Utibe-Abasi Sunday Udoh

Obstructive sleep apnea (OSA) is defined by repetitive episodes of partial or complete upper airway obstruction during sleep, leading to hypopneas or apneas respectively despite continued respiratory effort. Epidemiological estimates suggest that OSA affects approximately one billion individuals worldwide, with a higher prevalence in men than in women. The condition is primarily marked by intermittent hypoxia and sleep fragmentation, both of which contribute to a wide range of physiological, medical, and psychological consequences. These include increased sympathetic nervous system activity, oxidative stress, systemic inflammation, and downstream neurological, cardiovascular, and metabolic complications that ultimately accelerate biological aging and increase overall mortality. Among the cardiovascular end‐organ manifestations of OSA, hypertension, coronary artery disease, atrial fibrillation, and stroke are now well documented. OSA is also strongly associated with metabolic dysfunction, including insulin resistance, dyslipidemia, steatosis of the liver, and Type 2 diabetes. In addition, sleep apnea leads to excessive daytime sleepiness, impaired alertness and vigilance, memory deficits, and executive dysfunction. These impairments increase the risk of motor vehicle and workplace accidents and contribute to diminished quality of life and increased healthcare costs. Here, we provide an overview of the systemic consequences of sleep apnea and examine the mechanisms linking the disorder to altered physiological function. We also explore the psychological outcomes associated with OSA and highlight the substantial societal and economic burden imposed by untreated diseases on healthcare systems and on society at large.

MASH is a progressive liver disease closely associated with cellular senescence, which is present in more than 80% of hepatocytes in patients who develop hepatocellular carcinoma (HCC). Although MASH affects both sexes, the incidence of MASH-related HCC is two to four times higher in males. Our group has previously described two apoptotic switches during MASH progression and HCC development, implicating the ATP1A1 signalosome in the late switch. Here, we investigated the role of ATP1A1 and sex-specific differences in the early apoptotic switch during preclinical MASH progression. Male and female C57BL/6J mice (7 weeks old) were fed normal mouse chow (NMC) or a high-fat diet (HFD) for 12, 24, or 48 weeks (n = 5/sex/group). Total body weight (TBW) and body composition were assessed by serial measurement and echo-MRI. Plasma was analyzed by non-targeted metabolomics and glutathione profiling using LC-MS/MS. NAFLD activity scores (NAS), hepatic senescence, and apoptosis were quantified in liver tissue. Statistical analyses were performed using GraphPad Prism and R. Males gained greater TBW and lean and fat mass than females (p < 0.05). At 24 W, males demonstrated higher GSH:GSSG ratios and lower ophthalmate levels than females (p < 0.05), consistent with altered redox balance. HFD-fed females showed increased succinic and deoxycholic acid levels, whereas males exhibited higher butyric acid levels across all time points (p < 0.05). Males had a higher mTOR 1 expression at 24 W and P53 at 12 W compared to females on HFD, but a lower Grb2 expression at 24 W (p < 0.05). By 24 W, males had lower fibrosis scores and reduced apoptotic activity compared with females (p < 0.05), despite similar levels of cellular senescence. The expression of ATP1A1, survivin, and SMAC did not differ by sex or diet, although an upregulation trend in both ATP1A1 and survivin was noted in the male-HFD group. There is sexual dimorphism in the response to HFD during the transition from senescence to the apoptosis-first apoptotic switch in MASH progression.

Background. Metabolic dysfunction-associated steatotic liver disease (MASLD) affects more than 30% of the world population. Progression to its inflammatory state, MASH, is associated with increasing liver fibrosis, leading to end-stage liver disease (ESLD) and hepatocellular carcinoma (HCC). SW033291, an inhibitor of 15-PGDH (the PGE2 degradation enzyme), has been shown to increase in vivo regeneration of liver parenchyma, ameliorating oxidative stress and inflammation. We hypothesized that SW033291 abrogates MASH progression by inducing a paucity of the initial apoptotic switch and restoring physiological collagen’s microenvironment. Methods. The expression levels of the cell metabolic proteins FOXO1, mTOR, and SIRT7 were determined in a diet-induced MASH-mouse model at 16, 20, and 24 weeks. Non-targeted metabolomics in mouse plasma were measured by LC-MS/MS. Liver morphology and apoptotic activity were quantified by the NAS score and TUNEL assay, respectively. Statistical analyses between groups (NMC, HFD, and SW033291) were determined by ANOVA, t-test/Tukey’s post hoc test using GraphPad Prism. Metabolomics data were analyzed using R-lab. Results. The treated group showed significant decreases in total body fat, cellular oxidative stress, and inflammation and an increase in total lean mass with improved insulin resistance and favorable modulation of metabolic protein expressions (p < 0.05). SW033291 significantly decreased GS:SG, citric acid, and corticosterone, NAS scores (9.4 ± 0.2 vs. 6.2 ± 0.1, p < 0.05), liver fibrosis scores (1.3 ± 0.5 vs. 0.25 ± 0.1, p < 0.05), and apoptotic activity (43.9 ± 4.6 vs. 0.38 ± 0.1%, p < 0.05) compared with controls at 24W. Conclusions. The inhibition of 15-PGDH appears to normalize the metabolic and morphological disturbances during MASH progression with a paucity of the initial apoptotic switch, restoring normal collagen architecture. SW033291 warrants further investigation for its translation.

Circadian rhythms are endogenous behavioral or physiological cycles that are driven by a daily biological clock that persists in the absence of geophysical or environmental temporal cues. Circadian rhythm-related genes code for clock proteins that rise and fall in rhythmic patterns driving biochemical signals of biological processes from metabolism to physiology and behavior. Clock proteins have a pivotal role in liver metabolism and homeostasis, and their disturbances are implicated in various liver disease processes. Encoded genes play critical roles in the initiation and progression of metabolic dysfunction-associated steatohepatitis (MASH) to hepatocellular carcinoma (HCC) and their proteins may become diagnostic markers as well as therapeutic targets. Understanding molecular and metabolic mechanisms underlying circadian rhythms will aid in therapeutic interventions and may have broader clinical applications. The present review provides an overview of the role of the liver’s circadian rhythm in metabolic processes in health and disease, emphasizing MASH progression and the oncogenic associations that lead to HCC.

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related death worldwide. In metabolic dysfunction-associated steatohepatitis (MASH)-related HCC, cellular redox imbalance from metabolic disturbances leads to dysregulation of the α1-subunit of the Na/K-ATPase (ATP1A1) signalosome. We have recently reported that the normalization of this pathway exhibited tumor suppressor activity in MASH-HCC. We hypothesized that dysregulated signaling from the ATP1A1, mediated by cellular metabolic stress, promotes aberrant epigenetic modifications including abnormal post-translational histone modifications and dysfunctional autophagic activity, leading to HCC development and progression. Increased H3K9 acetylation (H3K9ac) and H3K9 tri-methylation (H3K9me3) were observed in human HCC cell lines, HCC-xenograft and MASH-HCC mouse models, and epigenetic changes were associated with decreased cell autophagy in HCC cell lines. Inhibition of the pro-autophagic transcription factor FoxO1 was associated with elevated protein carbonylation and decreased levels of reduced glutathione (GSH). In contrast, normalization of the ATP1A1 signaling significantly decreased H3K9ac and H3K9me3, in vitro and in vivo, with concomitant nuclear localization of FoxO1, heightening cell autophagy and cancer-cell apoptotic activities in treated HCC cell lines. Our results showed the critical role of the ATP1A1 signalosome in HCC development and progression through epigenetic modifications and impaired cell autophagy activity, highlighting the importance of the ATP1A1 pathway as a potential therapeutic target for HCC.

Metabolic dysfunction-associated steatohepatitis (MASH) is one of the major risk factors for chronic liver disease and hepatocellular carcinoma (HCC). The incidence of MASH in Western countries continues to rise, driving HCC as the third cause of cancer-related death worldwide. HCC has become a major global health challenge, partly from the obesity epidemic promoting metabolic cellular disturbances but also from the paucity of biomarkers for its early detection. Over 50% of HCC cases are clinically present at a late stage, where curative measures are no longer beneficial. Currently, there is a paucity of both specific and sensitive biological markers for the early-stage detection of HCC. The search for biological markers in the diagnosis of early HCC in high-risk populations is intense. We described the potential role of surrogates for a liver biopsy in the screening and monitoring of patients at risk for nesting HCC.

Autophagy, a cellular self-digestion process, involves the degradation of targeted cell components such as damaged organelles, unfolded proteins, and intracellular pathogens by lysosomes. It is a major quality control system of the cell and plays an important role in cell differentiation, survival, development, and homeostasis. Alterations in the cell autophagic machinery have been implicated in several disease conditions, including neurodegeneration, autoimmunity, cancer, infection, inflammatory diseases, and aging. In non-alcoholic fatty liver disease, including its inflammatory form, non-alcoholic steatohepatitis (NASH), a decrease in cell autophagic activity, has been implicated in the initial development and progression of steatosis to NASH and hepatocellular carcinoma (HCC). We present an overview of autophagy as it occurs in mammalian cells with an insight into the emerging understanding of the role of autophagy in NASH and NASH-related HCC.

Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related mortality worldwide, with an estimate of 0.84 million cases every year. In Western countries, because of the obesity epidemic, non-alcoholic steatohepatitis (NASH) has become the major cause of HCC. Intriguingly, the molecular mechanisms underlying tumorigenesis of HCC from NASH are largely unknown. We hypothesized that the growing uncoupled metabolism during NASH progression to HCC, manifested by lower cell redox status and an apoptotic ‘switch’ activity, follows a dysregulation of α1-Na/K-ATPase (NKA)/Src signalosome. Our results suggested that in NASH-related malignancy, α1-NKA signaling causes upregulation of the anti-apoptotic protein survivin and downregulation of the pro-apoptotic protein Smac/DIABLO via the activation of the PI3K → Akt pro-survival pathway with concomitant inhibition of the FoxO3 circuit, favoring cell division and primary liver carcinogenesis. Signalosome normalization using an inhibitory peptide resets apoptotic activity in malignant cells, with a significant decrease in tumor burden in vivo. Therefore, α1-NKA signalosome exercises in HCC the characteristic of a tumor suppressor, suggesting α1-NKA as a putative target for clinical therapy.

BACKGROUND. Two sequelae of non-alcoholic steatohepatitis (NASH), ESLD and HCC, have become the leading causes for liver transplantation in the Western. The present study aims to approach the cellular metabolic disturbances involved in NASH progression that are associated with microbiota community changes. METHODS. Metabolic effects and microbiota community changes were explored in the murine with NASH progression by blocking the Na/K-ATPase/Src/reactive oxygen amplification loop using the synthetic targeting peptide pNaKtide. DNA from the terminal ileum microbiota habitat was obtained and amplified by PCR to develop DNA bacterial phylogenic sequence analysis of wild type and treated animals at 12, 24 and 48 weeks. Induced changes by pSrc normalization at 24 weeks were correlated with liver morphological changes, intestinal CD4+/CD8+ ratio, and liver macrophage CD14+ expression. Differences among groups were evaluated by ANOVA/t-test and Principal Component Analysis (PCA). RESULTS. Microbiota communities varied significantly at all time points (12, 24 and 48 weeks), with an increase of Verrucomicrobia and a decrease of Bacteroidetes and Firmicutes in the HFD group. Microbiota community changes regressed to their wild-type state at 24 weeks on treated animals, and those changes were associated with a decrease in liver inflammation and senescence, lower ileum CD4+/CD8+ T cells and higher liver CD14+ cells (p<0.05). Concomitantly, the metabolic disturbances in our diet-induced NASH model were normalized by NKA/Src signaling blockage and exercise with a paucity of apoptotic activity, mitigation of cell senescence, and regression of liver fibrosis (p<0.01). CONCLUSIONS. pSrc inhibition at caveolar α1-Na/K-ATPase rescinded NASH-related metabolic disturbances establishing resident physiological microbiota communities with concomitant paucity on apoptotic activity and regression of liver fibrosis; effects that were associated with both gut and liver T-lymphocyte responses.

Background: Hepatocellular Carcinoma (HCC) is the second and fastest‐growing cause of cancer‐ related mortality worldwide. In the Western countries, due to the epidemic of obesity, non‐alcoholic steatohepatitis (NASH) has become the major cause of HCC. Intriguingly, the molecular mechanisms that underlie the progression of NASH to HCC is still unclear. Hypothesis: We hypothesized that, the growing uncoupled metabolism during NASH progression to ESLD and HCC manifested by lower cell oxi‐redox status and an apoptotic ‘switch’ activity, follows a dysregulation in the wild type Caveolar α1‐Na/K‐ATPase (NKA)/Src signalosome, promoting an amplification of the pSrc → PI3K→ Akt pathway, which mediates survivin overexpression driving local carcinogenesis. Methods: Expression of Cav‐1/Smac‐Diablo/Survivin proteins was performed by confocal‐microscopy on immuno‐stained HCC cell lines (Hep3B and SNU475), and livers in both NASH and NASH‐HCC rodent models, and in humans. Apoptotic activity was assayed via TUNEL. Tumor burden in rodents’ livers were evaluated using ImageJ software on H&E‐stained liver tissues and fibrosis via trichrome staining. Furthermore, signaling pathway studies were explored in‐vitro guided by RNA sequencing. Selective blockage of Src‐p at its kinase domain was performed by administration of a synthetic peptide (pNaKtide). Significant differences among groups were established at p<0.05 using ANOVA/Turkey’s post hoc test. Results: Blockage of Src‐p at the α1‐NKA promoted apoptosis of Human HCC cell lines and tumors of disease murine models in a dose dependent manner (p< 0.01). pNaKtide at IC50 drove the downregulation and upregulation of Survivin and SMAC expressions (p<0.05), respectively in HCC cell lines. In‐vivo, liver tumor burden and fibrosis were significantly lower in animals treated with pNaKtide vs non‐treated animals (p<0.01). Furthermore, Cav‐1 and Survivin expressions were significantly higher, while SMAC protein expression was significantly lower in livers from rodents with NASH/HCC vs animals treated with pNaKtide (p<0.01). Similar pattern of proteins expressions was noted in tumors from patients with NASH±HCC vs liver tissue from healthy subjects or subjects with liver metastases (p<0.05). In‐vitro, Src‐p at the α1‐NKA activates PI3K/Akt pathway with concomitant inhibition of the FoxO cascade, favoring cell division and primary liver carcinogenesis. Conclusions: Caveolar Src‐phosphorylation at the α1‐Na/K‐ATPase regulated Survivin/SMAC expressions, leading to cellular “switch” from apoptosis to cell division via the activation of the PI3K/Akt pro‐survival pathway with concomitant inhibition of the FoxO cascade. Therefore, point target blockage may be explored as a treatment for tumor regression in HCC.