An implication of the mitochondrial carrier SLC25A3 as an oxidative stress modulator in NAFLD

Killing hepatocellular carcinoma in the NAFLD/NASH stage: a comprehensive perspective on targeting regulated cell death

Nonalcoholic steatohepatitis (NASH) has been identified as a significant risk factor contributing to the rising incidence of hepatocellular carcinoma (HCC). With the evolving epidemiological characteristics of NASH, the incidence of NASH-related HCC has increased substantially. Recent advances in the study of regulated cell death (RCD) mechanisms have uncovered their roles in the pathogenesis of NAFLD/NASH and associated HCC, offering novel insights and directions for targeted therapeutic strategies. Although numerous studies have highlighted the critical role of RCD mechanisms in NAFLD/NASH and related HCC, significant challenges remain in developing effective targeted therapies and translating them into clinical applications. This review aims to summarize the current progress in understanding the role of RCD in NAFLD/NASH and associated HCC, explore potential therapeutic strategies and clinical applications, and provide new perspectives and therapeutic targets for treating NAFLD/NASH. Ultimately, the goal is to control disease progression at the NAFLD/NASH stage and prevent its progression to HCC.

The Role of Solute Carrier Family Transporters in Hepatic Steatosis and Hepatic Fibrosis

Solute carrier (SLC) family transporters are crucial transmembrane proteins responsible for transporting various molecules, including amino acids, electrolytes, fatty acids, and nucleotides. To date, more than fifty SLC transporter subfamilies have been identified, many of which are linked to the progression of hepatic steatosis and fibrosis. These conditions are often caused by factors such as non-alcoholic fatty liver disease and non-alcoholic steatohepatitis, which are major contributors to the global liver disease burden. The activity of SLC members regulates the transport of substrates across biological membranes, playing key roles in lipid synthesis and metabolism, mitochondrial function, and ferroptosis. These processes, in turn, influence the function of hepatocytes, hepatic stellate cells, and macrophages, thereby contributing to the development of hepatic steatosis and fibrosis. Additionally, some SLC transporters are involved in drug transport, acting as critical regulators of drug-induced hepatic steatosis. Beyond substrate transport, certain SLC members also exhibit additional functions. Given the pivotal role of the SLC family in hepatic steatosis and fibrosis, this review aimed to summarize the molecular mechanisms through which SLC transporters influence these conditions.

The association between basal metabolic rate and ischemic stroke: a Mendelian randomization study

Objective

This study aims to elucidate the potential impact of basal metabolic rate on ischemic stroke at the genetic prediction level through a two-sample Mendelian randomization analysis.

Methods

Using summary data from genome-wide association studies, we obtained information on basal metabolic rate and ischemic stroke from a large-scale genome-wide association study. MR analysis used inverse variance weighting, weighted median, MR-Egger, simple mode, and weighted estimation. Sensitivity analyses, including the MR-Egger method, MR-PRESSO, Cochran's Q-test, and leave-one-out assessment, were performed to assess the reliability of the results.

Results

Genetic susceptibility to basal metabolic rate was significantly associated with ischemic stroke in multiple models, including the inverse variance weighting model (OR, 1.108 [95% CI: 1.005-1.221]; p = 0.0392), the weighted median method (OR, 1.179 [95% CI: 1.020-1.363]; p = 0.0263), and MR-Egger (OR, 1.291 [95% CI: 1.002-1.663]; p = 0.0491). These results indicate a positive causal relationship between basal metabolic rate and ischemic stroke. The MR-Egger intercept and Cochran's Q-test indicated the absence of heterogeneity and horizontal pleiotropy in the analyses of basal metabolic rate and ischemic stroke.

Conclusion

The MR analysis suggests a positive correlation between basal metabolic rate and ischemic stroke.

Potential association of neutrophil-albumin ratio with non-alcoholic fatty liver disease: A cross-sectional study based on NHANES

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) has become a major public health problem in the world. Exploring objective biomarkers for the prevention, monitoring, and clinical evaluation of NAFLD is of guiding significance for clinical targeted prevention and treatment. There is a complex interaction between inflammation and NAFLD. Exploring NAFLD-related inflammatory markers is helpful for elucidating its pathogenic mechanism.

AIM

To explore the potential association between the inflamma-tory marker neutrophil to albumin ratio (NAR) and NAFLD based on the National Health and Nutrition Examination Survey (NHANES) database.

METHODS

The participant data set of the NHANES database from 2017 to 2018 was selected. They were divided into NAFLD group and non-NAFLD group according to the occurrence of NAFLD or not. The clinical data of the two groups were compared. Logistic regression analysis was used to analyze the relationship between NAR and NAFLD, and restricted cubic spline (RCS) and threshold effect analysis were performed to explore the potential turning point.

RESULTS

A total of 4526 participants were enrolled, including 1503 patients with NAFLD. The NAR level in the NAFLD group was significantly higher than that of the non-NAFLD group (P < 0.05). There were also significant differences in gender, age, body mass index, smoking status, hypertension, antihypertensive drugs, diabetes, hypoglycemic agents, alanine aminotransferase, aspartate aminotransferase, blood urea nitrogen, creatinine, uric acid, triglyceride, and total cholesterol between the two groups (P < 0.05 for), and these variables were therefore included in the adjusted model analyses. In model 1 without any adjustment, NAR levels were associated with the risk of NAFLD (OR = 2.154). In the model 2 (OR = 1.375), model 3 (OR = 1.693), and model 4 (OR = 1.817) adjusting for some variables, their independent association still existed. RCS curve analysis showed that there was a nonlinear relationship between NAR and NAFLD (P_{for overall} < 0.001, P_{for nonlinear} < 0.001). Threshold effect analysis showed that the inflection point of NAR influencing NAFLD risk was 1.436, and when NAR was lower than 1.436, the risk of NAFLD occurrence increased by 3.304 times for each additional unit of NAR (OR = 3.304; 95% confidence interval: 2.649-4.122; P < 0.001). However, this study did not found the potential value of NAR in distinguishing non-alcoholic steatohepatitis.

CONCLUSION

The levels of NAR show an independent association with NAFLD. When NAR is lower than 1.436, the risk of NAFLD increases with the increase of NAR level.

Association between neutrophil-albumin ratio and ultrasound-defined metabolic dysfunction-associated fatty liver disease in U.S. adults: evidence from NHANES 2017-2018

BACKGROUND

Metabolic dysfunction-associated fatty liver disease (MAFLD) is increasingly prevalent, and systemic inflammation markers may play a role in its pathogenesis. This study aimed to investigate the relationship between neutrophil-albumin ratio (NAR) and MAFLD.

METHODS

This population-based study was performed using data from NHANES 2017-2018 and included 4526 individuals with a median age of 44 years old, and the males account for 46.13% (n = 2088). Ultrasound-defined MAFLD was diagnosed using a controlled attenuation parameter (CAP) threshold of ≥ 285 dB/m. Differences in baseline characteristics between patients with CAP ≥ 285 dB/m and < 285 dB/m were analyzed. A generalized additive model (GAM) and restricted cubic splines (RCS) were applied to explore the nonlinear relationship between NAR and CAP, followed by generalized linear models (GLMs). Threshold effect analysis was performed to identify the inflection point in the nonlinear relationship. CAP-related variables were ranked using XG Boost and random forest algorithms, and predictive models were developed and evaluated.

RESULTS

The study population included 1,503 patients with CAP ≥ 285 dB/m. NAR was significantly elevated in subjects with CAP ≥ 285 dB/m (P < 0.001), and nonlinear relationships between NAR and CAP were observed. NAR was positively associated with CAP in three GLMs, and this relationship remained after adjusting for confounding factors or dividing NAR into tertiles. Additionally, when NAR < 1.436, a one-unit rise in NAR was linked to a 3.304-fold increase in the risk of NAFLD (OR = 3.304, 95% CI: 2.649-4.122). The NAR-based random forest model showed the best predictive performance with AUC values of 0.978 (training) and 0.813 (validation).

CONCLUSION

NAR is positively associated with CAP, and the NAR-based random forest model is optimal for predicting MAFLD risk, highlighting the importance of NAR in predicting MAFLD.

Inducers of Autophagy and Cell Death: Focus on Copper Metabolism

Copper is an essential trace element in biological systems, playing a key role in various physiological functions, including redox reactions and energy metabolism. However, an imbalance in copper homeostasis can induce oxidative stress, mitochondrial dysfunction, and inhibition of the ubiquitin-proteasome system, ultimately leading to significant cytotoxicity and cell death. According to recent research, copper can bind to lipoylation sites on proteins involved in the tricarboxylic acid cycle, causing aggregation of lipoylated proteins, the loss of Fe-S cluster proteins, proteotoxic stress, and ultimately, cell death. This new type of programmed cell death is called "Cuproptosis". Furthermore, autophagy may be activated by a disruption in copper homeostasis, while it plays a dual role in regulating copper-induced cell death by acting both as an inhibitor of cell death and as a promoter of cytotoxicity. This review summarizes research progress on copper metabolic patterns, molecular mechanisms of copper-induced cell death, and mechanisms of copper-induced autophagy-cytotoxicity interactions. Meanwhile, the application of copper-induced cell death in cancer therapy is discussed, aiming to provide new insights and guiding future research toward advancing cancer therapy.

Copper homeostasis and cuproptosis-related genes: Therapeutic perspectives in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD), a metabolic-associated fatty liver disease, has become the most common chronic liver disease worldwide. Recently, the discovery of cuproptosis, a newly identified mode of cell death, further highlighted the importance of copper in maintaining metabolic homeostasis. An increasing number of studies have confirmed that liver copper metabolism is closely related to the pathogenesis of NAFLD. However, the relationship between NAFLD and copper metabolism, especially cuproptosis, remains unclear. In this review, we aim to summarize the current understanding of copper metabolism and its dysregulation, particularly the role of copper metabolism dysregulation in the pathogenesis of NAFLD. More importantly, this review emphasizes potential gene-targeted therapeutic strategies, challenges and the future of cuproptosis-related genes in the treatment of NAFLD. This review aims to provide innovative therapeutic strategies for NAFLD.

Calcium signaling in mitochondrial intermembrane space

The mitochondrial intermembrane space (IMS) is a highly protected compartment, second only to the matrix. It is a crucial bridge, coordinating mitochondrial activities with cellular processes such as metabolites, protein, lipid, and ion exchange. This regulation influences signaling pathways for metabolic activities and cellular homeostasis. The IMS harbors various proteins critical for initiating apoptotic cascades and regulating reactive oxygen species production by controlling the respiratory chain. Calcium (Ca2+), a key intracellular secondary messenger, enter the mitochondrial matrix via the IMS, regulating mitochondrial bioenergetics, ATP production, modulating cell death pathways. IMS acts as a regulatory site for Ca2+ entry due to the presence of different Ca2+ sensors such as MICUs, solute carriers (SLCs); ion exchangers (LETM1/SCaMCs); S100A1, mitochondrial glycerol-3-phosphate dehydrogenase, and EFHD1, each with unique Ca2+ binding motifs and spatial localizations. This review primarily emphasizes the role of these IMS-localized Ca2+ sensors concerning their spatial localization, mechanism, and molecular functions. Additionally, we discuss how these sensors contribute to the progression and pathogenesis of various human health conditions and diseases.

Modulation of prostaglandin transport activity of SLCO2A1 by annexin A2 and S100A10

Solute carrier organic anion transporter family member 2A1 (SLCO2A1) is a prostaglandin (PG) transporter and serves as the osmosensitive ATP-permeable maxi-anion channel (Maxi-Cl). Since a heterotetrameric complex of annexin A2 (ANXA2) and S100A10 is obligatory for the channel activity, the present study aimed to determine if they regulate SLCO2A1-mediated PG transport. This study examined PGE2 uptake and ATP release in Anxa2 and/or S100a10 knockout (KO) murine breast C127 cells. Deletion of Slco2a1 decreased PGE2-d4 uptake by wild-type (WT) cells in an isotonic medium (290 mosmol/kgH2O). Decreased osmolarity (135 mosmol/kgH2O) stimulated ATP release but did not affect PGE2 uptake kinetics, showing Km (1,280 nM) and Vmax (10.38 pmol/15 s/mg protein) similar to those in isotonic medium (1,227 nM and 10.65 pmol/15 s/mg protein), respectively, in WT cells. Deletion of Anxa2 associated with loss of S100a10 diminished SLCO2A1-mediated ATP release and uncompetitively inhibited PGE2 uptake with lowered Km (376 nM) and Vmax (2.59 pmol/15 s/mg protein). Moreover, the immunoprecipitation assay confirmed the physical interaction of ANXA2 with SLCO2A1 in WT cells. Enforcement of ANXA2 expression to Anxa2 KO cells partially restored PGE2 uptake and increased Km (744.3 nM) and Vmax (9.07 pmol/15 s/mg protein), whereas the uptake clearance (Vmax/Km) did not change much regardless of ANXA2 expression. These results suggest that an ANXA2/S100A10 complex modulates PG transport activity but osmolality has little effect on it; therefore, the bound form of SLCO2A1, which functions as a PG transporter and Maxi-Cl, may exist regardless of changes in the cell volume.NEW & NOTEWORTHY A previous study indicated that the ANXA2/S100A10 complex represents the regulatory component of SLCO2A1-mediated Maxi-Cl channel activity. The present study showed that apparent PGE2 uptake by C127 cells was osmoinsensitive and uncompetitively inhibited by loss of ANXA2 expression, demonstrating that ANXA2 is a regulatory factor of SLCO2A1-mediated PG transport activity.