all participants. For immunogenicity, the geometric mean fold rise (GMFR) in anti-IL-17A antibody was increased with peak at day 71 or 85 and continued until day 141. In ELISpot assay, the number of IL-4 and IFN-γ spots was increased in a dose dependent manner. Furthermore, circulating follicular helper T cells was significantly increased in the FPP003 high-dose group. The adjuvant-free FPP003 peptide vaccine could be well-tolerated and beneficial approach in human.

Low circulating levels of soluble fibroblast activation protein (sFAP) are associated with poor outcomes in patients with ischemic stroke, while its function in the ischemic brain remains unclear. This study investigated the role of FAP in ischemic stroke. BALB/c mice were subjected to transient middle cerebral artery occlusion and treated with recombinant FAP (rFAP) or CPD60, a selective FAP inhibitor. Temporal and spatial patterns of FAP expression in brain were analyzed. sFAP showed a greater decrease in CSF than in serum after ischemic stroke. Astrocytes expressed FAP but did not secrete it. Meningeal fibroblasts constitutively released FAP, and this release decreased after exposure to Toll-like receptor (TLR) 4 ligands. In cultured microglial and macrophages, rFAP suppressed TLR2/4-induced cytokine production. rFAP protected neurons and decreased tumor necrosis factor-α and interleukin-1β levels in neuron-glia cultures. Systemic or intracerebroventricular administration of rFAP reduced post-ischemic inflammation and infarct volume, whereas CPD60 worsened tissue injury. FAP also inhibited monocyte migration and inflammation induced by C-C motif chemokine ligand 2 and complement C1q tumor necrosis factor-related protein 6, suggesting that these chemokines are potential substrates. Overall, FAP regulates post-ischemic inflammation and protects neurons after ischemic stroke, indicating its therapeutic potential in ischemic stroke.

Aging is a complex biological process characterized by a gradual decline in cellular and physiological function, increasing vulnerability to chronic diseases and mortality. It involves a set of interconnected mechanisms known as the hallmarks of aging, including genomic instability, telomere attrition, epigenetic alterations, loss of proteostasis, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, altered intercellular communication, and dysregulated nutrient sensing. These processes act at molecular, cellular, and systemic levels, contributing to age-related disorders such as neurodegeneration, cardiovascular disease, and metabolic syndromes. Emerging therapeutic strategies aim to delay or reverse aging by targeting specific hallmarks. These include senolytics to eliminate senescent cells, NAD+ boosters and mitophagy inducers to improve mitochondrial health, epigenetic reprogramming, and caloric restriction mimetics such as metformin and rapamycin to modulate nutrient-sensing pathways. Advances in regenerative medicine, gene editing, and organ cross-talk modulation are also contributing to the development of personalized, multi-targeted anti-aging therapies. Integration of omics technologies and biomarker research is expected to enhance our ability to monitor biological aging and optimize interventions for healthy longevity. This review highlights the current understanding of the hallmarks of aging and explores potential treatment strategies in light of our recent findings.

Background: Periostin (POSTN,PN) is a matricellular protein that contributes to breast-cancer progression, epithelial–mesenchymal transition (EMT), and therapy resistance. Among its isoforms, those containing exon 21 are preferentially expressed in the tumor microenvironment and promote malignant phenotypes. Our previous work demonstrated that POSTN blockade overcame paclitaxel resistance by restricting mesenchymal-like tumor subpopulations in breast cancer, highlighting POSTN’s role in chemoresistance. Building on this finding, we developed a novel monoclonal antibody targeting POSTN exon 21 (PN-21Ab) and investigated its combination with radiation and multiple chemotherapeutic agents. In murine xenograft models, PN-21Ab was administered with radiation (9 Gy) or with doxorubicin, eribulin, vinorelbine, or 5-fluorouracil (5-FU). Tumor growth and EMT-marker expression were analyzed. Combination therapy with PN-21Ab and radiation markedly suppressed tumor growth and EMT induction compared with radiation alone (p < 0.05). PN-21Ab also potentiated the antitumor efficacy of all tested drugs without apparent toxicity. Isoform analysis revealed that POSTN variants containing exon 21 were strongly associated with tumor progression and treatment resistance. These findings demonstrate that selective inhibition of POSTN exon 21 by PN-21Ab enhances the effects of radiation and chemotherapy and may provide a broadly applicable therapeutic strategy to overcome treatment resistance in breast cancer.

Aging societies around the world face increasing challenges in promoting healthy longevity. The 1st World Longevity Summit in Kyotango, Japan, convened experts to discuss advances in aging biology, lifestyle medicine, and community-based health strategies. The joint declaration outlined four pillars for healthy aging: bonds with communication, dietary fiber, physical activity, and “Ikigai”, a sense of purpose. This report highlights representative summit discussions and presents key insights on healthy longevity.

Background: Periostin (POSTN) is a type of matrix protein that functions by binding to other matrix proteins, cell surface receptors, or other molecules, such as cytokines and proteases. POSTN has four major splicing variants (PN1–4), which are primarily expressed in fibroblasts and cancer. We have reported that we should inhibit pathological POSTN (PN1–3), but not physiological POSTN (PN4). In particular, pathological POSTN with exon 17 is present in both stroma and cancer, but it is unclear whether the stroma or cancer pathological POSTN should be suppressed. Methods and Results: We transplanted 4T1 cells (breast cancer) secreting POSTN with exon 17 into 17KO mice lacking POSTN exon 17 to suppress stromal POSTN with exon 17. The results show that 17KO mice had smaller primary tumors and fewer metastases. Furthermore, to suppress cancer POSTN with exon 17, 4T1 cells transfected with POSTN exon 17 skipping oligo or control oligo were transplanted from the tail vein into the lungs. The results show that POSTN exon 17 skipping oligo significantly suppressed lung metastasis. Conclusions: These findings suggest that it is important to suppress POSTN exon 17 in both stroma and cancer. Antibody targeting POSTN exon 17 may be a therapeutic candidate for breast cancer.

(1) Background: Periostin (Pn) is a secreted protein found in the extracellular matrix, and it plays a variety of roles in the human body. Physiologically, Pn has a variety of functions, including bone formation and wound healing. However, it has been implicated in the pathogenesis of various malignant tumors and chronic inflammatory diseases. Pn has alternative splicing variants (ASVs), and our previous research revealed that aberrant ASVs contribute to the pathogenesis of breast cancer and heart failure. However, the difference in expression pattern between physiologically expressed Pn-ASVs and those expressed during pathogenesis is not clear. (2) Methods and results: We examined normal and breast cancer tissues, focusing on the Pn-ASVs expression pattern to assess the significance of pathologically expressed Pn-ASVs as potential diagnostic and therapeutic targets. We found that most physiologically expressed Pn isoforms lacked exon 17 and 21. Next, we used human breast cancer and normal adjacent tissue (NAT) to investigate the expression pattern of Pn-ASVs under pathological conditions. Pn-ASVs with exon 21 were significantly increased in tumor tissues compared with NAT. In situ hybridization identified the synthesis of Pn-ASVs with exon 21 in peri-tumoral stromal cells. Additionally, the in vivo bio-distribution of 89Zr-labeled Pn antibody against exon 21 (Pn-21Ab) in mice bearing breast cancer demonstrated selective and specific accumulation in tumors, while Pn-21Ab significantly suppressed tumor growth in the mouse breast cancer model. (3) Conclusions: Together, these data indicate that Pn-ASVs might have potential for use as diagnostic and therapeutic targets for breast cancer.

Metabolic dysfunction-associated steatohepatitis (MASH, previously termed non-alcoholic steatohepatitis (NASH)), is a major complication of obesity that promotes fatty liver disease. MASH is characterized by progressive tissue fibrosis and sterile liver inflammation that can lead to liver cirrhosis, cancer, and death. The molecular mechanisms of fibrosis in MASH and its systemic control remain poorly understood. Here, we identified the secreted-type pro-fibrotic protein, procollagen C-endopeptidase enhancer-1 (PCPE-1), as a brown adipose tissue (BAT)-derived adipokine that promotes liver fibrosis in a murine obesity-induced MASH model. BAT-specific or systemic PCPE-1 depletion in mice ameliorated liver fibrosis, whereas, PCPE-1 gain of function in BAT enhanced hepatic fibrosis. High-calorie diet-induced ER stress increased PCPE-1 production in BAT through the activation of IRE-1/JNK/c-Fos/c-Jun signaling. Circulating PCPE-1 levels are increased in the plasma of MASH patients, suggesting a therapeutic possibility. In sum, our results uncover PCPE-1 as a novel systemic control factor of liver fibrosis.

BACKGROUND:Myofibroblasts are primary cells involved in chronic response-induced cardiac fibrosis. Fibroblast activation protein (FAP) is a relatively specific marker of activated myofibroblasts and a potential target molecule. This study aimed to clarify whether a vaccine targeting FAP could eliminate myofibroblasts in chronic cardiac stress model mice and reduce cardiac fibrosis. METHODS:We coadministered a FAP peptide vaccine with a cytosine-phosphate-guanine (CpG) K3 oligonucleotide adjuvant to male C57/BL6J mice and confirmed an elevation in the anti-FAP antibody titer. After continuous angiotensin II and phenylephrine administration for 28 days, we evaluated the degree of cardiac fibrosis and the number of myofibroblasts in cardiac tissues. RESULTS:We found that cardiac fibrosis was significantly decreased in the FAP-vaccinated mice compared with the angiotensin II and phenylephrine control mice (3.45±1.11% versus 8.62±4.79%; P=4.59×10-3) and that the accumulation of FAP-positive cells was also significantly decreased, as indicated by FAP immunohistochemical staining (4077±1746 versus 7327±1741 cells/mm2; FAP vaccine versus angiotensin II and phenylephrine control; P=6.67×10-3). No systemic or organ-specific inflammation due to antibody-dependent cell cytotoxicity induced by the FAP vaccine was observed. Although the transient activation of myofibroblasts has an important role in maintaining the structural robustness in the process of tissue repair, the FAP vaccine showed no adverse effects in myocardial infarction and skin injury models. CONCLUSIONS:Our study demonstrates the FAP vaccine can be a therapeutic tool for cardiac fibrosis.

Pancreatic ductal adenocarcinoma (PDAC) characterized by an abundant cancer stroma is an aggressive malignancy with a poor prognosis. Periostin (Pn) is a key extracellular matrix (ECM) protein in various tumor progression. Previously, we described the role of Pn alternative splicing variants (ASVs) with specific functional features in breast cancer. Pn is known to associate with a chemoresistance of PDAC, but the functions of the Pn-ASVs remain largely unknown. In this study, we focused on physiological and pathological Pn-ASVs, and examined the characteristics of Pn-expressing cells and the difference in function of each ASV. We found that cancer-associated fibroblasts (CAFs) are a main source of Pn synthesis, which selectively secrete pathological Pn-ASVs with exon 21 both in mouse and human samples. RNA sequencing identified a gene signature of Pn-positive CAFs associated with ECM-related genes and chemokines, factors that shape the chemoresistance tumor microenvironment (TME). Additionally, only pathological Pn-ASVs interacted with heat shock protein 70-1a (HSP70-1a), leading to significant rescue of gemcitabine-induced PDAC apoptosis. In silico analysis revealed that the presence or absence of exon 21 changes the tertiary structure of Pn and the binding sites for HSP70-1a. Altogether, Pn-ASVs with exon 21 secreted from CAFs play a key role in supporting tumor growth by interacting with cancer cell-derived HSP70-1a, indicating that Pn-ASVs with exon 21 might be a potential therapeutic and diagnostic target in PDAC patients with rich stroma.

To combat the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), novel vaccine modalities, such as messenger RNA vaccines, were rapidly developed and have shown high efficacy. This new vaccine technology, underpinned by intensive immunological analysis, is now being applied to the production of other vaccines. For over 10 years, we have been developing therapeutic vaccines for non-infectious diseases. The epitope vaccine approach, which combines a B-cell epitope with exogenous T-cell epitopes presented through major histocompatibility complex molecules, has been proposed to induce antibody production. This vaccine type is designed to efficiently induce a blocking antibody response against the self-antigen without activating cytotoxic T cells. If therapeutic vaccines become established as treatment options for conditions such as hypertension or dyslipidemia, their administration-potentially only a few times per year-could replace the need for daily medication. Nucleic acid drugs, including small interfering RNA and antisense oligonucleotides, have recently received attention as long-term agonists, similar to vaccines. Therefore, therapeutic vaccines or nucleic acid drugs could represent a novel strategy for controlling the progression of cardiovascular diseases. It is hoped that the accumulation of immunological findings and advances in vaccine technology will provide valuable insights into the development of vaccines for treating cardiovascular diseases.

Although post-ischemic stroke process is essential for the repair of the infarcted area, excessive inflammation during this process can induce tissue damage. Damage-associated molecular patterns (DAMPs) released from injured cells in the early phase of ischemic stroke induce cytokine and chemokine production by activating microglia, thereby facilitating neutrophil and lymphocyte infiltration. However, the inhibition of neutrophils, lymphocytes, and their associated proinflammatory molecules has shown no apparent improvement in the functional outcomes and prognosis of post-ischemic stroke. Therefore, the selection of molecules and cell types that regulate cytokine production is important. Considering that the increase and infiltration of activated microglia/macrophages (M/M) is the major pathological change in ischemic stroke in humans and that DAMP/toll-like receptor (TLR) signaling is the starting point for microglial activation, the regulation of TLR signaling in M/M may be an important therapeutic strategy in the management of ischemic stroke.