Reversal of alopecia areata,osteoporosis follow treatment with activation of Tgr5 in mice

Background: Alopecia areata is an autoimmune hair loss disease with infiltration of pro-inflammatory cells into hair follicles. The role of Tgr5 in dermatitis has attracted considerable attention. The present study aimed to investigate the effect of Tgr5 in the development of Alopecia areata.Methods: The study utilized a comparison control group design with four groups of wild-type group, wild-type+INT777 group, Tgr5^−/− group, and Tgr5^−/−+INT777 group. The mice were treated with INT777 (30 mg/kg/day) or the carrier solution (DMSO) intraperitoneally for 7 weeks, and the back skin was collected and analyzed by histology and immunohistochemistry staining. The lumbar vertebrae 4 has also been analyzed by DXA and Micro-CT.Results: Tgr5^−/− mice displayed the decreasingly significant in hair area and length, skin thickness, and the ratio of anagen and telogen, collagen, and mast cell number and loss the bone mass than WT group. After treating with INT777, the appearance of alopecia areata and bone microstructure has improved. Immunohistochemistry and qPCR analysis showed that activation of Tgr5 can down-regulate the express of JAK1, STAT3, IL-6, TNF-α, and VEGF.Conclusion: These findings indicate that activation of Tgr5 mediated amelioration of alopecia areata and osteoporosis by down-regulated JAK1-STAT3 signaling pathway.     

Dietary vitamin A regulates wingless-related MMTV integration site signaling to alter the hair cycle

Alopecia areata (AA) is an autoimmune hair loss disease caused by a cell-mediated immune attack of the lower portion of the cycling hair follicle. Feeding mice 3–7 times the recommended level of dietary vitamin A accelerated the progression of AA in the graft-induced C3H/HeJ mouse model of AA. In this study, we also found that dietary vitamin A, in a dose dependent manner, activated the hair follicle stem cells (SCs) to induce the development and growth phase of the hair cycle (anagen), which may have made the hair follicle more susceptible to autoimmune attack. Our purpose here is to determine the mechanism by which dietary vitamin A regulates the hair cycle. We found that vitamin A in a dose-dependent manner increased nuclear localized beta-catenin (CTNNB1; a marker of canonical wingless-type Mouse Mammary Tumor Virus integration site family (WNT) signaling) and levels of WNT7A within the hair follicle bulge in these C3H/HeJ mice. These findings suggest that feeding mice high levels of dietary vitamin A increases WNT signaling to activate hair follicle SCs.     

A mouse model of clonal CD8+ T lymphocyte-mediated alopecia areata progressing to alopecia universalis

Alopecia areata is among the most prevalent autoimmune diseases, yet compared with other autoimmune conditions, it is not well studied. This in part results from limitations in the C3H/HeJ mouse and DEBR rat model systems most commonly used to study the disease, which display a low frequency and late onset. We describe a novel high-incidence model for spontaneous alopecia areata. The 1MOG244 T cell expresses dual TCRA chains, one of which, when combined with the single TCRB present, promotes the development of CD8(+) T cells with specificity for hair follicles. Retroviral transgenic mice expressing this TCR develop spontaneous alopecia areata at nearly 100% incidence. Disease initially follows a reticular pattern, with regionally cyclic episodes of hair loss and regrowth, and ultimately progresses to alopecia universalis. Alopecia development is associated with CD8(+) T cell activation, migration into the intrafollicular region, and hair follicle destruction. The disease may be adoptively transferred with T lymphocytes and is class I and not class II MHC-dependent. Pathologic T cells primarily express IFNG and IL-17 early in disease, with dramatic increases in cytokine production and recruitment of IL-4 and IL-10 production with disease progression. Inhibition of individual cytokines did not significantly alter disease incidence, potentially indicating redundancy in cytokine responses. These results therefore characterize a new high-incidence model for alopecia areata in C57BL/6J mice, the first to our knowledge to apply a monoclonal TCR, and indicate that class I MHC-restricted CD8(+) T lymphocytes can independently mediate the pathologic response.     

Heat treatment increases the incidence of alopecia areata in the C3H/HeJ mouse model

Alopecia areata (AA) is a common autoimmune disease characterized by non-scarring hair loss. Previous studies have demonstrated an association between AA and physiological/psychological stress. In this study, we investigated the effects of heat treatment, a physiological stress, on AA development in C3H/HeJ mice. Whereas this strain of mice are predisposed to AA at low incidence by 18 months of age, we observed a significant increase in the incidence of hair loss in heat-treated 8-month-old C3H/HeJ mice compared with sham-treated mice. Histological analysis detected mononuclear cell infiltration in anagen hair follicles, a characteristic of AA, in heat-treated mouse skin. As expected, increased expression of induced HSPA1A/B (formerly called HSP70i) was detected in skin samples from heat-treated mice. Importantly, increased HSPA1A/B expression was also detected in skin samples from C3H/HeJ mice that developed AA spontaneously. Our results suggest that induction of HSPA1A/B may precipitate the development of AA in C3H/HeJ mice. For future studies, the C3H/HeJ mice with heat treatment may prove a useful model to investigate stress response in AA.     

Noncicatrizing alopecias; with special reference to alopecia areata

Since the epochal work of Hamilton there has been general acceptance of the causal relationship of the male sex hormone, age and familial inheritance in development of male pattern baldness. Some of the medicaments used in recent years may cause a diffuse loss of scalp hair. Alopecia that accompanies disease states is probably due to generalized toxemia and disturbances in metabolism. Sometimes male pattern baldness occurs in physiologic states, as exemplified by diffuse hair loss occasionally in the postpartum period. Alopecia areata deserves a critical appraisal, since it may be evidence of underlying neuropsychotic states that need psychiatric diagnosis and treatment. The development of alopecia totalis or universalis in 50 per cent of the prepuberal cases of alopecia areata is of real significance, especially since so very few patients recover their normal scalp hair. The conclusions reached by the authors of two articles reporting on 368 cases of alopecia areata, alopecia totalis and alopecia universalis that the evidence is overwhelming against the malfunction of the endocrine glands as the cause of alopecia areata must be considered real contributions to our understanding of this condition.A few conditions simulate alopecia areata. Probably the ones which are seen most often are trichotillomania and patchy baldness caused by agents used in hair waving and straightening. Our findings in 22 cases of alopecia areata of a persistent inflammatory perivascular and perifollicular infiltrate, massive plugging of the ostia, disappearance of robust hair follicles and diminution in total number of hair follicles and sometimes fibrosis are not necessarily diagnostic of alopecia areata but seem to be very definitely characteristic. Treatment for alopecia areata is of little avail. At this time we do not recommend the general use of the corticosteroids despite the improvement of scalp appearance in the majority of instances in which the systemic administration of these hormones have been employed.     

NONCICATRIZING ALOPECIAS—With Special Reference to Alopecia Areata

Since the epochal work of Hamilton there has been general acceptance of the causal relationship of the male sex hormone, age and familial inheritance in development of male pattern baldness.Some of the medicaments used in recent years may cause a diffuse loss of scalp hair. Alopecia that accompanies disease states is probably due to generalized toxemia and disturbances in metabolism. Sometimes male pattern baldness occurs in physiologic states, as exemplified by diffuse hair loss occasionally in the postpartum period.Alopecia areata deserves a critical appraisal, since it may be evidence of underlying neuropsychotic states that need psychiatric diagnosis and treatment. The development of alopecia totalis or universalis in 50 per cent of the prepuberal cases of alopecia areata is of real significance, especially since so very few patients recover their normal scalp hair.The conclusions reached by the authors of two articles reporting on 368 cases of alopecia areata, alopecia totalis and alopecia universalis that the evidence is overwhelming against the malfunction of the endocrine glands as the cause of alopecia areata must be considered real contributions to our understanding of this condition.A few conditions simulate alopecia areata. Probably the ones which are seen most often are trichotillomania and patchy baldness caused by agents used in hair waving and straightening.Our findings in 22 cases of alopecia areata of a persistent inflammatory perivascular and perifollicular infiltrate, massive plugging of the ostia, disappearance of robust hair follicles and diminution in total number of hair follicles and sometimes fibrosis are not necessarily diagnostic of alopecia areata but seem to be very definitely characteristic.Treatment for alopecia areata is of little avail. At this time we do not recommend the general use of the corticosteroids despite the improvement of scalp appearance in the majority of instances in which the systemic administration of these hormones have been employed.     

Contribution of interleukin 1beta and KM loci to alopecia areata

Alopecia areata is a common skin disease in which proinflammatory cytokines such as IL-1beta may play a pathogenic role. In this study, we examined the distribution of genotypes of an IL-1beta single base change polymorphism at position +3953 in patients with alopecia areata. The distribution of immunoglobulin kappa light chain (KM) genotypes was similarly examined. The data obtained showed that the IL-1beta and KM loci act cooperatively to significantly increase susceptibility to alopecia areata.     

Comparative lipidomic analysis of inflammatory mediators in the aqueous humor and tear fluid of humans and rabbits

Metabolomics - Alopecia areata is a well-known autoimmune disease affecting humans. Polyamines are closely associated with proliferation and inflammation, and steroid hormones are involved in...     

Viral Load and a Locus on Chromosome 11 Affect the Late Clinical Disease Caused by Theiler’s Virus

Theiler's virus causes a persistent infection and a demyelinating disease of mice which is a model for multiple sclerosis. Susceptibility to viral persistence maps to several loci, including the interferon gamma locus. Inactivating the gene coding for the interferon gamma receptor makes 129/Sv mice susceptible to persistent infection and clinical disease, whereas inactivating the interferon gamma gene makes C57BL/6 mice susceptible to persistent infection but not to clinical disease. This difference in phenotype is due to the difference in genetic background. Clinical disease depends on high viral load and Tmevd5, a locus on chromosome 11. These results have consequences for the identification of viruses which might be implicated in multiple sclerosis.     

Both viral and host factors contribute to neurovirulence of bovine herpesviruses 1 and 5 in interferon receptor-deficient mice

Herpes simplex virus (HSV) type 1 and bovine herpesviruses 1 and 5 (BHV-1 and BHV-5) can use the same cellular receptor for entry, but only HSV is known to cause disease in mice. We hypothesized that components of either the innate or the adaptive immune system, or a combination of both, were responsible for curbing replication of BHVs in mice. Therefore, wild-type mice as well as mice with various combined genetic deficiencies in the alpha/beta interferon receptor or gamma interferon receptor and in the ability to produce mature B and T lymphocytes (RAG-2 deletion) were infected with BHV-1 and BHV-5 and monitored clinically, serologically, histopathologically, and virologically. A functional immune system protected the mice from disease and death due to BHV infection, and the immune response was Th1 like. BHV-5 was transported to the central nervous system by the axonal pathway, whereas viremia was required for this outcome with BHV-1. The alpha/beta interferon system was able to obstruct quantitative spread of the viruses in the infected organism. The gamma interferon system had a protective effect against BHV-1, even in mice with the RAG-2 deletion. In contrast, the same mice succumbed to neurological disease and death upon infection with BHV-5. Productively infected neurons were detected only in BHV-5-infected mice with an intact gamma interferon system. We conclude that the alpha/beta interferon system had a protective effect, while an intact gamma interferon system was required for efficient replication of BHV-5 in mouse neurons and for the development of neurological disease.     

Telogen elongation in the hair cycle of ob/ob mice

Alopecia impairs the physical and mental health of patients. We have previously shown that 8-week-old ob/ob mice have no reactivity to depilation, which is a stimulus that induces anagen transition in normal mice, while no hair cycle abnormalities have been reported in other studies until mice reach 7 weeks of age. Therefore, we hypothesized that ob/ob mice have abnormalities in hair cycle progression beyond 7 weeks of age. We examined 6- to 24-week-old ob/ob and 6- to 10-week-old normal mice. After acclimation, the dorsal skin was harvested and the hair cycle phase was identified histologically and immunohistochemically. Normal mice showed catagen–telogen and telogen–anagen transitions at 6 and 8–9 weeks old, respectively. In contrast, the anagen–catagen transition was observed in 7-week-old mice and the telogen phase was maintained from 10 to 24 weeks in most ob/ob mice. These results suggests that ob/ob mice are a possible model animal for telogen effluvium.     

Gamma interferon is critical for resistance to Theiler's virus-induced demyelination.

Administration of neutralizing monoclonal antibody to gamma interferon increased Theiler's virus-induced demyelination and virus antigen persistence in the spinal cord in susceptible SJL/J mice and completely abrogated resistance such that all C57BL/10SNJ mice developed demyelination. These experiments support the hypothesis that gamma interferon is critically important for resistance to Theiler's virus-induced disease but is not required for myelin destruction.     

Importance of interferons in recovery from mousepox.

Gamma interferon is shown to be critical in recovery of C57BL/6 mice from mousepox. Anti-gamma interferon treatment of mice infected in the footpad with ectromelia virus resulted in enhanced spread to and efficient virus replication in the spleen, lungs, ovaries, and, especially, liver. All treated, infected mice died within a mean of 7 days, 2.5 days earlier than mice with severe combined immunodeficiency that were given a comparable infection. On the other hand, alpha interferon appeared not to have a major role in controlling virus replication in tissues examined, and beta interferon was important for virus clearance in the liver and ovaries but not the spleen. Either anti-alpha, beta interferon or anti-beta interferon antibody therapy resulted in only 25% mortality. Infected control mice survived but showed persistence of ectromelia virus at the site of infection (the footpad) and transient presence of the virus in the spleen, liver, lungs, and ovaries and in the fibroreticular but not lymphoid cells of the draining popliteal lymph node. Depletion of gamma interferon but not alpha and/or beta interferon resulted in a significant reduction in the numbers of splenic T (especially gamma delta-TCR+), B, and Mac-1+ cells, although the proportion of Mac-1+ cells in the spleen increased compared with control values. Depletion of alpha, beta, or gamma interferons did not severely affect the generation of virus-specific cytotoxic T-lymphocyte responses or natural killer cell cytolytic activity. This study, in which a natural virus disease model was used, underscores the crucial importance of gamma interferon in virus clearance at all stages of infection and in all tissues tested except the primary site of infection, where virus clearance appears to be delayed.     

Structure and polymorphism of the human gene for the interferon-induced p78 protein (MX1): evidence of association with alopecia areata in the Down syndrome region

Alopecia areata (AA) is a chronic inflammatory disease characterised by patchy hair loss with T cell infiltration of hair follicles. AA occurs in approximately 0.1% of the general population, but this is increased to 9% in Down syndrome (DS). DS is associated with an additional copy (full or partial) of chromosome 21, and the DS region may potentially include genes involved in the pathogenesis of AA. MX1 is the gene encoding the interferon-induced p78 protein (MxA). MxA protein confers resistance to influenza viruses, and we have previously shown that MxA protein is strongly expressed in lesional anagen hair bulbs from patients with AA but not in normal follicles. We therefore studied the possible involvement of MX1 in the pathogenesis of AA. To establish markers in the MX1 region which could be screened by PCR-based methods, we defined the human MX1 exon/intron organisation and screened the exons and the introns by conformation-sensitive gel electrophoresis. We found that the MX1 gene contains 17 exons extending over 33 kb. The size and sequence of the region from exon 6 to exon 16 are highly conserved between human and mouse. Screening of 4747 bp within the MX1 gene revealed four single nucleotide polymorphisms in intron 6. These polymorphisms are concentrated within 147 bp and show strong linkage disequilibrium. In a case-control association study for the MX1 (+9959) polymorphism in 165 AA patients and 510 controls we found a significant association of this marker with AA (odds ratio 1.79, 95% CI 1.21-2.66, chi2 = 8.464, P = 0.0036). The risk of disease was greater for patchy AA (mild disease) and with early age at onset (odds ratio 2.34, 95% CI 1.24-4.43, P = 0.0072), providing new evidence of genetic heterogeneity in AA. Our demonstration of genetic association between the MX1 gene and disease supports the hypothesis that this is a new candidate gene in AA.     

Antibacterial activity of BCG-induced, interferon-containing sera

Sera from mice which have been vaccinated with BCG and challenged with old tuberculin contain gamma interferon. These same sera also express antibacterial activity. Using Staphylococcus aureus we demonstrated that its growth was inhibited at dilutions of sera as high as 1:320. A 4% concentration of sera reduced the growth rate of the S. aureus from 1.6 to 0.6 doubling times per hour. The activity was stable at 56 degrees C but destroyed by 80 degrees C. It was nondialysable and destroyed by acid conditions (pH 2.0) and by the proteolytic enzymes trypsin and chymotrypsin. Antibodies to gamma interferon neutralized the antiviral activity but not the antibacterial activity. Mitogen-induced and virus-induced interferons did not have activity. We subsequently demonstrated that the factor could be induced in mice using BCG without the secondary old tuberculin challenge. No gamma interferon was found in the sera of mice given BCG without old tuberculin. These findings indicate that the antibacterial activity of these sera is not dependent on the presence of gamma interferon. We will continue to work to characterize and identify the antibacterial component in these sera.     

Mice lacking alpha/beta and gamma interferon receptors are susceptible to junin virus infection

Junin virus (JUNV) causes a highly lethal human disease, Argentine hemorrhagic fever. Previous work has demonstrated the requirement for human transferrin receptor 1 for virus entry, and the absence of the receptor was proposed to be a major cause for the resistance of laboratory mice to JUNV infection. In this study, we present for the first time in vivo evidence that the disruption of interferon signaling is sufficient to generate a disease-susceptible mouse model for JUNV infection. After peripheral inoculation with virulent JUNV, adult mice lacking alpha/beta and gamma interferon receptors developed disseminated infection and severe disease.     

Is alopecia areata an autoimmune-response against melanogenesis-related proteins,exposed by abnormal MHC class I expression in the anagen hair bulb?

The etiology of alopecia areata (AA), a putative autoimmune disease characterized by sudden hair loss, has remained obscure. It is not understood, how the characteristic inflammatory infiltrate that selectively attacks anagen hair follicles in AA is generated. We hypothesize that this reflects an unexplored form of autoimmunity, a cytotoxic T cell attack on rhythmically synthesized autoantigens normally sequestered by a lack or very low level of MHC class I (MHC I)-expression, and suggest the following mechanism of AA pathogenesis: Microtrauma, neurogenic inflammation, or microbial antigens cause a localized breakdown of MHC I-"negativity" in the proximal anagen hair bulb via proinflammatory cytokines. This exposes autoantigens derived from melanogenesis-related proteins (MRP-DP), which are only generated during anagen, and triggers two successive waves of autoimmune responses: CD8+ cytotoxic T cells initiate AA after recognizing MRP-DP abnormally presented by MHC I molecules on hair matrix melanocytes and/or keratinocytes; a secondary attack, carried by CD4+ T cells and antigen presenting cells, is then mounted against MHC class II--presented additional autoantigens exposed by damaged melanocytes and keratinocytes. The latter causes most of the follicular damage, and extrafollicular disease, and depends greatly on the immunogenetic background of affected individuals. This unifying hypothesis explains the clinical heterogeneity and all salient features of AA, and argues that only the unlikely coincidence of multiple predisposing events triggers AA. The suppression of MHC I--expression and synthesis of MRP in the hair bulb, and the "tolerization" of MRP-DP autoreactive CD8+ T cells may be promising strategies for treating AA.     

Modulation by gamma interferon of antiviral cell-mediated immune responses in vivo.

Mice were infected with lymphocytic choriomeningitis virus and injected once 24 h later with a monoclonal antibody directed against gamma interferon. In comparison with controls, the increase of numbers of CD8+ T cells and the generation of virus-specific cytotoxic T lymphocytes in spleens and virus clearance from organs were diminished, as was the ability of spleen cells to transmit adoptive immunity to infected recipients. The same treatment slightly but consistently lessened rather than augmented the virus titers early in infection, which was also observed in thymusless nu/nu mice. Injection into infected mice of the lymphokine itself in quantities probably higher than are produced endogenously resulted in lower virus titers in spleens but higher titers in livers. The adoptive immunity in infected mice achieved by infusion of immune spleen cells was not altered by treating the recipients with gamma interferon monoclonal antibody. Such treatment did not measurably affect the production of antiviral serum antibodies. We conclude that in lymphocytic choriomeningitis virus-infected mice, gamma interferon is needed for the generation of antivirally active CD8+ T lymphocytes, and furthermore that in this experimental model, direct antiviral effects of the lymphokine elude detection.     

SOCS1 is a critical inhibitor of interferon gamma signaling and prevents the potentially fatal neonatal actions of this cytokine.

Mice lacking suppressor of cytokine signaling-1 (SOCS1) develop a complex fatal neonatal disease. In this study, SOCS1-/- mice were shown to exhibit excessive responses typical of those induced by interferon gamma (IFNgamma), were hyperresponsive to viral infection, and yielded macrophages with an enhanced IFNgamma-dependent capacity to kill L. major parasites. The complex disease in SOCS1-/- mice was prevented by administration of anti-IFNgamma antibodies and did not occur in SOCS1-/- mice also lacking the IFNgamma gene. Although IFNgamma is essential for resistance to a variety of infections, the potential toxic action of IFNgamma, particularly in neonatal mice, appears to require regulation. Our data indicate that SOCS1 is a key modulator of IFNgamma action, allowing the protective effects of this cytokine to occur without the risk of associated pathological responses.