Disease relevance of VSX1

• A VSX1 HD mutation, R166W, that impairs DNA binding and causes keratoconus in humans, hindered repressor function [1].
• H244R VSX1 is associated with selective cone ON bipolar cell dysfunction and macular degeneration in a PPCD family [2].
• The RINX gene maps to chromosome 20p11.2 to which no retinal disease has been assigned [3].
• The positive skin tests to PPD, candida and mumps persisted [4].
• The prevalence of abnormalities was high: intestinal parasites, 61%; positive tuberculin test (PPD) results 55%; anemia, 37%; hepatitis B antigenemia, 14%; and abnormal VDRL test results, 12% [5].

Psychiatry related information on VSX1

• This review considers the possible familial relationship of schizotypal and paranoid personality disorders (SPD, PPD) to schizophrenia (SCZ) and affective disorders (AD) [6].
• METHODS: Using a telephone survey and the Edinburgh Postnatal Depression Scale questionnaire we identified PPD in a sample of women who gave birth in HaEmek Medical Center. We also assessed the extent to which the women consulted with family physicians, gynecologists and/or pediatricians [7].
• CONCLUSIONS: Although many men in the postnatal period experience a variety of mental health problems, those who have a partner with PPD are themselves at increased risk for experiencing psychological symptoms and disturbances [8].

High impact information on VSX1

• To study antigen recognition by gamma delta+ lymphocytes we raised a gamma delta+ alpha beta- -CD4-CD8- line from an individual immune to PPD (purified protein derivative) [9].
• We showed that sera from normal subjects after antigenic challenge with intradermal PPD or Candida antigens or with subcutaneous tetanus vaccine contain a factor that blocks the binding of mouse monoclonal anti-Ia antibody to Ia-positive T cells or to B35 M cells, an Ia-positive human B cell line [10].
• We identified mutations in the VSX1 homeobox gene for two distinct inherited corneal dystrophies; posterior polymorphous dystrophy (PPD) and keratoconus [11].
• VSX1: a gene for posterior polymorphous dystrophy and keratoconus [11].
• VSX1 contains closely related homeo and CVC domains and, like CHX10, also repressed transcription [1].

Chemical compound and disease context of VSX1

• RESULTS: All the adjuvants were effective in inhibiting the development of allergen-induced airway eosinophilia, mucous production and, with the exception of PPD, also airway hyper-reactivity, when they were applied together with OVA/alum [12].
• We have also established the in vivo relevance of this in vitro test by determining the degree of correlation between responses to in vitro boosting with BCG and a positive or negative reaction in a hypersensitivity skin test using 5 IU of PPD (purified protein derivative of BCG) [13].
• No major long-term impact of chemoimmunotherapy (5-FU + BCG) on the immune parameters was observed except a transient increase in PPD reactivity approximately 1 year after commencement of treatment [14].
• This reaction was positive to PPD in CY treated mice immunized to BCG, while it was suppressed by the transfer of in vitro induced SC [15].
• Only delayed hypersensitivity response to DNCB, PPD, and Candida showed a correlation with histologic features such as tumor differentiation and lymphoreticular response [16].

Biological context of VSX1

• CHX10 is required first for retinal progenitor cell proliferation and later for bipolar cell differentiation, whereas VSX1 is important in the terminal differentiation of a subset of bipolar cells [1].
• Several ocular phenotypes have been mapped to the VSX1 region in both human and mouse genomes, and its candidacy for these disorders is discussed [17].
• VSX1 was localized to the 20p11-q11 region, which is homologous with the distal part of mouse chromosome 2 [17].
• In this paper we report the cDNA sequence, genomic structure, localization, and expression data of a novel paired-like homeobox-containing gene, VSX1, isolated from a human embryonic craniofacial cDNA library using the degenerate-PCR approach [17].
• CONCLUSIONS: Mutational analysis of the VSX1 gene in a series of Italian patients revealed one novel mutation and confirmed an important role played by this gene in a significant proportion of patients affected by keratoconus, when it is inherited as an autosomal dominant trait with variable expressivity and incomplete penetrance [18].

Anatomical context of VSX1

• Therefore, CHX10 and VSX1 may control retinal bipolar cell specification or differentiation by repressing genes required for the development of other cell types [1].
• METHODS: The expression of VSX1 was evaluated through semiquantitative RT-PCR, immunofluorescence and in situ hybridization both in corneas (either freshly obtained or wounded) and in collagenase/hyaluronidase-isolated keratocytes grown in the absence or presence of serum to promote keratocyte-to-myofibroblast differentiation [19].
• RESULTS: Quiescent or resting keratocytes normally residing in the corneal stroma or cultured in vitro in the absence of serum did not express VSX1 [19].
• CONCLUSIONS: The new mutation in the VSX1 (RINX) gene described in this report results in abnormal craniofacial features, absence of the roof of the sella turcica, and anomalous development of the corneal endothelium [20].
• PPD proved to be a good B cell activator for inducing polyclonal Ig production in PBL from healthy Japanese. Comparative studies of this response with PWM-induced Ig production showed that the cellular mechanisms involved in the two responses were different [21].

Associations of VSX1 with chemical compounds

• Because of these findings and a positive first-strength PPD tuberculin skin test result, the patient received antituberculosis and steroid therapy for six months with no effect [22].
• The immune status of the patients was evaluated by determining the antibody response to C. parvum, the E and EAC rosettes, the PHA response of blood lymphocytes, the skin-test reactivity to Candida and PPD, the response to DNCB and the chemotaxis and NBT-dye reduction capacity of neutrophil leucocytes [23].
• CONCLUSIONS: Taken together our data suggest that live BCG>hk-BCG>CpG-ODN >PPD are effective in suppressing allergen-induced Th2 responses [12].
• We obtained highly significant stimulation with PPD, tryptophane peptide of myelin, and tumour basic protein using Mantoux + cancer patients, but found no response to other basic proteins [24].
• Examination of the supernatant fluids from BCG-positive leucocyte cultures stimulated with PPD showed a correlation between histamine-release enhancing activity and interferon [25].

Other interactions of VSX1

• METHODS: DNA extraction, PCR amplification, and direct sequencing of the VSX1, BCL2L1, and ID1 genes were performed in 14 affected patients (12 families) as well as in unaffected family members and healthy control subjects [26].
• PURPOSE: To characterize the expression of the visual system homeobox gene (VSX1) in human corneal keratocytes both in vitro and in vivo [19].
• In wounded corneas or when cultured in the presence of serum to mimic wound-healing responses, keratocytes underwent fibroblastic transformation (with appearance of alpha-SMA and disappearance of CD-34 and keratocan signals) and started expressing VSX1 [19].
• Therefore, although we report a number of novel polymorphisms in the VSX1 and ID1 genes, the failure to identify any sequence variants that sort with the disease phenotype suggests that other genetic factors are involved in PPCD [26].

Analytical, diagnostic and therapeutic context of VSX1

• However, with either the G160D or P247R mutation, electroretinography detected abnormal function of the inner retina, where VSX1 is expressed [11].
• Sequence analysis indicated that the H244R variant in the VSX1 segregated with corneal and macular disease phenotypes in this family [2].
• METHODS: DNA extraction, PCR amplification, and direct sequencing of the VSX1 gene were performed in 100 unrelated patients with diagnoses of clinical and topographic features of KTCN [27].
• The 250-TU PPD and second-strength skin tests [28].
• However, the head-to-head comparative study on the titration curves of helper T cells in the two responses showed that PWM-induced helper activity was 2 to 5 times more effective than PPD-induced helper activity [21].

References