P38-Mediated Cellular Senescence in Conjunctivochalasis Fibroblasts

Study of IL-17 and Intercellular Adhesion Molecule-1 in Conjunctivochalasis Using Correlation Analysis

PURPOSE

The aim of this study was to observe the expression of interleukin (IL)-17 and intercellular adhesion molecule (ICAM)-1 in conjunctivochalasis (CCH) and to analyze the correlations between cytokines and the severity of CCH.

METHODS

Serum samples were collected from 22 patients with CCH and 18 normal controls (NCs). The Ocular Surface Disease Index, tear film break-up time, Schirmer I test, and corneal fluorescein staining were used to evaluate the ocular surface signs and symptoms. The concentrations of IL-17, IL-23, and ICAM-1 in serum and cellular supernatants were measured by enzyme-linked immunosorbent assays, and the gene expression levels of cytokines were measured by a quantitative real-time polymerase chain reaction. The relationships between serum concentrations of IL-17, IL-23, and ICAM-1 with clinical ocular surface parameters in CCH were analyzed using the Spearman correlation analysis.

RESULTS

The concentrations of IL-17 and ICAM-1 in serum and cellular supernatants of CCH were significantly higher than those of NCs (all P < 0.001). The concentrations of IL-23 in serum and cellular supernatants of CCH showed no significant difference from those of NCs ( P > 0.05). The mRNA expression levels of IL-17 and ICAM-1 in conjunctival fibroblasts of CCH were significantly higher than those of NCs (all P < 0.001). The mRNA expression of IL-23 in conjunctival fibroblasts of CCH was higher than that of NCs, without a significant difference ( P > 0.05). Furthermore, the serum concentrations of IL-17 and ICAM-1 were positively correlated with Ocular Surface Disease Index and fluorescein staining (all P < 0.05), and negatively correlated with break-up time and Schirmer I test of CCH (all P < 0.05).

CONCLUSIONS

The expression levels of IL-17 and ICAM-1 were significantly increased in CCH serum and associated with the disease severity. We postulate that IL-17 and ICAM-1 may play a role in the pathogenesis of CCH. IL-17 and ICAM-1 antagonists may be a potential treatment option for CCH in the future.

l-Theanine delays d-galactose-induced senescence by regulating the cell cycle and inhibiting apoptosis in rat intestinal cells

BACKGROUND

Intestinal senescence is associated with several aging-related diseases. l-Theanine (LTA) has demonstrated strong potential as an antioxidant and antisenescence agent. This study investigated the regulatory effect of LTA on cellular senescence using an in vitro model of d-galactose (D-Gal)-induced senescence in the rat epithelial cell line, intestinal epithelioid cell-6 (IEC-6).

RESULTS

Treatment of IEC-6 cells with 40 mg/mL D-Gal for 48 h resulted in the successful development of the senescent cell model. Compared with D-Gal alone, both LTA preventive and delayed intervention increased cell viability and the ratio of JC-1 monomers to aggregates, increased the antioxidant capacity, and decreased the advanced glycation end product (AGE) levels and the overall number of senescent cells. Preventive and delayed intervention with 1000 μM LTA alleviated the D-Gal-induced cell cycle arrest by regulating p38, p53, CDK4, and CDK6 expression at the mRNA and protein levels, and further induced CycD1 proteins. Moreover, LTA preventive intervention reduced apoptosis to a greater degree than delayed intervention by upregulating the expression of the receptors of AGEs, Bax, Bcl-2, and NF-κB at the mRNA and protein levels.

CONCLUSION

Our findings indicate that LTA intervention could attenuate senescence in IEC-6 cells by regulating the cell cycle and inhibiting apoptosis. © 2023 Society of Chemical Industry.

Occurrence, formation, and proteins perturbation of disinfection byproducts in indoor air resulting from chlorine disinfection

Increased amounts of chlorine disinfectant have been sprayed to inactivate viruses in the environment since the COVID-19 pandemic, and the health risk from chemicals, especially disinfection byproducts (DBPs), has unintentionally increased. In this study, we characterized the occurrence of haloacetic acids (HAAs) and trihalomethanes (THMs) in indoor air and evaluated their formation potential from typical indoor ingredients. Subsequently, the adverse effect of chloroacetic acid on A549 cells was depicted at the proteomic, transcriptional and silico levels. The results revealed that the total concentrations of HAAs and THMs ranged from 1.46 to 4.20 μg/m3 in ten indoor environments. Both classes of DBPs could be generated during the chlorination of prevalent terpenes by competing reactions, which are associated with the volatile state of indoor ingredients after disinfection. The C-type lectin receptor signaling pathway and cellular senescence were significantly perturbed pathways, which interfered with the development of lung fibrosis. The negative effect was further investigated by molecular docking and transcription, which showed that HAAs can interact with four C-type lectin receptor proteins by hydrogen bonds and inhibit the mRNA expression of related proteins. This study highlights the potential secondary biological risk caused by intensive DBPs generated from chlorination and draws our attention to the potential environmental factors leading to chronic respiratory disease.

Cellular senescence and ophthalmic diseases: narrative review

PURPOSE

Cellular senescence is a state of permanent growth arrest whereby a cell reaches its replicative limit. However, senescence can also be triggered prematurely in certain stressors including radiation, oxidative stress, and chemotherapy. This stress-induced senescence has been studied in the context of promoting inflammation, tumor development, and several chronic degenerative diseases of aging. Emerging research has elucidated the role of senescence in various ocular diseases.

METHODS

The literature search was performed using PubMed with using the query (senescence OR aging) AND (eye disease OR ocular disease OR ophthalmic disease OR cornea OR glaucoma OR cataract OR retina) on October 20th, 2022. No time restriction was proposed. Articles were excluded if they were not referenced in English.

RESULTS

Overall, 51 articles regarding senescence and ocular diseases were found and summarized in this study. Several signaling pathways have been implicated in the development of senescence. Currently, senescence has been linked to various corneal and retinal pathologies, as well as cataract and glaucoma. Given the number of pathologies, senolytics, which are small molecules with the ability to selective targeting of senescent cells, can be used as therapeutic or prophylactic agents.

CONCLUSIONS

Senescence has been shown to underlie the pathogenesis of numerous ocular diseases. The overall literature on senescence and ocular disease is growing rapidly. There is an ongoing debate whether or not cellular senescence detected in experiments contributes in a significant way to diseases. Research on understanding the mechanism of senescence from ocular cells and tissues is just beginning. Multiple animal models are required to test potential senolytics. Currently, no studies exist to date which have demonstrated the benefits of senolytic therapies in human studies.

The mechanism of Qijing Mingmu decoction on cellular senescence of conjunctivochalasis

BACKGROUND

Qijing Mingmu decoction (QJMM), a compound Chinese medicine preparation, which consists of Lycium barbarum, Polygonatum, Ophiopogon japonicus, Poria cocos, Glycyrrhiza, Eclipta prostrata and Ligusticum striatum, has been confirmed to be effective for the treatment of conjunctivochalasis (CCH) in clinic and reduce cellular senescence. However, the underlying mechanism is still unknown. Our previous study revealed that p38-mediated cellular senescence contributed to the pathogenesis of CCH.

METHODS

To explore whether p38 might be the potential therapeutic target of QJMM for CCH, CCH fibroblasts were treated with QJMM granule and then the effect of QJMM granule on the expression and promoter activity of p38α was determined by western blot and dual luciferase reporter gene assay, respectively. Meanwhile, the influence of QJMM granule on cell proliferation, oxidative stress, cellular senescence and the expression of the cellular senescence-associated genes were measured by corresponding methods.

RESULTS

QJMM granule significantly decreased the protein expression of p38α and p-p38α in CCH fibroblasts in a dose-dependent manner and inhibited p38α promoter activity. QJMM granule as well as the p38 inhibitor SB203580 reduced the level of reactive oxygen species and increased the activity of superoxide dismutase in CCH fibroblasts. QJMM granule and SB203580 promoted cell proliferation and reduced the percentage of SA-β-Gal-positive cells. The mRNA and protein expression of p53 and p21 was remarkably down-regulated by QJMM granule as well as SB203580 and that of SMP30 was up-regulated in CCH fibroblasts.

CONCLUSIONS

Our findings demonstrated that QJMM granule was effective for alleviating cellular senescence of CCH fibroblasts by p38 MAPK signaling and the followed p53/p21 signaling.

Qi Jing Mingmu decoction inhibits the p38 signaling pathway in conjunctivochalasis fibroblasts by down-regulation of Th17 cell differentiation

ETHNOPHARMACOLOGICAL RELEVANCE

Qi Jing Mingmu (QJMM) decoction is a traditional Chinese medicine that has been widely used for the clinical treatment of conjunctivochalasis (CCH). It is an effective treatment to relieve ocular symptoms including improving tear film and promoting tear secretion. However, its effects and molecular mechanisms need to be elucidated.

AIM OF THE STUDY

To determine whether QJMM decoction affected T helper 17 (Th17) cell differentiation of CCH patients.

MATERIALS AND METHODS

Blood samples and conjunctival tissues were collected from CCH patients and normal controls. The fibroblasts were separately induced, and CD4⁺ T cells were incubated with increasing concentrations of QJMM decoction and co-cultured with CCH fibroblasts. Th17 cell numbers were then analyzed using flow cytometry. Serum levels of interleukin 17 (IL-17) and IL-22 were detected using enzyme-linked immunosorbent assays. The expressions of signal proteins and genes were detected using western blotting and quantitative real-time PCR.

RESULTS

Compared with normal controls, Th17 cell numbers and serum levels of IL-17 and IL-22 were elevated in patients with CCH. QJMM decoction down-regulated the expressions of IL-17, IL-22, and STAT3 of CD4⁺T cells from CCH patients, suggesting that QJMM decoction impeded Th17 cell differentiation. QJMM decoction-treated CD4⁺ T cells inhibited the expression of p38 in CCH fibroblasts.

CONCLUSION

QJMM decoction inhibited Th17 cell differentiation of CD4⁺T cells from CCH patients, and QJMM decoction-treated CD4⁺T cells down-regulated the p38 signal pathway in CCH fibroblasts. Our study showed that Th17 cells may be good candidates for clinical treatment of CCH.

Mechanism of Akt regulation of the expression of collagens and MMPs in conjunctivochalasis

Akt is a central node of many signaling pathways, which plays important roles in cell survival, proliferation, migration, metabolism and collagen synthesis. Conjunctivochalasis (CCH) is one of the most common age-related ocular superficial diseases related to abnormalities in conjunctival extracellular matrix. Here, we studied the role of Akt regulating collagens and MMPs in the pathogenesis of CCH. Primary conjunctival fibroblasts were obtained from CCH patients (n = 13) and age-matched normal controls (n = 10). The levels of Akt, collagen type I, collagen type III, MMP1, and MMP3 were determined by Western blot, qRT-PCR, immunohistochemistry, and immunofluorescence staining. Normal control conjunctival fibroblasts were treated with Akt inhibitor A6730, and CCH fibroblasts were transfected with Akt overexpression vector. The expression of Akt in CCH was significantly lower than that in normal control of conjunctival tissues and cultured fibroblasts. Blocking Akt signaling with Akt inhibitor could inhibit the expression of collagen type I and collagen type III and upregulate the expression of MMP1 and MMP3. Meanwhile, compared with CCH fibroblasts transfected with control mimics, the protein and mRNA expression of collagen type I and collagen type III were increased significantly in Akt overexpression group, while the results of MMP1 and MMP3 in transfected fibroblasts were opposite. Taken together, Akt upregulated the expression of collagen type I and collagen type III and downregulated the expression of MMP1 and MMP3. Akt signaling pathway could provide a direct negative contribution to CCH and might be an attractive target for CCH therapy.

Pyrimethamine inhibits cell growth by inducing cell senescence and boosting CD8+ T-cell mediated cytotoxicity in colorectal cancer

BACKGROUND

The emergence of nonresponse or resistance to traditional chemotherapeutic agents is one of the main challenges of colorectal cancer (CRC) therapies. Thus, novel therapeutic drugs that can improve the clinical outcomes of CRC patients are urgently needed. The purpose of this study was to investigate the effects and mechanisms of pyrimethamine in CRC.

METHODS AND RESULTS

In this study, we assessed the role of pyrimethamine on CRC cell growth by cell counting kit-8 and colony formation assays. Cell cycle distribution and cellular senescence were determined by flow cytometry and senescence-associated β-galactosidase staining respectively. RNA-seq analysis and western blotting were used to investigate the potential pathways of pyrimethamine in CRC development. Moreover, animal experiments were performed to evaluate the effect of pyrimethamine in vivo. Our results demonstrated that pyrimethamine could inhibit cell growth by inducing S phase arrest followed by cellular senescence in CRC cells, and the p38MAPK-p53 axis was probably involved in that effect. In addition, pyrimethamine could also boost CD8⁺ T-cell mediated cytotoxicity and exert antitumor activity in vivo.

CONCLUSION

These results indicated that pyrimethamine may be a promising candidate agent for CRC treatment.

Cannabinoids as anti-ROS in aged pancreatic islet cells

AIMS

Cannabinoids are the chemical compounds with a high affinity for cannabinoid receptors affecting the central nervous system through the release of neurotransmitters. However, the current knowledge related to the role of such compounds in the regulation of cellular aging is limited. This study aimed to investigate the effect of cannabidiol and tetrahydrocannabinol on the function of aged pancreatic islets.

MAIN METHODS

The expression of p53, p38, p21, p16, and Glut2 genes and β-galactosidase activity were measured as hallmarks of cell aging applying real-time PCR, ELISA, and immunocytochemistry techniques. Pdx1 protein expression, insulin release, and oxidative stress markers were compared between young and aged rat pancreatic islet cells.

KEY FINDINGS

Upon the treatment of aged pancreatic islets cells with cannabidiol and tetrahydrocannabinol, the expression of p53, p38, p21 and the activity of β-galactosidase were reduced. Cannabidiol and tetrahydrocannabinol increase insulin release, Pdx1, Glut2, and thiol molecules expression, while the oxidative stress parameters were decreased. The enhanced expression of Pdx1 and insulin release in aged pancreatic islet cells reflects the extension of cell healthy aging due to the significant reduction of ROS.

SIGNIFICANCE

This study provides evidence for the involvement of cannabidiol and tetrahydrocannabinol in the oxidation process of cellular aging.