Immunologic abnormality in NZB/NZW F1 mice. Thymus-independent occurrence of B cell abnormality and requirement for T cells in the development of autoimmune disease, as evidenced by an analysis of the athymic nude individuals

Both NZB nu/+ and NZW nu/+ mice were microbially clean by cesarean section. The (NZB x NZW)F1 hybrid (NZB/W) nu/nu mice and nu/+ littermates were then generated by mating of NZB nu/+ with NZW nu/+mice under specific pathogen-free conditions. The female NZB/W F1 nu/nu mice did not develop autoimmune kidney disease, whereas all of nu/+ female littermates mice exhibited proteinuria and died of renal failure with a 50% survival time of 35 wk. Namely, nude mice had no signs of proteinuria up to the time of their death caused by other diseases rather than glomerulonephritis, and their mean survival time was greater than 45 wk. Nude mice had also no anti-ssDNA antibody in their serum. However, splenic B cells of NZB/W nude mice exhibited hyper-responsiveness to both LPS and B151-TRF2, a T cell-derived polyclonal B cell-stimulation factor, and produced large numbers of Ig-secreting cells and anti-TNP plaque-forming cells as well as anti-ssDNA antibody comparable to the nu/+ littermate mice. Interestingly, thymus-engrafted NZB/W nude mice developed autoimmune disease exemplified by the induction of anti-ssDNA antibody and proteinuria at approximately the same time as their nu/+ littermates. These results indicate that the B cell hyper-responsiveness found in NZB/W mice is apparently determined by the T cell-independent process, and T cells are obligatorily required for the development of autoimmune disease in NZB/W mice.     

Prevention of polydactyly manifestation in Polydactyly Nagoya (Pdn) mice by administration of cytosine arabinoside during pregnancy

Male mice heterozygous for the dominant polydactyly gene Pdn (Polydactyly Nagoya) were crossed with normal or heterozygous females of the same strain. Pregnant females were treated with 5 mg/kg of cytosine arabinoside (Ara-C) on day 12 of gestation. The offspring were removed on day 18 of gestation and examined for external malformations, and the fore- and hindlimbs were examined by means of bone- and cartilage-stained cleared specimens. In +/+ x Pdn/+ matings, Pdn/+ fetuses, bearing preaxial polydactyly of the distal phalangeal type in the hindlimb and deformity of the 1st digit in the forelimb, were obtained in about 50% of the nontreated group. In treated fetuses, however, the incidence of polydactyly and deformity of the 1st digit decreased to 1.4 and 10.1%, respectively. Nontreated Pdn/Pdn fetuses exhibited preaxial polydactyly of the duplicated or triplicated metacarpal/metatarsal type both in the fore- and hindlimbs. In the treated Pdn/Pdn fetuses, the number of preaxial extra digits decreased in both limbs. Some hindlimbs of the treated Pdn/Pdn fetuses exhibited five metatarsals, normally. In the vitally stained specimens at 6 and 24 hours after injection of Ara-C, preaxial marginal necrotic zones (fMI) were observed in almost all of the treated embryos from +/+ x Pdn/+ matings. However, approximately half of the embryos did not exhibit fMI in the nontreated control group at the same stage. Those embryos deficient in fMI were regarded as Pdn/+. These findings indicated that a subteratogenic dose of Ara-C prevented the genetic expression of polydactyly in almost all Pdn/+ and some cases of Pdn/Pdn mice.(ABSTRACT TRUNCATED AT 250 WORDS)     

A comparison of Babesia infections in intact,surgically splenectomised,and congenitally asplenic (Dh/+) mice

Infections with Babesia rodhaini and B. microti were studied in congenitally asplenic (Dh/+) mice, surgically splenectomised mice and intact mice. Mice without spleens were more susceptible to infections than intact mice, but Dh/+ mice were less susceptible than surgically splenectomised mice, indicating that some functional splenic activity had been taken over by other tissues in Dh/+ mice. It is suggested that this functional activity may be mediated by natural killer (NK) cells, and that Dh/+ mice could prove of value in the study of babesiosis in general and NK activity in particular.Male mice were more susceptible to infection than females.     

Characterization of the antioxidant status of the heterozygous manganese superoxide dismutase knockout mouse

The antioxidant status of several tissues (liver, kidney, lung, brain, heart, muscle, stomach, and spleen) from heterozygous manganese superoxide dismutase (MnSOD) mutant mice (Sod2-/+) was characterized. The activity of MnSOD was decreased (30 to 80%) in all tissues examined. The levels of mRNA coding for the major antioxidant enzymes (CuZnSOD, catalase, and glutathione peroxidase) were not significantly altered in liver, kidney, heart, lung, or brain in the Sod2-/+ mice. The activities of the enzymes were not altered in any of these tissues, with the exception of a decrease in glutathione peroxidase activity in muscle in the Sod2-/+ mice compared to the Sod2+/+ mice. Thus, there was no up-regulation of the activities of the major antioxidant enzymes to compensate for the decrease in MnSOD activity. Reduced glutathione levels were 30 to 50% lower in the lung, brain, and muscle of the Sod2-/+ mice compared to the wild-type Sod2+/+ mice. In addition, the ratio of GSH/GSSG was decreased approximately 50% in Sod2-/+ muscle, indicating that the decrease in MnSOD activity in the Sod2-/+ mice results in some degree of oxidative stress in this tissue.     

Variable biotherapeutic effects of Lactobacillus acidophilus isolates on orogastric and systemic candidiasis in immunodeficient mice

Two commercially available isolates of Lactobacillus acidophilus (NCFM and LA-1) were compared for their capacities to protect immunodeficient bg/bg-nu/un and bg/bg-nu/+ mice from candidiasis. L. acidophilus NCFM prolonged survival of adult and neonatal bg/bg-nu/nu mice, inhibited disseminated candidiasis in both mouse strains, suppressed weight loss associated with Candida albicans infection in bg/bg-nu/nu females, but did not decrease the severity or the incidente of orogastric candidiasis in gnotobiotic mice. L. acidophilus LA-1 suppressed numbers of C. albicans in the alimentary tracts of bg/bg-nu/+ mice and reduced the severity of mucosal candidiasis in bg/bg-nu/nuand bg/bg-nu/+ mice; however, L. acidophilus LA-1 did not improve the survival of bg/bg-nu/nu mice after oral challenge (colonization) with C. albicansand it was associated with lethality in gnotobiotic adult female bg/bg-nu/nu mice. These results demonstrate that the two isolates of L. acidophilus differed in their capacity to protect immunodeficient mice from candidiasis.     

Investigation of transplacental transmission of Caryospora bigenetica (Apicomplexa: Eimeriidae) in mice.

Five pairs of female Swiss-Webster mice were caged with 5 males (2 females/1 male). Eight females were inoculated orally with 2.6 x 10(5) Caryospora bigenetica oocysts either 3 days before mating, 3 days after mating (PMD), 9 PMD, or 16 PMD. The remaining 2 females were inoculated orally with Hanks' balanced salt solution and served as controls. One female from each cage delivered naturally at full term and the second female delivered by cesarean section on postmating day 18. The number of offspring per litter ranged from 7 to 12. One female produced a litter of 3 stillborn and 5 liveborn offspring. Seven of 8 female mice exhibited swollen muzzles and footpads 8 days after inoculation. Caryospora bigenetica was identified in tissues of muzzle, tongue, footpad, uterus, and placenta at necropsy. This is the first report of C. bigenetica in uterus and placenta. Clinical signs and tissue infections were not observed in control mice or in any offspring of the 10 female mice. This study presents evidence that C. bigenetica is not transmitted transplacentally.     

Impact of methylenetetrahydrofolate reductase deficiency and low dietary folate on the development of neural tube defects in splotch mice

BACKGROUND: The etiology of neural tube defects (NTDs) is multifactorial, with environmental and genetic determinants. Folate supplementation prevents the majority of NTDs, and a polymorphism in methylenetetrahydrofolate reductase (MTHFR) has become recognized as a genetic risk factor. The mechanisms by which folate affects NTD development are unclear. The Splotch (Sp) mouse is a well-characterized mouse model for studying spontaneous NTDs. To assess the potential interaction between folate metabolism and the Sp mutant in NTD development, we studied mice with both Sp and Mthfr mutations, as well as the interaction between Sp and low dietary folate. METHODS: Wild-type, single Mthfr+/-mutant, single Sp/+mutant, and double mutant (Mthfr+/-, Sp/+) female mice were mated with males of the same genotype. Embryos were examined for NTDs on gestational day (GD) 13.5. To investigate the effects of folate deficiency on Sp mice, Sp/+female mice were fed a control diet (CD), a moderately folic acid-deficient diet (MFADD), or a severely folic acid-deficient diet (SFADD). They were mated with Sp/+males and the embryos were examined. RESULTS: There were no differences in the incidence or severity of NTDs in embryos from double-mutant mating pairs compared to those from single Sp mutants. Embryos from Mthfr+/-dams did not exhibit NTDs. Diets deficient in folate did not influence the incidence or severity of NTDs in embryos from Sp/+mice. CONCLUSIONS: We did not observe an interaction between Sp and Mthfr mutations, or between the Sp mutation and low dietary folate, in NTD development in Splotch mice.     

Fetal effects on sexual behavior and aggression in young and old female mice treated with estrogen and testosterone

During fetal life female mice (Mus musculus) that develop between two male fetuses (2M females) have higher blood concentrations of testosterone than do females that do not develop next to a male fetus (0M females). In the first experiment reported here, sexual receptivity and sexual attractiveness to males were examined in young (5 month old) and old (17 month old) ovariectomized, estrogen- and progesterone-treated 0M and 2M female mice that were placed in like-age pairs with a male. Most males inseminated the 0M female prior to inseminating the 2M female regardless of age. In addition, 0M females were more likely to exhibit lordosis when mounted than were 2M females. When the same young females were 9 months of age and the old females were 21 months of age, they were treated with testosterone and again placed together in pairs along with a sexually receptive female. Young 2M females exhibited more aggression toward the testosterone-treated female partner, and also exhibited more mounting of the receptive female, than did young 0M females. But, both old 0M and old 2M females were highly aggressive and exhibited mounting. An increase in sensitivity to the effects of testosterone on behavior thus occurs during aging in 0M females, which are relatively insensitive to testosterone in young adulthood. In contrast, when treated with estrogen and progesterone, 0M females were more attractive to males and were more sexually receptive than 2M females regardless of age.     

Reduced reproductive performance in androgen-resistant Tfm/Tfm female mice

Androgen-resistant female mice (Tfm/Tfm) homozygous for the mutant gene Tfm were bred by making use of males chimaeric for the Tfm gene. All seven Tfm/Tfm females found were fertile, confirming that a normal level of androgen receptor protein is not essential for reproduction in female mice. However, when five of the seven were studied throughout their reproductive life they proved to have impaired reproductive performance and premature cessation of reproduction. No impairment of reproduction was seen in heterozygous Tfm/+ females. The ovarian histology suggested that in Tfm/Tfm the normal ageing processes were accelerated. This work is consistent with the work of others in that androgen is involved in the control of follicular maturation and atresia, and that the effect is mediated by the androgen receptor coded by the Tfm locus.     

Eliminating the synthesis of mature lamin A reduces disease phenotypes in mice carrying a Hutchinson-Gilford progeria syndrome allele

Hutchinson-Gilford progeria syndrome is caused by the synthesis of a mutant form of prelamin A, which is generally called progerin. Progerin is targeted to the nuclear rim, where it interferes with the integrity of the nuclear lamina, causes misshapen cell nuclei, and leads to multiple aging-like disease phenotypes. We created a gene-targeted allele yielding exclusively progerin (Lmna HG) and found that heterozygous mice (Lmna HG/+) exhibit many phenotypes of progeria. In this study, we tested the hypothesis that the phenotypes elicited by the Lmna HG allele might be modulated by compositional changes in the nuclear lamina. To explore this hypothesis, we bred mice harboring one Lmna HG allele and one Lmna LCO allele (a mutant allele that produces lamin C but no lamin A). We then compared the phenotypes of Lmna HG/LCO mice (which produce progerin and lamin C) with littermate Lmna HG/+ mice (which produce lamin A, lamin C, and progerin). Lmna HG/LCO mice exhibited improved HG/LCO fibroblasts had fewer misshapen nuclei than Lmna HG/+ fibroblasts (p < 0.0001). A likely explanation for these differences was uncovered; the amount of progerin in Lmna HG/LCO fibroblasts and tissues was lower than in Lmna HG/+ fibroblasts and tissues. These studies suggest that compositional changes in the nuclear lamina can influence both the steady-state levels of progerin and the severity of progeria-like disease phenotypes.     

Conditional Expression of the Androgen Receptor Increases Susceptibility of Bladder Cancer in Mice

Bladder cancer represents a significant human tumor burden, accounting for about 7.7% and 2.4% of all cancer cases in males and females, respectively. While men have a higher risk of developing bladder cancer, women tend to present at a later stage of disease and with more aggressive tumors. Previous studies have suggested a promotional role of androgen signaling in enhancing bladder cancer development. To directly assess the role of androgens in bladder tumorigenesis, we have developed a novel transgenic mouse strain, R26hAR^LoxP/+:Upk3a^GCE/+, in which the human AR transgene is conditionally expressed in bladder urothelium. Intriguingly, both male and female R26hAR^LoxP/+:Upk3a^GCE/+ mice display a higher incidence of urothelial cell carcinoma (UCC) than the age and sex matched control littermates in response to the carcinogen, N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN). We detect expression of the human AR transgene in CK5-positive and p63-positive basal cells in bladder urothelium. Further analyses of UCC tissues from R26hAR^LoxP/+:Upk3a^GCE/+ mice showed that the majority of tumor cells are of urothelial basal cell origin. Positive immunostaining of transgenic AR protein was observed in the majority of tumor cells of the transgenic mice, providing a link between transgenic AR expression and oncogenic transformation. We observed an increase in Ki67 positive cells within the UCC lesions of transgenic AR mice. Manipulating endogenous androgen levels by castration and androgen supplementation directly affected bladder tumor development in male and female R26hAR^LoxP/+:Upk3a^GCE/+ mice, respectively. Taken together, our data demonstrate for the first time that conditional activation of transgenic AR expression in bladder urothelium enhances carciongen-induced bladder tumor formation in mice. This new AR transgenic mouse line mimics certain features of human bladder cancer and can be used to study bladder tumorigenesis and for drug development.     

Effects on kidney disease, fertility and development in mice inheriting a protein-truncating Denys-Drash syndrome allele (Wt1 tmT396)

Denys-Drash syndrome (DDS) is caused by heterozygous mutations of the Wilms’ tumour suppressor gene, WT1, characterised by early-onset diffuse mesangial sclerosis often associated with male pseudohermaphroditism and/or Wilms’ tumourigenesis. Previously, we reported that the Wt1 ^tmT396 allele induces DDS kidney disease in mice. In the present study heterozygotes (Wt1 ^tmT396/+) were generated on inbred (129/Ola), crossbred (B6/129) and MF1 second backcross (MF1-N2) backgrounds. Whereas male heterozygotes on each background were fertile, inbred heterozygous females were infertile. Kidney disease (proteinuria and sclerosis) was not congenital and developed significantly earlier in inbred mice, although with variable onset. Disease onset in MF1-N2 stocks occurred later in Wt1 ^tmT396/+ mice than reported previously for Wt1 ^R394W/+ mice, and while no kidney disease has been reported in B6/129 Wt1 ^+/- mice, B6/129 Wt1 ^tmT396/+ mice were affected. Offspring of both male and female B6/129 and MF1-N2 Wt1 ^tmT396/+ mice developed kidney disease, but its incidence was significantly higher in offspring of female heterozygotes. Wt1 ^{tmT396/tmT396} embryos exhibited identical developmental abnormalities to those reported for Wt1 ^-/- embryos. The results indicate that the Wt1 ^tmT396 allele does not predispose to Wilms’ tumourigenesis or male pseudohermaphroditism, its effect on kidney disease and female fertility depends on genetic background, stochastic factors may affect disease onset, and disease transmission is subject to a partial parent-of-origin effect. Since the Wt1 ^tmT396 allele has no detectable intrinsic functional activity in vivo, and kidney disease progression is affected by the type of Wt1 mutation, the data support the view that DDS nephropathy results from a dominant-negative action rather than WT1 haploinsufficiency or gain-of-function.     

Enhancer-independent promoter activity of the mouse alphaB-crystallin/small heat shock protein gene in the lens and cornea of transgenic mice

The alphaB-crystallin/small heat shock protein gene is expressed very highly in the mouse eye lens and to a lesser extent in many other nonocular tissues, including the heart, skeletal muscle and brain. Previously we showed in transgenic mice that lens-specific alphaB-crystallin promoter activity is directed by a proximal promoter fragment (-164/+44) and that non-lens promoter activity depends on an upstream enhancer (-427/-259) composed of at least 5 cis-control elements. Here we have used truncated alphaB-crystallin promoter-CAT transgenes to test by biphasic CAT assays and/or histochemistry for specific expression in the cornea and lens. Deletion either of 87 bp (-427/-340) from the 5' end of the alphaB-crystallin enhancer or of the whole enhancer (-427/-258) abolished alphaB-crystallin promoter activity in all tissues except the lens and corneal epithelium when examined by the biphasic CAT assay in 4-5-week-old transgenic mice. These truncations also lowered promoter strength in the lens. The -426/+44-CAT, -339/+44-CAT and -164/+44-CAT (previously thought to be lens-specific in transgenic mice) transgenes were all expressed in the 4-6-week-old corneal epithelium when examined histochemically. Immunohistochemical staining confirmed the presence of endogenous alphaB-crystallin in the mature corneal epithelial cells. CAT gene expression driven by the alphaB-crystallin promoter with or without the enhancer was evident in the embryonic and 4-6-week-old lens. By contrast, activity of the alphaB-crystallin promoter/enhancer-CAT transgene was not detectable in the corneal epithelium before birth. Taken together, these results indicate that the intact enhancer of the alphaB-crystallin/small heat shock protein gene is required for promoter activity in all tissues tested except the lens and cornea.     

Identifizierung der genetischen Geschlechtschromosomen bei der monogenen Schmeißfliege Chrysomya rufifacies (Calliphoridae,Diptera)

Previous investigations have shown the sex determination in the monogenic blowfly Chrysomya rufifacies to be controlled by a cytologically not discernible homogamety-heterogamety mechanism in the female. Female-producing (thelygenic) females are assumed to be heterozygous for a dominant female sex realizer (F′) with sex-predetermining properties, while male-producing (arrhenogenic) females as well as males are supposed to be homozygous for the recessive allele (f). In order to identify the genetic sex chromosomes of C. rufifacies among its five pairs of long euchromatic chromosomes (nos.1–5) plus one pair of small heterochromatic ones (no. 6), all chromosomes were marked by reciprocal translocations induced by X-ray treatment of adult males. The inheritance of thirteen different heterozygous translocations has been analyzed. All of the translocations (eleven) between two of the four longer chromosomes did not show sex-linked inheritance, thus demonstrating the autosomal character of the chromosomes nos 1, 2, 3 and 4. The same is true for the translocation T6 (2/6). Therefore the small heterochromatic chromosome no. 6, corresponding to the morphologically differentiated sex chromosomes within the amphogenic calliphorid species, remains without sex determining function in the monogenic fly. This could be confirmed by the analysis of monosomic (monosomy-6) and trisomic (trisomy-6) individuals, which resulted from meiotic non-disjunction in T6/+ translocation heterozygotes. Contrary to these translocations, the heterozygous 5/2 translocation (T14) exhibited sex-linked inheritance: There was but a very low frequency (0,76 per cent) of recombinants resulting from crossing-over between F′/f and the translocation breakage point in thelygenic F₁ T14/+ females. The sex-linked inheritance of T14 was confirmed by the progeny of a thelygenic F₁ T14/+ female crossed to a homozygous T14/T14 translocation male. Among the offspring of that F₁ T14/+ female, which had received the translocation from its father, all of the F₂ T14/+ females were thelygenic compared to their arrhenogenic T14/T14 sisters. These results prove that the chromosomes of pair no. 5 genetically act as X′X-XX sex chromosomes in C. rufifacies.     

Effect of IL-12 encoding plasmid administration on tight-skin mouse

The tight-skin (Tsk/+) mutant mice, a putative murine model of scleroderma, are characterized by the excessive deposition of collagen and the presence of antinuclear antibodies. Type 2 cytokines, such as IL-4 and IL-6, are capable of regulating the synthesis of various matrix molecules, including type I collagen, by fibroblasts. IL-12 is well known to induce type 1 cytokine production and to reduce type 2 activity. Here, we examined the effect of IL-12 encoding plasmid (pCAGGSIL-12) on the disease progression of Tsk/+ mice. pCAGGSIL-12 plasmid or pCAGGS parental vector was injected intramuscularly 7 times at 3 week intervals into Tsk/+ mice. One week after the last injection, pCAGGSIL-12 administered Tsk/+ mice exhibited a marked decrease in the skin thickness compared with the mice treated with pCAGGS vector. The serum levels of antinuclear antibodies were diminished in pCAGGSIL-12 treated mice. IL-4 production by spleen cells from pCAGGSIL-12 plasmid treated mice was significantly lower than that from vector treated mice. These results indicate that pCAGGSIL-12 administration into Tsk/+ mice had beneficial effects in preventing the collagen accumulation in the skin and suppressing the autoimmunity via improvement of Th1/Th2 balance. The present study suggests that the IL-12 encoding plasmid administration might have a therapeutic effect on systemic sclerosis.     

Pathology of vaginal atresia in BALB/cA-nu/+ and BALB/cA-nu/nu mice

Vaginal atresia was observed with 5.8% morbidity (58/998 females) in adult BALB/cA-nu/+ and -nu/nu mice. Twenty-seven of the diseased mice were pathologically examined. In the affected mice, the vaginal orifice failed to open even 2 months of age and the perineal region was swollen, being scrotum-like. In addition, an increase of the follicle and a decrease of the corpus luteum were noticed in the ovary. This disorder was regarded as a malformation concerned with a heredity.     

Natural cellular resistance of beige mice against Cryptococcus neoformans

Previous reports have demonstrated that natural killer (NK) cells are capable of inhibiting the growth of Cryptococcus neoformans in vitro, and recent studies indicate that adoptively transferred NK cell-enriched spleen cell populations enhance clearance of cryptococci from the tissues of cyclophosphamide-pretreated recipients. The primary objective of these studies was to confirm that NK cells participate in early clearance of C. neoformans in vivo. Secondarily, the anti-cryptococcal activities of polymorphonuclear leukocytes and macrophages were examined. Seven-week-old C57BL/6 bg/+ mice, which have normal levels of NK cell activity, were compared with their bg/bg littermates, which have impaired NK cell function. One and 3 days after injecting both groups of mice i.v. with 2 X 10(4) cryptococci, we assessed the NK cell activities in spleens, lungs, and livers and clearance of the organism from corresponding tissues as determined by the mean log10 numbers of cryptococcal colony-forming units (CFU) per organ. Three days postinfection, the mean numbers of cryptococcal CFU in lungs and spleens of bg/+ mice were significantly lower than in the corresponding organs of bg/bg mice. NK cell activities in spleens and lungs of bg/+ mice were significantly higher than were the NK cell activities in similar cell populations from bg/bg mice. In contrast, the mean numbers of cryptococcal CFU in livers of the two groups of animals were nearly equivalent, a situation not unexpected, since liver NK cell activities were extremely low and similar in both groups of animals. Although these data indicated a correlation between early clearance of cryptococci from tissues and levels of NK cell activities in the corresponding tissues, it was also possible that differences in phagocytic cell function between the bg/+ and bg/bg animals could account for the observed differences in clearance of cryptococci from the tissues. Therefore, phagocytic cells from the two groups of animals were compared with respect to their abilities to phagocytize and inhibit the growth of cryptococci and to their abilities to respond to chemotactic stimuli in vivo. Peritoneal PMNL from bg/+ and bg/bg mice were similar in their abilities to phagocytize and inhibit the growth of cryptococci, as well as in their chemotactic responses to viable cryptococci or sodium caseinate. In addition, there were no differences in splenic macrophage functions between the two groups of mice.(ABSTRACT TRUNCATED AT 400 WORDS)     

Histochemical studies of 3 beta- and 20alpha-hydroxysteroiddehydrogenase in the adrenals and ovaries of the nu/nu mouse.

Adrenal glands and ovaries of nu/+ and nu/nu female mice were examined histochemically throughout the postnatal life for changes in distribution, intensity and appearance of activities of 3 steroid-converting enzymes. While the 3beta-OH-steroid- and pregnenolone-dehydrogenase did not reveal any difference, the 20alpha-hydroxysteroid-dehydrogenase (20alpha-OH SDH) showed a constant behaviour: the onset of the enzyme activity was detectable in the adrenals of nu/+ mice after the second week of age, in nu/nu mice 3--4 weeks later. The localization of 20alpha-OH-SDH was strictly confined to the zone of small cells, a zone lying between the x-zone and the zona fasciculata. In nu/+ mice, after reached sexual maturity at about 6--8 weeks of age, the enzyme progressively disappeared from the adrenals and simultaneously appeared in the ovaries. In nu/+nu mice, which had been kept separated from mating animals, the 20alpha-OH SDH persisted in adrenals even in adult stages. After pregnancy, both--nu/nu and nu/+, showed 20alpha-OH SDH-activity in ovaries and none in adrenals. In both, the enzyme was localized in involuting corpora lutea, whilst in nu/nu it was also present in the intersitial cells. This study indicates no disturbance in the formation of progesterone, but the process of its degradation, as indicated by 20alpha-OH SDH-activity, is definitely different in nu/+ and nu/nu.     

Hepatocyte growth factor ameliorates dermal sclerosis in the tight-skin mouse model of scleroderma

The tight-skin (TSK/+) mouse, a genetic model of systemic sclerosis (SSc), develops cutaneous fibrosis and defects in pulmonary architecture. Because hepatocyte growth factor (HGF) is an important mitogen and morphogen that contributes to the repair process after tissue injury, we investigated the role of HGF in cutaneous fibrosis and pulmonary architecture defects in SSc using TSK/+ mice. TSK/+ mice were injected in the gluteal muscle with either hemagglutinating virus of Japan (HVJ) liposomes containing 8 mug of a human HGF expression vector (HGF-HVJ liposomes) or a mock vector (untreated control). Gene transfer was repeated once weekly for 8 weeks. The effects of HGF gene transfection on the histopathology and expression of tumor growth factor (TGF)-beta and IL-4 mRNA in TSK/+ mice were examined. The effect of recombinant HGF on IL-4 production by TSK/+ CD4+ T cells stimulated by allogeneic dendritic cells (DCs) in vitro was also examined. Histologic analysis revealed that HGF gene transfection in TSK/+ mice resulted in a marked reduction of hypodermal thickness, including the subcutaneous connective tissue layer. The hypodermal thickness of HGF-treated TSK/+ mice was decreased two-fold to three-fold compared with untreated TSK/+ mice. However, TSK/+ associated defects in pulmonary architecture were unaffected by HGF gene transfection. HGF gene transfection significantly inhibited the expression of IL-4 and TGF-beta1 mRNA in the spleen and skin but not in the lung. We also performed a mixed lymphocyte culture and examined the effect of recombinant HGF on the generation of IL-4. Recombinant HGF significantly inhibited IL-4 production in TSK/+ CD4+ T cells stimulated by allogeneic DCs. HGF gene transfection inhibited IL-4 and TGF-beta mRNA expression, which has been postulated to have a major role in fibrinogenesis and reduced hypodermal thickness, including the subcutaneous connective tissue layer of TSK/+ mice. HGF might represent a novel strategy for the treatment of SSc.