COMMD10 is critical for Kupffer cell survival and controls Ly6Chi monocyte differentiation and inflammation in the injured liver

Fatty acid synthesis is indispensable for Kupffer cells to eliminate bacteria in ALD progression

BACKGROUND

Dysregulated fatty acid metabolism is closely linked to the development of alcohol-associated liver disease (ALD). KCs, which are resident macrophages in the liver, play a critical role in ALD pathogenesis. However, the effect of alcohol on fatty acid metabolism in KCs remains poorly understood. The current study aims to investigate fatty acid metabolism in KCs and its potential effect on ALD development.

METHODS

Wild-type C57BL/6 mice were fed a Lieber-DeCarli ethanol liquid diet for 3 days. Then, the liver injury and levels of intrahepatic bacteria were assessed. Next, we investigated the effects and underlying mechanisms of ethanol exposure on fatty acid metabolism and the phagocytosis of KCs, both in vivo and in vitro. Finally, we generated KCs-specific Fasn knockout and overexpression mice to evaluate the impact of FASN on the phagocytosis of KCs and ethanol-induced liver injury.

RESULTS

Using Bodipy493/503 to stain intracellular neutral lipids, we found significantly reduced lipid levels in KCs from mice fed an alcohol-containing diet for 3 days and in RAW264.7 macrophages exposed to ethanol. Mechanistically, alcohol exposure suppressed sterol regulatory element-binding protein 1 transcriptional activity, thereby inhibiting fatty acid synthase (FASN)-mediated de novo lipogenesis in macrophages both in vitro and in vivo. We show that genetic ablation and pharmacologic inhibition of FASN significantly impaired KC's ability to take up and eliminate bacteria. Conversely, KCs-specific Fasn overexpression reverses the impairment of macrophage phagocytosis caused by alcohol exposure. We also revealed that KCs-specific Fasn knockout augmented KCs apoptosis and exacerbated liver injury in mice fed an alcohol-containing diet for 3 days.

CONCLUSIONS

Our findings indicate the crucial role of de novo lipogenesis in maintaining effective KCs phagocytosis and suggest a therapeutic target for ALD based on fatty acid synthesis in KCs.

COMMD10 inhibited DNA damage to promote the progression of gastric cancer

PURPOSE

The copper metabolism MURR1 domain 10 (COMMD10) plays a role in a variety of tumors. Here, we investigated its role in gastric cancer (GC).

METHODS

Online prediction tools, quantitative real-time PCR, western blotting and immunohistochemistry were used to evaluate the expression of COMMD10 in GC. The effect of COMMD10 knockdown was investigated in the GC cell lines and in in vivo xenograft tumor experiments. Western blotting and immunofluorescence were used to explore the relationships between COMMD10 and DNA damage.

RESULTS

The expression of COMMD10 was upregulated in GC compared to that in para-cancerous tissue and correlated with a higher clinical TNM stage (P = 0.044) and tumor size (P = 0.0366). High COMMD10 expression predicted poor prognosis in GC. Knockdown of COMMD10 resulted in the suppression of cell proliferation, migration, and invasion, accompanied by cell cycle arrest and an elevation in apoptosis rate. Moreover, the protein expression of COMMD10 was decreased in cisplatin-induced DNA-damaged GC cells. Suppression of COMMD10 impeded DNA damage repair, intensified DNA damage, and activated ATM-p53 signaling pathway in GC. Conversely, restoration of COMMD10 levels suppressed DNA damage and activation of the ATM-p53 signaling cascade. Additionally, knockdown of COMMD10 significantly restrained the growth of GC xenograft tumors while inhibiting DNA repair, augmenting DNA damage, and activating the ATM-p53 signaling pathway in xenograft tumor tissue.

CONCLUSION

COMMD10 is involved in DNA damage repair and maintains genomic stability in GC; knockdown of COMMD10 impedes the development of GC by exacerbating DNA damage, suggesting that COMMD10 may be new target for GC therapy.

Exploring the Shared Genetic Architecture Between Obstructive Sleep Apnea and Body Mass Index

Purpose

The reciprocal comorbidity of obstructive sleep apnea (OSA) and body mass index (BMI) has been observed, yet the shared genetic architecture between them remains unclear. This study aimed to explore the genetic overlaps between them.

Methods

Summary statistics were acquired from the genome-wide association studies (GWASs) on OSA (Ncase = 41,704; Ncontrol = 335,573) and BMI (Noverall = 461,460). A comprehensive genome-wide cross-trait analysis was performed to quantify global and local genetic correlation, infer the bidirectional causal relationships, detect independent pleiotropic loci, and investigate potential comorbid genes.

Results

A positive significant global genetic correlation between OSA and BMI was observed (r g = 0.52, P = 2.85e-122), which was supported by three local signal. The Mendelian randomization analysis confirmed bidirectional causal associations. In the meta-analysis of cross-traits GWAS, a total of 151 single-nucleotide polymorphisms were found to be pleiotropic between OSA and BMI. Additionally, we discovered that the genetic association between OSA and BMI is concentrated in 12 brain regions. Finally, a total 134 expression-tissue pairs were observed to have a significant impact on both OSA and BMI within the specified brain regions.

Conclusion

Our comprehensive genome-wide cross-trait analysis indicates a shared genetic architecture between OSA and BMI, offering new perspectives on the possible mechanisms involved.

Decoding Gastric Cancer: Machine Learning Insights Into the Significance of COMMDs Family in Immunotherapy and Diagnosis

Copper, an indispensable trace element for the human body, serves not only as a crucial auxiliary factor in redox reactions within the organism but also as a significant constituent of numerous key metabolic enzymes. The COMMD family plays a vital role in regulating copper at both the cellular and systemic levels, particularly in the realm of tumor research, an area notably deficient in gastric cancer investigations. With the advancement of precision medical techniques, individualized and precise screening and treatment have become paramount considerations in the contemporary medical landscape for gastric cancer therapy. In light of this, we meticulously scrutinized existing transcriptomic datasets for gastric cancer, validating the expression levels and prognostic value of COMMD family genes. Simultaneously, employing the ssGSEA algorithm, we devised the COMMDs score. Enrichment analysis, gene mutations, and clinical features were incorporated into the assessment of this score. Furthermore, we contextualized the COMMDs score within the framework of the immune microenvironment, evaluating the relationship between the COMMDs family and immune factors as well as immune cells. The results suggest a correlation between the COMMDs score and various immune-related features. Based on this foundation, multiple machine learning approaches indicated Logistic Regression, with a remarkable ROC of 0.972, as the optimal diagnostic model. To accentuate the translational medical value of the COMMDs family, we selected COMMD10 as a differential gene in gastric cancer for further validation. Functional experiments revealed a decline in the proliferative and migratory capabilities of gastric cancer cells upon silencing COMMD10. Additionally, through pathway intervention, we unveiled the PI3K-AKT pathway as a potential mechanism through which COMMD10 influences gastric cancer activity. In summary, our study affirms the prospective role of the COMMDs family as potential markers for the diagnosis and treatment of gastric cancer in the future.

Cuproptosis: unveiling a new frontier in cancer biology and therapeutics

Copper plays vital roles in numerous cellular processes and its imbalance can lead to oxidative stress and dysfunction. Recent research has unveiled a unique form of copper-induced cell death, termed cuproptosis, which differs from known cell death mechanisms. This process involves the interaction of copper with lipoylated tricarboxylic acid cycle enzymes, causing protein aggregation and cell death. Recently, a growing number of studies have explored the link between cuproptosis and cancer development. This review comprehensively examines the systemic and cellular metabolism of copper, including tumor-related signaling pathways influenced by copper. It delves into the discovery and mechanisms of cuproptosis and its connection to various cancers. Additionally, the review suggests potential cancer treatments using copper ionophores that induce cuproptosis, in combination with small molecule drugs, for precision therapy in specific cancer types.

Repositioning baloxavir marboxil as VISTA agonist that ameliorates experimental asthma

V-type immunoglobulin domain-containing suppressor of T-cell activation (VISTA), a novel negative checkpoint regulator, plays an essential role in allergic pulmonary inflammation in mice. Treatment with a VISTA agonistic antibody could significantly improve asthma symptoms. Thus, for allergic asthma treatment, VISTA targeting may be a compelling approach. In this study, we examined the functional mechanism of VISTA in allergic pulmonary inflammation and screened the FDA-approved drugs for VISTA agonists. By using mass cytometry (CyTOF), we found that VISTA deficiency primarily increased lung macrophage infiltration in the OVA-induced asthma model, accompanied by an increased proportion of M1 macrophages (CD11b+F4/80+CD86+) and a decreased proportion of M2 macrophages (CD11b+F4/80+CD206+). Further in vitro studies showed that VISTA deficiency promoted M1 polarization and inhibited M2 polarization of bone marrow-derived macrophages (BMDMs). Importantly, we discovered baloxavir marboxil (BXM) as a VISTA agonist by virtual screening of FDA-approved drugs. The surface plasmon resonance (SPR) assays revealed that BXM (KD = 1.07 µM) as well as its active form, baloxavir acid (BXA) (KD = 0.21 µM), could directly bind to VISTA with high affinity. Notably, treatment with BXM significantly ameliorated asthma symptoms, including less lung inflammation, mucus secretion, and the generation of Th2 cytokines (IL-5, IL-13, and IL-4), which were dramatically attenuated by anti-VISTA monoclonal antibody treatment. BXM administration also reduced the pulmonary infiltration of M1 macrophages and raised M2 macrophages. Collectively, our study indicates that VISTA regulates pulmonary inflammation in allergic asthma by regulating macrophage polarization and baloxavir marboxil, and an old drug might be a new treatment for allergic asthma through targeting VISTA.

Oxidative Stress by the Mitochondrial Monoamine Oxidase B Mediates Calcium Pyrophosphate Crystal-Induced Arthritis

OBJECTIVE

Calcium pyrophosphate (CPP) crystal deposition in the joints is associated with a heterogeneous set of debilitating syndromes characterized by inflammation and pain, for which no effective therapies are currently available. Because we found that the mitochondrial enzyme monoamine oxidase B (MAO-B) plays a fundamental role in promoting inflammatory pathways, this study aims at assessing the efficacy of two clinical-grade inhibitors (iMAO-Bs) in preclinical models of this disease to pave the way for a novel treatment.

METHODS

We tested our hypothesis in two murine models of CPP-induced arthritis, by measuring cytokine and chemokine levels, along with immune cell recruitment. iMAO-Bs (rasagiline and safinamide) were administered either before or after crystal injection. To elucidate the molecular mechanism, we challenged in vitro primed macrophages with CPP crystals and assessed the impact of iMAO-Bs in dampening proinflammatory cytokines and in preserving mitochondrial function.

RESULTS

Both in preventive and therapeutic in vivo protocols, iMAO-Bs blunted the release of proinflammatory cytokines (interleukin [IL]-6 and IL1-β) and chemokines (CXCL10, CXCL1, CCL2 and CCL5) (n > 6 mice/group). Importantly, they also significantly reduced ankle swelling (50.3% vs 17.1%; P < 0.001 and 23.1%; P = 0.005 for rasagiline and safinamide, respectively). Mechanistically, iMAO-Bs dampened the burst of reactive oxygen species and the mitochondrial dysfunction triggered by CPP crystals in isolated macrophages. Moreover, iMAO-Bs blunted cytokine secretion and NLRP3 inflammasome activation through inhibition of the NF-κB and STAT3 pathways.

CONCLUSION

iMAO-Bs dampen inflammation in murine models of crystal-induced arthropathy, thereby uncovering MAO-B as a promising target to treat these diseases.

Behind the monocyte's mystique: uncovering their developmental trajectories and fates

Monocytes are circulating myeloid cells that are derived from dedicated progenitors in the bone marrow. Originally thought of as mere precursors for the replacement of tissue macrophages, it is increasingly clear that monocytes execute distinct effector functions and may give rise to monocyte-derived cells with unique properties from tissue-resident macrophages. Recently, the advent of novel experimental approaches such as single-cell analysis and fate-mapping tools has uncovered an astonishing display of monocyte plasticity and heterogeneity, which we believe has emerged as a key theme in the field of monocyte biology in the last decade. Monocyte heterogeneity is now recognized to develop as early as the progenitor stage through specific imprinting mechanisms, giving rise to specialized effector cells in the tissue. At the same time, monocytes must overcome their susceptibility towards cellular death to persist as monocyte-derived cells in the tissues. Environmental signals that preserve their heterogenic phenotypes and govern their eventual fates remain incompletely understood. In this review, we will summarize recent advances on the developmental trajectory of monocytes and discuss emerging concepts that contributes to the burgeoning field of monocyte plasticity and heterogeneity.

Liver macrophages in health and disease

Single-cell and spatial transcriptomic technologies have revealed an underappreciated heterogeneity of liver macrophages. This has led us to rethink the involvement of macrophages in liver homeostasis and disease. Identification of conserved gene signatures within these cells across species and diseases is enabling the correct identification of specific macrophage subsets and the generation of more specific tools to track and study the functions of these cells. Here, we discuss what is currently known about the definitions of these different macrophage populations, the markers that can be used to identify them, how they are wired within the liver, and their functional specializations in health and disease.

The Dual Role of Innate Immune Response in Acetaminophen-Induced Liver Injury

Acetyl-para-aminophenol (APAP), a commonly used antipyretic analgesic, is becoming increasingly toxic to the liver, resulting in a high rate of acute hepatic failure in Europe and the United States. Excessive APAP metabolism in the liver develops an APAP-protein adduct, which causes oxidative stress, MPTP opening, and hepatic necrosis. HMGB-1, HSP, nDNA, mtDNA, uric acid, and ATP are DMAPs released during hepatic necrosis. DMAPs attach to TLR4-expressing immune cells such KCs, macrophages, and NK cells, activating them and causing them to secrete cytokines. Immune cells and their secreted cytokines have been demonstrated to have a dual function in acetaminophen-induced liver injury (AILI), with a role in either proinflammation or pro-regeneration, resulting in contradicting findings and some research confusion. Neutrophils, KCs, MoMFs, NK/NKT cells, γδT cells, DCs, and inflammasomes have pivotal roles in AILI. In this review, we summarize the dual role of innate immune cells involved in AILI and illustrate how these cells initiate innate immune responses that lead to persistent inflammation and liver damage. We also discuss the contradictory findings in the literature and possible protocols for better understanding the molecular regulatory mechanisms of AILI.