Fluoxetine, fluvoxamine, and hearing loss or tinnitus after cisplatin treatment: A retrospective cohort study.

Cisplatin use is often limited by its ototoxic side effects, which can lead to irreversible hearing loss. Preventing cisplatin-induced ototoxicity is crucial to improve patient outcomes. Fluoxetine and fluvoxamine, both selective serotonin reuptake inhibitors antidepressants, inhibit the NLR pyrin domain-containing protein 3 inflammasome, a potential therapeutic target for preventing ototoxicity. However, human studies have not evaluated if these antidepressants may protect against cisplatin-induced ototoxicity. The object of this study is to assess the association between fluoxetine or fluvoxamine use and incidence of hearing loss or tinnitus in a large cohort of patients receiving cisplatin chemotherapy. We use a retrospective cohort study within the U.S. Department of Veterans Affairs healthcare system. Adult patients with cancer who received cisplatin chemotherapy between 2000 and 2023 are included. Incidence of ototoxicity, defined by international classification of diseases revision 9-CM or international classification of diseases revision 10-CM diagnoses of hearing loss or tinnitus is compared between concurrent use of fluoxetine or fluvoxamine and cisplatin alone. A total of 20,552 patients were included. Of those, 489 received cisplatin and fluoxetine or fluvoxamine. After propensity score adjustment, the hazard of ototoxicity was lower in the group receiving fluoxetine or fluvoxamine compared to the group receiving cisplatin alone (HR = 0.62, 95% CI = (0.41-0.94)). Fluoxetine or fluvoxamine use may be associated with a reduced risk of cisplatin-induced ototoxicity. Randomized clinical trials are needed to confirm these findings and establish the efficacy of the medications in ototoxicity prevention. Further research is also warranted to investigate the potential mechanisms underlying this protective effect.

Therapeutic targeting of telomerase ameliorates experimental choroidal neovascularization.

Choroidal neovascularization (CNV) is the principal driver of blindness in neovascular age-related macular degeneration (nvAMD). Increased activity of telomerase, has been associated with endothelial cell proliferation, survival, migration, and invasion in the context of tumor angiogenesis. Expanding on this knowledge, we investigated the role of telomerase in the development of CNV in mouse model. We observed increased gene expression and activity of telomerase in mouse CNV. Genetic deficiency of the telomerase components, telomerase reverse transcriptase (Tert) and telomerase RNA component (Terc) suppressed laser-induced CNV in mice. Similarly, a small molecule inhibitor of TERT (BIBR 1532), and antisense oligonucleotides (ASOs) targeting Tert and Terc reduced CNV growth. Bone marrow chimera studies suggested that telomerase activity in non-bone marrow-derived cells is crucial for the development of CNV. Comparison of BIBR 1532 with VEGF neutralizing therapeutic strategy in mouse revealed a comparable level of angiosuppressive activity. However, when BIBR and anti-VEGF antibodies were administered as a combination at sub-therapeutic doses, a statistically significant suppression of CNV was observed. These findings underscore the potential benefits of combining sub-therapeutic doses of BIBR and anti-VEGF antibodies for developing newer therapeutic strategies for NV-AMD. Telomerase inhibition with BIBR 1532 suppressed induction of multiple cytokines and growth factors critical for neovascularization. In conclusion, our study identifies telomerase as a promising therapeutic target for treating neovascular disease of the eye and thus provides a proof of principle for further exploration of telomerase inhibition as a novel treatment strategy for nvAMD.

Cancer-derived exosomal Alu RNA promotes colorectal cancer progression.

Inflammation plays a crucial role in cancer progression, but the relevance of the inflammasome remains unclear. Alu RNA was the first endogenous nucleic acid shown to activate the NLRP3 (nucleotide-binding domain leucine-rich repeat containing 3) inflammasome. Here, we showed that Alu RNA can induce epithelial-to-mesenchymal transition (EMT) through NLRP3 inflammasome activation and IL-1ß release in colorectal cancer (CRC) cells. Alu RNA is stored, transported and transferred to CRC cells by exosomes. Exosomal Alu RNA promotes tumorigenesis by inducing invasion, metastasis and EMT via NLRP3 inflammasome activation. Consistent with these data, we found that significantly increased Alu RNA expression correlates with the induction of NLRP3 priming in human CRC patients. Furthermore, the level of Alu RNA in circulating exosomes correlates with CRC progression in a preclinical model. These findings reveal the direct involvement of Alu RNA in cancer pathogenesis, and its presence in CRC cell-derived exosomes could be used as a noninvasive diagnostic biomarker.

Alzheimer Disease Treatment With Acetylcholinesterase Inhibitors and Incident Age-Related Macular Degeneration.

Importance: Age-related macular degeneration (AMD) is a serious and common ophthalmologic disorder that is hypothesized to result, in part, from inflammatory reactions in the macula. Alzheimer disease (AD) treatment, acetylcholinesterase inhibitors (AChEIs), have anti-inflammatory effects and it remains unclear if they modify the risk of AMD. Objective: To investigate the association between AChEI medications and the incidence of AMD. Design, Setting, and Participants: This propensity score-matched retrospective cohort study took place at health care facilities within the US Department of Veterans Affairs (VA) health care system from January 2000 through September 2023. Participants included patients diagnosed with AD between ages 55 and 80 years with no preexisting diagnosis of AMD in the VA database. Exposure: AChEIs prescription dispensed as pharmacologic treatments for AD. Main Outcomes and Measure: The first diagnosis of AMD. Results: A total of 21 823 veterans with AD (mean [SD] age, 72.3 [6.1] years; 21 313 male participants [97.7%] and 510 female participants [2.3%]) were included. Propensity score-matched Cox model reveals each additional year of AChEI treatment was associated with a 6% lower hazard of AMD (hazard ratio, 0.94; 95% CI, (0.89-0.99). Conclusions and Relevance: This observational study reports a small reduction in the risk of AMD among veterans with AD receiving AChEIs. Randomized clinical trials would be needed to determine if there is a cause-and-effect relationship and further research is required to validate these findings across diverse populations.

Effects of donor-specific microvascular anatomy on hemodynamic perfusion in human choriocapillaris.

Evidence from histopathology and clinical imaging suggest that choroidal anatomy and hemodynamic perfusion are among the earliest changes in retinal diseases such as age-related macular degeneration (AMD). However, how inner choroidal anatomy affects hemodynamic perfusion is not well understood. Therefore, we sought to understand the influences of choroidal microvascular architecture on the spatial distribution of hemodynamic parameters in choriocapillaris from human donor eyes using image-based computational hemodynamic (ICH) simulations. We subjected image-based inner choroid reconstructions from eight human donor eyes to ICH simulation using a kinetic-based volumetric lattice Boltzmann method to compute hemodynamic distributions of velocity, pressure, and endothelial shear stress. Here, we demonstrate that anatomic parameters, including arteriolar and venular arrangements and intercapillary pillar density and distribution exert profound influences on inner choroidal hemodynamic characteristics. Reductions in capillary, arteriolar, and venular density not only reduce the overall blood velocity within choriocapillaris, but also substantially increase its spatial heterogeneity. These first-ever findings improve understanding of how choroidal anatomy affects hemodynamics and may contribute to pathogenesis of retinal diseases such as AMD.

Y chromosome proteins in female tissues.

Unreliable protein-based tools are impeding sex-based research.

Anti-HIV Drugs Reduce Risk of Prediabetes and Progression to Type 2 Diabetes in HIV-Infected Patients.

The aim of this study was to investigate whether the use of nucleoside reverse transcriptase inhibitors (NRTIs) impacts the incidence of prediabetes or type 2 diabetes mellitus (T2DM) or the progression from prediabetes to T2DM in people living with HIV (PLWH). We conducted a retrospective cohort study using the U.S. Veterans Health Administration database among adult patients with an HIV diagnosis from the year 2000 until 2021 to determine the incidence of prediabetes and further progression to T2DM among NRTI exposed and unexposed patients. A multistate model was used to evaluate progression from normoglycemia to prediabetes and then to T2DM, and covariate adjustment with the Cox proportional hazards model was used to estimate the hazard ratios. Among 32,240 veterans diagnosed with HIV, prediabetes and T2DM were observed among 20.2% and 20.7% of patients, respectively. Among those diagnosed with prediabetes, 31.8% progressed to T2DM. Patients exposed to NRTIs at any time (86.6%), had a reduced risk of prediabetes [HR 0.50 (0.47-0.53 95% CI)] and among prediabetics, a lower risk of progression to T2DM [HR 0.73 (0.63-0.85 95% CI)] when compared to patients who never used NRTIs. In summary, NRTIs may reduce the risk of developing prediabetes and the progression from prediabetes to T2DM in PLWH.

Kamuvudine-9 Protects Retinal Structure and Function in a Novel Model of Experimental Rhegmatogenous Retinal Detachment.

Purpose: Rhegmatogenous retinal detachment (RRD) is a vision-threatening event that benefits from surgical intervention. While awaiting surgical reattachment, irreversible hypoxic and inflammatory damage to the retina often occurs. An interim therapy protecting photoreceptors could improve functional outcomes. We sought to determine whether Kamuvudine-9 (K-9), a derivative of nucleoside reverse transcriptase inhibitors (NRTIs) that inhibits inflammasome activation, and the NRTIs lamivudine (3TC) and azidothymidine (AZT) could protect the retina following RRD. Methods: RRD was induced in mice via subretinal injection (SRI) of 1% carboxymethylcellulose (CMC). To simulate outcomes following the clinical management of RRD, we determined the optimal conditions by which SRI of CMC induced spontaneous retinal reattachment (SRR) occurs over 10 days (RRD/SRR). K-9, 3TC, or AZT was administered via intraperitoneal injection. Inflammasome activation pathways were monitored by abundance of cleaved caspase-1, IL-18, and cleaved caspase-8, and photoreceptor death was assessed by TUNEL staining. Retinal function was assessed by full-field scotopic electroretinography. Results: RRD induced retinal inflammasome activation and photoreceptor death in mice. Systemic administration of K-9, 3TC, or AZT inhibited retinal inflammasome activation and photoreceptor death. In the RRD/SRR model, K-9 protected retinal electrical function during the time of RRD and induced an improvement following retinal reattachment. Conclusions: K-9 and NRTIs exhibit anti-inflammatory and neuroprotective activities in experimental RRD. Given its capacity to protect photoreceptor function during the period of RRD and enhance retinal function following reattachment, K-9 shows promise as a retinal neuroprotectant and warrants study in RRD. Further, this novel RRD/SRR model may facilitate experimental evaluation of functional outcomes relevant to RRD.

Association between Fluoxetine Use and Overall Survival among Patients with Cancer Treated with PD-1/L1 Immunotherapy.

Checkpoint inhibitors can be a highly effective antitumor therapy but only to a subset of patients, presumably due to immunotherapy resistance. Fluoxetine was recently revealed to inhibit the NLRP3 inflammasome, and NLRP3 inhibition could serve as a target for immunotherapy resistance. Therefore, we evaluated the overall survival (OS) in patients with cancer receiving checkpoint inhibitors combined with fluoxetine. A cohort study was conducted among patients diagnosed with lung, throat (pharynx or larynx), skin, or kidney/urinary cancer treated with checkpoint inhibitor therapy. Utilizing the Veterans Affairs Informatics and Computing Infrastructure, patients were retrospectively evaluated during the period from October 2015 to June 2021. The primary outcome was overall survival (OS). Patients were followed until death or the end of the study period. There were 2316 patients evaluated, including 34 patients who were exposed to checkpoint inhibitors and fluoxetine. Propensity score weighted Cox proportional hazards demonstrated a better OS in fluoxetine-exposed patients than unexposed (HR: 0.59, 95% CI 0.371-0.936). This cohort study among cancer patients treated with checkpoint inhibitor therapy showed a significant improvement in the OS when fluoxetine was used. Because of this study's potential for selection bias, randomized trials are needed to assess the efficacy of the association of fluoxetine or another anti-NLRP3 drug to checkpoint inhibitor therapy.

Reduction of human Alzheimer's disease risk and reversal of mouse model cognitive deficit with nucleoside analog use.

Innate immune signaling through the NLRP3 inflammasome has been implicated in the pathogenesis of Alzheimer's disease (AD), the most prevalent form of dementia. We previously demonstrated that nucleoside reverse transcriptase inhibitors (NRTIs), drugs approved to treat HIV and hepatitis B infections, also inhibit inflammasome activation. Here we report that in humans, NRTI exposure was associated with a significantly lower incidence of AD in two of the largest health insurance databases in the United States. Treatment of aged 5xFAD mice (a mouse model of amyloid-ß deposition that expresses five mutations found in familial AD) with Kamuvudine-9 (K-9), an NRTI-derivative with enhanced safety profile, reduced Aß deposition and reversed their cognitive deficit by improving their spatial memory and learning performance to that of young wild-type mice. These findings support the concept that inflammasome inhibition could benefit AD and provide a rationale for prospective clinical testing of NRTIs or K-9 in AD.

Phagocytosis in the retina promotes local insulin production in the eye.

The retina is highly metabolically active, relying on glucose uptake and aerobic glycolysis. Situated in close contact to photoreceptors, a key function of cells in the retinal pigment epithelium (RPE) is phagocytosis of damaged photoreceptor outer segments (POS). Here we identify RPE as a local source of insulin in the eye that is stimulated by POS phagocytosis. We show that Ins2 messenger RNA and insulin protein are produced by RPE cells and that this production correlates with RPE phagocytosis of POS. Genetic deletion of phagocytic receptors ('loss of function') reduces Ins2, whereas increasing the levels of the phagocytic receptor MerTK ('gain of function') increases Ins2 production in male mice. Contrary to pancreas-derived systemic insulin, RPE-derived local insulin is stimulated during starvation, which also increases RPE phagocytosis. Global or RPE-specific Ins2 gene deletion decreases retinal glucose uptake in starved male mice, dysregulates retinal physiology, causes defects in phototransduction and exacerbates photoreceptor loss in a mouse model of retinitis pigmentosa. Collectively, these data identify RPE cells as a phagocytosis-induced local source of insulin in the retina, with the potential to influence retinal physiology and disease.

Allopurinol and the Risk of Diabetic Macular Edema among U.S. Veterans with Type 2 Diabetes.

BACKGROUND: By inhibiting xanthine oxidase, subsequent inflammatory cytokine release and the resulting breakdown of the blood-retina barrier, allopurinol may limit the inflammation-driving diabetic macular edema (DME). METHODS: We examined the relationship between allopurinol and DME among type 2 diabetic United States veterans using a retrospective cohort study.  We used propensity score matching and Cox hazard models to estimate the risk of DME. RESULTS: Propensity score-matched Cox models revealed allopurinol was associated with a 24.6% reduction in the risk of DME (HR = 0.754; 95% CI = (0.684-0.831)). CONCLUSION: Allopurinol could reduce the risk of DME, one of the major causes of visual disturbance among diabetic patients. Further research into the effects of allopurinol on DME is warranted.

Subretinal injection in mice to study retinal physiology and disease.

Subretinal injection (SRI) is a widely used technique in retinal research and can be used to deliver nucleic acids, small molecules, macromolecules, viruses, cells or biomaterials such as nanobeads. Here we describe how to undertake SRI of mice. This protocol was adapted from a technique initially described for larger animals. Although SRI is a common procedure in eye research laboratories, there is no published guidance on the best practices for determining what constitutes a 'successful' SRI. Optimal injections are required for reproducibility of the procedure and, when carried out suboptimally, can lead to erroneous conclusions. To address this issue, we propose a standardized protocol for SRI with 'procedure success' defined by follow-up examination of the retina and the retinal pigmented epithelium rather than solely via intraoperative endpoints. This protocol takes 7-14 d to complete, depending on the reagent delivered. We have found, by instituting a standardized training program, that trained ophthalmologists achieve reliable proficiency in this technique after ~350 practice injections. This technique can be used to gain insights into retinal physiology and disease pathogenesis and to test the efficacy of experimental compounds in the retina or retinal pigmented epithelium.

The Learning Curve of Murine Subretinal Injection Among Clinically Trained Ophthalmic Surgeons.

Purpose: Subretinal injection (SRI) in mice is widely used in retinal research, yet the learning curve (LC) of this surgically challenging technique is unknown. Methods: To evaluate the LC for SRI in a murine model, we analyzed training data from three clinically trained ophthalmic surgeons from 2018 to 2020. Successful SRI was defined as either the absence of retinal pigment epithelium (RPE) degeneration after phosphate buffered saline injection or the presence of RPE degeneration after Alu RNA injection. Multivariable survival-time regression models were used to evaluate the association between surgeon experience and success rate, with adjustment for injection agents, and to calculate an approximate case number to achieve a 95% success rate. Cumulative sum (CUSUM) analyses were performed and plotted individually to monitor each surgeon's simultaneous performance. Results: Despite prior microsurgery experience, the combined average success rate of the first 50 cases in mice was only 27%. The predicted SRI success rate did not reach a plateau above 95% until approximately 364 prior cases. Using the 364 training cases as a cutoff point, the predicted probability of success for cases 1 to 364 was 65.38%, and for cases 365 to 455 it was 99.32% (P < 0.0001). CUSUM analysis showed an initial upward slope and then remained within the decision intervals with an acceptable success rate set at 95% in the late stage. Conclusions: This study demonstrates the complexity and substantial LC for successful SRI in mice with high confidence. A systematic training system could improve the reliability and reproducibility of SRI-related experiments and improve the interpretation of experimental results using this technique. Translational Relevance: Our prediction model and monitor system allow objective quantification of technical proficiency in the field of subretinal drug delivery and gene therapy for the first time, to the best of our knowledge.