Ganglioside GM3 prevents high fat diet-induced hepatosteatosis via attenuated insulin signaling pathway

Lipid metabolism dysregulation in umbilical cord plasma of newborns from mothers with preeclampsia is associated with neonatal physical parameters at birth

BACKGROUND

Preeclampsia is linked to fetal growth restriction and may have long-term implications for the offspring. Despite its significance, the fundamental mechanisms remain inadequately elucidated. The objective of this investigation was to undertake an untargeted lipidomics analysis of umbilical cord plasma, with the intention of investigating lipidomic profile alterations in newborns of mothers with preeclampsia and evaluating the associations between lipidomic patterns and neonatal physical parameters at birth.

METHODS

25 newborns from mothers with preeclampsia (PE group) and 25 newborns from healthy mothers (control group) were involved in the present investigation. Untargeted lipidomics was performed using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) to contrast the lipid compositions present in umbilical cord plasma. Co-expression correlation analysis was performed to explore the relationships between lipidomic patterns and neonatal weight and length percentile at birth.

RESULTS

Marked discrepancies in lipid metabolism profiles were detected in the comparison of the PE and control groups. In total, 364 separate lipids were noted, with AcylGlcADG (20:3-22:6-22:6) and GM3(d39:1) exhibiting the most significant decreases. Conversely, Cer-NS (d20:1-24:0) and DGTS (2:0-19:0) displayed the most significant increases. The primary lipid metabolic pathways altered in newborns from mothers with preeclampsia were enriched in choline and glycerophospholipid metabolic processes. Additionally, 20 distinct lipids exhibited significant associations with neonatal birth weight percentile between the two groups, while 21 distinct lipids showed significant associations with neonatal birth length percentile.

CONCLUSIONS

Lipid profile disorders were identified in the umbilical cord plasma of infants born to mothers with preeclampsia, and the metabolic disturbances identified in this group correlated with neonatal physical parameters at birth. These findings suggest that lipidomic disorders in newborns from preeclamptic mothers may correlate with intrauterine growth outcomes.

Long-lasting recombinant HEXA treatment improves hepatic steatosis and glycemic control in mild, but not severe, metabolic dysfunction-associated steatohepatitis

The prevalence of metabolic dysfunction-associated steatohepatitis (MASH) is increasing at an alarming rate. To date, only one therapy has been provisionally approved for the treatment of MASH and liver fibrosis, and novel strategies are urgently needed. In addition, the frequent coexistence of MASH and type 2 diabetes has further intensified interest in devising comprehensive therapies to simultaneously tackle both diseases. We have recently shown that increasing hepatic and/or circulating levels of hexosaminidase A (HEXA), a lysosomal enzyme that remodels GM2 to GM3 gangliosides within lipid rafts, offers therapeutic benefits for metabolic dysfunction-associated steatotic liver disease (MASLD) and type 2 diabetes. Taking advantage of the MUP-uPA mouse model of MASH, including both wild-type (WT) mice with mild MASH and MUP-uPA mice with severe MASH and fibrosis, we show that biweekly treatment with a long-lasting HEXA-FC analog improves features of MASLD, including hepatic steatosis and hepatocyte ballooning, in mice with mild MASH, as well as glycemic control across both mouse models. Mechanistically, HEXA-FC enhances hepatic fatty acid oxidation and peripheral glucose disposal while not impacting endogenous glucose production. Together, these outcomes suggest that while HEXA-FC treatment may offer therapeutic benefits in mild MASH and insulin resistance, it is ineffective against severe MASH and liver fibrosis.NEW & NOTEWORTHY The prevalence of metabolic dysfunction-associated steatohepatitis (MASH) and type 2 diabetes is increasing. Here, we show that chronic FC-HEXA recombinant protein treatment reduces hepatic lipid accumulation and improves blood glucose control in mice with mild MASH and insulin resistance.

Bioactive sphingolipids as emerging targets for signal transduction in cancer development

Sphingolipids, crucial components of cellular membranes, play a vital role in maintaining cellular structure and signaling integrity. Disruptions in sphingolipid metabolism are increasingly implicated in cancer development. Key bioactive sphingolipids, such as ceramides, sphingosine-1-phosphate (S1P), ceramide-1-phosphate (C1P), and glycosphingolipids, profoundly impact tumor biology. They influence the behavior of tumor cells, stromal cells, and immune cells, affecting tumor aggressiveness, angiogenesis, immune modulation, and extracellular matrix remodeling. Furthermore, abnormal expression of sphingolipids and their metabolizing enzymes modulates the secretion of tumor-derived extracellular vesicles (TDEs), which are key players in creating an immunosuppressive tumor microenvironment, remodeling the extracellular matrix, and facilitating oncogenic signaling within in situ tumors and distant pre-metastatic niches (PMNs). Understanding the role of sphingolipids in the biogenesis of tumor-derived extracellular vesicles (TDEs) and their bioactive contents can pave the way for new biomarkers in cancer diagnosis and prognosis, ultimately enhancing comprehensive tumor treatment strategies.

APOE genotype dictates lipidomic signatures in primary human hepatocytes

Apolipoprotein E (APOE) genetic variants are most notably known for their divergent impact on the risk of developing Alzheimer's disease. While APOE genotype has been consistently shown to modulate lipid metabolism in a variety of cellular contexts, the effect of APOE alleles on the lipidome in hepatocytes is unknown. In this study, we investigated the contribution of APOE alleles to lipidomic profiles of donor-derived primary human hepatocytes from 77 subjects. Lipidomic data obtained by liquid chromatography-mass spectrometry were analyzed across ε2/ε3, ε3/ε3, and ε3/ε4 genotypes to reveal how APOE modulates lipid relative levels over age and between groups. Hepatic APOE concentration, measured by ELISA, was assessed for correlation with lipid abundance in subjects grouped as per APOE genotype and sex. APOE genotype-specific differential lipidomic signatures associated with age for multiple lipid classes but did not differ between sexes. Compared to ε2/ε3, ε3/ε4 hepatocytes had higher abundance of acylcarnitines (AC) and acylphosphatidylglycerol (AcylPG) as a class, as well as higher medium and long-chain ACs, AcylPG, phosphatidylglycerol (PG), bis(monoacylglycerol)phosphate (BMP), monoacylglycerol (MG) and diacylglycerol (DG) species. The ε3/ε4 hepatocytes also exhibited a higher abundance of medium and long-chain ACs compared to the ε3/ε3 hepatocytes. Only in the ε3/ε4 hepatocytes, APOE concentration was lower and showed a negative correlation with BMP levels, specifically in females. APOE genotype dictates a differential lipidome in primary human hepatocytes. The lipids involved suggest mitochondrial dysfunction with accompanying alterations in neutral lipid storage, reflective of a general disturbance of free fatty acid metabolism in human hepatocytes with the ε4 allele.