Self-Reported Sexual Behavior of Transgender Youth.

INTRODUCTION: Research indicates that transgender/gender diverse (TGD) youth are more likely to engage in sexual behavior, have more sexual partners, and initiate sexual behavior earlier than their cisgender peers. However, no gender-inclusive self-report survey questionnaires (ie, those that do not assume the gender of sexual partners or body parts used for sex) exist to assess the sexual behavior of TGD youth. The current study illustrates a questionnaire with nuanced wording to more accurately portray the sexual behavior of TGD youth presenting for gender-affirming medical care compared with national adolescent norms. METHODS: A retrospective chart review was conducted of 323 youth, ages 13-18, presenting to a pediatric gender clinic between 2015 and 2021. The youth self-reported their gender identity (ie, masculine, feminine, gender queer, questioning/unsure), sexual behaviors, and partners via a REDCAP survey. RESULTS: Rates of dating among TGD youth were significantly lower than national norms (33.7% vs 68.3%; χ2= 172.644, P < .0001), as was sexual behavior (14.9% vs. 39.5% χ2= 80.419, P < .0001). Rates of self-reported involuntary sexual activity among TGD youth did not differ significantly from national norms (7.1% vs. 6.9%, ns). The body parts used for sex, the number of sexual partners, and the gender identity of sexual partners are reported. DISCUSSION: The results suggest that rates of dating and sexual behavior among TGD youth are significantly lower than national norms, supporting a need for screening of sexual health among TGD youth utilizing gender-inclusive measures. A standardized gender-inclusive questionnaire of sexual behavior is needed to improve data accuracy and help develop inclusive programs to address the sexual health needs of TGD youth.

Distinct molecular mechanisms contribute to the reduction of melanoma growth and tumor pain after systemic and local depletion of alpha-Synuclein in mice.

Epidemiological studies show a coincidence between Parkinson's disease (PD) and malignant melanoma. It has been suggested that this relationship is due, at least in part, to modulation of alpha-Synuclein (αSyn/Snca). αSyn oligomers accumulate in PD, which triggers typical PD symptoms, and in malignant melanoma, which increases the proliferation of tumor cells. In addition, αSyn contributes to non-motor symptoms of PD, including pain. In this study, we investigated the role of αSyn in melanoma growth and melanoma-induced pain in a mouse model using systemic and local depletion of αSyn. B16BL6 wild-type as well as αSyn knock-down melanoma cells were inoculated into the paws of αSyn knock-out mice and wild-type mice, respectively. Tumor growth and tumor-induced pain hypersensitivity were assessed over a period of 21 days. Molecular mechanisms were analyzed by RT-PCR and Western Blot in tumors, spinal cord, and sciatic nerve. Our results indicate that both global and local ablation of Snca contribute to reduced tumor growth and to a reduction of tumor-induced mechanical allodynia, though mechanisms contributing to these effects differ. While injection of wild-type cells in Snca knock-out mice strongly increased the immune response in the tumor, local Snca knock-down decreased autophagy mechanisms and the inflammatory reaction in the tumor. In conclusion, a knockdown of αSyn might constitute a promising approach to inhibiting the progression of melanoma and reducing tumor-induced pain.

Body Mass Index Categories of Transgender and Gender Diverse Youth: Clinical Associations and Predictors.

Background: Transgender/gender diverse (TGD) youth are at risk for weight-related problems. We describe factors associated with their body mass index (BMI) category. Methods: Chart review of 228 TGD patients, 12-20 years (u = 15.7, standard deviation 1.3), 72% female assigned at birth. BMI percentile was calculated using CDC growth charts. We examined bivariate relationships of 18 clinically derived factors, utilizing analysis of variance (ANOVA) for continuous variables and chi-squared/Fisher's exact test for categorical variables. Nonparametric Classification and Regression Tree (CART) analyses were used to predict BMI category. Results: Almost half (49.6%) of TGD youth presenting for their initial visit for pediatric gender-affirming care fell in the healthy weight range, 4.4% in the underweight range, 16.7% in the overweight range, and 29.4% in the obese range. Self-described weight, weight management intentions, unhealthy weight management, prescription of psychiatric medications, and medications associated with weight gain were associated with BMI category. Use of psychiatric medications (54.8%) and medications associated with weight gain (39.5%) was associated with BMI in the overweight/obese categories. Youth with obesity most often reported unhealthy weight management. In CART models, self-described weight was the strongest predictor of BMI category. Conclusion: TGD youth have high rates of underweight and overweight/obesity. Unhealthy BMI should be treated as part of gender-affirming care. Self-described body weight is associated with weight category. More than half of TGD youth were prescribed psychiatric medications; those with overweight and obesity were more likely prescribed psychiatric and medications with associated weight gain. Youth with obesity were most likely to use unhealthy weight management.

The Role of AlphαSynuclein in Mouse Models of Acute, Inflammatory and Neuropathic Pain.

(1) AlphαSynuclein (αSyn) is a synaptic protein which is expressed in the nervous system and has been linked to neurodegenerative diseases, in particular Parkinson's disease (PD). Symptoms of PD are mainly due to overexpression and aggregation of αSyn and include pain. However, the interconnection of αSyn and pain has not been clarified so far. (2) We investigated the potential effects of a αSyn knock-out on the nociceptive behaviour in mouse models of acute, inflammatory and neuropathic pain. Furthermore, we assessed the impact of αSyn deletion on pain-related cellular and molecular mechanisms in the spinal cord in these models. (3) Our results showed a reduction of acute cold nociception in αSyn knock-out mice while responses to acute heat and mechanical noxious stimulation were similar in wild type and knock-out mice. Inflammatory nociception was not affected by αSyn knock-out which is also mirrored by unaltered inflammatory gene expression. In contrast, in the SNI model of neuropathic pain, αSyn knock-out mice showed decreased mechanical allodynia as compared to wild type mice. This effect was associated with reduced proinflammatory mechanisms and suppressed activation of MAP kinase signalling in the spinal cord while endogenous antinociceptive mechanisms are not inhibited. (4) Our data indicate that αSyn plays a role in neuropathy and its inhibition might be useful to ameliorate pain symptoms after nerve injury.

Weight Status, Medication Use, and Recreational Activities of Treatment-Naïve Transgender Youth.

Background: Studies of transgender/gender diverse (TGD) youth indicate a high prevalence of overweight/obesity and concern for unhealthy weight management behavior. This study describes the association of weight status with medication use and recreational activities among treatment-naïve, pediatric TGD patients. Methods: This study is a chart review of 277 patients [aged 9-18 years, 79.1% female sex assigned at birth (SAB), and 86.3% white] seen at a medical center from 2017 to 2020. BMI was calculated by age and SAB using CDC growth charts. BMI percentile (BMI%) and BMI z-score (BMIz) were used to define weight status. Results: By BMI% category, 3.6% patients were in the underweight range (BMI <5%); 50.5% had BMI >85%; and 30.3% had BMI >95%. Overweight and obesity rates were higher than national norms (χ2 = 15.152, p < 0.01). Female SAB participants had higher BMIz values than male SAB participants. Youth who reported watching/listening to media (t = 3.50, p < 0.01) and parent-reported creative arts involvement (t = 1.97, p = 0.05) were associated with higher BMIz values. Conversely, spending time with friends and family was associated with a lower BMIz. Over half of the patients were prescribed medications, and those patients taking medications had higher BMIz values than those not taking medications (t = -1.96, p < 0.05). Female SAB, involvement in sedentary recreational activities, and taking medications to treat gastrointestinal conditions were associated with elevated BMIz. Conclusions: Overweight/obesity is a common problem among TGD youth. TGD youth should be considered a high-risk group and targeted in obesity prevention and treatment efforts. Interventions to decrease sedentary activities and improve connections with friends and family are promising strategies to address overweight and obesity among TGD youth.

Gender dysphoria in adolescents with Ehlers-Danlos syndrome.

Objectives: Ehlers-Danlos Syndrome represents a family of heritable connective tissue disorders that include joint hypermobility, tissue fragility, and skin hyperextensibility. Ehlers-Danlos Syndrome presents with clinical sequela across multiple body systems that require multidisciplinary care. Little is known about adolescents with Ehlers-Danlos Syndrome who are transgender and gender diverse. To date, there have been no reports of transgender and gender diverse youth in pediatric patients with Ehlers-Danlos Syndrome. The objective of this study was to characterize transgender and gender diverse adolescents with Ehlers-Danlos Syndrome seen in a pediatric multidisciplinary specialty clinic. Methods: A retrospective chart review was performed and it was found that 28 patients were seen in the Ehlers-Danlos Syndrome multidisciplinary clinic were reported being transgender and gender diverse. Chart review included analysis of all documents in the electronic medical record, including demographic data, gender identity, chosen pronouns, specialty care previously received for Ehlers-Danlos Syndrome, symptoms and conditions related to it, and medications. Results: Of the 166 total adolescents seen in the pediatric multidisciplinary Ehlers-Danlos Syndrome clinic during the study period, 17% reported gender dysphoria. The average age at Ehlers-Danlos Syndrome diagnosis was 13.5 years (range 8-17 years). Most (61%) reported their gender identity as transgender, followed by nonbinary (14%). Most had preferred male (he/him) pronouns (47%), followed by nonbinary (they/them) pronouns (39%). The vast majority reported fatigue (75%), musculoskeletal issues (96%), psychiatric issues (86%), cardiac issues (71%), gastrointestinal issues (68%), and neurologic issues (79%). Conclusions: Here we report the first cohort of transgender and gender diverse adolescents in the Ehlers-Danlos syndrome population and show an association between the two. This report increases awareness for providers who care for patients with Ehlers-Danlos Syndrome. As care for those with Ehlers-Danlos Syndrome is often complex and multidisciplinary, providers should adopt practices of gender-affirming medical care that contribute to improved care and outcomes.

Exercise-Induced Changes in Bioactive Lipids Might Serve as Potential Predictors of Post-Exercise Hypotension. A Pilot Study in Healthy Volunteers.

Post-exercise hypotension (PEH) is the phenomenon of lowered blood pressure after a single bout of exercise. Only a fraction of people develops PEH but its occurrence correlates well with long-term effects of sports on blood pressure. Therefore, PEH has been suggested as a suitable predictor for the effectivity of exercise as therapy in hypertension. Local vascular bioactive lipids might play a potential role in this context. We performed a cross-over clinical pilot study with 18 healthy volunteers to investigate the occurrence of PEH after a single short-term endurance exercise. Furthermore, we investigated the plasma lipid profile with focus on arachidonic acid (AA)-derived metabolites as potential biomarkers of PEH. A single bout of ergometer cycling induced a significant PEH in healthy volunteers with the expected high inter-individual variability. Targeted lipid spectrum analysis revealed significant upregulation of several lipids in the direct post-exercise phase. Among these changes, only 15- hydroxyeicosatetranoic acid (HETE) correlated significantly with the extent of PEH but in an AA-independent manner, suggesting that 15-HETE might act as specific PEH-marker. Our data indicate that specific lipid modulation might facilitate the identification of patients who will benefit from exercise activity in hypertension therapy. However, larger trials including hypertonic patients are necessary to verify the clinical value of this hypothesis.

The Specific IKKε/TBK1 Inhibitor Amlexanox Suppresses Human Melanoma by the Inhibition of Autophagy, NF-κB and MAP Kinase Pathways.

Inhibitor-kappaB kinase epsilon (IKKε) and TANK-binding kinase 1 (TBK1) are non-canonical IκB kinases, both described as contributors to tumor growth and metastasis in different cancer types. Several hints indicate that they are also involved in the pathogenesis of melanoma; however, the impact of their inhibition as a potential therapeutic measure in this "difficult-to-treat" cancer type has not been investigated so far. We assessed IKKε and TBK1 expression in human malignant melanoma cells, primary tumors and the metastasis of melanoma patients. Both kinases were expressed in the primary tumor and in metastasis and showed a significant overexpression in tumor cells in comparison to melanocytes. The pharmacological inhibition of IKKε/TBK1 by the approved drug amlexanox reduced cell proliferation, migration and invasion. Amlexanox did not affect the cell cycle progression nor apoptosis induction but significantly suppressed autophagy in melanoma cells. The analysis of potential functional downstream targets revealed that NF-кB and ERK pathways might be involved in kinase-mediated effects. In an in vivo xenograft model in nude mice, amlexanox treatment significantly reduced tumor growth. In conclusion, amlexanox was able to suppress tumor progression potentially by the inhibition of autophagy as well as NF-кB and MAP kinase pathways and might therefore constitute a promising candidate for melanoma therapy.

Inhibition of the protein kinase IKKepsilon attenuates neuropathic pain in mice.

Inhibitor-kappaB kinase epsilon (IKKε, Ikbke) constitutes an NF-κB activating kinase with high homology to the classical I-κB kinase subunits, IKKα and IKKß. It is expressed in nociceptive neurons in the spinal cord and in dorsal root ganglia (DRG) and involved in inflammatory nociception. Under inflammatory conditions, IKKε deficient mice show significantly less nociceptive behavior in comparison to wild type mice associated with reduced activation of NF-κB and attenuated NF-κB-dependent gene expression. The role of IKKε in neuropathic pain has not been investigated so far. We applied the spared nerve injury (SNI) model of neuropathic pain in mice and found an increased expression of IKKε in the spinal cord, the DRGs and the sciatic nerve after induction of neuropathy. Genetic depletion of IKKε or pharmacological inhibition by amlexanox led to a significant reduction of mechanical hyperalgesia and cold allodynia in comparison to control mice. Transcription factor ELISA indicated that the effects are mediated by reduced activation of NF-κB. Furthermore, immunofluorescence staining, qPCR and Western Blot analyses revealed that the decreased pain-like behavior was associated with a reduced activation of microglia, diminished expression of c-fos as well as a decreased activation of MAP-Kinases. In summary, we conclude that IKKε modulates mechanisms of neuropathic pain by activating NF-κB. The administration of IKKε inhibitors might therefore constitute a new and promising approach for the therapy of neuropathic pain.

From friendfunding to crowdfunding: Relevance of relationships, social media, and platform activities to crowdfunding performance.

Crowdfunding involves raising small amounts of money from a large number of people, typically via the Internet and social networks, to fund a project. Crowdfunding projects are mainly funded by the project creator's relatively small network of family and friends. We argue that mobilizing funders outside this close network positively contributes to the success of a crowdfunding success. To study how project creators seek to attract funding from more distant/potential resources (latent ties) in addition to existing networks (strong and weak ties), we examined usage of social media (Facebook and Twitter) and the crowdfunding platform (website). We analyzed 10 cultural projects hosted on the Dutch crowdfunding platform "Voordekunst." Our results contribute to theorizing on latent tie activation by demonstrating that social media messages and platform updates add economic value to the crowdfunding effort. Our study also explains the moderating effect of these messages on funders of various tie strengths.

AMPK contributes to aerobic exercise-induced antinociception downstream of endocannabinoids.

Physical exercise has been repeatedly associated with decreased nociceptive responses but the underlying mechanisms have still not been fully clarified. In this study, we investigated exercise-induced effects after a single bout of treadmill running on the mouse model of formalin-induced inflammatory nociception. As potential molecular mediators, we focused on endogenous endocannabinoids as well as AMP-activated protein kinase (AMPK). Our results showed that wild type mice display a reduced nociceptive response in the formalin test after treadmill running, while exercise had no effect on inflammatory nociception in AMPKα2 knockout mice. Levels of the endocannabinoid anandamide (AEA) were increased after physical activity in both wild type and AMPKα2 knockout mice, in association with decreased expression of the AEA-hydrolyzing enzyme FAAH and an increased level of the cannabinoid receptor 1 (CB1). Accordingly, treatment of wild type mice with the CB1 inverse agonist AM251 prior to the treadmill running reversed exercise-induced antinociception. However, if mice received AM251 in combination with the AMPK activator 5-amino-1-ß-d-ribofuranosyl-imidazole-4-carboxamide (AICAR), the positive effect of treadmill running on inflammatory nociception was restored, indicating that AMPK affects exercise-induced antinociception downstream of endocannabinoids. This assumption was further supported by cell culture experiments showing AMPK activation after stimulation of neuronal cells with AEA. In conclusion, our data suggest that AMPK is an intermediate effector in endocannabinoid-mediated exercise-induced antinociception. This article is part of the Special Issue entitled "A New Dawn in Cannabinoid Neurobiology".

AMP-activated kinase and the endogenous endocannabinoid system might contribute to antinociceptive effects of prolonged moderate caloric restriction in mice.

Background: Caloric restriction is associated with broad therapeutic potential in various diseases and an increase in health and life span. In this study, we assessed the impact of caloric restriction on acute and inflammatory nociception in mice, which were either fed ad libitum or subjected to caloric restriction with 80% of the daily average for two weeks. Results: The behavioral tests revealed that inflammatory nociception in the formalin test and in zymosan-induced mechanical hypersensitivity were significantly decreased when mice underwent caloric restriction. As potential mediators of the diet-induced antinociception, we assessed genes typically induced by inflammatory stimuli, AMP-activated kinase, and the endocannabinoid system which have all already been associated with nociceptive responses. Zymosan-induced inflammatory markers such as COX-2, TNFα, IL-1ß, and c-fos in the spinal cord were not altered by caloric restriction. In contrast, AMPKα2 knock-out mice showed significant differences in comparison to C57BL/6 mice and their respective wild type littermates by missing the antinociceptive effects after caloric restriction. Endocannabinoid levels of anandamide and 2-arachidonyl glyceroldetermined in serum by LC-MS/MS were not affected by either caloric restriction alone or in combination with zymosan treatment. However, cannabinoid receptor type 1 expression in the spinal cord, which was not altered by caloric restriction in control mice, was significantly increased after caloric restriction in zymosan-induced paw inflammation. Since increased cannabinoid receptor type 1 signaling might influence AMP-activated kinase activity, we analyzed effects of anandamide on AMP-activated kinase in cell culture and observed a significant activation of AMP-activated kinase. Thus, endocannabionoid-induced AMP-activated kinase activation might be involved in antinociceptive effects after caloric restriction. Conclusion: Our data suggest that caloric restriction has an impact on inflammatory nociception which might involve AMP-activated kinase activation and an increased activity of the endogenous endocannabinoid system by caloric restriction-induced cannabinoid receptor type 1 upregulation.

Rab7-a novel redox target that modulates inflammatory pain processing.

Chronic pain is accompanied by production of reactive oxygen species (ROS) in various cells that are important for nociceptive processing. Recent data indicate that ROS can trigger specific redox-dependent signaling processes, but the molecular targets of ROS signaling in the nociceptive system remain largely elusive. Here, we performed a proteome screen for pain-dependent redox regulation using an OxICAT approach, thereby identifying the small GTPase Rab7 as a redox-modified target during inflammatory pain in mice. Prevention of Rab7 oxidation by replacement of the redox-sensing thiols modulates its GTPase activity. Immunofluorescence studies revealed Rab7 expression to be enriched in central terminals of sensory neurons. Knockout mice lacking Rab7 in sensory neurons showed normal responses to noxious thermal and mechanical stimuli; however, their pain behavior during inflammatory pain and in response to ROS donors was reduced. The data suggest that redox-dependent changes in Rab7 activity modulate inflammatory pain sensitivity.

Progranulin overexpression in sensory neurons attenuates neuropathic pain in mice: Role of autophagy.

Peripheral or central nerve injury is a frequent cause of chronic pain and the mechanisms are not fully understood. Using newly generated transgenic mice we show that progranulin overexpression in sensory neurons attenuates neuropathic pain after sciatic nerve injury and accelerates nerve healing. A yeast-2-hybrid screen revealed putative interactions of progranulin with autophagy-related proteins, ATG12 and ATG4b. This was supported by colocalization and proteomic studies showing regulations of ATG13 and ATG4b and other members of the autophagy network, lysosomal proteins and proteins involved in endocytosis. The association of progranulin with the autophagic pathway was functionally confirmed in primary sensory neurons. Autophagy and survival were impaired in progranulin-deficient neurons and improved in progranulin overexpressing neurons. Nerve injury in vivo caused an accumulation of LC3b-EGFP positive bodies in neurons of the dorsal root ganglia and nerves suggesting an impairment of autophagic flux. Overexpression of progranulin in these neurons was associated with a reduction of the stress marker ATF3, fewer protein aggregates in the injured nerve and enhanced stump healing. At the behavioral level, further inhibition of the autophagic flux by hydroxychloroquine intensified cold and heat nociception after sciatic nerve injury and offset the pain protection provided by progranulin. We infer that progranulin may assist in removal of protein waste and thereby helps to resolve neuropathic pain after nerve injury.

The impact of endurance exercise on global and AMPK gene-specific DNA methylation.

Alterations in gene expression as a consequence of physical exercise are frequently described. The mechanism of these regulations might depend on epigenetic changes in global or gene-specific DNA methylation levels. The AMP-activated protein kinase (AMPK) plays a key role in maintenance of energy homeostasis and is activated by increases in the AMP/ATP ratio as occurring in skeletal muscles after sporting activity. To analyze whether exercise has an impact on the methylation status of the AMPK promoter, we determined the AMPK methylation status in human blood samples from patients before and after sporting activity in the context of rehabilitation as well as in skeletal muscles of trained and untrained mice. Further, we examined long interspersed nuclear element 1 (LINE-1) as indicator of global DNA methylation changes. Our results revealed that light sporting activity in mice and humans does not alter global DNA methylation but has an effect on methylation of specific CpG sites in the AMPKα2 gene. These regulations were associated with a reduced AMPKα2 mRNA and protein expression in muscle tissue, pointing at a contribution of the methylation status to AMPK expression. Taken together, these results suggest that exercise influences AMPKα2 gene methylation in human blood and eminently in the skeletal muscle of mice and therefore might repress AMPKα2 gene expression.

The protein kinase IKKepsilon contributes to tumour growth and tumour pain in a melanoma model.

Inhibitor-kappaB kinase epsilon (IKKε) constitutes a non-canonical I-κB kinase, which amongst others modulates NF-κB activity. IKKε and NF-κB have both been described for their role in cell proliferation and their dysregulation has been associated with tumourigenesis and metastasis in multiple cancer types. Accordingly, overexpression and constitutive activation of NF-κB have also been shown in melanoma, however, the role of IKKε in this cancer type has not been investigated so far. Thus, we determined IKKε expression in malignant melanoma cells and we were able to show a significant overexpression of IKKε in tumour cells in comparison to melanocytes. Inhibition of IKKε either by shRNA or the pharmacological inhibitor amlexanox resulted in reduced cell proliferation associated with a cell cycle block in the G1-phase. Functional analysis indicated that NF-κB, Akt1 and MAPK pathways might be involved in the IKKε-mediated effects. In vivo, we applied a mouse melanoma skin cancer model to assess tumour growth and melanoma-associated pain in IKKε knockout mice as well as C57BL/6 mice after inoculation with IKKε-negative cells. In IKKε knockout mice, tumour growth was not altered as compared to IKKε wild type mice. However, melanoma associated pain was strongly suppressed accompanied by a reduced mRNA expression of a number of pain-relevant genes. In contrast, after inoculation of IKKε-depleted tumour cells, the development of melanoma was almost completely prevented. In conclusion, our data suggest that IKKε in the tumour plays an essential role in tumour initiation and progression while IKKε expression in tumour surrounding tissues contributes to melanoma-associated pain.

Needle detachment in a slim and physically active child with insulin pump treatment.

Insulin pump therapy (CSII) is well established in pediatric patients with type 1 diabetes. In childhood diabetes, insulin pump treatment shows considerable advantages such as fewer injections, increased flexibility, fewer hypoglycemic events and lower HbA1c levels. Side effects such as catheter obstruction, technical pump failure, and dermatological complications have been observed, but are rarely reported. The reported patient is a physically very active and slim 10-year-old boy with reduced subcutaneous fatty tissue. After strong muscular activity an accidental rupture of the infusion set and needle detachment occurred in October 2013. X-ray and ultrasound imaging localized the needle in the musculus rectus femoris dexter. The needle was kept in situ and oral antibiotic treatment to prevent inflammatory reaction was prescribed. Repeated ultrasound measurements documented that the needles position had remained unchanged. Steel needle catheters (Sure-T infusion set, 6 mm) positioned in a thin layer of subcutaneous fat tissue of the thigh, combined with intense sports activity can result in a needle rupture and penetration into the muscle. Careful monitoring provides an alternative to surgery and lowers the risk of muscular necrosis. Because of differences in the distribution of subcutaneous fat tissue, an individualized catheter selection is necessary in pump treatment for children and adolescents, requiring a variety of different catheter sets.

Age-Dependent Changes in the Inflammatory Nociceptive Behavior of Mice.

The processing of pain undergoes several changes in aging that affect sensory nociceptive fibers and the endogenous neuronal inhibitory systems. So far, it is not completely clear whether age-induced modifications are associated with an increase or decrease in pain perception. In this study, we assessed the impact of age on inflammatory nociception in mice and the role of the hormonal inhibitory systems in this context. We investigated the nociceptive behavior of 12-month-old versus 6-8-week-old mice in two behavioral models of inflammatory nociception. Levels of TRP channels, and cortisol as well as cortisol targets, were measured by qPCR, ELISA, and Western blot in the differently aged mice. We observed an age-related reduction in nociceptive behavior during inflammation as well as a higher level of cortisol in the spinal cord of aged mice compared to young mice, while TRP channels were not reduced. Among potential cortisol targets, the NF-κB inhibitor protein alpha (IκBα) was increased, which might contribute to inhibition of NF-κB and a decreased expression and activity of the inducible nitric oxide synthase (iNOS). In conclusion, our results reveal a reduced nociceptive response in aged mice, which might be at least partially mediated by an augmented inflammation-induced increase in the hormonal inhibitory system involving cortisol.

AMP-activated protein kinase is activated by non-steroidal anti-inflammatory drugs.

AMP-activated kinase (AMPK) is a cellular energy sensor, which is activated in stages of increased adenosine triphosphate (ATP) consumption. Its activation has been associated with a number of beneficial effects such as decrease of inflammatory processes and inhibition of disease progression of diabetes and obesity. A recent study suggested that salicylate, the active metabolite of the non-steroidal anti-inflammatory drug (NSAID) acetyl-salicylic acid (aspirin), is able to activate AMPK pharmacologically. This observation raised the question whether or not other NSAIDs might also act as AMPK activators and whether this action might contribute to their cyclooxygenase (COX)-independent anti-inflammatory properties. In this study, we investigated mouse and human neuronal cells and liver tissue of mice after treatment with various NSAIDs. Our results showed that the non-selective acidic NSAIDs ibuprofen and diclofenac induced AMPK activation similar to aspirin while the COX-2 selective drug etoricoxib and the non-opioid analgesic paracetamol, both drugs have no acidic structure, failed to activate AMPK. In conclusion, our results revealed that AMPK can be activated by specific non-steroidal anti-inflammatory drugs such as salicylic acid, ibuprofen or diclofenac possibly depending on the acidic structure of the drugs. AMPK might therefore contribute to their antinociceptive and anti-inflammatory properties.