@phdthesis{Hirschmann2020, author = {Hirschmann, Anna}, title = {microRNA-Genexpressionsprofile in Blut-, Haut- und Nervenproben von Patienten mit Polyneuropathien}, doi = {10.25972/OPUS-21701}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-217010}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2020}, abstract = {Die Polyneuropathie (PNP) ist die h{\"a}ufigste St{\"o}rung des peripheren Nervensystems bei Erwachsenen. Die Suche nach der Ursache bleibt in vielen F{\"a}llen erfolglos, ist aber unverzichtbar, da die Therapiewahl von der {\"A}tiologie der Erkrankung abh{\"a}ngt. Geeignete Biomarker k{\"o}nnten die Differentialdiagnose unter Umst{\"a}nden erleichtern. microRNAs (miRNAs) sind in dieser Hinsicht vielversprechend, da in vielen Studien bei Nervende- und regenerationsprozessen sowie in neuropathischen Schmerzmodellen eine Dysregulation beschrieben wurde. In dieser Studie wurde die Expression zweier miRNAs, miR-103a und miR-let-7d, sowie eines Zielmolek{\"u}ls der miR-103a, des Kalziumkanals Cav1,2, in einer großen Kohorte von PNP-Patienten unterschiedlicher {\"A}tiologie in Blut, Haut- und Nervenbiopsien untersucht. Insgesamt wurden 116 Patienten und 22 Kontroll-probanden in die Studie eingeschlossen. Nach der Isolation von RNA aus weißen Blutzellen (WBC), Haut- und Nervenbiopsien folgte die Expressionsbestimmung mittels qRT-PCR. W{\"a}hrend sich jeweils Unterschiede zwischen PNP-Patienten und Kontrollen und zwischen Patienten mit entz{\"u}ndlicher und solchen mit nicht-entz{\"u}ndlicher PNP zeigten, wurden keine Unterschiede in der Expression zwischen den {\"a}tiologischen Subgruppen oder zwischen Patienten mit schmerzhafter und schmerzloser PNP festgestellt. In den Nervenbiopsien der Patientenkohorte ergab sich eine inverse Korrelation der miR-103a und ihrem Zielgen Cacna1c, die darauf hinweisen k{\"o}nnte, dass Cacna1c von der miR-103a negativ reguliert wird. Da in unserer Patientenkohorte keine Unterschiede zwischen den PNP-Subgruppen auftraten, scheint der Einsatz der miR-103a und miR-let-7d als diagnostische Biomarker zur {\"a}tiologischen Einordnung einer PNP nicht gerechtfertigt. Dennoch deuten unsere Ergebnisse auf eine m{\"o}gliche Rolle der untersuchten miRNAs bei Entstehung und Verlauf von PNP hin. F{\"u}r ein tieferes pathophysiologisches Verst{\"a}ndnis der miRNAs vor allem bei entz{\"u}ndlichen Neuropathien, k{\"o}nnte die Untersuchung von weiteren miRNAs und Zielgenen Aufschluss geben.}, subject = {miRNS}, language = {de} } @phdthesis{Karl2017, author = {Karl, Franziska}, title = {The role of miR-21 in the pathophysiology of neuropathic pain using the model of B7-H1 knockout mice}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-156004}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2017}, abstract = {The impact of microRNA (miRNA) as key players in the regulation of immune and neuronal gene expression and their role as master switches in the pathophysiology of neuropathic pain is increasingly recognized. miR-21 is a promising candidate that could be linked to the immune and the nociceptive system. To further investigate the pathophysiological role of miR-21 in neuropathic pain, we assesed mice deficient of B7 homolog 1 (B7-H1 ko), a protein with suppressive effect on inflammatory responses. B7-H1 ko mice and wildtype littermates (WT) of three different age-groups, young (8 weeks), middle-aged (6 months), and old (12 months) received a spared nerve injury (SNI). Thermal withdrawal latencies and mechanical withdrawal thresholds were determined. Further, we investigated anxiety-, depression-like and cognitive behavior. Quantitative real time PCR was used to determine miR-21 relative expression in peripheral nerves, dorsal root ganglia and white blood cells (WBC) at distinct time points after SNI. Na{\"i}ve B7-H1 ko mice showed mechanical hyposensitivity with increasing age. Young and middle-aged B7-H1 ko mice displayed lower mechanical withdrawal thresholds compared to WT mice. From day three after SNI both genotypes developed mechanical and heat hypersensitivity, without intergroup differences. As supported by the results of three behavioral tests, no relevant differences were found for anxiety-like behavior after SNI in B7-H1 ko and WT mice. Also, there was no indication of depression-like behavior after SNI or any effect of SNI on cognition in both genotypes. The injured nerves of B7-H1 ko and WT mice showed higher miR-21 expression and invasion of macrophages and T cells 7 days after SNI without intergroup differences. Perineurial miR-21 inhibitor injection reversed SNI-induced mechanical and heat hypersensitivity in old B7-H1 ko and WT mice. This study reveals that reduced mechanical thresholds and heat withdrawal latencies are associated with miR-21 induction in the tibial and common peroneal nerve after SNI, which can be reversed by perineurial injection of a miR-21 inhibitor. Contrary to expectations, miR-21 expression levels were not higher in B7-H1 ko compared to WT mice. Thus, the B7-H1 ko mouse may be of minor importance for the study of miR-21 related pain. However, these results spot the contribution of miR-21 in the pathophysiology of neuropathic pain and emphasize the crucial role of miRNA in the regulation of neuronal and immune circuits that contribute to neuropathic pain.}, subject = {neuropathic pain}, language = {en} } @article{KarlGriesshammerUeceyleretal.2017, author = {Karl, Franziska and Grießhammer, Anne and {\"U}{\c{c}}eyler, Nurcan and Sommer, Claudia}, title = {Differential Impact of miR-21 on Pain and Associated Affective and Cognitive Behavior after Spared Nerve Injury in B7-H1 ko Mouse}, series = {Frontiers in Molecular Neuroscience}, volume = {10}, journal = {Frontiers in Molecular Neuroscience}, number = {219}, doi = {10.3389/fnmol.2017.00219}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-170722}, year = {2017}, abstract = {MicroRNAs (miRNAs) are increasingly recognized as regulators of immune and neuronal gene expression and are potential master switches in neuropathic pain pathophysiology. miR-21 is a promising candidate that may link the immune and the pain system. To investigate the pathophysiological role of miR-21 in neuropathic pain, we assessed mice deficient of B7 homolog 1 (B7-H1), a major inhibitor of inflammatory responses. In previous studies, an upregulation of miR-21 had been shown in mouse lymphocytes. Young (8 weeks), middle-aged (6 months), and old (12 months) B7-H1 ko mice and wildtype littermates (WT) received a spared nerve injury (SNI). We assessed thermal withdrawal latencies and mechanical withdrawal thresholds. Further, we performed tests for anxiety-like and cognitive behavior. Quantitative real time PCR was used to determine miR-21 relative expression in peripheral nerves, and dorsal root ganglia (DRG) at distinct time points after SNI. We found mechanical hyposensitivity with increasing age of na{\"i}ve B7-H1 ko mice. Young and middle-aged B7-H1 ko mice were more sensitive to mechanical stimuli compared to WT mice (young: p < 0.01, middle-aged: p < 0.05). Both genotypes developed mechanical and heat hypersensitivity (p < 0.05) after SNI, without intergroup differences. No relevant differences were found after SNI in three tests for anxiety like behavior in B7-H1 ko and WT mice. Also, SNI had no effect on cognition. B7-H1 ko and WT mice showed a higher miR-21 expression (p < 0.05) and invasion of macrophages and T cells in the injured nerve 7 days after SNI without intergroup differences. Our study reveals that increased miR-21 expression in peripheral nerves after SNI is associated with reduced mechanical and heat withdrawal thresholds. These results point to a role of miR-21 in the pathophysiology of neuropathic pain, while affective behavior and cognition seem to be spared. Contrary to expectations, B7-H1 ko mice did not show higher miR-21 expression than WT mice, thus, a B7-H1 knockout may be of limited relevance for the study of miR-21 related pain.}, language = {en} }