Multipotent nestin-positive stem cells reside in the stroma of human eccrine and apocrine sweat glands and can be propagated robustly in vitro.

Human skin harbours multiple different stem cell populations. In contrast to the relatively well-characterized niches of epidermal and hair follicle stem cells, the localization and niches of stem cells in other human skin compartments are as yet insufficiently investigated. Previously, we had shown in a pilot study that human sweat gland stroma contains Nestin-positive stem cells. Isolated sweat gland stroma-derived stem cells (SGSCs) proliferated in vitro and expressed Nestin in 80% of the cells. In this study, we were able to determine the precise localization of Nestin-positive cells in both eccrine and apocrine sweat glands of human axillary skin. We established a reproducible isolation procedure and characterized the spontaneous, long-lasting multipotent differentiation capacity of SGSCs. Thereby, a pronounced ectodermal differentiation was observed. Moreover, the secretion of prominent cytokines demonstrated the immunological potential of SGSCs. The comparison to human adult epidermal stem cells (EpiSCs) and bone marrow stem cells (BMSCs) revealed differences in protein expression and differentiation capacity. Furthermore, we found a coexpression of the stem cell markers Nestin and Iα6 within SGSCs and human sweat gland stroma. In conclusion the initial results of the pilot study were confirmed, indicating that human sweat glands are a new source of unique stem cells with multilineage differentiation potential, high proliferation capacity and remarkable self renewal. With regard to the easy accessibility of skin tissue biopsies, an autologous application of SGSCs in clinical therapies appears promising.

CD44 variant isoforms control experimental autoimmune encephalomyelitis by affecting the lifespan of the pathogenic T cells.

CD44 variant (CD44(v)) isoforms play important roles in the development of autoimmune disorders, including colitis and arthritis, but their role in multiple sclerosis (MS) has been explored only to a limited extent. We determined the functional relevance of CD44(v) isoforms in MS and its animal model, experimental autoimmune encephalomyelitis (EAE). Genetic ablation of CD44(v7) and CD44(v10) isoforms significantly reduced the clinical EAE burden, as well as the number of inflammatory infiltrates. CD44(v7) and CD44(v10) expression on both memory T and antigen-presenting cells, participated in the development of adoptive transfer EAE. Significantly reduced mRNA expression of Th1 signature genes was detected in the brains of CD44(v10-/-) mice compared with those of CD44(WT) mice. Furthermore, forkhead transcription factor 3 (Foxp3), Bcl-2, and inducible nitric oxide synthase (iNOS) levels were reduced in CD44(v10-/-) brains, whereas active caspase-3 was elevated. Brain-infiltrating CD4(hi)CD44(v10+) T cells preceded EAE onset and paralleled disease severity in wild-type but not in CD44(v7-/-) and CD44(v10-/-) mice. CD44(v7) and CD44(v10) expression contributed to EAE by increasing the longevity of autoreactive CD4(hi)panCD44(hi) T cells. Accordingly, the absence of CD44(v7) and CD44(v10) led to increased apoptosis in the inflammatory infiltrates and reduced Th1 responses, resulting in marked disease reduction. Although absent in noninflamed human brains, we detected CD44(v3), CD44(v7), and CD44(v10) isoforms on glial cells and on perivascular infiltrating cells of MS lesions. We conclude that CD44(v7) and CD44(v10), expressed on autoreactive CD4(hi)panCD44(hi) T cells, are critically involved in the pathogenesis of classic EAE by increasing their life span. Targeting these short CD44(v) isoform regions may reduce inflammatory processes and clinical symptoms in MS.

The use of human sweat gland-derived stem cells for enhancing vascularization during dermal regeneration.

Vascularization is a key process in tissue engineering and regeneration and represents one of the most important issues in the field of regenerative medicine. Thus, several strategies to improve vascularization are currently under clinical evaluation. In this study, stem cells derived from human sweat glands were isolated, characterized, seeded in collagen scaffolds, and engrafted in a mouse full skin defect model for dermal regeneration. Results showed that these cells exhibit high proliferation rates and express stem cell and differentiation markers. Moreover, cells responded to angiogenic environments by increasing their migration (P<0.001) and proliferation (P<0.05) capacity and forming capillary-like structures. After seeding in the scaffolds, cells distributed homogeneously, interacting directly with the scaffold, and released bioactive molecules involved in angiogenesis, immune response, and tissue remodeling. In vivo, scaffolds containing cells were used to induce dermal regeneration. Here we have found that the presence of the cells significantly improved vascularization (P<0.001). As autologous sweat gland-derived stem cells are easy to obtain, exhibit a good proliferation capacity, and improve vascularization during dermal regeneration, we suggest that the combined use of sweat gland-derived stem cells and scaffolds for dermal regeneration might improve dermal regeneration in future clinical settings.

Coexpression of CD44 variant isoforms and receptor for hyaluronic acid-mediated motility (RHAMM, CD168) is an International Prognostic Index and C-MYC gene status-independent predictor of poor outcome in diffuse large B-cell lymphomas.

OBJECTIVE: Expression of CD44 variant (v) isoforms substantiates poor prognosis in patients with hematological malignancies. We have previously shown that CD44v6 expression in diffuse large B-cell lymphoma (DLBCL) correlates with advanced disease stage and is predominantly detected in non-germinal center B-cell-like DLBCL subtypes. With the growing number of associated molecules found to form functional complexes with CD44, we analyzed a larger cohort of cyclophosphamide, doxorubicin, vincristine, prednisone, and equivalently treated DLBCL patients to define the prognostic role of such CD44-associated molecules. MATERIALS AND METHODS: Two-hundred and ninety formalin-fixed, paraffin-embedded primary DLBCL tissue samples were analyzed in tissue microarrays. To obtain potential biologically meaningful associations, optimal cutoff values were established by receiver operating characteristic curves. The prognostic significance of every possible multimarker phenotype was also addressed. RESULTS: We showed that coexpression of any of the CD44v with the receptor for hyaluronic acid-mediated motility (RHAMM, CD168) identifies a subgroup of DLBCL patients with a very poor prognosis, independent of the International Prognostic Index. These patients did not show C-MYC translocations or amplifications. CD44v-RHAMM coexpression was most prevalent in non-germinal center DLBCL cases and usually coincided with expression of osteopontin. CONCLUSION: Evaluation of CD44v-RHAMM coexpression may improve the accuracy of DLBCL prognosis and identify a subgroup of patients who will benefit from therapeutic alternatives to cyclophosphamide, doxorubicin, vincristine, and prednisone.

Discovery of herpesviruses in bats.

Seven novel gammaherpesviruses (GHV) and one novel betaherpesvirus were discovered in seven different European bat species (order Chiroptera, family Vespertilionidae) with a pan-herpesvirus PCR assay, targeting the DNA polymerase (DPOL) gene. The sequences of six bat GHV were similarly related to members of the gammaherpesvirus genera Percavirus and Rhadinovirus. The seventh GHV was related to the porcine lymphotropic herpesvirus 1 (genus Macavirus). The betaherpesvirus appeared to be a distant relative of human cytomegalovirus. For three bat GHV a 3.6 kbp locus was amplified and sequenced, spanning part of the glycoprotein B gene and the majority of the DPOL gene. In phylogenetic analysis, the three bat GHV formed a separate clade with similar distance to the Percavirus and Rhadinovirus clades. These novel viruses are the first herpesviruses to be described in bats.

PH-Functional Phosphines with 1,1'-Biphenyl-2,2'-bis(methylene) and 1,1'-Binaphthyl-2,2'-bis(methylene) Backbones.

The first PH-functional phosphines (1, 3, and 5) containing the 1,1'-binaphthyl-2,2'-bis(methylene) or 1,1'-biphenyl-2,2'-bis(methylene) backbone have been obtained by two-phase phosphination of 2,2'-bis(halomethyl)-1,1'-binaphthyls with PH(3) or in a protected-group synthesis using P(SiMe(3))(3) as the starting material. The 4,5-dihydro-3H-dinaphtho[2,1-c:1',2'-e]phosphepine (1) is configurationally stable, as indicated by the inequivalence of the two CH(2) and naphthyl substituents in the (13)C{(1)H} NMR spectra. The X-ray crystal structure of 1.0.5C(6)H(5)CH(3) shows an intracyclic C-P-C angle of 99.5(2) degrees, the interplanar angle of the phosphepine ring system being 67.6(5) degrees. The borane adduct 7 of the secondary phosphine 1 has been employed for the syntheses of atropisomeric mono- and bidentate ligands (8-14) with the bulky 1,1'-binaphthyl moieties. Results of force field calculations on the conformations of 1, 3, and 14 are presented. The ability of these phosphines to form mononuclear and polynuclear complexes with transition-metal centers is discussed. Compound 14 exhibits a large variety of low-energy conformations, and some of them seem to be capable of forming mononuclear transition-metal complexes.

Water-Soluble Phosphines. 6.(1) Tailor-Made Syntheses of Chiral Secondary and Tertiary Phosphines with Sulfonated Aromatic Substituents: Structural and Quantum Chemical Studies.

Chiral water-soluble secondary phosphines (2-6) were obtained by nucleophilic phosphination of FC(6)H(4)-4-SO(3)K (1a), FC(6)H(3)-2,4-(SO(3)K)(2) (1b), and FC(6)H(4)-2-SO(3)K (1c) with RPH(2) (R = Ph, 2,4,6-Me(3)C(6)H(2), 2,4,6-iPr(3)C(6)H(2)) in the superbasic medium DMSO/KOH by employing steric control of substitution at phosphorus by bulky substituents R and sulfonic groups in the ortho position of the aromatic ring systems in 1b or 1c. The secondary phosphines may be deprotonated in DMSO/KOH to give phosphido anions which on reaction with alkyl halides (PhCH(2)Cl, Br(CH(2))(3)Br, and C(12)H(25)Br) yield mono- or bidentate tertiary phosphines (7-10). Ligands of this type are alternatively accessible by nucleophilic arylation of secondary phosphines, e.g. Ph(Me)PH or Ph(H)P(CH(2))(3)P(H)Ph with 1a or 1b, respectively. The crystal structure of the starting material 1b.H(2)O (space group P2(1)/m) has been determined. In the solid state of 1b.H(2)O the individual molecules are interconnected by ionic interactions between the potassium cations and the SO(3)(-) anions. The C-F bond (C(1)-F 1.347(4) Å) is shorter than that in C(6)H(5)F (1.356(4) Å). The unit cell of 7a.0.5H(2)O (space group P&onemacr;), the first structurally characterized chiral phosphine with a sulfonated phenyl substituent, contains the two enantiomers. Due to the asymmetrical substitution at phosphorus the PC(3) skeletons are significantly distorted (P(1)-C(1,11,31) 1.864(10), 1.825(8), 1.841(7) Å). The electronic structure of sulfonated fluorobenzenes FC(6)H(5)(-)(n)()(SO(3)M)(n)() (M = K, NH(4), n = 1-3) is discussed on the basis of quantum chemical calculations. In particular, the reactivity difference toward nucleophilic phosphination within the series is rationalized in terms of steric factors and of the -I effect of the sulfonic groups.