Examination of telomere lengths in muscle tissue casts doubt on replicative aging as cause of progression in Duchenne muscular dystrophy.

The mean telomere length (TL) of somatic cells indicates their replicative age. In comparison with normal leukocytes (-0.03 kbp/y, 6.2 kbp at 80 y), we found advanced TL shortening in premature aging due to ataxia-telangiectasia or the Nijmegen chromosomal breakage syndrome. Duchenne muscular dystrophy (DMD) has been related to replicative senescence of satellite cells (SCs) caused by increased fiber turnover. Therefore, we determined TLs in DMD muscle. Because the regenerated fiber nuclei are produced by SCs. telomeres of both fiber and SC nuclei should be shortened. In DMD the SC number is increased. We determined that up to the age of 7 y the sum of fiber and SC nuclei should be large enough (73%) for the detection of TL shortening. Normal muscle fibers have negligible turnover rates, and, as expected, we did not find age-related TL shortening (10-83 y, n = 24, 8.3 +/- 0.5 kbp). Surprisingly, there was only slight TL shortening in patient muscles (DMD, 0.3-4.8 y, n = 4, 8.3 +/- 0.7 kbp; 5-7 y, n = 7, 7.9 +/- 0.4 kbp; limb-girdle muscular dystrophy 2C, 13 y, 7.6 kbp; Becker muscular dystrophy, 7 y, 8.5 kbp). Similarly, the peak positions of the telomere blots varied only slightly (DMD, 10.0 +/- 0.9 kbp; normal: 10.7 +/- 0.9 kbp). In accordance with our TL findings we derived less than 4 annual doublings per SC from published histologic data on DMD.

Advanced telomere shortening in respiratory chain disorders.

Cell and tissue damage in respiratory chain disorders have been related to increased production of reactive oxygen species (ROS). We measured telomere lengths in such disorders since ROS have also been implicated with telomere shortening. We investigated whole blood cell DNA of 14 patients with MELAS-related mitochondriopathy and two patients with the LHON-associated G11778A mutation of the mitochondrial genome. The phenotypes were variable and included an unusual case of schizophrenia-like psychosis associated with the A3243G mutation. As compared to healthy controls telomere shortening in the patient group was advanced (P < or = 0.006). We compare this finding with the accelerated telomere shortening in Down's syndrome and in chromosomal breakage syndromes. We discuss possible relations between advanced telomere shortening and selective constraints that act on proliferating cells with respiratory chain dysfunction.

Inhibition of histamine release from human granulocytes by ions of the rare earth elements lanthanum and cerium.

The influence of the ATPase inhibitors, lanthanum or cerium, on histamine release in basophils and mast cells was studied. Both compounds inhibited IgE- or A23187-induced histamine release. To exclude a general inhibition of calcium-dependent reactions in the cell, we tested the influence of these compounds on phagocytosis and superoxide production of neutrophil granulocytes. Phagocytosis of Candida albicans was inhibited partially, superoxide generation, measured by the INT test after stimulation with zymosan or aggregated gamma globulin, was not affected. Because of the inhibitory effect of lanthanum or cerium compounds on membrane ATPase and immunological function of epidermal Langerhans cells we propose that these compounds may be used in the treatment of atopic eczema, where both histamine-releasing mast cells and IgE-bearing Langerhans cell play a pathogenetically important role.

The influence of topical dermatological treatment modalities on epidermal Langerhans cells and contact sensitization in mice.

The influence of the widely used topical dermatological treatment modalities anthralin, coal tar and pyrogallol on surface markers of epidermal Langerhans cells and contact sensitization was studied and compared with that of a PUVA treatment. A common effect of all dermatological therapies tested was inhibition of Langerhans cell ATPase, whereas an effect on MHC class II antigens was found only after PUVA or tar treatment. The induction of contact hypersensitivity was inhibited only by PUVA, and not by the other treatments. These results show that various forms of topical therapy influence surface markers and immunological function of epidermal Langerhans cells differently.

The influence of interferon-gamma and interleukin-4 on IgE production in B lymphocytes of patients with atopic dermatitis. A possible criterion for selection of patients for interferon therapy.

The regulation of IgE production in B lymphocytes of patients with atopic dermatitis by interleukin-4 (IL-4) and interferon-gamma (IFN-gamma) was studied. IL-4 stimulated IgE production in vitro in B-cells of healthy donors and of children with atopic dermatitis, but had only a marginal effect on the high basal level of IgE production by lymphocytes from adult patients with atopic dermatitis. The addition of IFN-gamma prevented in all cases the stimulation of IgE synthesis induced by IL-4. The production of IgG and IgM was differently influenced. These results indicate that the in vitro production of IgE by mononuclear cells from adult patients is more resistant to the regulatory effects of IL-4 and IFN-gamma than is that in B cells of children with atopic dermatitis. We propose that a previous in vitro test of the responsiveness of IgE-producing B cells to IFN-gamma may be used to select patients with atopic dermatitis for treatment with IFN-gamma.

[Effect of treatment with salt from the Dead Sea (Tomesa therapy) on epidermal Langerhans cells--a clinical study]. / Der Einfluss einer Behandlung mit Salz des Toten Meeres (Tomesa-Therapie) auf epidermale Langerhanszellen--Eine klinische Studie.

Among the therapeutical modes of psoriasis, sea-water baths with salts from the Dead Sea in combination with ultraviolet light (Tomesa therapy) play an important part. In a previous paper, we showed that treatment of isolated murine skin with Tomesa salt solutions resulted in an irreversible decrease of ATPase-positive epidermal Langerhans' cells. Our present study is concerned with the treatment of healthy persons and psoriasis patients with baths containing Tomesa salts, which lead to reduced amounts of detectable Langerhans' cells in the epidermis, as well. Baths containing sodium chloride in comparable concentrations, however, were without effect at all. Our findings demonstrate that the antipsoriatic activity of Tomesa therapy is not only due to physical effects but may also be the result of definable pharmacological actions of the salts on skin cells.

Stimulation of the recruitment of epidermal Langerhans cells by splenopentin.

Splenopentin (SP-5: Arg-Lys-Glu-Val-Tyr), a pentapeptide corresponding to the residues 32-36 of the splenic hormone splenin, increases dose-dependently the number of bone marrow colonies (M and GM colonies). Therefore, we tested the stimulatory effect of SP-5 on the recruitment of epidermal Langerhans cells in skin deprived of these cells. A high dose of cyclophosphamide or dexamethasone led to a drastic decrease of LC density in murine skin with slow and incomplete restoration. SP-5 accelerated Langerhans cell recruitment and led to pretreatment levels of Langerhans cell density in the skin. These results indicate that SP-5 may possibly be used to treat disorders (e.g., HIV infection) where impaired Langerhans cell density and function can lead to secondary cutaneous infections.

[The effect of Tomesa therapy on epidermal Langerhans cells in experimental animals]. / Die Wirkung der Tomesa-Therapie auf epidermale Langerhanszellen im Experiment.

In the last years a new therapy of psoriasis was developed, which consists in a treatment with salt solutions, resembling the water of the Dead Sea, and ultraviolet light (Tomesa-therapy). We studied the influence of the used salt on ATPase positive epidermal Langerhans cells in murine ear skin. An irreversible partial reduction of the Langerhans cell ATPase was found after salt treatment of separated epidermis or of full skin preparations. These results may have implications for the optimization and broader application of this therapy.

The effect of PUVA treatment on acid hydrolases in human polymorphonuclear leukocytes.

The activity of intracellular acid hydrolases in polymorphonuclear leukocytes (PMNL) from psoriatic patients and normal control subjects was determined. No significant differences between healthy and psoriatic individuals were detected, but a slight decrease in acid hydrolase activity was found in PMNL of psoriasis patients during PUVA therapy. PUVA treatment of PMNL in vitro at intensities that may be achieved in situ in the epidermis led to intracellular inactivation of acid hydrolases, which was not due to secretion of the enzymes or cell damage. The decrease in PMNL hydrolase activity appeared to be evoked by PUVA-generated reactive oxygen species because reduced glutathione prevented this decrease. The activity of free extracellular acid hydrolases was not affected by PUVA, and the superoxide production of PUVA-treated PMNL was increased. These results suggest that intracellular inactivation of acid hydrolases and possibly other lysosomal enzymes in PMNL or monocytes infiltrating the epidermis may contribute to the antipsoriatic activity of PUVA therapy.

Biochemical and immunological relationships of prostatic and leukocytic acid phosphatases and their subcellular localization.

Human acid phosphatases from various sources were purified by a new rapid procedure including chromatofocusing and gel permeation chromatography on an FPLC system. Isoenzymes 2a and 4 (Mr 105,000 and 76,000, respectively) are the prevalent acid phosphatases in prostate, leukocytes and bone marrow. Additional forms are proteolytic products formed during isolation procedure. The source of elevated acid phosphatase in blood serum in metastasizing prostatic carcinoma can be either prostate itself, the tumour or, more likely, bone marrow cells destroyed during the invasion by the tumour cells. Distribution of isoenzymes is not organ specific. It was found using an antiserum against isoenzyme 4 that immunoreactivity is confined to the specific secretory granules both of prostatic epithelium and leukocytes.