The Role of Hexokinase Domain Containing Protein-1 in Glucose Regulation During Pregnancy

Metabolic pathways mediating insulin resistance and gestational diabetes mellitus discovered by high-dimensional systematic Mendelian randomization

BACKGROUND

Gestational diabetes mellitus (GDM), characterized by insulin resistance (IR) and β-cell dysfunction, is one of the most common complications of pregnancy with unmet needs of prevention methods.

OBJECTIVE

To investigate the causal role of insulin resistance and metabolic pathways in the pathogenesis of GDM with our proposed high-dimensional systematic Mendelian randomization (hdsMR) framework.

METHODS

Cases with GDM and controls with normal glucose tolerance were recruited at the University of Hong Kong-Shenzhen Hospital from 2015 to 2018. A total of 566 participants (aged > 18 years), including 274 with GDM, were enrolled after excluding subjects with major chronic diseases or long-term use of medications affecting glycolipid metabolism. Clinical characteristics and serum samples were collected during the GDM screening stage, and the genome and metabolome were tested. A novel hdsMR framework was proposed to estimate the causal role of IR index (Homeostasis Model Assessment of Insulin Resistance, HOMA-IR) and metabolic pathways in the pathogenesis of GDM.

RESULTS

Our hdsMR method confirmed that HOMA-IR was causal to GDM (odds ratio, 1.17; 95% confidence interval, 1.04-1.32) and revealed that two metabolic pathways (glyoxylate and dicarboxylate metabolism pathway and lysine degradation pathway) mediated 14.6% and 8.4%, respectively, between HOMA-IR and GDM. In an independent validation cohort comprising 255 pre-diabetic individuals, we showed that both pathways could be intervened through diet (P < 0.05). Furthermore, glyoxylate and dicarboxylate metabolism pathway was significantly associated with adverse pregnancy outcomes in GDM.

CONCLUSIONS

These results indicated that targeting specific metabolic pathways through dietary intervention is worth exploring as a possible GDM prevention approach, and hdsMR is more efficient in finding causal mediating metabolic pathways than traditional MR methods.

HKDC1 promotes ovarian cancer progression through boosting lipid metabolism and immune escape by stabilizing G6PC/G6PC2

Ovarian cancer (OC) is a significant health challenge, yet the mechanisms driving its progression remain unclear. This study explored the role of hexokinase domain-containing protein 1 (HKDC1) in OC, focusing on tumor growth, lipid metabolism, and immune evasion. Human OC cell lines (SKOV3 and HEY) and the murine OC cell line (ID8) were used to knock down and overexpress HKDC1. An ID8-based epithelial OC mouse model was established to validate the in vitro findings. Our results demonstrated that HKDC1 was upregulated in OC and promoted cell proliferation, migration, and invasion. HKDC1 enhanced lipid accumulation by elevating levels of free fatty acids (FFA), triglycerides, phospholipids, cholesterol, and neutral lipid, while upregulating key enzymes (ACC1, FASN, SCD1, HMGCS1, and HMGCR). It promoted immune escape through PD-L1 upregulation, inhibiting T cell proliferation and reducing IFN-γ, granzyme B, and perforin levels while increasing PD-1 levels. HKDC1 knockdown reversed these effects, which were restored by adding FFA. Mechanistically, HKDC1 interacted with and stabilized glucose-6-phosphatase catalytic subunits (G6PC/G6PC2), supporting its tumor-promoting functions. These findings were confirmed in an OC mouse model, highlighting HKDC1 as a key driver of OC progression through lipid biosynthesis and immune suppression, offering potential therapeutic targets.

Hepatic HKDC1 deletion alleviates western diet-induced MASH in mice

The global prevalence of Metabolic Dysfunction-Associated Steatohepatitis (MASH) has been rising sharply, closely mirroring the increasing rates of obesity and metabolic syndrome. MASH exhibits a strong sexual dimorphism where females are affected with more severe forms after menopause. Hexokinase domain-containing protein 1 (HKDC1) has recently been recognized for its role in liver diseases, where its expression is minimal under normal conditions but significantly increases in response to metabolic stressors like obesity and liver injury. This selective upregulation suggests HKDC1's potential specialization in hepatic glucose and lipid dysregulation, linking it closely to the progression of MASH. This study aims to clarify the role of HKDC1 in Western diet-induced MASH in female mice by examining its impact on hepatic glucose and lipid metabolism, offering insights into its potential as a therapeutic target and addressing the need for sex-specific research in liver disease. This study reveals that HKDC1 expression is elevated in obese women with MASH and correlates with liver pathology. In a mouse model, liver-specific HKDC1 knockout (HKDC1LKO) protected against Western diet-induced obesity, glucose intolerance, and MASH features, including steatosis, inflammation, and fibrosis. Transcriptomic analysis showed that HKDC1 deletion reduced pro-inflammatory and pro-fibrotic gene expression, while gut microbiome analysis indicated a shift toward MASH-protective bacteria. These findings suggest that HKDC1 may exacerbate MASH progression through its role in metabolic and inflammatory pathways, making it a potential therapeutic target.

Hepatic HKDC1 Deletion Alleviates Western Diet-Induced MASH in Mice

The global prevalence of Metabolic dysfunction-associated steatohepatitis (MASH) has been rising sharply, closely mirroring the increasing rates of obesity and metabolic syndrome. MASH exhibits a strong sexual dimorphism where females are affected with more severe forms after menopause. Hexokinase domain-containing protein 1 (HKDC1) has recently been recognized for its role in liver diseases, where its expression is minimal under normal conditions but significantly increases in response to metabolic stressors like obesity and liver injury. This selective upregulation suggests HKDC1s potential specialization in hepatic glucose and lipid dysregulation, linking it closely to the progression of MASLD and MASH. This study aims to clarify the role of HKDC1 in Western diet-induced MASH in female mice by examining its impact on hepatic glucose and lipid metabolism, offering insights into its potential as a therapeutic target and addressing the need for sex-specific research in liver disease. This study reveals that HKDC1 expression is elevated in obese women with MASH and correlates with liver pathology. In a mouse model, liver-specific HKDC1 knockout (HKDC1LKO) protected against Western diet-induced obesity, glucose intolerance, and MASH features, including steatosis, inflammation, and fibrosis. Transcriptomic analysis showed that HKDC1 deletion reduced pro-inflammatory and pro-fibrotic gene expression, while gut microbiome analysis indicated a shift toward MASH-protective bacteria. These findings suggest that HKDC1 may exacerbate MASH progression through its role in metabolic and inflammatory pathways, making it a potential therapeutic target.

Understanding the Genetic Landscape of Gestational Diabetes: Insights into the Causes and Consequences of Elevated Glucose Levels in Pregnancy

Background/Objectives: During pregnancy, physiological changes in maternal circulating glucose levels and its metabolism are essential to meet maternal and fetal energy demands. Major changes in glucose metabolism occur throughout pregnancy and consist of higher insulin resistance and a compensatory increase in insulin secretion to maintain glucose homeostasis. For some women, this change is insufficient to maintain normoglycemia, leading to gestational diabetes mellitus (GDM), a condition characterized by maternal glucose intolerance and hyperglycaemia first diagnosed during the second or third trimester of pregnancy. GDM is diagnosed in approximately 14.0% of pregnancies globally, and it is often associated with short- and long-term adverse health outcomes in both mothers and offspring. Although recent studies have highlighted the role of genetic determinants in the development of GDM, research in this area is still lacking, hindering the development of prevention and treatment strategies. Methods: In this paper, we review recent advances in the understanding of genetic determinants of GDM and glycaemic traits during pregnancy. Results/Conclusions: Our review highlights the need for further collaborative efforts as well as larger and more diverse genotyped pregnancy cohorts to deepen our understanding of the genetic aetiology of GDM, address research gaps, and further improve diagnostic and treatment strategies.

A novel role of FoxO3a in the migration and invasion of trophoblast cells: from metabolic remodeling to transcriptional reprogramming

Background

The forkhead box O3a protein (FoxO3a) has been reported to be involved in the migration and invasion of trophoblast, but its underlying mechanisms unknown. In this study, we aim to explore the transcriptional and metabolic regulations of FoxO3a on the migration and invasion of early placental development.

Methods

Lentiviral vectors were used to knock down the expression of FoxO3a of the HTR8/SVneo cells. Western blot, matrigel invasion assay, wound healing assay, seahorse, gas-chromatography-mass spectrometry (GC–MS) based metabolomics, fluxomics, and RNA-seq transcriptomics were performed.

Results

We found that FoxO3a depletion restrained the migration and invasion of HTR8/SVneo cells. Metabolomics, fluxomics, and seahorse demonstrated that FoxO3a knockdown resulted in a switch from aerobic to anaerobic respiration and increased utilization of aromatic amino acids and long-chain fatty acids from extracellular nutrients. Furthermore, our RNA-seq also demonstrated that the expression of COX-2 and MMP9 decreased after FoxO3a knockdown, and these two genes were closely associated with the migration/invasion progress of trophoblast cells.

Conclusions

Our results suggested novel biological roles of FoxO3a in early placental development. FoxO3a exerts an essential effect on trophoblast migration and invasion owing to the regulations of COX2, MMP9, aromatic amino acids, energy metabolism, and oxidative stress.

Differential proteomics of placentas reveals metabolic disturbance and oxidative damage participate yak spontaneous miscarriage during late pregnancy

Background

High spontaneous miscarriage rate in yak, especially during late pregnancy, have caused a great economic loss to herdsmen living in the Qinghai-Tibet plateau. However, the mechanism underlying spontaneous miscarriage is still poorly understood. In the present study, placenta protein markers were identified to elucidate the pathological reasons for yak spontaneous miscarriage through isobaric tags for relative and absolute quantification (iTRAQ) proteomic technology and bioinformatic approaches.

Results

Subsequently, a total of 415 differentially expressed proteins (DEPs) were identified between aborted and normal placentas. The up-regulated DEPs in the aborted placentas were significantly associated with “spinocerebellar ataxia”, “sphingolipid signalling”, “relaxin signalling”, “protein export”, “protein digestion and absorption” and “aldosterone synthesis and secretion” pathway. While the down-regulated DEPs in the aborted placentas mainly participated in “valine, leucine and isoleucine degradation”, “PPAR signalling”, “peroxisome”, “oxidative phosphorylation”, “galactose metabolism”, “fatty acid degradation”, “cysteine and methionine metabolism” and “citrate cycle” pathway.

Conclusions

The results implied that the identified DEPs could be considered as placental protein markers for yak miscarriage during late pregnancy, and biomacromolecule metabolic abnormality and oxidative damage might be responsible for the high spontaneous miscarriage rate in yak. These findings provide an important theoretical basis for deciphering the pathologic mechanism of late spontaneous miscarriage in yak.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-022-03354-w.