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Journal of Applied Physiology... Jun 2024This systematic review and meta-analysis examined the physiological mechanisms responsible for lower peak exercise leg oxygen uptake (V̇o) in patients with chronic... (Meta-Analysis)
Meta-Analysis Review
This systematic review and meta-analysis examined the physiological mechanisms responsible for lower peak exercise leg oxygen uptake (V̇o) in patients with chronic disease. Studies measuring peak leg V̇o (primary outcome) and its physiological determinants during large (cycle) or small muscle mass exercise (single-leg knee extension, SLKE) in patients with chronic disease were included in this meta-analysis. Pooled estimates for each outcome were reported as a weighted mean difference (WMD) between chronic disease and controls. We included 10 studies that measured peak leg V̇o in patients with chronic disease ( = 109, mean age: 45 yr; encompassing chronic obstructive pulmonary disease, COPD, heart failure with reduced ejection fraction, HFrEF, or chronic renal failure, RF) and age-matched controls ( = 88). In pooled analysis, peak leg V̇o (WMD; -0.23 L/min, 95% CI: -0.32 to -0.13), leg oxygen (O) delivery (WMD: -0.27 L/min, 95% CI: -0.37 to -0.17), and muscle O diffusive conductance (WMD: -5.2 mL/min/mmHg, 95% CI: -7.1 to -3.2) were all significantly lower during cycle and SLKE exercise in chronic disease versus controls. These results highlight that during large and small muscle mass exercise in patients with COPD, HFrEF, or RF, there is no single factor causing peak V̇o limitations. Specifically, the lower peak V̇o in these pathologies is due to not only the expected impairments in convective O delivery but also impairments in muscle oxygen diffusive transport from capillary to mitochondria. Whether impaired muscle O transport is caused solely by inactivity or additional muscle pathology remains in question. Peripheral (skeletal muscle and vasculature) factors contribute significantly to reduced exercise capacity during both large and small muscle mass exercise in chronic diseases such as COPD, HFrEF, or RF and should be important targets of therapy in addition to the primary organs (lungs, heart, and kidneys) affected by disease.
Topics: Humans; Oxygen Consumption; Leg; Muscle, Skeletal; Chronic Disease; Exercise; Pulmonary Disease, Chronic Obstructive; Oxygen; Heart Failure
PubMed: 38482572
DOI: 10.1152/japplphysiol.00918.2023 -
Journal of Cancer Research and Clinical... Jan 2024Human papilloma virus (HPV)-positive head and neck squamous cell carcinoma (HNSCC) displays distinct epidemiological, clinical, and molecular characteristics compared to... (Review)
Review
PURPOSE
Human papilloma virus (HPV)-positive head and neck squamous cell carcinoma (HNSCC) displays distinct epidemiological, clinical, and molecular characteristics compared to the negative counterpart. Alterations in autophagy play an important role in cancer, and emerging evidence indicates an interplay of autophagy in HNSCC carcinogenesis and tumor promotion. However, the influence of HPV infection on autophagy in HNSCC has received less attention and has not been previously reviewed. Therefore, we here aimed to systematically review the role of autophagy explicitly in HPV HNSCC.
METHODS
Studies accessible in PubMed, Embase, Scopus, and Web of Science investigating HNSCC, highlighting the molecular biological differences between HPV and HPV HNSCC and its influences on autophagy in HNSCC were analyzed according to the PRISMA statement. A total of 10 articles were identified, included, and summarized.
RESULTS
The HPV16 E7 oncoprotein was reported to be involved in the degradation of AMBRA1 and STING, and to enhance chemotherapy-induced cell death via lethal mitophagy in HNSCC cells. Autophagy-associated gene signatures correlated with HPV-subtype and overall survival. Additionally, immunohistochemical (IHC) analyses indicate that high LC3B expression correlates with poor overall survival in oropharyngeal HNSCC patients.
CONCLUSION
HPV may dampen general bulk autophagic flux via degradation of AMBRA1 but may promote selective autophagic degradation of STING and mitochondria. Interpretations of correlations between autophagy-associated gene expressions or IHC analyses of autophagy-related (ATG) proteins in paraffin embedded tissue with clinicopathological features without biological validation need to be taken with caution.
Topics: Humans; Squamous Cell Carcinoma of Head and Neck; Papillomavirus Infections; Head and Neck Neoplasms; Carcinoma, Squamous Cell; Autophagy; Adaptor Proteins, Signal Transducing
PubMed: 38291202
DOI: 10.1007/s00432-023-05514-3 -
Molecules (Basel, Switzerland) Jun 2024Our hypothesis that controlled ozone applications interfere with the redox balance of a biological organism (first published in 1998 with a preclinical trial on... (Review)
Review
Our hypothesis that controlled ozone applications interfere with the redox balance of a biological organism (first published in 1998 with a preclinical trial on protecting the liver from CCl intoxication) has been verified over the past two decades in reactive oxygen species (ROS)-induced mitochondrial pathologies, such as rheumatoid arthritis, osteoarthritis, aging processes and type 2 diabetes, and in the prevention of intoxications. Low-dose ozone acts as a redox bioregulator: the restoration of the disturbed redox balance is comprehensible in a number of preclinical and clinical studies by a remarkable increase in the antioxidant repair markers, here mainly shown as a glutathione increase and a reduction in oxidative stress markers, mainly malondialdehyde. The mechanism of action is shown, and relevant data are displayed, evaluated and comprehensively discussed: the repair side of the equilibrium increases by 21% up to 140% compared to the non-ozone-treated groups and depending on the indication, the stress markers are simultaneously reduced, and the redox system regains its balance.
Topics: Oxidative Stress; Ozone; Oxidation-Reduction; Humans; Mitochondria; Reactive Oxygen Species; Animals; Antioxidants; Biomarkers
PubMed: 38930804
DOI: 10.3390/molecules29122738 -
Genome Research Apr 2024Mitochondrial DNA (mtDNA) variants cause a range of diseases from severe pediatric syndromes to aging-related conditions. The percentage of mtDNA copies carrying a...
Mitochondrial DNA (mtDNA) variants cause a range of diseases from severe pediatric syndromes to aging-related conditions. The percentage of mtDNA copies carrying a pathogenic variant, variant allele frequency (VAF), must reach a threshold before a biochemical defect occurs, termed the biochemical threshold. Whether the often-cited biochemical threshold of >60% VAF is similar across mtDNA variants and cell types is unclear. In our systematic review, we sought to identify the biochemical threshold of mtDNA variants in relation to VAF by human tissue/cell type. We used controlled vocabulary terms to identify articles measuring oxidative phosphorylation (OXPHOS) complex activities in relation to VAF. We identified 76 eligible publications, describing 69, 12, 16, and 49 cases for complexes I, III, IV, and V, respectively. Few studies evaluated OXPHOS activities in diverse tissue types, likely reflective of clinical access. A number of cases with similar VAFs for the same pathogenic variant had varying degrees of residual activity of the affected complex, alluding to the presence of modifying variants. Tissues and cells with VAFs <60% associated with low complex activities were described, suggesting the possibility of a biochemical threshold of <60%. Using Kendall rank correlation tests, the VAF of the m.8993T > G variant correlated with complex V activity in skeletal muscle (τ = -0.58, = 0.01, n = 13); however, no correlation was observed in fibroblasts ( = 0.7, n = 9). Our systematic review highlights the need to investigate the biochemical threshold over a wider range of VAFs in disease-relevant cell types to better define the biochemical threshold for specific mtDNA variants.
Topics: Humans; DNA, Mitochondrial; Gene Frequency; Genetic Variation; Mitochondria; Mitochondrial Diseases; Oxidative Phosphorylation
PubMed: 38627095
DOI: 10.1101/gr.278200.123 -
PloS One 2024This study aimed to assess the correlation between the circulating cell-free mitochondria DNA and inflammation factors in noninfectious disease by meta-analysis of data... (Meta-Analysis)
Meta-Analysis
OBJECTIVE
This study aimed to assess the correlation between the circulating cell-free mitochondria DNA and inflammation factors in noninfectious disease by meta-analysis of data from eligible studies.
MATERIALS AND METHODS
Through a comprehensive searching of pubmed, embase, web of science, cochrane from establishment of the database to October 31, 2022, studies were selected that investigated the association of circulating cell free mitochondria DNA with inflammatory factors in non-infectious diseases. Studies that met the inclusion criteria and were published in English or Chinese were included. Data of each correlation coefficients were extracted from the paper and 95% confidence intervals were calculated. Sensitivity and heterogeneity tests were carried out for each data.
RESULTS
A total of 660 articles were retrieved and 22 were included in this meta-analysis, including 2600 patients. A fixed effects model was employed to examine ISS and IL-8, others were analyzed using random effects models. The correlation coefficient between mtDNA and ISS score was 0.37 (95%CI = [0.232;0.494]), p<0.0001, heterogeneity I2 = 46%, p = 0.11). The correlation coefficients between mtDNA and inflammatory factors are as follows: TNFα, 0.405 [(95%CI = [0.253;0.538], p<0.0001, heterogeneity I2 = 77%, p = 0.0001]. IL-6, 0.469 [(95%CI = [0.296;0.612]), p = 0.0001, heterogeneity I2 = 93%, p<0.0001]. CRP, 0.333[(95%CI = [0.149;0.494]), p = 0.005, heterogeneity I2 = 85%, p<0.0001]. IL-8, 0.343[(95%CI = [0.233;0.524]), p = 0.001, heterogeneity I2 = 50%, p = 0.09]. PCT, 0.333 [(95%CI = [0.06;0.64]), p = 0.09,heterogeneity I2 = 64%,p = 0.06]. There were no significant publication bias for TNFα, IL-6 and CRP.
CONSLUSION
Circulating cell free mtDNA was moderate positively correlated with the expression of inflammatory factors and the degree of trauma.
Topics: Humans; Noncommunicable Diseases; Tumor Necrosis Factor-alpha; Interleukin-6; Interleukin-8; Inflammation; DNA, Mitochondrial; Mitochondria
PubMed: 38241222
DOI: 10.1371/journal.pone.0289338