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PubMed1978

Simple method for preparation of specific antisera against viral proteins: rabbit antisera against equine infectious anemia virus proteins p26 and p16.

A simple method for preparation of highly specific antisera against equine infectious anemia virus proteins p26 and p16 is described. Viral proteins were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The motility of the viral proteins in the gel was compared with standards. Unstained portions of the slab gel were sliced into 5-mm bands, emulsified with Freund's complete adjuvant, and injected into rabbits to produce specific antisera.

Animals↗

PubMed2026

Microsatellite instability in penile cancer: comparative analysis of primary tumors and metastases.

BACKGROUND: Penile cancer (PeCA) presents high morbidity and mortality and is more prevalent in underdeveloped countries. The presence of nodal metastasis at diagnosis or as early recurrence carries a worse prognosis, making it important to determine whether clinically relevant biomarkers are maintained between primary tumors and corresponding lymph node metastases. We aim to describe the presence of DNA microsatellite instability (MSI) in primary PeCA tumors and locoregional lymph nodes affected by metastatic cells, as well as to assess HPV status through p16 expression. METHODS: A total of 116 patients were comparatively evaluated between the primary tumor and lymph node metastases. The evaluation of p16 and mismatch repair proteins was done by immunohistochemistry, and MSI status was assessed using a hexa-plex marker by polymerase chain reaction, followed by fragment analysis. RESULTS: All patients underwent a standard lymphadenectomy (inguinal or pelvic), with a pN0 frequency of 33.6%. MSI-H was found in three patients (2.6%), with correspondence between the presence of the biomarker in the primary tumors and the lymph node metastases. A second validation was performed using IHC for MMR, with MLH1/PMS2 loss in MSI-H cases. 22.8% of patients expressed p16 by immunohistochemistry. p16 positivity was associated with a 55% reduction in the risk of death. All MSI-H patients were p16 positive. CONCLUSION: MSI-H occurs in 2,6% of the sample and is associated predominantly with MLH1/PMS2 loss and p16 positivity. Together, these findings suggest potential interactions between HPV- associated carcinogenesis and genomic instability. Further prospective, biomarker-driven trials are warranted to define their prognostic and therapeutic relevance in PeCA.

HPV↗

PubMed1978

Expression of two differentiation antigens on normal and cultured human T cells.

An antiserum specific for human T lymphocytes (AMT) was used to examine patterns of T cell surface antigen expression and to isolate their reactive membrane antigens. By a quantitative adsorption assay, different plateaus of AMT reactivity with blood T cells were observed after serial adsorptions with individual T cell lines. MOLT-3 cells removed 95% of AMT activity to blood T cells whereas MOLT-4 removed 70% and HSB-2 removed only 30%. A cross-adsorption analysis demonstrated that each of the three cell lines differed in their adsorbing efficiency to remove AMT antibodies reactive with the reciprocal cell lines. Radiolabeled membrane proteins were solubilized with either sodium deoxycholate (DOC) or NP-40 detergents, precipitated with AMT, and Staphylococcus aureus Cowan strain I, and analyzed by sodium dodecyl sulfate-polyacrylamide disc gel electrophoresis (SDS-PAGE). Two distinct T lymphocyte antigens of approximately 25,000 daltons (p25) and 16,000 (p16) were identified on MOLT-3 cells. Similar relative quantities of p25 and p16 were detected on human peripheral T cells and thymocytes. MOLT-4 cells contained less of the p25 peak than did MOLT-3. HSB-2 cells gave a small peak in the same general location as the MOLT-3 p25 peak, and a relatively large p16 peak. Adsorption of AMT with HSB-2 removed the capacity of the antiserum to precipitate p16 from MOLT-3, but did not eliminate reactivity with p25.

Animals↗

PubMed2026

2026 International Society for the Study of Vulvovaginal Disease terminology for vulvar intraepithelial neoplasia and squamous intraepithelial lesions.

The 2026 International Society for the Study of Vulvovaginal Disease terminology for vulvar intraepithelial neoplasia and squamous intraepithelial lesion requires p16 and p53 immunohistochemistry for classification into human papillomavirus-associated or human papillomavirus-independent disease. p16 and p53 are tumor suppressor proteins; block positive p16 staining is a surrogate marker for genomic integration of oncogenic human papillomavirus, while null or overexpressed p53 staining correlates with TP53 mutation. Human papillomavirus-associated and human papillomavirus-independent vulvar intraepithelial neoplasia represent 2 distinct entities with different diagnostic considerations, treatments, surveillance strategies, and prognoses. The designation of 'neoplasia' vs 'lesion' reflects biological behavior, with neoplasia signifying an established risk of progression to cancer. Human papillomavirus-associated disease maintains a 2-tier nomenclature: human papillomavirus-associated vulvar intraepithelial neoplasia for precursors to vulvar squamous cell carcinoma vs low-grade squamous intraepithelial lesion and condyloma for transient human papillomavirus manifestations. While human papillomavirus-associated vulvar intraepithelial neoplasia is preferred, high-grade squamous intraepithelial lesion is retained as acceptable in some settings to maintain consistency with nomenclature for analogous lesions across the lower genital tract. Human papillomavirus-independent disease almost always arises from longstanding lichen sclerosus. The updated terminology for human papillomavirus-independent precursors to squamous cell carcinoma is human papillomavirus-independent vulvar intraepithelial neoplasia, subcategorized as p53 mutant or p53 wild type. Verrucous vulvar intraepithelial neoplasia is a subtype of p53 wild type human papillomavirus-independent vulvar intraepithelial neoplasia and the usual precursor to verrucous carcinoma. Vulvar aberrant maturation encompasses human papillomavirus-independent lesions of uncertain neoplastic potential arising in lichen sclerosus that raise concern for but are not diagnostic of human papillomavirus-independent vulvar intraepithelial neoplasia. Collaboration between clinicians and pathologists is essential to achieve accurate diagnosis, optimal individualized treatment, and consistent application of this terminology in practice and research.

Humans↗

PubMed2026

Menopausal timing and senescent-immune coupling in age-related lobular involution of the human breast: a longitudinal cohort study.

BACKGROUND: Incomplete postmenopausal breast involution leaves persistent epithelial-rich lobules and elevated breast density in about 40% of women and is associated with higher breast cancer risk, but why remodelling stalls remains unclear. METHODS: We studied a longitudinal cohort of 81 women with paired benign breast biopsies (baseline age 45-55 years; follow-up 2-10 years), all with baseline NanoString transcriptomics and two-timepoint digital morphometry, and with multiplex immunofluorescence in spatial-imaging subsets (baseline n = 14-16 depending on panel; follow-up n = 14). A separate postmenopausal endpoint cohort (12 women: eight noninvoluted, four completely involuted), profiled by genome-wide expression array and multiplex immunofluorescence, defined the persistent-lobule phenotype. FINDINGS: Noninvoluted postmenopausal tissue retained a proliferation-competent, tumour-associated epithelial state and showed immune accumulation at lobular boundaries with reduced access to p16+ (senescence-associated) epithelial foci. The same SASP and innate immune programmes that predicted slower involution across the menopausal transition predicted faster involution after menopause. Follow-up boundary CD45→p16 engagement was directionally consistent with this reversal in Pre→Post and Post→Post women. Spatial imaging resolved this reversal into a perimenopausal stall architecture and a postmenopausal clearance-associated architecture marked by direct CD16+ innate-effector engagement of p16+ epithelium; macrophage targeting provided convergent support (two-sided exact permutation interaction p = 0.0077). INTERPRETATION: Menopausal timing conditions whether senescent-immune programmes couple to productive clearance or to spatially uncoupled surveillance and persistent risk-associated tissue. Biomarker interpretation should therefore be anchored to menopausal timing. FUNDING: Casey DeSantis Cancer Fund and US National Cancer Institute.

Humans↗

PubMed1979

Primate retroviruses: intracistronic mapping of type D viral gag gene by use of nonconditional replication mutants.

Nonconditional replication mutants of squirrel monkey retrovirus (SMRV), an endogenous type D virus of primates, are shown to be defective in post-translational processing of nonglycosylated virus-coded structural proteins. Utilizing such mutants, in combination with sensitive radioimmunological assays, we demonstrate the existence of a 72,000-molecular-weight precursor polyprotein (Pr72gag) encoded by a region of the SMRV genome designated gag. Post-translational cleavage of this precursor polyprotein gives rise to virion structural proteins of 35,000 (p35), 16,000 (p16), 12,000 (p12), and 9,000 (p9) molecular weight. Three of these viral proteins, p35, p16, and p9, are shown to be phosphorylated. Analysis of viral antigen expression in cell lines nonproductively infected with either of two replication-defective SMRV mutants or mink cells productively infected with wild-type SMRV resulted in the detection of several SMRV Pr72gag intermediate cleavage products. Adjacent proteins within such intermediates are identified by use of specific competition immunoassays, and the intracistropic order of individual structural proteins with SMRV Pr72gag was tentatively deduced as NH2-p16-p12-p35-p9-COOH.

Animals↗

PubMed2025

Molecular Characterization and Epidemiology of Human Noroviruses in the Sverdlovsk Region, Russian Federation.

Human noroviruses (HuNoVs) stand as the primary cause of acute viral gastroenteritis outbreaks worldwide, particularly impacting children under the age of five. In Russia, reports of norovirus gastroenteritis have surged, especially in the post-COVID-19 era starting in 2022, with elevated infection rates reported into 2024. These viruses exhibit significant mutational variability, leading to the emergence of recombinant strains that can evade immune responses. A comprehensive examination of the complete genome is crucial for understanding the evolution of norovirus genes and for predicting potential outbreaks. This research focuses on analyzing the genotypic composition of HuNoVs circulating in the Sverdlovsk region during 2024, using Sanger sequencing and next-generation sequencing (NGS). Biological samples were collected (n = 384) from patients diagnosed with norovirus infection within the region. Bioinformatics analysis targeted the nucleotide sequences of the ORF1/ORF2 fragment and the assembly of complete genomes for the GII.4 and GII.7 genotypes. In total, 220 HuNoVs were characterized, representing 57.3% of the collected samples. The main capsid variants forming the predominant genotypic profile included GII.4 (n = 88, 40%), GII.7 (n = 86, 39%), and GII.17 (n = 14, 6%). Using NGS, we successfully assembled 8 out of 10 complete genomes for noroviruses GII.4[P16] and GII.7[P7]. Non-synonymous substitutions appeared at amino acid sites corresponding to the subdomains of VP1 in these strains. This molecular-genetic analysis provides contemporary insights into the genotypic composition, circulation patterns, and evolutionary dynamics associated with the dominant genovariants GII.4[P16] and GII.7[P7].

Norovirus↗

PubMed2026

Diagnostic utility of high-risk HPV polymerase chain reaction-based testing in head and neck FNA specimens with indeterminate cytomorphology.

BACKGROUND: Fine-needle aspiration (FNA) is critical in the initial diagnosis of many high-risk human papillomavirus (HR-HPV)-associated, metastatic oropharyngeal squamous cell carcinomas. Updated guidelines recommend HR-HPV-specific polymerase chain reaction (PCR) analysis over p16 immunohistochemistry on FNA specimens because p16 performs poorly on cytology material. PCR-based assays on liquid cytology material have demonstrated excellent analytic performance; however, the diagnostic utility of a positive HR-HPV PCR result in specimens with indeterminate cytomorphology remains uncharacterized. METHODS: The authors retrospectively identified 279 head and neck FNA specimens that had paired HR-HPV PCR testing on residual liquid cytology material over a 5-year period. The positive predictive value for histopathologically confirmed squamous cell carcinoma on surgical follow-up was calculated within each cytologic interpretive category. RESULTS: The HR-HPV PCR results were positive in 50.2% of specimens, negative in 40.9%, and indeterminate in 9.0%. The HR-HPV positivity rate ranged from 0% in specimens categorized as negative for malignancy to 57.3% in cytologically positive specimens, with 19.0%, 41.2%, and 50.0% positivity in the atypical, suspicious, and nondiagnostic categories, respectively. Among cytologically indeterminate specimens with positive HR-HPV PCR results (n = 14), the positive predictive value was 100% (95% confidence interval, 78.5%-100.0%). Blinded slide review additionally identified 15 cytologically positive specimens in which the definitive malignant interpretation depended substantially on HR-HPV positivity; all 15 were confirmed as squamous cell carcinoma. CONCLUSIONS: A positive HR-HPV PCR result on liquid cytology material carries a positive predictive value of 100% for malignancy in cytologically indeterminate head and neck FNA specimens. These findings support integrating HR-HPV PCR analysis into routine cytologic interpretation with the potential to upgrade some indeterminate specimens to malignant when HR-HPV is detected, expediting definitive treatment and sparing patients additional, invasive sampling.

Humans↗

PubMed2026

Refining the Multivariable Predictive-Prognostic PREDICTR-OPC Model for Survival in Surgical Escalation for Oropharyngeal Squamous Cell Carcinoma.

OBJECTIVES: The PREDICTR-OPC model is the only prognostic classifier for oropharyngeal squamous cell carcinoma (OPSCC) also predictive of surgical outcomes. Of the four biomarkers included, survivin contributes minimally and presents practical limitations. This study aimed to refine and simplify the model by removing survivin, then re-assess its prognostic predictive performance compared to the original. METHODS: This retrospective cohort study analyzed a multi-center training cohort (n = 600) and an external validation cohort (n = 385) of OPSCC patients. Tumor biopsies were stained for p16, high-risk human papillomavirus (HR-HPV) DNA, tumor-infiltrating lymphocytes (TILs), and survivin and independently scored by at least three certified pathologists. Cox proportional hazards models assessed overall survival (OS), comparing three-biomarker (p16, HR-HPV, TILs) and four-biomarker models. Hazard ratios (HRs) for OS were estimated in the validation cohort, adjusting for covariates. Discrimination, calibration, and decision curve analysis (DCA) evaluated performance and clinical utility. RESULTS: Among 985 patients (median age: 57 years), median OS = 8.8 years (95% CI: 6.9-10.5). The three-biomarker model yielded HR = 4.10 (95% CI: 2.41-6.98, p < 0.001) for high- vs. low-risk groups in the validation cohort, comparable to the four-biomarker model (HR = 4.24, p < 0.001). Surgery was associated with improved OS in high-risk (HR = 0.45, p = 0.001) but not low-risk (HR = 0.83, p = 0.72) patients, consistent with the original model. The models performed similarly across all metrics (e.g., Concordance Index: 0.71 vs. 0.72; Brier Score: 0.22 for both) as was model fit (Likelihood Ratio Test: p = 0.066). DCA revealed comparable clinical benefit. CONCLUSION: Removing survivin preserves PREDICTR-OPC's predictive performance, offering a more cost-effective, easier-to-implement tool for OPSCC treatment recommendations.

Humans↗

PubMed2026

Histopathologic, Genomic, and Clinical Characteristics of Primary Cutaneous Melanocytic Tumors With Concomitant NRAS Q61 and IDH1 R132C Mutations.

Cutaneous melanocytic tumors with concomitant NRAS Q61 and IDH1 R132C mutations have been described as intermediate-grade melanocytomas with characteristic biphasic morphology, but the malignant end of this genotype-defined spectrum remains poorly characterized. We assessed histopathologic, immunohistochemical, molecular, and clinical features of 16 primary cutaneous melanocytic tumors harboring both mutations. Following integrated review, 7 tumors were classified as melanocytoma and 9 as melanoma. Melanocytomas showed reproducible biphasic architecture with congenital nevus-like features, a biphasic HMB-45 pattern, low Ki-67, PRAME negativity, retained p16, and minimal copy number variations (CNVs). Melanomas retained partial morphologic overlap in a subset but were distinguished by higher-grade cytology, immunohistochemical features supportive of malignancy, and progression-associated genomic alterations, including TERT promoter mutation (9/9), 9p21/CDKN2A loss (4/7), and higher CNV burden. NRAS and IDH1 variant allele frequencies were strongly concordant (r = 0.83, P < 0.001), supporting their presence in the same dominant clone. Clinically, two patients presented with stage IIIB disease, but no distant metastasis or melanoma-related death occurred during a median melanoma follow-up of 3.9 years (IQR, 2.5-5.1). In exploratory analyses, moderate-to-severe atypia (RR, 6.2; 95% CI, 1.0-38.8; P = .009), Ki-67 ≥10% (RR, 4.4; 95% CI, 1.1-18.4; P = .003), lymphocytic infiltrate (RR, 2.4; 95% CI, 1.1-5.3; P = .03), absence of the typical biphasic pattern (RR, 2.4; 95% CI, 1.1-5.3; P = .03), and complete p16 loss (RR, 2.4; 95% CI, 1.1-5.3; P = .03) were associated with molecular or clinical progression to melanoma, defined as the presence of at least one of the following: TERT promoter mutation, pathogenic CDKN2A mutation, 9p21/CDKN2A loss, ≥3 genome-wide segmental CNVs, or any metastasis. These findings support the existence of NRAS/IDH1 co-mutated melanoma as the malignant counterpart of NRAS/IDH1-mutated melanocytoma within a single genotype-defined spectrum.

IDH1 mutations↗

PubMed1977

Purification and structural characterisation of human HLA-linked B-cell antigens.

The human B cell-specific alloantigen which is closely linked genetically to HLA contains two non-covalently associated, sialogycoprotein subunits of molecular weight (MW) 29,000 (p29), and 34,000 (p34). Although p29 and p34 have different amino-terminal sequences, their tyrosine peptide maps indicate considerable similarity in other portions of their polypeptide chains. Thus the genes for their proteins may have evolved by duplication of a common ancestral gene. Another lymphocyte cell surface protein of MW 16,000 (p16) has also been characterised. Both p16 and p44 (the heavy chain of HLA-A,B antigens) have been compared with p29 and p34.

Amino Acid Sequence↗

PubMed1977

Assembly of Bacillus subtilis phage phi29. 1. Mutants in the cistrons coding for the structural proteins.

The effect of mutations in the cistrons coding for the phage structural proteins has been studied by analyzing the phage-related structures accumulated after restrictive infection. Infection with susmutants in cistron 8, lacking both the major head and the fiber protein, does not produce any phage-related structure, suggesting a single route for the assembly of phage phi29; infection with ts mutants in this cistron produces isometric particles. Mutants is cistron 9, coding for the tail protein, TP1, produce DNA-free prolate heads with an internal core; these particles are abortive and contain the head proteins HPO, HP1 and HP3, the upper collar protein NP2 and the nonstructural proteins p7, p15 and p16. Mutants in cistron 10, coding for the upper collar protein, NP2, produce DNA-free isometric heads also with an internal core; they contain the head proteins and the nonstructural protein p7, suggesting that this protein forms the internal core. Mutants in cistrons 11 and 12, coding for the lower collar protein, NP3, and the neck appendages, NP1, respectively, give rise to the formation of DNA-containing normal capsids and DNA-free prolate particles, more rounded at the corners than the normal capsids and with an internal core; the DNA-containing 11-particles are formed by the head proteins and the upper collar protein; the DNA-free 11-particles contain, besides these proteins, the nonstructural protein p7 and a small amount of proteins p15 and 16. The DNA-containing 12-particles have all the normal phage structural proteins except the neck appendages, formed by protein NP1; the DNA-free particles are similar to the DNA-free 11-particles. After restricitive infection mutant sus14(1241) has a delayed lysis phenotype and produces a phage burst higher than normal, after artificial lysis. It produces DNA-containing particles, identical to wild-type phage, which have all the normal phage structural proteins, and DNA-free prolate particles, more rounded at the corners than the final phage particles and with an internal core; the last particles contain the same proteins as the DNA-free 11 or 12-particles. These particles could represent a prohead state, ready for DNA encapsulation. None of the DNA-containing particles have the nonstructural proteins p7, p15 or p16, suggesting that these proteins are released from the proheads upon DNA encapsulation.

Bacillus subtilis↗

PubMed1979

Simultaneous purification of murine mammary tumor virus structural proteins: analysis of antigenic reactivities of native gp34 by radioimmunocompetition assays.

All the structural proteins (gp47, gp34, p27, p23, p16, and p12) of the murine mammary tumor virus (MuMTV) were simultaneously purified utilizing alkylagarose chromatography as the initial fractionation step. Least-hydrophobic MuMTV polypeptides (p23, p16) and the slightly hydrophobic p27 were separated from moderately hydrophobic proteins gp47 and p12 by passage through octylimino (C(8))-agarose; the gp47 and p12 could be removed from the matrix by elution with ethylene glycol, whereas the most hydrophobic MuMTV protein, gp34, was eluted using nonionic detergent together with ethylene glycol. Subsequent purification steps involved ion-exchange or gel filtration chromatography. The resulting protein preparations appeared near-homogeneous on analysis by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. Recoveries of MuMTV proteins, based on their approximate individual contribution to total virus protein, ranged from about 20% for gp47 to greater than 100% for the minor structural component p23, the major phosphoprotein of MuMTV. Antiserum against purified C3H MuMTV gp34, together with purified, radioiodinated gp34, was used to develop a radioimmunoassay which showed that from 13 to 14% of total MuMTV protein by weight is gp34. Using this assay system, the group-specific antigenic reactivity of gp34 was also demonstrated. When solubilized preparations of C3H, RIII, and GR MuMTV's were used as competing antigens in gp34 radioimmunoassays with anti-C3H MuMTV serum, both group- and type-specific differences in antigenic reactivity were found.

Animals↗

PubMed2026

Disruption of CTCF binding by germline non-coding variants in CDKN2B suppress CDKN2A expression and predispose to melanoma.

Some melanoma-prone families linked to the 9p21 locus, harboring the established susceptibility gene CDKN2A, lack pathogenic protein-coding variants. Using whole-exome and targeted sequencing, we identified three rare single-nucleotide variants in two melanoma-prone families and one sporadic melanoma case. Variants map to a conserved CTCF-bound region within the first intron of CDKN2B that physically interacts with CDKN2A. Analysis of UK Biobank showed significant enrichment of variants in this region in melanoma cases. Variants result in diminished CTCF binding in vitro. CTCF ChIP-seq in fibroblasts from the carriers of the largest family demonstrated loss of CTCF binding, accompanied by weakened promoter interactions and allele-specific reduction of CDKN2A p16 transcript expression from the variant haplotype. CRISPR-based perturbation of this region and editing of the large family variant into melanocytes resulted in reduced expression of p14 and p16 CDKN2A transcripts. These findings suggest that non-coding regulatory variants function as high-penetrance susceptibility alleles in melanoma families by altering CDKN2A function.

Journal Article↗

PubMed2024

Genome-wide screening and functional validation of methylation barriers near promoters.

CpG islands near promoters are normally unmethylated despite being surrounded by densely methylated regions. Aberrant hypermethylation of these CpG islands has been associated with the development of various human diseases. Although local genetic elements have been speculated to play a role in protecting promoters from methylation, only a limited number of methylation barriers have been identified. In this study, we conducted an integrated computational and experimental investigation of colorectal cancer methylomes. Our study revealed 610 genes with disrupted methylation barriers. Genomic sequences of these barriers shared a common 41-bp sequence motif (MB-41) that displayed homology to the chicken HS4 methylation barrier. Using the CDKN2A (P16) tumor suppressor gene promoter, we validated the protective function of MB-41 and showed that loss of such protection led to aberrant hypermethylation. Our findings highlight a novel sequence signature of cis-acting methylation barriers in the human genome that safeguard promoters from silencing.

Animals↗

PubMed2025

Integrated Multiomics Analyses of the Molecular Landscape of Sarcopenia in Alcohol-Related Liver Disease.

BACKGROUND: Skeletal muscle is a major target for ethanol-induced perturbations, leading to sarcopenia in alcohol-related liver disease (ALD). The complex interactions and pathways involved in adaptive and maladaptive responses to ethanol in skeletal muscle are not well understood. Unlike hypothesis-driven experiments, an integrated multiomics-experimental validation approach provides a comprehensive view of these interactions. METHODS: We performed multiomics analyses with experimental validation to identify novel regulatory mechanisms of sarcopenia in ALD. Studies were done in a comprehensive array of models including ethanol-treated (ET) murine and human-induced pluripotent stem cell-derived myotubes (hiPSCm), skeletal muscle from a mouse model of ALD (mALD) and human patients with alcohol-related cirrhosis and controls. We generated 13 untargeted datasets, including chromatin accessibility (assay for transposase accessible chromatin), RNA sequencing, proteomics, phosphoproteomics, acetylomics and metabolomics, and conducted integrated multiomics analyses using UpSet plots and feature extraction. Key findings were validated using immunoblots, redox measurements (NAD+/NADH ratio), imaging and senescence-associated molecular phenotype (SAMP) assays. Mechanistic studies included mitochondrial-targeted Lactobacillus brevis NADH oxidase (MitoLbNOX) to increase redox ratio and MitoTempo as a mitochondrial free radical scavenger. RESULTS: Multiomics analyses revealed enrichment in mitochondrial oxidative function, protein synthesis and senescence pathways consistent with the known effects of hypoxia-inducible factor 1α (HIF1α) during normoxia. Across preclinical and clinical models, HIF1α targets (n = 32 genes) and signalling genes (n > 100 genes) (n = 3 ATACseq, n = 65 phosphoproteomics, n = 10 acetylomics, n = 6 C2C12 proteomics, n = 106 C2C12 RNAseq, n = 64 hiPSC RNAseq, n = 30 hiPSC proteomics, n = 3 mouse proteomics, n = 25 mouse RNAseq, n = 8 human RNAseq, n = 3 human proteomics) were increased. Stabilization of HIF1α (C2C12, 6hEtOH 0.24 ± 0.09; p = 0.043; mALD 0.32 ± 0.074; p = 0.005; data shown as mean difference ± standard error mean) was accompanied by enrichment in the early transient and late change clusters, -log(p-value) = 1.5-3.8, of the HIF1α signalling pathway. Redox ratio was reduced in ET myotubes (C2C12: 15512 ± 872.1, p < 0.001) and mALD muscle, with decreased expression of electron transport chain components (CI-V, p < 0.05) and Sirt3 (C2C12: 0.067 ± 0.023, p = 0.025; mALD: 0.41 ± 0.12, p = 0.013). Acetylation of mitochondrial proteins was increased in both models (C2C12: 107364 ± 4558, p = 0.03; mALD: 40036 ± 18 987, p = 0.049). Ethanol-induced SAMP was observed across models (P16: C2C12: 0.2845 ± 0.1145, p < 0.05; hiPSCm: 0.2591, p = 0.041). MitoLbNOX treatment reversed redox imbalance, HIF1α stabilization, global acetylation and myostatin expression (p < 0.05). CONCLUSIONS: An integrated multiomics approach, combined with experimental validation, identifies HIF1α stabilization and accelerated post-mitotic senescence as novel mechanisms of sarcopenia in ALD. These findings show the complex molecular interactions leading to mitochondrial dysfunction and progressive sarcopenia in ALD.

Sarcopenia↗

PubMed1977

The genome-associated, specific RNA binding proteins of avian and mammalian type C viruses.

A structural protein purified from the Rous sarcoma virus (RSV) can specificially bind in vitro to purified avian, but not mammalian, type C viral RNA. Following ultraviolet irradiation of viral particles under conditions which stabilize the polyploid 70S viral RNA, the same polypeptide can be directly purified from the RSV genome. Based on its electrophoretic mobility in polyacrylamide gels containing sodium dodecylsulfate, the RNA binding protein has been identified as the major phosphoprotein (p19) of avian type C viruses. Similar experiments show that the major phosphoproteins of mammalian type C viruses (p12 for murine viruses and p16 for endogenous primate viruses) are also the specific RNA binding proteins and, similarly, are found closely associated with the 70S RNA genomes in the intact viral particles.

Avian Sarcoma Viruses↗

PubMed1979

Antigenic variation in visna virus.

Two antigenic variants of visna virus were isolated sequentially from a single sheep inoculated with a plaque-purified strain of virus designated 1514. The genetically stable variants, LV1-1 and LV1-4, are of two classes: LV1-1 is partially neutralized by antibody to the inoculum strain 1514, while LV1-4 is not neutralized by antibody to 1514. The genetic mechanism responsible for generating the antigenic variants was investigated by comparing the chymotryptic and tryptic maps of the envelope glycoprotein gp135 and core polypeptides (p30, p16, p14), and by comparing the pattern of large oligonucleotides produced by digestion of the RNAs by T1 ribonuclease. We show that only the peptide maps of gp135 differ among strains, that the number of peptide fragments altered is small and that gp135 is the polypeptide that elicits neutralizing antibody. The maps of the RNAs are identical. We conclude that mutation in the glycoprotein gene rather than recombination is more probably responsible for antigenic variation, and speculate on the special aspects of visna virus replication relevant to this phenomenon.

Amino Acid Sequence↗