Cytomegalovirus infection during daratumumab therapy in patients with newly diagnosed multiple myeloma.

The introduction of daratumumab has improved treatment outcomes for multiple myeloma (MM). However, infectious complications are a concern in patients receiving daratumumab. Although some reports have explored the association between daratumumab and cytomegalovirus (CMV) infection, most of these have focused on relapsed or refractory cases, and few describe patients with newly diagnosed MM (NDMM). In this study, we retrospectively analyzed CMV infections in 53 patients with NDMM who received daratumumab as induction therapy. CMV infection was defined as CMV antigenemia positivity. The median age at treatment initiation was 71 years (range, 50-82 years), and 50.9% of the patients were female. The median duration of daratumumab administration was 10.0 months (range, 0.3-63.8 months). Nine patients developed CMV infection, and the cumulative incidence rate at six months was 18.1% (95% confidence interval: 8.9-30.1%). One patient experienced CMV retinitis and required antiviral therapy, while the remaining eight patients did not require treatment and could be managed through observation. Few cases of CMV infection during daratumumab treatment for NDMM required treatment. However, the incidence of CMV infection was not negligible, suggesting that regular monitoring for CMV is worth considering to ensure more appropriate management during daratumumab treatment.

Cytomegalovirus Reactivation during Elotuzumab Therapy in Patients with Multiple Myeloma.

INTRODUCTION: Some treatments are associated with cytomegalovirus (CMV) reactivation (CMVRA) in patients with multiple myeloma (MM). However, no reports exist on the association between elotuzumab and CMVRA. Therefore, we assessed the incidence of CMVRA in patients with MM who received elotuzumab therapy. METHODS: The medical records of 85 patients who underwent elotuzumab therapy were included in the retrospective analysis for CMV positivity. RESULTS: Thirty patients were tested for CMV antigenemia during elotuzumab therapy, and 16 were positive for CMV antigenemia; the cumulative incidence rate of CMVRA 6 months after elotuzumab initiation was 18.4%. The history of allogeneic stem cell transplantation (allo-HSCT) was significantly more common in the CMVRA group (31.2%) than that of the group without CMVRA (8.7%). However, even among patients who did not undergo allo-HSCT, the cumulative incidence rate of CMVRA at 6 months was 15.1%. During CMVRA, the symptoms included fever in 8 cases, while retinitis was observed in 1 case. Five patients required antiviral therapy and CMV antigenemia resolved in all but 1 case. CONCLUSION: Although the patient population was heterogeneous, CMVRA cannot be underestimated during elotuzumab therapy, and evaluation of CMVRA, especially in symptomatic cases, is clinically important.

Involvement of retinoic acid­inducible gene­I in radiation­induced senescence of human umbilical vein endothelial cells.

In 2012, the threshold radiation dose (0.5 Gy) for cardiovascular and cerebrovascular diseases was revised, and this threshold dose may be exceeded during procedures involving radiation such as interventional radiology. Therefore, in addition to regulating radiation dose, it is necessary to develop strategies to prevent and mitigate the development of cardiovascular disease. Cellular senescence is irreversible arrest of cell proliferation. Although cellular senescence is one of the mechanisms for suppressing cancer, it also has adverse effects. For example, senescence of vascular endothelial cells is involved in development of vascular disorders. However, the mechanisms underlying induction of cellular senescence are not fully understood. Therefore, the present study explored the factors involved in the radiation-induced senescence in human umbilical vein endothelial cells (HUVECs). The present study reanalyzed the gene expression data of senescent normal human endothelial cells and fibroblast after irradiation (NCBI Gene Expression Omnibus accession no. GSE130727) and microarray data of HUVECs 24 h after irradiation (NCBI Gene Expression Omnibus accession no. GSE76484). Numerous genes related to viral infection and inflammation were upregulated in radiation-induced senescent cells. In addition, the gene group involved in the retinoic acid-inducible gene-I (RIG-I)-like receptor (RLR) signaling pathway, which plays an important role to induce anti-viral response, was altered in irradiated HUVECs. Therefore, to investigate the involvement of RIG-I and melanoma differentiation-associated gene 5 (MDA5), which are RLRs, in radiation-induced senescence of HUVECs, the protein expression of RIG-I and MDA5 and the activity of senescence-associated ß-galactosidase (SA-ß-gal), a representative senescence marker, were analyzed. Of note, knockdown of RIG-I in HUVECs significantly decreased radiation-increased proportion of cells with high SA-ß-gal activity (i.e., senescent cells), whereas this phenomenon was not observed in MDA5-knockdown cells. Taken together, the present results suggested that RIG-I, but not MDA5, was associated with radiation-induced senescence in HUVECs.

Uric acid-driven NLRP3 inflammasome activation triggers lens epithelial cell senescence and cataract formation.

Excessive uric acid (UA) is associated with age-related cataract. A previous study showed that a high UA level in the aqueous humor stimulated the senescence of lens epithelial cells (LECs), leading to cataract progression. To better understand the underlying mechanisms, we investigated UA-driven senescence in human lens tissue samples obtained during surgery, rat lens organ cultures, and in vivo experiments, using senescence-associated ß-galactosidase (SA-ß-gal) staining, electronic microscopy, Western blotting, and histological analyses. Initially, we identified markedly higher expressions of NLRP3 and caspase-1 in the lens capsules of hyper-uricemic patients compared to normo-uricemic patients. This increase was accompanied by a significant rise in the SA-ß-gal positive rate. We next built a cataract model in which rat lenses in an organ culture system were treated with an increasing dosage of UA. Notably, opacification was apparent in the lenses treated with 800 µM of UA starting on the fifth day. Mechanistically, UA treatment not only significantly induced the expression of NLRP3, caspase-1, and IL-1ß, but also upregulated the levels of SA-ß-gal and the senescence regulators p53 and p21. These effects were fully reversed, and lens opacification was ameliorated by the addition of MCC950, a selective NLRP3 antagonist. Moreover, an in vivo model showed that intravitreal UA injection rapidly induced cataract phenotypes within 21 days, an effect significantly mitigated by co-injection with MCC950. Together, our findings suggest that targeting the UA-induced NLRP3 inflammasome with MCC950 could be a promising strategy for preventing cataract formation associated with inflammageing.

[A retrospective analysis of 124 patients with multiple myeloma who received up-front autologous hematopoietic cell transplantation following triplet induction therapy].

The IFM/DFCI group reported that VRD induction followed by up-front autologous peripheral blood stem cell transplantation (ASCT) and maintenance therapy led to median PFS of 50 months, which established up-front ASCT as the standard of care even in the era of novel agents. We conducted a retrospective analysis on outcomes of patients who received triplet induction therapy followed by up-front ASCT at our institution. A total of 124 patients received ASCT between November 2016 and December 2021 at Japanese Red Cross Medical Center. Patient characteristics, treatment response before and after ASCT, and PFS and OS were retrospectively analyzed. VRD-based induction therapy was used for 94%. Among 118 evaluable patients, 116 (98%) received either consolidation and/or maintenance therapy. Best responses were ≥CR 77% and ≥VGPR 94%, respectively. Sixty-eight out of 104 patients achieved MRD-negativity by multiparameter FCM (<10-5). Five-year estimated PFS and OS were 54.7% and 80.2%, respectively. Age ≥65, high-risk cytogenetic abnormalities, and

Real-World Clinical Outcomes in Patients With Multiple Myeloma Administered With Elotuzumab-Based Treatment.

Objective Elotuzumab is used to treat relapsed and/or refractory multiple myeloma (MM). However, the optimal patient selection and sequencing in MM therapy are less clear. Therefore, this retrospective cohort study assessed the clinical outcomes of patients with MM who underwent elotuzumab-based therapy. Methods We reviewed the medical records of 85 patients with relapsed/refractory MM who received elotuzumab for the first time. Participants were divided into progressive disease (PD group) and those without PD (non-PD group) at elotuzumab treatment initiation, and each group was analyzed separately. Survival rates were calculated using Kaplan-Meier curves and compared using log-rank tests. Results The median follow-up period was 33.6 (range: 0.5-72.0) months. The median progression-free survival (PFS) and overall survival (OS) of PD and non-PD groups at elotuzumab therapy initiation were 5.3 months and not reached (NR), respectively (P < 0.0001), and 26.8 months and NR, respectively. Patients with triple-class refractory disease in both groups had worse PFS and OS. Twenty-one patients in the non-PD group received elotuzumab as post-hematopoietic stem cell transplantation, whose PFS and OS were NR (95% CI, 21.4 months-NR) and NR (95% CI, NR-NR), respectively. Conclusions Elotuzumab exhibited limited therapeutic efficacy in patients with triple-class refractory MM but better treatment outcomes in situations with adequate disease control and post-transplant treatment.

Reduced glutathione level in the aqueous humor of patients with primary open-angle glaucoma and normal-tension glaucoma.

Glaucoma is a leading cause of blindness worldwide in older people. Profiling the aqueous humor, including the metabolites it contains, is useful to understand physiological and pathological conditions in the eye. In the current study, we used mass spectrometry (MS) to characterize the aqueous humor metabolomic profile and biological features of patients with glaucoma. Aqueous humor samples were collected during trabeculectomy surgery or cataract surgery and analyzed with global metabolomics. We included 40 patients with glaucoma (32 with POAG, 8 with NTG) and 37 control subjects in a discovery study. VIP analysis revealed five metabolites that were elevated and three metabolites that were reduced in the glaucoma patients. The identified metabolomic profile had an area under the receiver operating characteristic curve of 0.953. Among eight selected metabolites, the glutathione level was significantly decreased in association with visual field defects. Moreover, in a validation study to confirm the reproducibility of our findings, the glutathione level was reduced in NTG and POAG patients compared with a cataract control group. Our findings demonstrate that aqueous humor profiling can help to diagnose glaucoma and that various aqueous humor metabolites are correlated with clinical parameters in glaucoma patients. In addition, glutathione is clearly reduced in the aqueous humor of glaucoma patients with both IOP-dependent and IOP-independent disease subtypes. These findings indicate that antioxidant agents in the aqueous humor reflect glaucomatous optic nerve damage and that excessive oxidative stress may be involved in the pathogenesis of glaucoma.

Real-world clinical outcomes in patients with relapsed and refractory multiple myeloma receiving VTD-PACE treatment in the era of monoclonal antibodies.

Bortezomib (Velcade), thalidomide, dexamethasone, platinum (cisplatin), adriamycin (doxorubicin), cyclophosphamide, and etoposide (VTD-PACE) are commonly used as salvage treatment for patients with relapsed/refractory multiple myeloma (RRMM). However, its outcomes in the era of monoclonal antibodies remain unclear. Therefore, this retrospective cohort study assessed the clinical outcomes of 60 patients with RRMM (median four prior treatment lines) administered VTD-PACE. The median follow-up period was 11.1 months, during which they received a median of two cycles of VTD-PACE. The overall response rate (ORR) was 66.7%; ORRs of 53.1 and 82.1% were noted in patients with ≥ 4 and ≤ 3 prior lines (P = 0.027), respectively. The median overall survival (OS) was 17 months, with a median progression-free survival (PFS) of 9.8 months. Using the 3-month time point after VTD-PACE treatment as a landmark, 54 patients were still alive. Landmark analysis was conducted for PFS and OS of patients who received or did not receive HSCT or CART after VTD-PACE treatment. Patients who underwent subsequent hematopoietic stem cell transplantation (HSCT) or chimeric antigen receptor T-cell therapy (CART) following VTD-PACE showed a trend of longer PFS and OS than those who did not undergo subsequent HSCT or CART. The median OS in patients with and without renal dysfunction was 10.7 months and 21.5 months, respectively (P = 0.0091). Therefore, VTD-PACE is useful as a bridging therapy for HSCT or CART, as a response can be expected regardless of organ damage, disease risk, or history of anti-CD38 antibody use.

[Acute myeloid leukemia with t (8;21) translocation diagnosed at 21 weeks of gestation resulting in full-term delivery without chemotherapy].

A 28-year-old female was diagnosed with acute myeloid leukemia (AML) due to t (8;21) (q22;q22.1); RUNX1-RUNX1T1 at 21 weeks of gestation. Because no adverse prognostic genetic mutations were discovered, we decided to continue the pregnancy without chemotherapy for as long as possible. After careful monitoring with blood tests every two weeks, the disease did not progress until full-term, and a cesarean section was performed at 39 weeks of gestation. About two months after delivery, blasts in the peripheral blood increased to 46.5%, and myeloblasts in the bone marrow increased to 21.2%. The patient received idarubicin and cytarabine induction therapy, followed by three cycles of high-dose cytarabine consolidation therapy, and complete remission was maintained. Here we report a rare case who could avoid chemotherapy until full-term labor without progression of AML.

ΔNp63 Regulates Radioresistance in Human Head and Neck Squamous Carcinoma Cells.

Radiation therapy is commonly used to treat head and neck squamous cell carcinoma (HNSCC); however, recurrence results from the development of radioresistant cancer cells. Therefore, it is necessary to identify the underlying mechanisms of radioresistance in HNSCC. Previously, we showed that the inhibition of karyopherin-ß1 (KPNB1), a factor in the nuclear transport system, enhances radiation-induced cytotoxicity, specifically in HNSCC cells, and decreases the localization of SCC-specific transcription factor ΔNp63. This suggests that ΔNp63 may be a KPNB1-carrying nucleoprotein that regulates radioresistance in HNSCC. Here, we determined whether ΔNp63 is involved in the radioresistance of HNSCC cells. Cell survival was measured by a colony formation assay. Apoptosis was assessed by annexin V staining and cleaved caspase-3 expression. The results indicate that ΔNp63 knockdown decreased the survival of irradiated HNSCC cells, increased radiation-induced annexin V+ cells, and cleaved caspase-3 expression. These results show that ΔNp63 is involved in the radioresistance of HNSCC cells. We further investigated which specific karyopherin-α (KPNA) molecules, partners of KPNB1 for nuclear transport, are involved in nuclear ΔNp63 expression. The analysis of nuclear ΔNp63 protein expression suggests that KPNA1 is involved in nuclear ΔNp63 expression. Taken together, our results suggest that ΔNp63 is a KPNB1-carrying nucleoprotein that regulates radioresistance in HNSCC.

DPP-4 Inhibitors Attenuate Fibrosis After Glaucoma Filtering Surgery by Suppressing the TGF-ß/Smad Signaling Pathway.

Purpose: This study investigated the effect of dipeptidyl peptidase-4 inhibitors (DPP-4is) on fibrosis after glaucoma filtering surgery with clinical data and an in vitro model that used transforming growth factor-ß (TGF-ß) to induce human Tenon's fibroblast (HTF) fibrosis. Methods: The medical records of 41 eyes of 35 patients with diabetes with neovascular glaucoma (NVG) who received initial trabeculectomy were retrospectively reviewed. The surgical success rate was compared between cases that received (n = 23) and did not receive (n = 18) DPP-4i treatment for diabetes. The antifibrotic effects of linagliptin (a DPP-4i) were evaluated with quantitative real-time PCR for fibrosis markers (α-smooth muscle actin, collagen Iα, and fibronectin), a scratch assay, and a collagen gel contraction assay of primary cultured HTFs treated with TGF-ß1 and linagliptin. Western blotting analysis was performed to evaluate the levels of phosphorylated Smad2 and Smad3 in the presence of linagliptin. Results: The Kaplan-Meier curve for bleb survival was higher in patients who received DPP-4is (P = 0.017, log-rank test). The in vitro experiments demonstrated that treatment with linagliptin attenuated the elevated levels of fibrosis markers induced by TGF-ß1 in HTFs. Linagliptin treatment also prevented the migration and gel contraction of HTFs. Linagliptin inhibited the phosphorylation of Smad2 and Smad3, which is the canonical pathway of TGF-ß signaling. Conclusions: The current study indicates the potential effect of DPP-4is for maintaining bleb function after glaucoma filtering surgery in patients with diabetes with NVG. Our results demonstrate that linagliptin attenuates fibrotic change in HTFs by inhibiting TGF-ß/Smad signaling.

DAP3-mediated cell cycle regulation and its association with radioresistance in human lung adenocarcinoma cell lines.

Mitochondria play important roles in the cellular response to various types of stress, including that triggered by ionizing radiation. We have previously reported that the mitochondrial ribosomal protein death-associated protein 3 (DAP3) regulates the radioresistance of human lung adenocarcinoma (LUAD) cell lines A549 and H1299. However, the underlying mechanism of this regulation remains to be elucidated. To this end, we have herein investigated the role of DAP3 in the cell cycle regulation after irradiation. Notably, the DAP3 knockdown attenuated the radiation-induced increase of the G2/M cell population. Furthermore, western blotting analysis has revealed that the DAP3 knockdown decreased the expression of proteins related to the G2/M arrest, such as those of the phosphorylated cdc2 (Tyr15) and the phosphorylated checkpoint kinase 1 (Ser296), in irradiated A549 cells and H1299 cells. Moreover, by using a chk1 inhibitor, we were able to demonstrate that chk1 is involved in the radiation-induced G2/M arrest in both A549 and H1299 cells. Notably, the chk1 inhibitor was able to enhance the radiosensitivity of H1299 cells, while both chk1 inhibitor-abolished G2 arrest and inhibition of chk2-mediated events such as downregulation of radiation-induced p21 expression were required for enhancing radiosensitivity of A549 cells. Collectively, our findings reveal a novel role of DAP3 to regulate G2/M arrest through pchk1 in irradiated LUAD cells and suggest that chk1-mediated G2/M arrest regulates the radioresistance of H1299 cells, whereas both the chk1-mediated G2/M arrest and the chk2-mediated events contribute to the radioresistance of A549 cells.

Real-world clinical outcomes in patients with multiple myeloma treated with isatuximab after daratumumab treatment.

Isatuximab and daratumumab are anti-CD38 monoclonal antibodies used to treat refractory multiple myeloma. Isatuximab is often used after unsuccessful daratumumab treatment; however, the clinical benefits of receiving isatuximab after daratumumab treatment have not been fully evaluated. Therefore, this retrospective cohort study assessed the clinical outcomes of 39 patients with multiple myeloma who were administered isatuximab after daratumumab. The median follow-up period was 8.7 months (range 0.1-25.0 months). The overall response rate was 46.2% (18 patients). The 1-year overall survival was 53.9%, with a median progression-free survival of 5.6 months. The median progression-free survival in patients with high and normal lactate dehydrogenase levels was 4.5 and 9.6 months, respectively (P = 0.004). The median progression-free survival in patients with and without triple-class refractory disease was 5.1 months and not reached, respectively (P = 0.001). The median overall survival in patients with high and normal lactate dehydrogenase levels was not reached and 9.3 months, respectively (P = 0.001). The median overall survival in patients with and without triple-class refractory disease was 9.9 months and not reached, respectively (P = 0.038). Our findings provide insight into the optimal use and timing of anti-CD38 antibody therapy.

Novel partial deletions, frameshift and missense mutations of CSF1R in patents with CSF1R-related leukoencephalopathy.

BACKGROUND AND PURPOSE: Colony-stimulating factor 1 receptor (CSF1R)-related leukoencephalopathy is an adult-onset leukoencephalopathy caused by mutations in CSF1R. The present study aimed to explore the broader genetic spectrum of CSF1R-related leukoencephalopathy in association with clinical and imaging features. METHODS: Mutational analysis of CSF1R was performed for 100 consecutive patients with adult-onset leukoencephalopathy. Sequence and copy number variation (CNV) analyses of CSF1R were performed. The genomic ranges of the deletions were determined by long-read sequencing. Ligand-dependent autophosphorylation of CSF1R was examined in cells expressing the CSF1R mutants identified in this study. RESULTS: CSF1R mutations were identified in 15 patients, accounting for 15% of the adult-onset leukoencephalopathy cases. Seven novel and five previously reported CSF1R mutations were identified. The novel mutations, including three missense and one in-frame 3 bp deletion, were located in the tyrosine kinase domain (TKD) of CSF1R. Functional assays revealed that none of the novel mutations in the TKD showed autophosphorylation of CSF1R. Two partial deletions of CSF1R were identified that resulted in lack of the C-terminal region, including the distal TKD, in two patients. Various clinical features including cognitive impairment, psychiatric symptoms and gait disturbance were observed. Various degrees of the white matter lesions and corpus callosum abnormalities on magnetic resonance imaging and characteristic calcifications on computed tomography were observed as imaging features. CONCLUSIONS: Our results highlight the importance of examining the CNV of CSF1R even when Sanger or exome sequencing reveals no CSF1R mutations. Genetic examination of sequences and CNV analyses of CSF1R are recommended for an accurate diagnosis of CSF1R-related leukoencephalopathy.

Membrane skeleton hyperstability due to a novel alternatively spliced 4.1R can account for ellipsoidal camelid red cells with decreased deformability.

The red blood cells (RBCs) of vertebrates have evolved into two basic shapes, with nucleated nonmammalian RBCs having a biconvex ellipsoidal shape and anuclear mammalian RBCs having a biconcave disk shape. In contrast, camelid RBCs are flat ellipsoids with reduced membrane deformability, suggesting altered membrane skeletal organization. However, the mechanisms responsible for their elliptocytic shape and reduced deformability have not been determined. We here showed that in alpaca RBCs, protein 4.1R, a major component of the membrane skeleton, contains an alternatively spliced exon 14-derived cassette (e14) not observed in the highly conserved 80 kDa 4.1R of other highly deformable biconcave mammalian RBCs. The inclusion of this exon, along with the preceding unordered proline- and glutamic acid-rich peptide (PE), results in a larger and unique 90 kDa camelid 4.1R. Human 4.1R containing e14 and PE, but not PE alone, showed markedly increased ability to form a spectrin-actin-4.1R ternary complex in viscosity assays. A similar facilitated ternary complex was formed by human 4.1R possessing a duplication of the spectrin-actin-binding domain, one of the mutations known to cause human hereditary elliptocytosis. The e14- and PE-containing mutant also exhibited an increased binding affinity to ß-spectrin compared with WT 4.1R. Taken together, these findings indicate that 4.1R protein with the e14 cassette results in the formation and maintenance of a hyperstable membrane skeleton, resulting in rigid red ellipsoidal cells in camelid species, and suggest that membrane structure is evolutionarily regulated by alternative splicing of exons in the 4.1R gene.

Adult T-cell leukemia/lymphoma complicated by Pneumocystis pneumonia in a non-endemic area.

Adult T-cell leukemia/lymphoma (ATLL) is a human T-cell leukemia virus type 1-inducing unevenly-distributed T-cell malignancy, which is often complicated by opportunistic infections. Here, we discuss the case of a 75-year-old woman presenting with Pneumocystis pneumonia (PCP) who was subsequently diagnosed with ATLL in Tokyo, a non-endemic area of ATLL. In addition to the elevated soluble interleukin-2 receptor and the detection of flower cells in the screening blood test, the high-resolution computed tomography findings, atypical of PCP, were clues to the diagnosis of ATLL. ATLL should be considered as an underlying disease when patients present with PCP, even in non-endemic areas.

Antimicrobial prescription practices for outpatients with uncomplicated cystitis in Japan.

To promote antimicrobial stewardship, we studied antimicrobial prescription rates for uncomplicated cystitis, a common outpatient disease requiring antibiotic treatment. This multicenter retrospective study was performed from January 1, 2018, to December 31, 2020, in Japan, targeting outpatients aged ≥ 20 years whose medical records revealed International Classification of Diseases (ICD-10) codes suggesting uncomplicated cystitis (N300). The data of 1445 patients were collected and that of 902 patients were analyzed. The overall median patient age was 71 years and a proportion of those aged less than 50 years was 18.8% with a female dominance (82.6%). Antimicrobials were prescribed for 884 patients (98.0%) and a total of 623 patients (69.1%) were treated with broad-spectrum drugs, including fluoroquinolones (36.0%), third-generation cephalosporins (29.9%) and faropenem (3.1%). A logistic regression model revealed that the broad-spectrum agents were significantly prescribed for the older patients, male patients, and those who visited internists. Recurrence was observed in 37 (4.1%) cases, and the multivariate analysis suggested any of age, sex, or antimicrobial types were not associated with the recurrence. Collectively, approximately two-thirds of antimicrobials prescribed for uncomplicated cystitis were broad-spectrum agents. The present data would be an indicator for antimicrobial prescriptions in uncomplicated cystitis in Japan.

Glutathione Trisulfide Prevents Lipopolysaccharide-induced Inflammatory Gene Expression in Retinal Pigment Epithelial Cells.

We investigated the effects of glutathione trisulfide (GSSSG) on lipopolysaccharide (LPS)-induced inflammatory gene expression in immortalized ARPE-19, and primary human and mouse retinal pigment epithelial (RPE) cells. Sulfane sulfur molecules were significantly increased in GSSSG-treated ARPE-19 cells. GSSSG prevented the LPS-induced upregulation of interleukin (IL)-1ß, IL-6, and C-C motif chemokine ligand 2 (CCL2) in ARPE-19/primary RPE cells. Moreover, GSSSG prevented the activation of the nuclear factor-kappa B p65 subunit, and promoted the activation of extracellular signal-regulated kinase 1/2 (ERK1/2) in LPS-treated ARPE-19 cells. ERK1/2 inhibition prevented the GSSSG-mediated inhibition of LPS-induced IL-6 and CCL2 upregulation. Additionally, ERK1/2 activation prevented the upregulation of these genes in the absence of GSSSG. Knockdown of HMOX1 or NRF2, known as anti-oxidative genes, did not affect the activity of GSSSG in the context of LPS stimulation. These findings suggest that GSSSG attenuates LPS-induced inflammatory gene expression via ERK signaling hyperactivation, independently of the NRF2/HMOX1 pathway.