Plasminogenuria is associated with podocyte injury, edema, and kidney dysfunction in incident glomerular disease.

Urinary plasminogen/plasmin, or plasmin (ogen) uria, has been demonstrated in proteinuric patients and exposure of cultured podocytes to plasminogen results in injury via oxidative stress pathways. A causative role for plasmin (ogen) as a "second hit" in kidney disease progression has yet to have been demonstrated in vivo. Additionally, association between plasmin (ogen) uria and kidney function in glomerular diseases remains unclear. We performed comparative studies in a puromycin aminonucleoside (PAN) nephropathy rat model treated with amiloride, an inhibitor of plasminogen activation, and measured changes in plasmin (ogen) uria. In a glomerular disease biorepository cohort (n = 128), we measured time-of-biopsy albuminuria, proteinuria, and plasmin (ogen) uria for correlations with kidney outcomes. In cultured human podocytes, plasminogen treatment was associated with decreased focal adhesion marker expression with rescue by amiloride. Increased glomerular plasmin (ogen) was found in PAN rats and focal segmental glomerulosclerosis (FSGS) patients. PAN nephropathy was associated with increases in plasmin (ogen) uria and proteinuria. Amiloride was protective against PAN-induced glomerular injury, reducing CD36 scavenger receptor expression and oxidative stress. In patients, we found associations between plasmin (ogen) uria and edema status as well as eGFR. Our study demonstrates a role for plasmin (ogen)-induced podocyte injury in the PAN nephropathy model, with amiloride having podocyte-protective properties. In one of the largest glomerular disease cohorts to study plasminogen, we validated previous findings while suggesting a potentially novel relationship between plasmin (ogen) uria and estimated glomerular filtration rate (eGFR). Together, these findings suggest a role for plasmin (ogen) in mediating glomerular injury and as a viable targetable biomarker for podocyte-sparing treatments.

A new face of the HPV epidemic: Oropharyngeal cancer in the elderly.

OBJECTIVES: As the human papillomavirus (HPV) epidemic continues to grow, the number of elderly patients with oropharyngeal squamous cell carcinoma (OPSCC) is rapidly increasing. Despite this observation, this cohort remains understudied. We aimed to understand HPV prevalence and characteristics within this cohort as well as its impact on disease control in elderly patients. METHODS AND MATERIALS: We identified patients aged ≥70 with newly diagnosed, non-metastatic, OPSCC treated with curative intent at our institution from 2007 to 2018. Logistic regression and survival analyses were used for outcome-specific endpoints. RESULTS: In total, 88 patients were identified with a median age of 73 (interquartile range [IQR]: 71-78) and a median Charlson Comorbidity Index of 6 (IQR: 5-7). Eighty-two percent were ECOG 0 or 1 performance. Of note, 70% of the cohort had HPV+ tumors. Fifty-one percent of patients were AJCC 8th edition stage I/II and 49% were stage III/IV. Median follow-up time was 2.5 years (IQR: 0.9-4.7). Eight percent had surgery alone, 27% underwent adjuvant RT, and 64% received definitive RT. Sixty-four percent received concurrent chemotherapy. By both univariate and multivariable analyses, HPV+ status was significantly associated with improved locoregional control (LRC), overall survival (OS), and disease specific survival (DSS). CONCLUSIONS: In our cohort of elderly patients with OPSCC, the majority was HPV+, which was associated with improved clinical outcomes. There are many challenges when managing elderly patients with OPSCC, but as the population ages and the HPV epidemic evolves, these patients should be considered for elderly specific clinical trials.

The role of GDF11 in aging and skeletal muscle, cardiac and bone homeostasis.

GDF11 is a secreted factor in the TGFß family of cytokines. Its nearest neighbor evolutionarily is myostatin, a factor discovered as being a negative regulator of skeletal muscle growth. High profile studies several years ago suggested that GDF11 declines with age, and that restoration of systemic GDF11 to 'youthful' levels is beneficial for several age-related conditions. Particularly surprising was a report that supplementation of GDF11 aided skeletal muscle regeneration, as its homolog, myostatin, has the opposite role. Given this apparent contradiction in functionality, multiple independent labs sought to discern differences between the two factors and better elucidate age-related changes in circulating GDF11, with most failing to reproduce the initial finding of declining GDF11 levels, and, importantly, all subsequent studies examining the effects of GDF11 on skeletal muscle described an inhibitory effect on regeneration - and that higher doses induce skeletal muscle atrophy and cachexia. There have also been several studies examining the effect of GDF11 and/or the downstream ActRII pathway on cardiac function, along with several interesting reports on bone. A review of the GDF11 literature, as it relates in particular to aging and skeletal muscle, cardiac and bone biology, is presented.

Signaling pathways controlling skeletal muscle mass.

The molecular mechanisms underlying skeletal muscle maintenance involve interplay between multiple signaling pathways. Under normal physiological conditions, a network of interconnected signals serves to control and coordinate hypertrophic and atrophic messages, culminating in a delicate balance between muscle protein synthesis and proteolysis. Loss of skeletal muscle mass, termed "atrophy", is a diagnostic feature of cachexia seen in settings of cancer, heart disease, chronic obstructive pulmonary disease, kidney disease, and burns. Cachexia increases the likelihood of death from these already serious diseases. Recent studies have further defined the pathways leading to gain and loss of skeletal muscle as well as the signaling events that induce differentiation and post-injury regeneration, which are also essential for the maintenance of skeletal muscle mass. In this review, we summarize and discuss the relevant recent literature demonstrating these previously undiscovered mediators governing anabolism and catabolism of skeletal muscle.