Josef Schröder

Luminescent Dual Sensors Reveal Extracellular pH-Gradients and Hypoxia on Chronic Wounds That Disrupt Epidermal Repair

Wound repair is a quiescent mechanism to restore barriers in multicellular organisms upon injury. In chronic wounds, however, this program prematurely stalls. It is known that patterns of extracellular signals within the wound fluid are crucial to healing. Extracellular pH (pHe) is precisely regulated and potentially important in signaling within wounds due to its diverse cellular effects. Additionally, sufficient oxygenation is a prerequisite for cell proliferation and protein synthesis during tissue repair. It was, however, impossible to study these parameters in vivo due to the lack of imaging tools. Here, we present luminescent biocompatible sensor foils for dual imaging of pHe and oxygenation in vivo. To visualize pHe and oxygen, we used time-domain dual lifetime referencing (tdDLR) and luminescence lifetime imaging (LLI), respectively. With these dual sensors, we discovered centripetally increasing pHe-gradients on human chronic wound surfaces. In a therapeutic approach, we identify pHe-gradients as pivotal governors of cell proliferation and migration, and show that these pHe-gradients disrupt epidermal barrier repair, thus wound closure. Parallel oxygen imaging also revealed marked hypoxia, albeit with no correlating oxygen partial pressure (pO2)-gradient. This highlights the distinct role of pHe-gradients in perturbed healing. We also found that pHe-gradients on chronic wounds of humans are predominantly generated via centrifugally increasing pHe-regulatory Na+/H+-exchanger-1 (NHE1)-expression. We show that the modification of pHe on chronic wound surfaces poses a promising strategy to improve healing. The study has broad implications for cell science where spatial pHe-variations play key roles, e.g. in tumor growth. Furthermore, the novel dual sensors presented herein can be used to visualize pHe and oxygenation in various biomedical fields.

Cowpox and a cat.

In August, 2001, three people, a boy aged 14 years, awoman aged 20, and a man aged 54, living in neigh-bouring households in Schirnding, Germany, werescratched while playing with a cat. 2 days later, the 20-year-old woman had an itchy nodule, surrounded byerythema, on her right forearm where she had beenscratched. She also had malaise, night sweats, andpainful right axillary lymph nodes. The next day, furtherlesions developed on her right arm and in her left groin.She was admitted to the Department of Dermatology,University of Regensburg. While she was there, thenodule on her forearm increased to 4 2·5 cm (figure)with a necrotic black eschar in the centre with a raisedrim by day 20. The other two people had similar lesions,but these remained localised and neither had anymalaise. The 54-year-old had a history of smallpoxvaccination in childhood. The cat had an ulceratednodule on its right ear.Histopathology of a skin biopsy specimen and electron-microscopy of scab tissue showed vacuolar degenerationof keratinocytes, eosinophilic cytoplasmic inclusions, andbrick-shaped 200 300 nm orthopoxvirus particles.Confluent African green monkey kidney MA 104 cells(ATCC No. CRL-2378) were used for propagation ofviruses, and extracted DNA was subjected to PCR withprimers targeting the vaccinia virus gene of the 14 kDaprotein (A27L) and the acidophilic inclusion protein gene(A-type inclusion body, ATI).

Proteomic Profiling Implies Mitochondrial Dysfunction in Tachycardia-Induced Heart Failure

BACKGROUND/OBJECTIVES Molecular mechanisms of congestive heart failure as reflected by alterations of protein expression patterns are still incompletely analyzed. We therefore investigated intraventricular (ie, left ventricular congestive heart failure [LV-CHF] vs. LV-control [CTRL], and right ventricular [RV]-CHF vs. RV-CTRL) and interventricular (ie, LV-CHF vs. RV-CHF, and LV-CTRL vs. RV-CTRL) protein expression differences in an animal model. METHODS The model of rapid ventricular pacing in rabbits was combined with a proteomic approach using 2-dimensional gel electrophoresis. Identification of proteins was done by matrix-assisted laser desorption/ionization-tandem mass spectrometry (MALDI-MS/MS). RESULTS Rapid ventricular pacing-induced heart failure was characterized by LV dilatation, dysfunction, and hypotension as well as by increased BNP gene expression. By comparing LV-CHF vs. LV-CTRL, proteins were found to be underexpressed at 3 crucial points of cellular energy metabolism. In RV-CHF vs. RV-CTRL, proteins belonging to respiratory chain complexes were underexpressed, but additionally a disturbance in the nitric oxide-generating enzymatic apparatus was seen. Regarding the interventricular analyses, a stronger expression of energetic pathways was accompanied by an underexpression of contractile and stress response proteins in failing left vs. right ventricles. Finally, significant protein expression differences were found in LV-CTRL vs. RV-CTRL reflecting a higher expression of contractile, stress response, and respiratory chain proteins in LV tissue. CONCLUSIONS In tachycardia-induced heart failure, significant inter- and intraventricular protein expression patterns were found with a predominance of proteins, which are involved in cellular energy metabolism.

Interatrial differences of basal molecular set-up and changes in tachycardia-induced heart failure–a proteomic profiling study

Left and right atria show compelling differences regarding organogenesis and specific clinical diseases. In congestive heart failure (CHF), remodelling of the atria occurs leading to increased arrhythmogenic susceptibility and deterioration of clinical symptoms. We aimed to assess the basal left and right atrial molecular set‐up and different chamber‐specific atrial changes in heart failure.

Familial primary localized cutaneous amyloidosis with an oncostatin M receptor‐β mutation, Pro694Leu

F. Brehmer, C. S. Seitz, A. Schwarz, C. Engelke, H. A. Haenssle, M. P. Sch€ on, and S. Emmert Department of Dermatology, Venereology and Allergology G€ottingen, Germany and Department of Diagnostic and Interventional Radiology, Georg August University, Robert-Koch-Strasse, 40, D 37075, Göttingen, Germany E-mail: semmert@gwdg.de Conflict of interest: none declared. Accepted for publication 31 January 2013

Minozyklin-induzierte Hyperpigmentierung

ZusammenfassungEine wohlbekannte Nebenwirkung von Minozyklin sind Hyperpigmentierungen der Haut. Wir stellen 2 Patienten im Alter von 49 und 54 Jahren vor, bei denen es nach Einnahme von Minozyklin zum Auftreten von Hyperpigmentierungen an den Unterschenkeln bzw. im Gesicht gekommen ist. Der 54jährige Patient hatte über 3 Jahre lang wegen einer Lungensilikose prophylaktisch Minozyklin eingenommen, bevor im Gesicht symptomlose schwärzliche Flecken auftraten. Bei dem anderen Patienten kam es nach nur 6-monatiger Einnahme von Minozyklin wegen einer Follikulitis zum Auftreten von grauschwarzen Flecken an beiden Unterschenkeln. Eine Probebehandlung mit dem Rubinlaser führte bei diesem Patienten zu einer Rückbildung der Pigmentierung im behandelten Areal. Die verschiedenen klinischen und histologischen Formen der Minozyklin-induzierten Hyperpigmentierung werden anhand der Fallbeispiele besprochen.SummaryA common adverse effect of minocycline therapy is cutaneous pigmentation. We describe two patients who presented with hyperpigmentation caused by minocycline. One patient, aged 54 years, had taken minocycline due to lung silicosis for 3 years before black pigmentation of the face occurred. The other 49 year-old patient developed grey-black hyperpigmentation on both lower legs after a 6-month therapy with minocycline for folliculitis. This patient was treated with the Q-switched ruby laser and the pigmentation resolved in the treated area. The different clinical and histological forms of minocycline-induced hyperpigmentation are discussed.

Combined Inhibition of the Renin-Angiotensin System and Neprilysin Positively Influences Complex Mitochondrial Adaptations in Progressive Experimental Heart Failure

Background Inhibitors of the renin angiotensin system and neprilysin (RAS-/NEP-inhibitors) proved to be extraordinarily beneficial in systolic heart failure. Furthermore, compelling evidence exists that impaired mitochondrial pathways are causatively involved in progressive left ventricular (LV) dysfunction. Consequently, we aimed to assess whether RAS-/NEP-inhibition can attenuate mitochondrial adaptations in experimental heart failure (HF). Methods and Results By progressive right ventricular pacing, distinct HF stages were induced in 15 rabbits, and 6 animals served as controls (CTRL). Six animals with manifest HF (CHF) were treated with the RAS-/NEP-inhibitor omapatrilat. Echocardiographic studies and invasive blood pressure measurements were undertaken during HF progression. Mitochondria were isolated from LV tissue, respectively, and further worked up for proteomic analysis using the SWATH technique. Enzymatic activities of citrate synthase and the electron transfer chain (ETC) complexes I, II, and IV were assessed. Ultrastructural analyses were performed by transmission electron microscopy. During progression to overt HF, intricate expression changes were mainly detected for proteins belonging to the tricarboxylic acid cycle, glucose and fat metabolism, and the ETC complexes, even though ETC complex I, II, or IV enzymatic activities were not significantly influenced. Treatment with a RAS-/NEP-inhibitor then reversed some maladaptive metabolic adaptations, positively influenced the decline of citrate synthase activity, and altered the composition of each respiratory chain complex, even though this was again not accompanied by altered ETC complex enzymatic activities. Finally, ultrastructural evidence pointed to a reduction of autophagolytic and degenerative processes with omapatrilat-treatment. Conclusions This study describes complex adaptations of the mitochondrial proteome in experimental tachycardia-induced heart failure and shows that a combined RAS-/NEP-inhibition can beneficially influence mitochondrial key pathways.

Nodular Cutaneous Amyloidosis Resembling a Giant Tumor.

A 79-year-old man presented with a large tumor on the left side of his head, which had grown over 5 years. Regional lymph nodes were impalpable and computed tomography revealed no signs of bone infiltration. Histology showed that the entire dermis was filled with amorphous eosinophilic material. Immunohistochemistry was negative for cytokeratin, but showed that the dermis and parts of the subcutis were filled with amyloid consisting of immunoglobulin light chains. There were no signs of paraproteinemia or underlying plasmocytoma. In electron microscopy, the typical amyloid fibrils were found. The tumor was completely removed via curettage. At 1-year follow-up, the patient was doing fine with no signs of relapse or systemic disease.

Nodular Cutaneous Amyloidosis at the Temple

A 52-year-old woman presented with a large partially yellow and erythematous tumor on her right temple. She reported that it had grown over the last 4 years. Regional lymph nodes were impalpable. A punch biopsy showed eosinophilic material in the dermis and subcutis. Immunohistochemistry showed positive staining for kappa and lambda light chains. Electron microscopy showed the typical amyloid fibrils (7–10 nm in diameter). There was no evidence of systemic amyloidosis, paraproteinemia or underlying plasmacytoma. The tumor was completely removed via curettage. At follow-up, the patient presented in good health with no signs of relapse.

Erythrodermia Congenitalis Ichthyosiformis Bullosa of Brocq

A 50-year-old man presented with congenital scaling and hyperkeratosis on his palms, the soles of his feet and the extensor areas of his joints. The flexural areas were unaffected. His maternal grandmother, questionably his maternal uncle, his mother, all three brothers, one of his two sisters as well as two nephews and three nieces have or had similar skin changes. A punch biopsy was taken from the left palm. Clinical and histological signs led to the diagnosis of erythrodermia congenitalis ichthyosiformis bullosa of Brocq. We confirmed this genetically and found a heterozygous duplication (c.1752dupT) in the keratin 1 gene (KRT-1). To our knowledge, this is the first case of this skin condition reported in the literature with a heterozygous duplication (c.1752dupT) in KRT-1.