P16-EXPRESSING SENESCENT CELLS ARE A DOUBLE-EDGED SWORD IN SHAPING IMMUNE RESPONSES WITH AGE

Aging results in the accumulation of senescent cells which can cause dysfunction in many contexts but the effects on immune responses remain unclear. Here, we aimed to probe the effects of clearing senescent cells in aged mice on the immune response to influenza infection. We utilized a powerful p16 trimodality reporter mouse model (p16-3MR): under the control of the p16 promoter, these mice express cassettes encoding luciferase, RFP, and herpesvirus thymidine kinase (HSV-TK). p16 is commonly upregulated in senescent cells so this model allows us to selectively delete those cells by treating with ganciclovir (GCV), which will induce apoptosis in cells expressing HSV-TK. We hypothesized that while p16-expressing senescent cells may exacerbate dysfunctional responses to a primary infection, they may play a protective role in resolving inflammation and fostering memory cell generation. We found that deletion of p16-expressing cells enhanced viral clearance and decreased infiltration of pro-inflammatory flu-specific CD8 T cells during the primary response to infection. Conversely, at 30 days post infection, there were fewer flu-specific CD8 memory T cells and lower amounts of anti-viral antibodies in the lungs of GCV treated mice. We also observed perturbations in memory T cell trafficking in GCV treated mice. Furthermore, GCV treated mice were unable to mount an effective memory response and were unable to control viral load following a heterosubtypic challenge. This suggests that targeting senescent cells may potentiate primary responses while limiting the ability to form durable and protective immune memory with age.

Recruitment Challenges and Strategies for Multimodal Intervention Trials

Determining ways to improve hip fracture recovery in older adults is important, however recruitment of this target population into clinical trials is challenging. Multimodal interventions that target multiple mechanisms of recovery may improve outcomes, but each component presents unique recruitment barriers. While exercise interventions have been shown to be beneficial for hip fracture recovery, offering exercise following completion of conventional physical therapy can be viewed as a burdensome time commitment. Hormone replacement therapy may hold promise for overcoming anabolic resistance, but concern about adverse side effects can also deter participation. STEP-HI is a multisite trial testing whether exercise and testosterone can improve hip fracture recovery in older women. In this talk, recruitment barriers experienced in STEP-HI and strategies employed to overcome these barriers will be discussed. Strategies include: partnering with hospitals, skilled nursing facilities and orthopedic surgeons. providing talks and education materials; and featuring past participant testimonials in recruitment materials.

A multi-center trial of exercise and testosterone therapy in women after hip fracture: Design, methods and impact of the COVID-19 pandemic

BACKGROUND

Up to 75% of hip fracture patients never recover to their pre-fracture functional status. Supervised exercise that includes strength training can improve functional recovery after hip fracture. The role of testosterone replacement for augmenting the effects of exercise in older women after hip fracture is unknown.

METHODS

The Starting Testosterone and Exercise after Hip Injury (STEP-HI) Study is a 6-month Phase 3 multicenter randomized placebo-controlled trial designed to compare supervised exercise (EX) plus 1% testosterone topical gel, with EX plus placebo gel, and with enhanced usual care (EUC). Female hip fracture patients age ≥ 65 years are being recruited from clinical centers across the United States. Participants are community dwelling and enrolled within 24 weeks after surgical repair of the fracture. The EX intervention is a center-based program of progressive resistance training. The EUC group receives a home exercise program and health education. Participants receive dietary counseling, calcium and vitamin D. The primary outcome is the Six Minute Walk Distance. Secondary outcomes include physical performance measures, self-reported function and quality of life, and dual energy x-ray absorptiometry measures of body composition and bone mineral density.

RESULTS

Enrollment, interventions, and follow-up are ongoing. We describe the impact of the coronavirus disease 2019 pandemic on the trial, including modifications made to allow continuation of the interventions and outcome data collection using remote video and audio technology.

CONCLUSIONS

Results from the STEP-HI study are expected to have important clinical and public health implications for management of the growing population of hip fracture patients.

The Prevention of Infections in Older Adults: Vaccination

All living beings are at risk for experiencing infections; humans are no exception. The prestige and credibility of modern medicine is built in large part on achievements in preventing and treating infectious diseases. For most of human history, there was little that could be done to prevent and treat infections. Millions of humans, of all ages, have died from infections; and in some parts of the world, infection-related deaths remain common. Advances in preventing and treating infectious diseases include improved sanitization, sterilization, pasteurization, immunization, and antibiotics. Vaccination has played a major role in the prevention of lethal diseases, such as smallpox, diphtheria, cholera, and influenza. Because of developing or waning immune function, the young and the old are at particularly high risk of experiencing infections. Influenza and pneumonia remain common causes of death in older adults. Influenza, in particular, has the potential to result in premature mortality for all age groups, including those who are older and particularly those who live in congregate settings. Vaccination is important in promoting healthy aging. J Am Geriatr Soc 68:207-214, 2019.

Glutamine and hyperammonemic crises in patients with urea cycle disorders

Blood ammonia and glutamine levels are used as biomarkers of control in patients with urea cycle disorders (UCDs). This study was undertaken to evaluate glutamine variability and utility as a predictor of hyperammonemic crises (HACs) in UCD patients.

METHODS

The relationships between glutamine and ammonia levels and the incidence and timing of HACs were evaluated in over 100 adult and pediatric UCD patients who participated in clinical trials of glycerol phenylbutyrate.

RESULTS

The median (range) intra-subject 24-hour coefficient of variation for glutamine was 15% (8-29%) as compared with 56% (28%-154%) for ammonia, and the correlation coefficient between glutamine and concurrent ammonia levels varied from 0.17 to 0.29. Patients with baseline (fasting) glutamine values >900 μmol/L had higher baseline ammonia levels (mean [SD]: 39.6 [26.2]μmol/L) than patients with baseline glutamine ≤ 900 μmol/L (26.6 [18.0]μmol/L). Glutamine values >900 μmol/L during the study were associated with an approximately 2-fold higher HAC risk (odds ratio [OR]=1.98; p=0.173). However, glutamine lost predictive significance (OR=1.47; p=0.439) when concomitant ammonia was taken into account, whereas the predictive value of baseline ammonia ≥ 1.0 upper limit of normal (ULN) was highly statistically significant (OR=4.96; p=0.013). There was no significant effect of glutamine >900 μmol/L on time to first HAC crisis (hazard ratio [HR]=1.14; p=0.813), but there was a significant effect of baseline ammonia ≥ 1.0 ULN (HR=4.62; p=0.0011).

CONCLUSIONS

The findings in this UCD population suggest that glutamine is a weaker predictor of HACs than ammonia and that the utility of the predictive value of glutamine will need to take into account concurrent ammonia levels.

Influenza infection results in upregulation of inflammatory and atrophy genes in murine skeletal muscle (VIR5P.1146)

Though influenza is a respiratory infection, myalgia is a common symptom and associations with acute myositis and rhabdomyolysis have been noted. It is currently unclear if these symptoms are secondary due to the systemic response or if muscle may contribute to inflammation. Further, the effect of influenza on muscle damage and potential repair is not well established. We aimed to determine the expression level of select myokines, atrophy, and myogenic markers in skeletal muscle during influenza infection. Young C57BL/6 mice were inoculated with Pr8 influenza virus (IN, 500 EID50) and sacrificed 7 or 15 days post infection (DPI) or were uninfected (n=4/group). Gastrocnemius gene expression was analyzed via RT-qPCR. Myostatin, IL4, IL6, IL6 receptor alpha, Ubiquitin B, Ubiquitin C, Foxo1, Atrogin-1, and MuRF-1 gene expression was upregulated 7 DPI indicating increased inflammation, protein degradation, and atrophy. Expression of positive regulators of muscle growth and maintenance (Igf-1, MyoD, and Mef2C) was downregulated at this time as well. At 15 DPI Atrogin-1 and MuRF-1 were downregulated though upregulation of myogenic markers did not occur. Our results indicate influenza infection is associated with muscle-localized inflammation, protein degradation, and atrophy that is resolved by day 15 post infection. It is known that influenza infection in the elderly leads to increased disability and loss of independence; it is likely muscle atrophy is a contributing factor.

Elevated phenylacetic acid levels do not correlate with adverse events in patients with urea cycle disorders or hepatic encephalopathy and can be predicted based on the plasma PAA to PAGN ratio

BACKGROUND

Phenylacetic acid (PAA) is the active moiety in sodium phenylbutyrate (NaPBA) and glycerol phenylbutyrate (GPB, HPN-100). Both are approved for treatment of urea cycle disorders (UCDs) - rare genetic disorders characterized by hyperammonemia. PAA is conjugated with glutamine in the liver to form phenylacetyleglutamine (PAGN), which is excreted in urine. PAA plasma levels ≥ 500 μg/dL have been reported to be associated with reversible neurological adverse events (AEs) in cancer patients receiving PAA intravenously. Therefore, we have investigated the relationship between PAA levels and neurological AEs in patients treated with these PAA pro-drugs as well as approaches to identifying patients most likely to experience high PAA levels.

METHODS

The relationship between nervous system AEs, PAA levels and the ratio of plasma PAA to PAGN were examined in 4683 blood samples taken serially from: [1] healthy adults [2], UCD patients of ≥ 2 months of age, and [3] patients with cirrhosis and hepatic encephalopathy (HE). The plasma ratio of PAA to PAGN was analyzed with respect to its utility in identifying patients at risk of high PAA values.

RESULTS

Only 0.2% (11) of 4683 samples exceeded 500 μg/ml. There was no relationship between neurological AEs and PAA levels in UCD or HE patients, but transient AEs including headache and nausea that correlated with PAA levels were observed in healthy adults. Irrespective of population, a curvilinear relationship was observed between PAA levels and the plasma PAA:PAGN ratio, and a ratio>2.5 (both in μg/mL) in a random blood draw identified patients at risk for PAA levels>500 μg/ml.

CONCLUSIONS

The presence of a relationship between PAA levels and reversible AEs in healthy adults but not in UCD or HE patients may reflect intrinsic differences among the populations and/or metabolic adaptation with continued dosing. The plasma PAA:PAGN ratio is a functional measure of the rate of PAA metabolism and represents a useful dosing biomarker.

Epithelial to mesenchymal transition (EMT) seems to be regulated differently in endometriosis and the endometrium

PURPOSE

Epithelial-mesenchymal transition (EMT) endows cells with migratory and invasive properties, a prerequisite for the establishment of endometriotic lesions. However, the role EMT might play in the pathophysiology of endometriosis is still unknown. Therefore, we examined five recognized markers for EMT in endometrium and endometriosis: E-cadherin, N-cadherin, Twist, Snail and Slug.

METHODS

Immunohistochemistry was used for peritoneal, ovarian and rectovaginal endometriotic lesions (n = 27) and endometrium (n = 13). Reverse transcription polymerase chain reaction was applied to tissue samples and primary cell cultures of endometriotic lesions (n = 9) and endometrium (n = 8).

RESULTS

In endometriosis and endometrium E-cadherin, N-cadherin, Twist, Snail and Slug were expressed on protein and mRNA level. E-cadherin expression was strong in epithelial cells, but single E-cadherin-negative cells were frequently present in endometriosis. In endometriosis N-cadherin, Twist and Snail expression were upregulated in comparison with endometrium. The expression of E- and N-cadherin was inversely correlated, while that of N-cadherin and Twist was positively correlated.

CONCLUSION

This study strongly suggests that EMT may be regulated differently in endometriosis and the endometrium. Future research should further elucidate the regulation of EMT in the endometrium and endometriosis.

Urinary phenylacetylglutamine as dosing biomarker for patients with urea cycle disorders

We have analyzed pharmacokinetic data for glycerol phenylbutyrate (also GT4P or HPN-100) and sodium phenylbutyrate with respect to possible dosing biomarkers in patients with urea cycle disorders (UCD).

STUDY DESIGN

These analyses are based on over 3000 urine and plasma data points from 54 adult and 11 pediatric UCD patients (ages 6-17) who participated in three clinical studies comparing ammonia control and pharmacokinetics during steady state treatment with glycerol phenylbutyrate or sodium phenylbutyrate. All patients received phenylbutyric acid equivalent doses of glycerol phenylbutyrate or sodium phenylbutyrate in a cross over fashion and underwent 24-hour blood samples and urine sampling for phenylbutyric acid, phenylacetic acid and phenylacetylglutamine.

RESULTS

Patients received phenylbutyric acid equivalent doses of glycerol phenylbutyrate ranging from 1.5 to 31.8 g/day and of sodium phenylbutyrate ranging from 1.3 to 31.7 g/day. Plasma metabolite levels varied widely, with average fluctuation indices ranging from 1979% to 5690% for phenylbutyric acid, 843% to 3931% for phenylacetic acid, and 881% to 1434% for phenylacetylglutamine. Mean percent recovery of phenylbutyric acid as urinary phenylacetylglutamine was 66.4 and 69.0 for pediatric patients and 68.7 and 71.4 for adult patients on glycerol phenylbutyrate and sodium phenylbutyrate, respectively. The correlation with dose was strongest for urinary phenylacetylglutamine excretion, either as morning spot urine (r = 0.730, p < 0.001) or as total 24-hour excretion (r = 0.791 p<0.001), followed by plasma phenylacetylglutamine AUC(24-hour), plasma phenylacetic acid AUC(24-hour) and phenylbutyric acid AUC(24-hour). Plasma phenylacetic acid levels in adult and pediatric patients did not show a consistent relationship with either urinary phenylacetylglutamine or ammonia control.

CONCLUSION

The findings are collectively consistent with substantial yet variable pre-systemic (1st pass) conversion of phenylbutyric acid to phenylacetic acid and/or phenylacetylglutamine. The variability of blood metabolite levels during the day, their weaker correlation with dose, the need for multiple blood samples to capture trough and peak, and the inconsistency between phenylacetic acid and urinary phenylacetylglutamine as a marker of waste nitrogen scavenging limit the utility of plasma levels for therapeutic monitoring. By contrast, 24-hour urinary phenylacetylglutamine and morning spot urine phenylacetylglutamine correlate strongly with dose and appear to be clinically useful non-invasive biomarkers for compliance and therapeutic monitoring.

Current Opinion of Obstetricians on the Prescription of Emergency Contraception: A German-American Comparison

Background: There are no current studies on the opinions of obstetricians and gynaecologists in Germany about emergency contraception (or post-coital contraception, morning-after pill). The opinions of a large group of physicians were collected using of a questionnaire and compared with the results of an American survey (n = 1154). Methods: A two-part questionnaire was used - part 1: sociodemographic data, part 2: 4 scenarios to illustrate the possible advantages and disadvantages of free access to emergency contraception as well as 4 indications and situations for which emergency contraception can be prescribed. Results: The response rate was 91.7 % (165/180 questionnaires). 63.9 % (103/161) of the German responding physicians were of the opinion that women with access to emergency contraception experienced unwanted pregnancies less frequently than those without access. Merely 26.2 % of the responding physicians supported the prescription-free availability of emergency contraception in apothecaries. The German-American comparison ultimately revealed only a few major differences, e.g., in answers to the question whether or not access to emergency contraception could reduce the number of unwanted pregnancies (89 vs. 64 %). Conclusions: The high rejection rate of free access to emergency contraception of almost 70 % in our surveyed group supports the current position published by the German Society for Gynaecology and Obstetrics (Deutsche Gesellschaft für Gynäkologie und Geburtshilfe) and the German Professional Union of Gynaecologists (deutscher Berufsverband der Frauenärzte). Since other medical organisations, e.g., WHO, supported the prescription-free access to levonorgestrel formulations as emergency contraception a few years ago, it would be interesting to ask a larger sample of German gynaecologists and obstetricians about their opinions on emergency contraception.

Estrogen and progestogen receptor positive endometriotic lesions and disseminated cells in pelvic sentinel lymph nodes of patients with deep infiltrating rectovaginal endometriosis: a pilot study

BACKGROUND

Deep infiltrating endometriosis (DIE) shows similarities to malignant diseases. A recent study involving DIE patients found endometriosis in mesorectal lymph nodes (LNs) after segmental bowel resection. However, it is unclear whether this observation is a local phenomenon or a sign of systemic disease. Therefore, we conducted a prospective study to investigate the occurrence of endometriosis in pelvic sentinel lymph nodes (SLNs) in patients with DIE.

METHODS

Fourteen patients underwent primary surgery for symptomatic DIE. Combined vaginal laparoscopic-assisted resection of the rectovaginal septum was performed. Dye was injected into the visible/palpable nodule. SLNs were removed from the iliac region. In order to identify endometriotic cells, immunohistochemical analysis of estrogen and progestogen receptors, CD10 and cytokeratin was performed.

RESULTS

In 12 out of 14 patients with DIE, SLNs were detected. The localization of the SLN followed the typical LN spread of the upper vagina. In three patients, we could detect typical endometriotic lesions in the LNs. Ten out of 12 (83.3%) SLNs showed disseminated estrogen and/or progestogen positive cells.

CONCLUSIONS

By using immunohistochemistry, we could demonstrate endometriotic lesions and endometriotic-like cells in pelvic SLNs of patients with DIE suggesting the potential for lymphatic spread of the disease.

[Angiogenesis and endometriose]

Endometriosis is considered a chronic disease of women during their reproductive phase, which resembles many signs of malignancy. So far, therapeutic options for endometriosis-associated pain and infertility are unsatisfactory and often lead to recurrence of disease after termination of treatment. Angiogenesis seems to play an important role in the pathogenesis of endometriosis. The use of angiogenesis inhibitors may add an important new tool to well-established treatment schedules. Therefore, it is very important to thoroughly investigate the role of angiogenesis in endometriosis with respect to the female reproductive system.

[Aromatase inhibitors--theoretical concept and present experiences in the treatment of endometriosis]

The medical treatment of endometriosis needs to be optimized. Therapeutic management strategies of endometriosis-associated pain or recurrent disease is primarily aimed at downregulating the ovarian function or at antagonizing the effect of estrogen in ectopic endometrial implants. In this context, basic research is delivering powerful tools for the possible development of new, specific treatment modalities. Recently, aromatase overexpression has been detected in endometriotic tissue. Aromatase (p450arom) is responsible for conversion of C19 androgens to estrogen in several human tissues. Aromatase activity gives rise to local estrogen biosynthesis, which, in turn, stimulates prostaglandin E(2) production by upregulation of cyclooxygenase-2 (COX-2), thus establishing a positive feedback cycle. Another abnormality in endometriosis, i. e. the deficiency in 17 beta-hydroxysteroiddehydrogenase type-II (17 beta-HSD-Type-II) expression, impairs the inactivation of estradiol to estrone. In contrast to the eutopic endometrium, these molecular aberrations collectively favour accumulation of increasing amounts of local estradiol and prostaglandin E(2) in endometriosis. In several human cell lines, prostaglandin and estrogen concentrations are associated with proliferation, migration, angiogenesis, apoptosis resistance, and even invasiveness. Consequently, aromatase and COX-2 are promising new therapeutic targets. In summary, specific aromatase inhibitors (such as Letrozole, Anastrozol or Exemestan) or selective COX-2 inhibitors (e.g. Celecoxib, Rofecoxib) are of great interest to be studied in clinical trials in premenopausal woman with endometriosis to extend the spectrum of currently available treatment options.

COX-2-Expression in extragenitalen Endometrioseläsionen als neuer Therapieansatz?

OBJECTIVE

Extragenital endometriosis is a rare form of endometriosis. Due to its invasive and metastatic properties it resembles some features of malignant tumours. Cyclooxygenase (COX)-2 is a rate-limiting enzyme in the biosynthesis of prostaglandins and is mainly expressed in inflammatory and malignant processes. In this study we investigated the COX-2 expression in extragenital endometriosis.

MATERIAL AND METHODS

Tissue was obtained of 13 women with rectal and vaginal endometriosis, scar endometriosis and endometriosis of the omentum majus. The COX-2 expression was investigated by immunohistochemistry.

RESULTS

In the glandular epithelium a COX-2 overexpression was found in all cases and in the stroma a weak to moderate COX-2 expression was found in half of the cases. A hormonal therapy at the time of surgery had no influence on the COX-2 expression in extragenital endometriosis.

CONCLUSION

The high COX-2 expression in extragenital endometriosis is believed to be strongly correlated with the pathological abnormalities this of disease.