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.

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.

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.

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.

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.

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.

TANK-binding kinase 1 (TBK1) modulates inflammatory hyperalgesia by regulating MAP kinases and NF-κB dependent genes.

BACKGROUND: TANK-binding kinase (TBK1) is a non-canonical IκB kinase (IKK) involved in the regulation of type I interferons and of NF-κB signal transduction. It is activated by viral infections and inflammatory mediators and has therefore been associated with viral diseases, obesity, and rheumatoid arthritis. Its role in pain has not been investigated so far. Due to the important roles of NF-κB, classical IκB Kinases and the IKK-related kinase, IKKε, in inflammatory nociception, we hypothesized that TBK1, which is suggested to form a complex with IKKε under certain conditions, might also alter the inflammatory nociceptive response. METHODS: We investigated TBK1 expression and regulation in "pain-relevant" tissues of C57BL/6 mice by immunofluorescence, quantitative PCR, and Western blot analysis. Furthermore, nociceptive responses and the underlying signal transduction pathways were assessed using TBK1(-/-) mice in two models of inflammatory nociception. RESULTS: Our data show that TBK1 is expressed and regulated in the spinal cord after peripheral nociceptive stimulation and that a deletion of TBK1 alleviated the inflammatory hyperalgesia in mice while motor function and acute nociception were not altered. TBK1-mediated effects are at least partially mediated by regulation of NF-κB dependent COX-2 induction but also by alteration of expression of c-fos via modulation of MAP kinases as shown in the spinal cord of mice and in cell culture experiments. CONCLUSION: We suggest that TBK1 exerts pronociceptive effects in inflammatory nociception which are due to both modulation of NF-κB dependent genes and regulation of MAPKs and c-fos. Inhibition of TBK1 might therefore constitute a novel effective tool for analgesic therapy.

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.

LPS inhibits caspase 3-dependent apoptosis in RAW264.7 macrophages induced by the AMPK activator AICAR.

AMP-activated kinase is a cellular energy sensor which is activated in stages of increased ATP consumption. Its activation has been associated with a number of beneficial effects such as decreasing inflammatory processes and the disease progress of diabetes and obesity, respectively. Furthermore, AMPK activation has been linked with induction of cell cycle arrest and apoptosis in cancer and vascular cells, indicating that it might have a therapeutic impact for the treatment of cancer and atherosclerosis. However, the impact of AMPK on the proliferation of macrophages, which also play a key role in the formation of atherosclerotic plaques and in inflammatory processes, has not been focused so far. We have assessed the influence of AICAR- and metformin-induced AMPK activation on cell viability of macrophages with and without inflammatory stimulation, respectively. In cells without inflammatory stimulation, we found a strong induction of caspase 3-dependent apoptosis associated with decreased mTOR levels and increased expression of p21. Interestingly, these effects could be inhibited by co-stimulation with bacterial lipopolysaccharide (LPS) but not by other proinflammatory cytokines suggesting that AICAR induces apoptosis via AMPK in a TLR4-pathway dependent manner. In conclusion, our results revealed that AMPK activation is not only associated with positive effects but might also contribute to risk factors by disturbing important features of macrophages. The fact that LPS is able to restore AMPK-associated apoptosis might indicate an important role of TLR4 agonists in preventing unfavorable cell death of immune cells.

The effect of social health insurance on prenatal care: the case of Ghana.

Many developing countries have introduced social health insurance programs to help address two of the United Nations' millennium development goals-reducing infant mortality and improving maternal health outcomes. By making modern health care more accessible and affordable, policymakers hope that more women will seek prenatal care and thereby improve health outcomes. This paper studies how Ghana's social health insurance program affects prenatal care use and out-of-pocket expenditures, using the two-part model to model prenatal care expenditures. We test whether Ghana's social health insurance improved prenatal care use, reduced out-of-pocket expenditures, and increased the number of prenatal care visits. District-level differences in the timing of implementation provide exogenous variation in access to health insurance, and therefore strong identification. Those with access to social health insurance have a higher probability of receiving care, a higher number of prenatal care visits, and lower out-of-pocket expenditures conditional on spending on care.

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.

The protein kinase IKKε is a potential target for the treatment of inflammatory hyperalgesia.

Inhibitor-κB kinase ε (IKKε) was only recently identified as an enzyme with high homology to the classical I-κB kinase subunits, IKKα and IKKß. Despite this similarity, it is mainly discussed as a repressor of viral infections by modulating type I IFNs. However, in vitro studies also showed that IKKε plays a role in the regulation of NF-κB activity, but the distinct mechanisms of IKKε-mediated NF-κB activation are not clear. Given the paramount role of NF-κB in inflammation, we investigated the regulation and function of IKKε in models of inflammatory hyperalgesia in mice. We found that IKKε was abundantly expressed in nociceptive neurons in the spinal cord and in dorsal root ganglia. IKKε mRNA and protein levels rapidly increased in spinal cord and dorsal root ganglia during hind paw inflammation evoked by injection of zymosan or formalin. IKKε knockout mice showed normal nociceptive responses to acute heat or mechanical stimulation. However, in inflammatory pain models, IKKε-deficient mice exhibited a significantly reduced nociceptive behavior in comparison with wild type mice, indicating that IKKε contributed to the development of inflammatory hyperalgesia. Antinociceptive effects were associated with reduced activation of NF-κB and attenuated NF-κB-dependent induction of cyclooxygenase-2, inducible NO synthase, and metalloproteinase-9. In contrast, IRF-3, which is an important IKKε target in viral infections, was not regulated after inflammatory nociceptive stimulation. Therefore, we concluded that IKKε modulates inflammatory nociceptive sensitivity by activation of NF-κB-dependent gene transcription and may be useful as a therapeutic target in the treatment of inflammatory pain.

Community level risk factors for maternal mortality in Madagascar.

This paper explores the effect of risk and socioeconomic factors on maternal mortality at the community level in Madagascar using a unique, nationwide panel of communes (i.e., counties). Previous work in this area uses individual or cross-country data to study maternal mortality, however, studying maternal mortality at the community level is imperative because this is the level at which most policy is implemented. The results show that longer travel time from the community to the hospital leads to a high level of maternal mortality. The findings suggest that improvement to transportation systems and access to hospitals with surgery rooms are needed to deal with obstetric complications and reduce maternal mortality.

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.

Cofilin phosphorylation is involved in nitric oxide/cGMP-mediated nociception.

There is convincing evidence that nitric oxide (NO), cGMP and cGMP-dependent protein kinase I (PKG-I) are involved in the development of hyperalgesia in response to noxious stimuli. However, downstream target proteins contributing to nociception have not been completely identified so far. Several reports indicate a role of the NO/cGMP/PKG cascade in the regulation of neurite outgrowth which is suggested to be involved in specific mechanisms of nociception. Since neurite outgrowth is strongly dependent on modulation of cytoskeleton proteins we were interested in the impact of PKG-I activation on the actin cytoskeleton and its role in inflammatory hyperalgesia. Therefore we investigated the actin-destabilising protein cofilin and its NO-dependent effects in vitro in primary neuronal cultures as well as in vivo in the zymosan-induced paw inflammation model in rats. In primary neurons from rats, treatment with the PKG-I activator 8-Br-cGMP induced a time-dependent phosphorylation of cofilin and significantly increased neurite outgrowth. Further functional analysis revealed that the underlying signal transduction pathways involve activation of the Rho-GTPases RhoA, Rac1 and Cdc42 and their corresponding downstream targets Rho-kinase (ROCK) and p21-activated kinase (PAK). In vivo, treatment of rats with the NO-synthase inhibitor l-NAME and the ROCK-inhibitor Y-27632, respectively, led to a significant decrease of cofilin phosphorylation in the spinal cord and resulted in antinociceptive effects in a model of inflammatory hyperalgesia. Our results suggest that cofilin represents a downstream target of NO/cGMP/PKG signal transduction in neurons thus indicating that it is involved in NO-mediated nociception.