The hypoxanthine guanine phosphoribosyltransferase (HPRT) gene is mutated by a variety of genotoxic agents in adult rat liver (ARL) epithelial cell lines. By polymerase chain reaction (PCR) amplification and DNA sequencing of rat ARL cell HPRT gene sequences with mouse- and rat-specific oligonucleotides, a large portion of the rat HPRT transcriptional promoter region was sequenced. This region exhibits approximately 60% homology with the corresponding mouse sequence, contains a similar G/C-rich region at its 3' end, and contains a similar series of 6-nucleotide (nt) GGGCGG repeats. To determine if this region is a target for mutation by different genotoxins, HPRT-deficient ARL mutants induced by 2-acetylaminofluorene (AAF), N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), or 7,12-dimethyl-benz[a]anthracene (DMBA) were isolated and studied. A 1003-nt fragment of predominantly HPRT regulatory sequences was amplified by PCR using purified genomic DNA from 17 independent mutants and sequenced directly. None of the 17 mutants examined exhibited any alterations in the transcriptional regulatory region or the 5' untranslated region of HPRT exon 1 after direct sequencing analysis of PCR products. In addition, none of the 2-AAF-induced mutants exhibited differences in in vitro transcription rates as determined by nuclear run-on analysis. These data suggest that regulatory sequences of the HPRT gene are not a primary target for mutation by the genotoxins studied.
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http://dx.doi.org/10.1016/0165-7992(94)90073-6 | DOI Listing |
Diagnostics (Basel)
December 2024
Department of Pediatrics, MacKay Memorial Hospital, Taipei 104217, Taiwan.
BMC Mol Cell Biol
January 2025
Department of Stomatology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, 150001, China.
Background: Inactivation or mutations of FAM20C causes human Raine Syndrome, which manifests as lethal osteosclerosis bone dysplasia or non-lethal hypophosphatemia rickets. However, it is only hypophosphatemia rickets that was reported in the mice with Fam20c deletion or mutations. To further investigate the local and global impacts of Fam20c mutation, we constructed a knock-in allele carrying Fam20c mutation (D446N) found in the non-lethal Raine Syndrome.
View Article and Find Full Text PDFArch Toxicol
December 2024
Department of Human Genetics, National Institute of Health Dr. Ricardo Jorge, Avenida Padre Cruz, 1649-016, Lisbon, Portugal.
Emerging cellulose nanomaterials (CNMs) may have commercial impacts in multiple sectors, being their application particularly explored in the food sector. Thus, their potential adverse effects in the gastrointestinal tract should be evaluated before marketing. This work aimed to assess the safety of two CNMs (CNF-TEMPO and CMF-ENZ) through the investigation of their cytotoxicity, genotoxicity (comet and micronucleus assays), and capacity to induce reactive oxygen species in human intestinal cells, and their mutagenic effect using the Hprt gene mutation assay.
View Article and Find Full Text PDFJ Inflamm Res
December 2024
Department of Critical Care Medicine, Taizhou Hospital of Zhejiang Province Affiliated to Wenzhou Medical University, Taizhou, 317000, People's Republic of China.
Introduction: Sepsis-induced acute lung injury (ALI), a critical sequela of systemic inflammation, often progresses to acute respiratory distress syndrome, conferring high mortality. Although UMI-77 has demonstrated efficacy in mitigating lung injury in sepsis, the molecular mechanisms underlying its action have not yet been fully elucidated.
Methods: This study aimed to delineate the mechanism by which UMI-77 counteracts sepsis-induced ALI using comprehensive transcriptomic and metabolomic analyses.
Adv Sci (Weinh)
December 2024
Department of Orthopedic Surgery, Shanghai Institute of Microsurgery on Extremities, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, 600 Yishan Road, Shanghai, 200233, China.
Small colony variant (SCV) is strongly linked to antibiotic resistance and the persistence of osteomyelitis. However, the intrinsic phenotypic instability of SCV has hindered a thorough investigation of its pathogenic mechanisms. In this study, phenotypically stable SCV strains are successfully recovered from clinical specimens, characterized by elevated drug resistance and reduced immunogenicity.
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