Multiple early factors anticipate post-acute COVID-19 sequelae.

Post-acute sequelae of COVID-19 (PASC) represent an emerging global crisis. However, quantifiable risk factors for PASC and their biological associations are poorly resolved. We executed a deep multi-omic, longitudinal investigation of 309 COVID-19 patients from initial diagnosis to convalescence (2-3 months later), integrated with clinical data and patient-reported symptoms. We resolved four PASC-anticipating risk factors at the time of initial COVID-19 diagnosis: type 2 diabetes, SARS-CoV-2 RNAemia, Epstein-Barr virus viremia, and specific auto-antibodies. In patients with gastrointestinal PASC, SARS-CoV-2-specific and CMV-specific CD8+ T cells exhibited unique dynamics during recovery from COVID-19. Analysis of symptom-associated immunological signatures revealed coordinated immunity polarization into four endotypes, exhibiting divergent acute severity and PASC. We find that immunological associations between PASC factors diminish over time, leading to distinct convalescent immune states. Detectability of most PASC factors at COVID-19 diagnosis emphasizes the importance of early disease measurements for understanding emergent chronic conditions and suggests PASC treatment strategies.

Multi-Omics Resolves a Sharp Disease-State Shift between Mild and Moderate COVID-19.

We present an integrated analysis of the clinical measurements, immune cells, and plasma multi-omics of 139 COVID-19 patients representing all levels of disease severity, from serial blood draws collected during the first week of infection following diagnosis. We identify a major shift between mild and moderate disease, at which point elevated inflammatory signaling is accompanied by the loss of specific classes of metabolites and metabolic processes. Within this stressed plasma environment at moderate disease, multiple unusual immune cell phenotypes emerge and amplify with increasing disease severity. We condensed over 120,000 immune features into a single axis to capture how different immune cell classes coordinate in response to SARS-CoV-2. This immune-response axis independently aligns with the major plasma composition changes, with clinical metrics of blood clotting, and with the sharp transition between mild and moderate disease. This study suggests that moderate disease may provide the most effective setting for therapeutic intervention.

VEGF in Signaling and Disease: Beyond Discovery and Development.

The discovery of vascular endothelial-derived growth factor (VEGF) has revolutionized our understanding of vasculogenesis and angiogenesis during development and physiological homeostasis. Over a short span of two decades, our understanding of the molecular mechanisms by which VEGF coordinates neurovascular homeostasis has become more sophisticated. The central role of VEGF in the pathogenesis of diverse cancers and blinding eye diseases has also become evident. Elucidation of the molecular regulation of VEGF and the transformative development of multiple therapeutic pathways targeting VEGF directly or indirectly is a powerful case study of how fundamental research can guide innovation and translation. It is also an elegant example of how agnostic discovery and can transform our understanding of human disease. This review will highlight critical nodal points in VEGF biology, including recent developments in immunotherapy for cancer and multitarget approaches in neovascular eye disease.

Immunity as biophysics at the surface of a T cell.

Different antibodies can bind to the same targets on the surface of immune cells with opposite biologic effects. These effects-agonism, antagonism, or partial agonism-are so poorly understood that drug developers must screen antibodies for relevant desired characteristics. In this issue of Immunity, Lippert et al. define molecular mechanisms that dictate antibody behavior, ushering in an era of directed antibody design.

The cancer-immunity cycle: Indication, genotype, and immunotype.

The cancer-immunity cycle provides a framework to understand the series of events that generate anti-cancer immune responses. It emphasizes the iterative nature of the response where the killing of tumor cells by T cells initiates subsequent rounds of antigen presentation and T cell stimulation, maintaining active immunity and adapting it to tumor evolution. Any step of the cycle can become rate-limiting, rendering the immune system unable to control tumor growth. Here, we update the cancer-immunity cycle based on the remarkable progress of the past decade. Understanding the mechanism of checkpoint inhibition has evolved, as has our view of dendritic cells in sustaining anti-tumor immunity. We additionally account for the role of the tumor microenvironment in facilitating, not just suppressing, the anti-cancer response, and discuss the importance of considering a tumor's immunological phenotype, the "immunotype". While these new insights add some complexity to the cycle, they also provide new targets for research and therapeutic intervention.

Early IFN-α signatures and persistent dysfunction are distinguishing features of NK cells in severe COVID-19.

Longitudinal analyses of the innate immune system, including the earliest time points, are essential to understand the immunopathogenesis and clinical course of coronavirus disease (COVID-19). Here, we performed a detailed characterization of natural killer (NK) cells in 205 patients (403 samples; days 2 to 41 after symptom onset) from four independent cohorts using single-cell transcriptomics and proteomics together with functional studies. We found elevated interferon (IFN)-α plasma levels in early severe COVD-19 alongside increased NK cell expression of IFN-stimulated genes (ISGs) and genes involved in IFN-α signaling, while upregulation of tumor necrosis factor (TNF)-induced genes was observed in moderate diseases. NK cells exert anti-SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) activity but are functionally impaired in severe COVID-19. Further, NK cell dysfunction may be relevant for the development of fibrotic lung disease in severe COVID-19, as NK cells exhibited impaired anti-fibrotic activity. Our study indicates preferential IFN-α and TNF responses in severe and moderate COVID-19, respectively, and associates a prolonged IFN-α-induced NK cell response with poorer disease outcome.

Top 10 Challenges in Cancer Immunotherapy.

Cancer immunotherapy is a validated and critically important approach for treating patients with cancer. Given the vast research and clinical investigation efforts dedicated to advancing both endogenous and synthetic immunotherapy approaches, there is a need to focus on crucial questions and define roadblocks to the basic understanding and clinical progress. Here, we define ten key challenges facing cancer immunotherapy, which range from lack of confidence in translating pre-clinical findings to identifying optimal combinations of immune-based therapies for any given patient. Addressing these challenges will require the combined efforts of basic researchers and clinicians, and the focusing of resources to accelerate understanding of the complex interactions between cancer and the immune system and the development of improved treatment options for patients with cancer.

Epigenetic Reprogramming Drives Epithelial Disruption in Chronic Obstructive Pulmonary Disease.

Chronic obstructive pulmonary disease (COPD) remains a major public health challenge that contributes greatly to mortality and morbidity worldwide. Although it has long been recognized that the epithelium is altered in COPD, there has been little focus on targeting it to modify the disease course. Therefore, mechanisms that disrupt epithelial cell function in patients with COPD are poorly understood. In this study, we sought to determine whether epigenetic reprogramming of the cell-cell adhesion molecule E-cadherin, encoded by the CDH1 gene, disrupts epithelial integrity. By reducing these epigenetic marks, we can restore epithelial integrity and rescue alveolar airspace destruction. We used differentiated normal and COPD-derived primary human airway epithelial cells, genetically manipulated mouse tracheal epithelial cells, and mouse and human precision-cut lung slices to assess the effects of epigenetic reprogramming. We show that the loss of CDH1 in COPD is due to increased DNA methylation site at the CDH1 enhancer D through the downregulation of the ten-eleven translocase methylcytosine dioxygenase (TET) enzyme TET1. Increased DNA methylation at the enhancer D region decreases the enrichment of RNA polymerase II binding. Remarkably, treatment of human precision-cut slices derived from patients with COPD with the DNA demethylation agent 5-aza-2'-deoxycytidine decreased cell damage and reduced air space enlargement in the diseased tissue. Here, we present a novel mechanism that targets epigenetic modifications to reverse the tissue remodeling in human COPD lungs and serves as a proof of concept for developing a disease-modifying target.

Uptake, effectiveness and safety of COVID-19 vaccines in individuals at clinical risk due to immunosuppressive drug therapy or transplantation procedures: a population-based cohort study in England.

BACKGROUND: Immunocompromised individuals are at increased risk of severe COVID-19 outcomes, underscoring the importance of COVID-19 vaccination in this population. The lack of comprehensive real-world data on vaccine uptake, effectiveness and safety in these individuals presents a critical knowledge gap, highlighting the urgency to better understand and address the unique challenges faced by immunocompromised individuals in the context of COVID-19 vaccination. METHODS: We analysed data from 12,274,946 people in the UK aged > 12 years from 01/12/2020 to 11/04/2022. Of these, 583,541 (4.8%) were immunocompromised due to immunosuppressive drugs, organ transplants, dialysis or chemotherapy. We undertook a cohort analysis to determine COVID-19 vaccine uptake, nested case-control analyses adjusted for comorbidities and sociodemographic characteristics to determine effectiveness of vaccination against COVID-19 hospitalisation, ICU admission and death, and a self-controlled case series assessing vaccine safety for pre-specified adverse events of interest. RESULTS: Overall, 93.7% of immunocompromised individuals received at least one COVID-19 vaccine dose, with 80.4% having received three or more doses. Uptake reduced with increasing deprivation (hazard ratio [HR] 0.78 [95%CI 0.77-0.79] in the most deprived quintile compared to the least deprived quintile for the first dose). Estimated vaccine effectiveness against COVID-19 hospitalisation 2-6 weeks after the second and third doses compared to unvaccinated was 78% (95%CI 72-83) and 91% (95%CI 88-93) in the immunocompromised population, versus 85% (95%CI 83-86) and 86% (95%CI 85-89), respectively, for the general population. Results showed COVID-19 vaccines were protective against intensive care unit (ICU) admission and death in both populations, with effectiveness of over 92% against COVID-19-related death and up to 95% in reducing ICU admissions for both populations following the third dose. COVID-19 vaccines were generally safe for immunocompromised individuals, though specific doses of ChAdOx1, mRNA-1273 and BNT162b2 raised risks of specific cardiovascular/neurological conditions. CONCLUSIONS: COVID-19 vaccine uptake is high in immunocompromised individuals on immunosuppressive drug therapy or who have undergone transplantation procedures, with documented disparities by deprivation. Findings suggest that COVID-19 vaccines are protective against severe COVID-19 outcomes in this vulnerable population, and show a similar safety profile in immunocompromised individuals and the general population, despite some increased risk of adverse events. These results underscore the importance of ongoing vaccination prioritisation for this clinically at-risk population to maximise protection against severe COVID-19 outcomes.

TGFß attenuates tumour response to PD-L1 blockade by contributing to exclusion of T cells.

Therapeutic antibodies that block the programmed death-1 (PD-1)-programmed death-ligand 1 (PD-L1) pathway can induce robust and durable responses in patients with various cancers, including metastatic urothelial cancer. However, these responses only occur in a subset of patients. Elucidating the determinants of response and resistance is key to improving outcomes and developing new treatment strategies. Here we examined tumours from a large cohort of patients with metastatic urothelial cancer who were treated with an anti-PD-L1 agent (atezolizumab) and identified major determinants of clinical outcome. Response to treatment was associated with CD8+ T-effector cell phenotype and, to an even greater extent, high neoantigen or tumour mutation burden. Lack of response was associated with a signature of transforming growth factor ß (TGFß) signalling in fibroblasts. This occurred particularly in patients with tumours, which showed exclusion of CD8+ T cells from the tumour parenchyma that were instead found in the fibroblast- and collagen-rich peritumoural stroma; a common phenotype among patients with metastatic urothelial cancer. Using a mouse model that recapitulates this immune-excluded phenotype, we found that therapeutic co-administration of TGFß-blocking and anti-PD-L1 antibodies reduced TGFß signalling in stromal cells, facilitated T-cell penetration into the centre of tumours, and provoked vigorous anti-tumour immunity and tumour regression. Integration of these three independent biological features provides the best basis for understanding patient outcome in this setting and suggests that TGFß shapes the tumour microenvironment to restrain anti-tumour immunity by restricting T-cell infiltration.

Acute cholecystitis, obesity, and steatohepatitis constitute the lethal triad for bile duct injury (BDI) during laparoscopic cholecystectomy.

OBJECTIVE: The most feared complication during laparoscopic cholecystectomy remains a bile duct injury (BDI). Accurately risk-stratifying patients for a BDI remains difficult and imprecise. This study evaluated if the lethal triad of acute cholecystitis, obesity, and steatohepatitis is a prognostic measure for BDI. METHODS: A retrospective review of the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) registry was performed. All laparoscopic cholecystectomy cases within the main NSQIP database for 2012-2019 were queried. Two study cohorts were constructed. One with the lethal triad of acute cholecystitis, BMI ≥ 30, and steatohepatitis. The other cohort did not have the full triad present. Multivariate analysis was performed via logistic regression modeling with calculation of odds ratios (OR) to identify independent factors for BDI. An uncontrolled and controlled propensity score match analysis was performed. RESULTS: A total of 387,501 cases were analyzed. 36,887 cases contained the lethal triad, the remaining 350,614 cases did not have the full triad. 860 BDIs were identified resulting in an overall incidence rate 0.22%. There were 541 BDIs within the lethal triad group with 319 BDIs in the other cohort and an incidence rate of 1.49% vs 0.09% (P < 0.001). Multivariate analysis identified the lethal triad as an independent risk factor for a BDI by over 15-fold (OR 16.35, 95%CI 14.28-18.78, P < 0.0001) on the uncontrolled analysis. For the controlled propensity score match there were 29,803 equivalent pairs identified between the cohorts. The BDI incidence rate remained significantly higher with lethal triad cases at 1.65% vs 0.04% (P < 0.001). The lethal triad was an even more significant independent risk factor for BDI on the controlled analysis (OR 40.13, 95%CI 7.05-356.59, P < 0.0001). CONCLUSIONS: The lethal triad of acute cholecystitis, obesity, and steatohepatitis significantly increases the risk of a BDI. This prognostic measure can help better counsel patients and potentially alter management.

Methylome-wide Analysis of Chronic HIV Infection Reveals Five-Year Increase in Biological Age and Epigenetic Targeting of HLA.

HIV-infected individuals are living longer on antiretroviral therapy, but many patients display signs that in some ways resemble premature aging. To investigate and quantify the impact of chronic HIV infection on aging, we report a global analysis of the whole-blood DNA methylomes of 137 HIV+ individuals under sustained therapy along with 44 matched HIV- individuals. First, we develop and validate epigenetic models of aging that are independent of blood cell composition. Using these models, we find that both chronic and recent HIV infection lead to an average aging advancement of 4.9 years, increasing expected mortality risk by 19%. In addition, sustained infection results in global deregulation of the methylome across >80,000 CpGs and specific hypomethylation of the region encoding the human leukocyte antigen locus (HLA). We find that decreased HLA methylation is predictive of lower CD4 / CD8 T cell ratio, linking molecular aging, epigenetic regulation, and disease progression.

Carceral-community epidemiology, structural racism, and COVID-19 disparities.

Black and Hispanic communities are disproportionately affected by both incarceration and COVID-19. The epidemiological relationship between carceral facilities and community health during the COVID-19 pandemic, however, remains largely unexamined. Using data from Cook County Jail, we examine temporal patterns in the relationship between jail cycling (i.e., arrest and processing of individuals through jails before release) and community cases of COVID-19 in Chicago ZIP codes. We use multivariate regression analyses and a machine-learning tool, elastic regression, with 1,706 demographic control variables. We find that for each arrested individual cycled through Cook County Jail in March 2020, five additional cases of COVID-19 in their ZIP code of residence are independently attributable to the jail as of August. A total 86% of this additional disease burden is borne by majority-Black and/or -Hispanic ZIPs, accounting for 17% of cumulative COVID-19 cases in these ZIPs, 6% in majority-White ZIPs, and 13% across all ZIPs. Jail cycling in March alone can independently account for 21% of racial COVID-19 disparities in Chicago as of August 2020. Relative to all demographic variables in our analysis, jail cycling is the strongest predictor of COVID-19 rates, considerably exceeding poverty, race, and population density, for example. Arrest and incarceration policies appear to be increasing COVID-19 incidence in communities. Our data suggest that jails function as infectious disease multipliers and epidemiological pumps that are especially affecting marginalized communities. Given disproportionate policing and incarceration of racialized residents nationally, the criminal punishment system may explain a large proportion of racial COVID-19 disparities noted across the United States.

COVID-19 within families amplifies the prosociality gap between adolescents of high and low socioeconomic status.

COVID-19 has had worse health, education, and labor market effects on groups with low socioeconomic status (SES) than on those with high SES. Little is known, however, about whether COVID-19 has also had differential effects on noncognitive skills that are important for life outcomes. Using panel data from before and during the pandemic, we show that COVID-19 affects one key noncognitive skill, that is, prosociality. While prosociality is already lower for low-SES students prior to the pandemic, we show that COVID-19 infections within families amplify the prosociality gap between French high school students of high and low SES by almost tripling its size in comparison to pre-COVID-19 levels.

Analysis of omega-3 and omega-6 polyunsaturated fatty acid metabolism by compound-specific isotope analysis in humans.

Natural variations in the 13C:12C ratio (carbon-13 isotopic abundance [δ13C]) of the food supply have been used to determine the dietary origin and metabolism of fatty acids, especially in the n-3 PUFA biosynthesis pathway. However, n-6 PUFA metabolism following linoleic acid (LNA) intake remains under investigation. Here, we sought to use natural variations in the δ13C signature of dietary oils and fatty fish to analyze n-3 and n-6 PUFA metabolism following dietary changes in LNA and eicosapentaenoic acid (EPA) + DHA in adult humans. Participants with migraine (aged 38.6 ± 2.3 years, 93% female, body mass index of 27.0 ± 1.1 kg/m2) were randomly assigned to one of three dietary groups for 16 weeks: 1) low omega-3, high omega-6 (H6), 2) high omega-3, high omega-6 (H3H6), or 3) high omega-3, low omega-6 (H3). Blood was collected at baseline, 4, 10, and 16 weeks. Plasma PUFA concentrations and δ13C were determined. The H6 intervention exhibited increases in plasma LNA δ13C signature over time; meanwhile, plasma LNA concentrations were unchanged. No changes in plasma arachidonic acid δ13C or concentration were observed. Participants on the H3H6 and H3 interventions demonstrated increases in plasma EPA and DHA concentration over time. Plasma δ13C-EPA increased in total lipids of the H3 group and phospholipids of the H3H6 group compared with baseline. Compound-specific isotope analysis supports a tracer-free technique that can track metabolism of dietary fatty acids in humans, provided that the isotopic signature of the dietary source is sufficiently different from plasma δ13C.

Cigarette smoke-induced injury induces distinct sex-specific transcriptional signatures in mice tracheal epithelial cells.

The airway epithelial barrier is crucial for defending against respiratory insults and diseases. Disruption of epithelial integrity contributes to respiratory diseases, and sex-specific differences in susceptibility and severity have been observed. However, sex-specific differences in the context of respiratory diseases are often overlooked, especially in murine models. In this study, we investigated the in vitro transcriptomics of male and female murine tracheal epithelial cells (mTECs) in response to chronic cigarette smoke (CS) exposure using an International Organization for Standardization (ISO) puff regimen. Our findings reveal sex-specific differences in the baseline characteristics of airway epithelial cells. Female mTECs demonstrated stronger barrier function and higher ciliary function compared with males. The barrier function was disrupted in both males and females following chronic CS, but the difference was more significant in females due to their higher baseline. Female mice exhibited transcriptional signatures suggesting dedifferentiation with increased basal cells and markers of cellular senescence. Pathway analysis indicated potential protective roles of planar cell polarity (PCP) in preventing dedifferentiation in male mice exposed to CS. We also observed sex-specific differences in the DNA damage response and antioxidant levels, suggesting distinct mechanisms underlying cellular stress. Understanding these sex-specific mechanisms could facilitate the development of targeted therapeutic strategies for lung diseases associated with environmental insults. Recognizing sex-based differences in disease susceptibility and treatment response can lead to personalized care and improved outcomes. Clinical trials should consider sex as a biological variable to develop effective interventions that address the unique differences between men and women in respiratory diseases.NEW & NOTEWORTHY The study underscores the importance of considering sex-specific differences in the airway epithelium in respiratory diseases such as COPD. Differences in gene expression between males and females at baseline and in response to chronic injury in the airway epithelium could have implications on disease susceptibility, both in COPD and other respiratory diseases. Therefore, understanding these differences is crucial for developing targeted therapies to treat respiratory diseases based on a sex-specific manner.

Omega-3 polyunsaturated fatty acids and the psychiatric post-acute sequelae of COVID-19: A one-year retrospective cohort analysis of 33,908 patients.

BACKGROUND: Early prevention and management of psychiatric symptoms in long COVID (or post-COVID-19 conditions) are crucial for reducing long-term disability. Existing clinical guidelines recommend the use of omega-3 polyunsaturated fatty acids (PUFAs) as a promising therapeutic approach for various common psychiatric disorders due to their anti-inflammatory and neuroprotective characteristics. This study aims to investigate the potential efficacy of omega-3 PUFAs in alleviating the psychiatric sequelae following COVID-19. METHODS: This 1-year retrospective cohort study used the TriNetX electronic health records network to examine the effects of omega-3 PUFAs supplements on psychiatric sequelae in adults diagnosed with COVID-19. Using propensity-score matching, the study compared those who used omega-3 PUFAs supplements with those who did not, assessing outcomes including depression, anxiety disorders, insomnia, and other somatic conditions up to a year after COVID-19 diagnosis. RESULTS: In 16,962 patients who received omega-3 PUFAs supplements and 2,248,803 who did not, omega-3 supplementation significantly reduced the risk of developing psychiatric sequelae post-COVID-19 diagnosis (HR, 0.804; 95% CI, 0.729 to 0.888). Specifically, the risks for depression (HR, 0.828; 95% CI, 0.714 to 0.960), anxiety disorders (HR, 0.833; 95% CI, 0.743 to 0.933), and insomnia (HR, 0.679; 95% CI, 0.531 to 0.869) were reduced in the omega-3 group. This effect was consistent across sex, race, 18-59 age group, and patients with less than two doses of the COVID-19 vaccine. The omega-3 group also had a lower risk of cough and myalgia, but no significant difference was noted for other symptoms like chest pain, abnormal breathing, abdominal issues, fatigue, headache, and cognitive symptoms. CONCLUSION: Omega-3 PUFAs may require re-evaluation as a preventive strategy against adverse mental health outcomes post-COVID-19 in placebo-controlled clinical trials.

The outcomes of same-day discharge following holmium laser enucleation of the prostate (HoLEP) surgeries: our experience during the COVID-19 pandemic.

OBJECTIVE: To describe the outcomes of Same-Day Discharge (SDD) following Holmium Laser Enucleation of the Prostate (HoLEP) in patients during the COVID-19 pandemic. METHODS: A retrospective review of HoLEP surgeries at a single institution between January 2021 and March 2022 was performed. Patient demographic and operative data were collected, and postoperative outcomes were evaluated in terms of safety and efficacy and compared in both groups using a t-test and chi-square test. Logistic regression was also performed to identify factors that correlate with the failure of SDD. RESULTS: A total of 155 patients were identified; 135 patients were successfully discharged on the same day and 20 were admitted (87% SDD rate). Admitted HoLEP patients had a significantly higher median prostate-specific antigen (5.7 vs 3.9 ng/dL, P < 0.001), prostate volume (152.3 vs 100.6 mL, P < 0.001), and enucleated tissue weight (90.3 vs 56.9 g, P = 0.04) compared to the SDD group. The SDD group had a 2.9% (n = 4) readmission rate and a 5.2% (n = 7) Emergency Department (ED) visit rate. There was no significant difference in the rate of postoperative ED visits (P = 0.64), readmissions (P = 0.98), complications, and catheterization time (P = 0.98) between both groups. Preoperative predictors of SDD failure included prostate gland volume > 150 mL (OR = 7.17; CI 2.01-25.67; P < 0.01) and history of antiplatelet/anticoagulation use (OR = 6.59; CI 2.00-21.67; P < 0.01). CONCLUSION: Same-day discharge following HoLEP is a safe and effective approach that can be performed in most patients using a liberal discharge criteria and relying on postoperative findings only.

Elements of cancer immunity and the cancer-immune set point.

Immunotherapy is proving to be an effective therapeutic approach in a variety of cancers. But despite the clinical success of antibodies against the immune regulators CTLA4 and PD-L1/PD-1, only a subset of people exhibit durable responses, suggesting that a broader view of cancer immunity is required. Immunity is influenced by a complex set of tumour, host and environmental factors that govern the strength and timing of the anticancer response. Clinical studies are beginning to define these factors as immune profiles that can predict responses to immunotherapy. In the context of the cancer-immunity cycle, such factors combine to represent the inherent immunological status - or 'cancer-immune set point' - of an individual.

P16INK4a Upregulation Mediated by SIX6 Defines Retinal Ganglion Cell Pathogenesis in Glaucoma.

Glaucoma, a blinding neurodegenerative disease, whose risk factors include elevated intraocular pressure (IOP), age, and genetics, is characterized by accelerated and progressive retinal ganglion cell (RGC) death. Despite decades of research, the mechanism of RGC death in glaucoma is still unknown. Here, we demonstrate that the genetic effect of the SIX6 risk variant (rs33912345, His141Asn) is enhanced by another major POAG risk gene, p16INK4a (cyclin-dependent kinase inhibitor 2A, isoform INK4a). We further show that the upregulation of homozygous SIX6 risk alleles (CC) leads to an increase in p16INK4a expression, with subsequent cellular senescence, as evidenced in a mouse model of elevated IOP and in human POAG eyes. Our data indicate that SIX6 and/or IOP promotes POAG by directly increasing p16INK4a expression, leading to RGC senescence in adult human retinas. Our study provides important insights linking genetic susceptibility to the underlying mechanism of RGC death and provides a unified theory of glaucoma pathogenesis.