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Intraocular pressure (IOP) is currently the only modifiable risk factor for glaucoma and all licensed treatments lower IOP. However, many patients continue to lose vision despite IOP-lowering treatment. Identifying biomarkers for progressive vision loss would have considerable clinical utility. We demonstrate that lower peripheral blood mononuclear cell (PBMC) oxygen consumption rate (OCR) is strongly associated with faster visual field (VF) progression in patients treated by lowering IOP (P< 0.001, 229 eyes of 139 participants), explaining 13% of variance in the rate of progression. In a separate reference cohort of untreated patients with glaucoma (213 eyes of 213 participants), IOP explained 16% of VF progression variance. OCR is lower in patients with glaucoma (n= 168) than in controls (n= 50; P< 0.001) and is lower in patients with low baseline IOP (n= 99) than those with high baseline IOP (n= 69; P< 0.01). PBMC nicotinamide adenine dinucleotide (NAD) levels are lower in patients with glaucoma (n= 29) compared to controls (n= 25; P< 0.001) and strongly associated with OCR (P< 0.001). Our results support PBMC OCR and NAD levels as new biomarkers for progressive glaucoma.

We report for the first time that IFNG gene expression requires high mobility group (HMG)A1, the architectural transcription factor mediating enhanceosome formation. This finding is supported by our direct studies of T cells isolated from the HMGA1-transgenic mice displaying an up-regulation of IFN-γ production and of HMGA1-deficient mice exhibited a decreased IFN-γ induction. In parallel transfection studies in EL4 cells, we observed elevated IFNG gene promoter activity in cells stably over-expressing HMGA1 and a reduction of such activity in cells expressing dominant-negative HMGA1. In vitro binding assays further demonstrated a specific interaction of HMGA1 to defined regions of the IFNG gene proximal promoter.

To assess whether retinoblastoma formation is associated with the expression of high mobility group (HMG) A2 protein, a transcription factor that is highly expressed during embryogenesis and completely repressed in normal adult tissues, we performed Northern and Western blots and RT-PCR analyses, and immunohistochemistry to test for HMGA2expression. We used established retinoblastoma cell lines in tumors grown in nude mice and clinical retinoblastoma specimens, and contrasted these tumors with normal embryonic and adult retina. Adenoviral-mediated antisense experiments were conducted on the retinoblastoma cell lines to suppress HMGA2 expression and determine if cell proliferation is HMGA2-dependent. We also transfected a retinoblastoma cell line to identify cis-regulatory elements and transcription initiation sites on the HMGA2gene promoter. HMGA2gene expression was silenced in terminally differentiated retina of 6-wk-old mice, but it was detected in retina of a 13.5-d postcoitum embryo. Reactivation of HMGA2gene expression was observed in the retinoblastoma cell lines Y79, WERI-Rb1, and TOTL-1, in tumors derived from some of these cells propagated in nude mice, and in a high frequency of retinoblastomas excised from human patients. This suggests that expression of HMGA2gene in retinoblastoma cells involves a derepression process. By using an antisense approach to block HMGA2 expression, we observed a decrease in the number of proliferating retinoblastoma cells. As a 1st step toward understanding HMGA2gene reactivation in retinoblastoma, we mapped the 2 transcription initiation sites and associated positive regulatory elements within the WERI-Rb1 cells. Our discovery of derepression of HMGA2gene expression in retinoblastoma provides the 1st evidence that this protein might contribute to neoplastic transformation of retina cells.

The paired-like homeodomain transcription factor CRX (cone-rod homeobox) is involved in regulating photoreceptor gene expression and rod outer segment development. Mutations in CRXhave been associated with several retinal degenerative diseases. These conditions range from Leber congenital amaurosis (a severe cone and rod degeneration of childhood onset) to adult onset cone-rod dystrophy and retinitis pigmentosa (an adult onset condition that primarily affects rods). The goal of this study is to better understand the molecular basis of CRX function and to provide insight into how mutations in CRX cause such a variety of clinical phenotypes. We performed deletion analysis in conjunction with DNA binding and transient transfection-based transactivation studies to identify the functional domains within CRX. DNA binding requires a complete homeodomain. Furthermore, truncated proteins that did not contain an intact homeodomain failed to demonstrate detectable expression in tissue culture upon transfection. Transactivation analysis indicated that both the OTX tail and the WSP domain are important for controlling positive regulatory activity of CRX. Interestingly, the mapped CRX transactivation domains were also critical when coexpressed with NRL. Specifically, the synergy between CRX and NRL was constant regardless of which CRX variant was used.

The high mobility group (HMG) I proteins are small, non‐histone chromosomal proteins that promote gene activation during development and within rapidly dividing cells. They do so by facilitating enhanceosome formation on inducible genes, via both protein/DNA and protein/protein interactions. The HMG I‐C gene is tightly regulated, normally being expressed exclusively during embryonic development. However, HMG I‐C expression is also observed frequently in a number of tumor types, and this expression has been shown to contribute to the malignant transformation process. With the aim of dissecting pathways that lead to aberrant expression of HMG I‐C in tumor cells, we have analyzed HMG I‐C gene regulation in the human hepatoma cell line PLC/PRF/5. One of the two HMG I‐C transcripts detected in this cell line originates from a novel downstream initiation site at nucleotide −161 relative to the first methionine. Transcription from the downstream initiation site is mediated by a PRE located between nt −222 and −217. We show here that the Sp1 and Sp3 transcription factors interact with the PRE and transactivate the HMG I‐C promoter in a cooperative fashion. This study provides the first characterization of this downstream HMG I‐C promoter.

The high mobility group (HMG) I proteins are small, non-histone chromosomal proteins that promote gene activation during development and within rapidly dividing cells. They do so by facilitating enhanceosome formation on inducible genes, via both protein/DNA and protein/protein interactions. The HMG I-C gene is tightly regulated, normally being expressed exclusively during embryonic development. However, HMG I-C expression is also observed frequently in a number of tumor types, and this expression has been shown to contribute to the malignant transformation process. With the aim of dissecting pathways that lead to aberrant expression of HMG I-C in tumor cells, we have analyzed HMG I-C gene regulation in the human hepatoma cell line PLC/PRF/5. One of the two HMG I-C transcripts detected in this cell line originates from a novel downstream initiation site at nucleotide −161 relative to the first methionine. Transcription from the downstream initiation site is mediated by a PRE located between nt −222 and −217. We show here that the Sp1 and Sp3 transcription factors interact with the PRE and transactivate the HMG I-C promoter in a cooperative fashion. This study provides the first characterization of this downstream HMG I-C promoter.

The clinicopathological data of adult Chinese patients identified to have ‘significant pulmonary thromboembolism (PTE)’ at autopsy in Queen Mary Hospital (QMH) Hong Kong, from 1990 to 1994 inclusive, were analysed retrospectively. The prevalence of PTE was documented and data were compared with published series of Caucasian patients. The parameters studied included sex-age distribution, associated diseases, symptomatology, site of venous thrombosis, duration of admission and intervals between surgery and death. The rate of PTE was 4.7% (4.5% in males and 5.2% in females). The mean age of PTE patients was significantly higher than that of non-PTE patients (p< 0.001). Two clinicopathological features worthy of note are: (1) as in Caucasian patients, most Chinese patients with ‘significant PTE’ do not present with leg symptoms although many of them are found to have deep vein thrombosis (DVT) at postmortem; and (2) DVT in these patients is found in the calf veins rather than in the more proximal deep veins. The recently identified racial differences in hemostasis that may contribute to the differences between Chinese and Caucasian people are discussed.

The gene on chromosome 12 coding for the human protein HMGI-C has been cloned and partially sequenced. It consists of five exons, the first and last of which include long untranslated regions. The 5′ UTR Includes a (CA/T)n tract and a polymorphic (CT)n tract. Exons II, III and IV (87,51 and 33 bp) are dispersed over →30 kb. Exons Mil separately encode the three basic DNA binding domains (‘A-T hooks’), exon IV encodes an 11 amino acid sequence characteristic of HMGI-C and absent from the human HMGI(Y) gene [Friedmann. M., Holth.L.T, Zoghbi,H.Y. and Reeves.R. (1993) Nucleic Acids Res., 21, 4259-1267], whilst exon V encodes the acidic C-terminal domain, which is subject to multiple phosphorylation. The HMGI-C gene is thus a striking example of the separation of functional protein elements into different coding exons.