Keratin 1 maintains skin integrity and participates in an inflammatory network in skin through interleukin-18.

Keratin 1 (KRT1) and its heterodimer partner keratin 10 (KRT10) are major constituents of the intermediate filament cytoskeleton in suprabasal epidermis. KRT1 mutations cause epidermolytic ichthyosis in humans, characterized by loss of barrier integrity and recurrent erythema. In search of the largely unknown pathomechanisms and the role of keratins in barrier formation and inflammation control, we show here that Krt1 is crucial for maintenance of skin integrity and participates in an inflammatory network in murine keratinocytes. Absence of Krt1 caused a prenatal increase in interleukin-18 (IL-18) and the S100A8 and S100A9 proteins, accompanied by a barrier defect and perinatal lethality. Depletion of IL-18 partially rescued Krt1(-/-) mice. IL-18 release was keratinocyte-autonomous, KRT1 and caspase-1 dependent, supporting an upstream role of KRT1 in the pathology. Finally, transcriptome profiling revealed a Krt1-mediated gene expression signature similar to atopic eczema and psoriasis, but different from Krt5 deficiency and epidermolysis bullosa simplex. Our data suggest a functional link between KRT1 and human inflammatory skin diseases.

Copper starvation-inducible protein for cytochrome oxidase biogenesis in Bradyrhizobium japonicum.

Microarray analysis of Bradyrhizobium japonicum grown under copper limitation uncovered five genes named pcuABCDE, which are co-transcribed and co-regulated as an operon. The predicted gene products are periplasmic proteins (PcuA, PcuC, and PcuD), a TonB-dependent outer membrane receptor (PcuB), and a cytoplasmic membrane-integral protein (PcuE). Homologs of PcuC and PcuE had been discovered in other bacteria, namely PCu(A)C and YcnJ, where they play a role in cytochrome oxidase biogenesis and copper transport, respectively. Deletion of the pcuABCDE operon led to a pleiotropic phenotype, including defects in the aa(3)-type cytochrome oxidase, symbiotic nitrogen fixation, and anoxic nitrate respiration. Complementation analyses revealed that, under our assay conditions, the tested functions depended only on the pcuC gene and not on pcuA, pcuB, pcuD, or pcuE. The B. japonicum genome harbors a second pcuC-like gene (blr7088), which, however, did not functionally replace the mutated pcuC. The PcuC protein was overexpressed in Escherichia coli, purified to homogeneity, and shown to bind Cu(I) with high affinity in a 1:1 stoichiometry. The replacement of His(79), Met(90), His(113), and Met(115) by alanine perturbed copper binding. This corroborates the previously purported role of this protein as a periplasmic copper chaperone for the formation of the Cu(A) center on the aa(3)-type cytochrome oxidase. In addition, we provide evidence that PcuC and the copper chaperone ScoI are important for the symbiotically essential, Cu(A)-free cbb(3)-type cytochrome oxidase specifically in endosymbiotic bacteroids of soybean root nodules, which could explain the symbiosis-defective phenotype of the pcuC and scoI mutants.

Case management and care expertise as a prevention approach for adults with intellectual disabilities (FaPP-MgB): study protocol for a randomized-controlled trial.

BACKGROUND: Adults with intellectual disabilities have a higher prevalence of unhealthy eating habits, stress, low levels of mobility, and comparable drug consumption as the general population. Consequently, they suffer from several chronic diseases earlier and more often, but there are fewer prevention and health promotion services including this population. The goal of this study is to determine if an advanced practice nursing approach in the community with home visits is an effective way to improve the health status of adults with intellectual disabilities. METHODS: We will conduct a randomized-controlled trial with waiting list design in Hamburg, Germany. Inclusion criteria are diagnosis ICD F70-F79 and exclusion criteria are care level > 3 according to the German Social Code XI or being at the end-of-life. Participants will be block randomized. The intervention consists of advanced practice nurses performing case management, social space analysis, prevention planning, and counseling through four outreach home visits on nutrition, mobility, addiction, and stress. Comparison is usual care. The primary outcome is health status (WHODAS) after 12 months. Secondary outcomes are health-related quality of life (EQ-5D) and resilience (RS-11) after 6 and 12 months. The calculated sample size is 256 with an estimated dropout of 30%. Raters and analysts will be blinded. Analysis will be performed using ANCOVAs. DISCUSSION: By providing case management and utilizing their nursing expertise, advanced practice nurses will provide valuable input and guidance on prevention and health promotion for people with intellectual disabilities. They will close the gap between health and social care, which is prominent in Germany, through cooperation between the existing care sectors. The findings will be disseminated in peer-reviewed journals and presented at national and international conferences. TRIAL REGISTRATION: German Clinical Trials Register, DRKS00028771 , registered 4 July 2022, Universal Trial Number: U1111-1277-0595.

Keratoplasty after mustard gas injury: clinical outcome and histology.

PURPOSE: Ocular injury by mustard gas can lead to severe eye damage with a delayed course. We report the corneal histology and follow-up after keratoplasty in a patient with mustard gas injury. METHODS: The patient presented with recurrent painful corneal inflammation in both eyes not improving under local therapy. Visual acuity impaired to handmovements. A penetrating keratoplasty was performed on the left eye and afterwards an autorotation keratoplasty on the right eye with a later corneal graft. RESULTS: After the operation of the left eye the patient was immediately painfree and the visual acuity improved to 0,4. So far there have been no signs for transplant rejection or inflammation. Histology of the cornea revealed massive stromal necrosis, and signs of chronic inflammation. Despite denervation of the cornea after autorotation keratoplasty the right eye was still painful and became only painfree after corneal transplantation. CONCLUSION: There has been not much experience with corneal transplantation after mustard gas injury and there is a high risk for transplant rejection due to inflammation and vascularisation of the cornea. Successful and painfree healing with keratoplasty seems only possible after complete removal of the necrotic material.

Skin fragility and impaired desmosomal adhesion in mice lacking all keratins.

Keratins perform major structural and regulatory functions in epithelia. Owing to redundancy, their respective contribution to epidermal integrity, adhesion, and cell junction formation has not been addressed in full. Unexpectedly, the constitutive deletion of type II keratins in mice was embryonic lethal ∼ E9.5 without extensive tissue damage. This prompted us to analyze keratin functions in skin where keratins are best characterized. Here, we compare the mosaic and complete deletion of all type II keratins in mouse skin, with distinct consequences on epidermal integrity, adhesion, and organismal survival. Mosaic knockout (KO) mice survived ∼ 12 days while global KO mice died perinatally because of extensive epidermal damage. Coinciding with absence of keratins, epidermal fragility, inflammation, increased epidermal thickness, and increased proliferation were noted in both strains of mice, accompanied by significantly smaller desmosomes. Decreased desmosome size was due to accumulation of desmosomal proteins in the cytoplasm, causing intercellular adhesion defects resulting in intercellular splits. Mixing different ratios of wild-type and KO keratinocytes revealed that ∼ 60% of keratin-expressing cells were sufficient to maintain epithelial sheets under stress. Our data reveal a major contribution of keratins to the maintenance of desmosomal adhesion and epidermal integrity with relevance for the treatment of epidermolysis bullosa simplex and other keratinopathies.

Neuronal functions, feeding behavior, and energy balance in Slc2a3+/- mice.

Homozygous deletion of the gene of the neuronal glucose transporter GLUT3 (Slc2a3) in mice results in embryonic lethality, whereas heterozygotes (Slc2a3+/-) are viable. Here, we describe the characterization of heterozygous mice with regard to neuronal function, glucose homeostasis, and, since GLUT3 might be a component of the neuronal glucose-sensing mechanism, food intake and energy balance. Levels of GLUT3 mRNA and protein in brain were reduced by 50% in Slc2a3+/- mice. Electrographic features examined by electroencephalographic recordings give evidence for slightly but significantly enhanced cerebrocortical activity in Slc2a3+/- mice. In addition, Slc2a3+/- mice were slightly more sensitive to an acoustic startle stimulus (elevated startle amplitude and reduced prepulse inhibition). However, systemic behavioral testing revealed no other functional abnormalities, e.g., in coordination, reflexes, motor abilities, anxiety, learning, and memory. Furthermore, no differences in body weight, blood glucose, and insulin levels were detected between wild-type and Slc2a3+/- littermates. Food intake as monitored randomly or after intracerebroventricular administration of 2-deoxyglucose or d-glucose, or food choice for carbohydrates/fat was not affected in Slc2a3+/- mice. Taken together, our data indicate that, in contrast to Slc2a1, a single allele of Slc2a3 is sufficient for maintenance of neuronal energy supply, motor abilities, learning and memory, and feeding behavior.

Transscleral resection of a ciliary body leiomyoma in a child: case report and review of the literature.

PURPOSE: To present the case of a patient with leiomyoma of the ciliary body and discuss the histological features and treatment of this rare intraocular tumor. METHODS/CASE REPORT: A 13-year-old boy presented with an asymptomatic tumor of the right eye. Visual acuity was 20/20 in both eyes. Ophthalmoscopy revealed an amelanotic, vascularized ciliary body tumor with exudative retinal detachment and partial transillumination. On ultrasound examination the tumor height was 8 mm and a low internal reflectivity was found. T2-weighted MRI scans showed a hypointense and T1-weighted scans a hyperintense intraocular mass with significant Gd-TPA enhancement. On the assumption that the diagnosis was consistent with an amelanotic ciliary body melanoma, a transscleral resection with adjuvant ruthenium-106 brachytherapy was performed. Visual acuity was 20/40 at 6 months after the operation. RESULTS: Routine stains revealed a pleomorphic tumor composed mainly of spindle cells with palisading in some areas and a prominent intercellular fibrillary background. Immunohistochemistry showed positivity for desmin, vimentin and actin. No reactivity with S-100 and HMB-45 was seen. Intracytoplasmatic filaments and micropinocytotic vesicles were detected by transmission electron microscopy. These findings were consistent with the diagnosis of a ciliary body leiomyoma. CONCLUSION: Typical clinical features of leiomyoma include a dome-shaped configuration and translucency, but the final diagnosis can only be confirmed by histology with the aid of immunohistochemistry and electron microscopy. Though rare, leiomyoma should be considered in the differential diagnosis of amelanotic uveal tumors. Transscleral resection is the treatment of choice of anterior uveal leiomyomas, with a fairly good visual prognosis.