Lactate metabolism in human health and disease

Metabolic reprogramming of astrocytes: Emerging roles of lactate

Lactate serves as a key energy metabolite in the central nervous system, facilitating essential brain functions, including energy supply, signaling, and epigenetic modulation. Moreover, it links epigenetic modifications with metabolic reprogramming. Nonetheless, the specific mechanisms and roles of this connection in astrocytes remain unclear. Therefore, this review aims to explore the role and specific mechanisms of lactate in the metabolic reprogramming of astrocytes in the central nervous system. The close relationship between epigenetic modifications and metabolic reprogramming was discussed. Therapeutic strategies for targeting metabolic reprogramming in astrocytes in the central nervous system were also outlined to guide future research in central nervous system diseases. In the nervous system, lactate plays an essential role. However, its mechanism of action as a bridge between metabolic reprogramming and epigenetic modifications in the nervous system requires future investigation. The involvement of lactate in epigenetic modifications is currently a hot research topic, especially in lactylation modification, a key determinant in this process. Lactate also indirectly regulates various epigenetic modifications, such as N6-methyladenosine, acetylation, ubiquitination, and phosphorylation modifications, which are closely linked to several neurological disorders. In addition, exploring the clinical applications and potential therapeutic strategies of lactic acid provides new insights for future neurological disease treatments.

Lactate metabolism and lactylation in kidney diseases: insights into mechanisms and therapeutic opportunities

The kidney is essential for lactate metabolism. Under normal conditions, the renal cortex mainly absorbs and metabolizes lactate, with minimal amounts excreted in urine. This process is part of a glucose-lactate recycling system between the cortex and medulla. In conditions such as acute kidney injury (AKI) and diabetic kidney disease (DKD), the kidney's ability to metabolize lactate is impaired, leading to lactate accumulation and exacerbated renal dysfunction. Novel post-translational modifications, such as lactylation, are critical in kidney disease pathophysiology by modulating gene transcription, protein function, and cellular metabolism. Lactylation is involved in inflammatory responses and tumor promotion in AKI, mitochondrial dysfunction in DKD, and tumor progression in clear cell renal cell carcinoma (ccRCC). The lactate-lactylation axis is central to the Warburg effect in ccRCC, where tumor cells preferentially rely on glycolysis rather than oxidative phosphorylation. Understanding the mechanisms of lactate metabolism and lactylation in kidney diseases may offer new therapeutic strategies. This review examines the role of lactate esters, especially lactylation, in kidney diseases, with a focus on their regulatory mechanisms and potential as therapeutic targets.

Utilization of lactate trajectory models for predicting acute kidney injury and mortality in patients with hyperlactatemia: insights across three independent cohorts

This study aims to investigate the association between lactate trajectories and the risk of acute kidney injury (AKI) and hospital mortality in patients with hyperlactatemia. We conducted a multicenter retrospective study using data from three independent cohorts. By the lactate levels during the first 48 h of ICU admission, patients were classified into distinct lactate trajectories using group-based trajectory modeling (GBTM) method. The primary outcomes were AKI incidence and hospital mortality. Logistic regression analysis assessed the association between lactate trajectories and clinical outcomes, with adjusting potential confounders. Patients were divided into three trajectories: mild hyperlactatemia with rapid recovery (Traj-1), severe hyperlactatemia with gradual recovery (Traj-2), and severe hyperlactatemia with persistence (Traj-3). Traj-3 was an independent risk factor of both hospital mortality (all p < 0.001) and AKI development (all p < 0.001). Notably, Traj-2 was also associated with increased risk of mortality and AKI development (all p < 0.05) using Traj-1 as reference, except for the result in the Tianjin Medical University General Hospital (TMUGH) cohort for mortality in adjusted model (p = 0.123). Our finding was still robust in subgroup and sensitivity analysis. In the combination cohort, both Traj-2 and Traj-3 were considered as independent risk factor for hospital mortality and AKI development (all p < 0.001). When compared with the Traj-3, Traj-2 was only significantly associated with the decreased risk of hospital mortality (OR 0.17, 95% CI 0.14-0.20, p < 0.001), but no with the likelihood of AKI development (OR 0.90, 95% CI 0.77-1.05, p = 0.172). Lactate trajectories provide valuable information for predicting AKI and mortality in critically ill patients.

Lactate induces oxidative phosphorylation in osteoblasts via Gpr81-Stat3 signaling

Lactate has long been regarded as an end product of glycolysis and a metabolic "waste product" under hypoxic conditions, but recent studies have revealed that lactate plays a central role in energy metabolism reprogramming and intercellular communication. However, it remains unknown whether lactate promotes osteogenic differentiation through metabolic reprogramming. Here, we showed that lactate significantly increased the cellular ATP content, activated succinate dehydrogenase activity, and enhanced oxygen consumption rate in pre-osteoblast MC3T3-E1 cells. Moreover, lactate treatment increased oxidative phosphorylation (OXPHOS) in parathyroid hormone (PTH)-treated MC3T3-E1 cells. Microarray and RNA-sequencing analysis revealed that Stat3 signaling was enriched in MC3T3-E1 cells treated with lactate or co-treated with lactate and PTH. Immunoblotting verification analysis further showed that lactate activated the Jak2-Stat3-Y705 and Akt-Stat3-S727 signaling. Inhibition of Jak2-Stat3-Y705 signaling by AG490 interrupted lactate-induced osteoblast differentiation. Inhibition of Gpr81 by 3-OBA or decrease in Gpr81 expression by Gpr81 siRNA, but not the interruption of MCT1 by AZD3965, led to the inhibition of the Gpr81-Jak2-Stat3-Y705 and Gpr81-Akt-Stat3-S727 signaling, and OXPHOS and cell differentiation of MC3T3-E1 cells were also inhibited. Furthermore, we demonstrated that the Gpr81 subunit Gβγ plays a central role in lactate-Gpr81 signaling. Lastly, osteoblast Gpr81-deficient mice showed lower bone formation. Thus, these findings propose a novel signaling mechanism by which lactate regulates cell differentiation as well as OXPHOS through the activation of Stat3 signaling by Gpr81.

Exercise-mediated muscle-hypothalamus crosstalk: Improvement for cognitive dysfunction caused by disrupted circadian rhythm

In contemporary societal evolution, the increasing disruption of the natural sleep-wake cycle, attributable to factors such as shift work and overexposure to artificial light, has been paralleled by a marked escalation in the incidence of cognitive impairments and the prevalence of neurodegenerative diseases. Current management strategies for cognitive impairments include pharmacological and non-pharmacological interventions. Pharmacological interventions for cognitive impairments typically involve medications to manage cognitive symptoms and improve neurological functions. However, these drugs show limited long-term efficacy in slowing disease progression and may cause side effects. Given the widespread occurrence of cognitive dysfunction, it is crucial to develop accessible non-pharmacological interventions. Physical activity and exercise have emerged as pivotal lifestyle determinants known to exert a modulatory effect on the risk profile for cognitive dysfunction caused by disrupted circadian rhythms. The skeletal muscle, a dynamic tissue, undergoes a profound morphological and metabolic reconfiguration in response to physical exertion, along with the secretion of myokines. Additionally, the hypothalamus, particularly the ventromedial nuclei, arcuate nuclei, and the suprachiasmatic nucleus, have crucial functions in regulating physical activity, influencing energy metabolism, and managing circadian cycles. Nevertheless, the communication between the hypothalamus and skeletal muscle during exercise is not fully understood. This narrative review integrates current knowledge on the interaction between the hypothalamus and skeletal muscle during exercise, emphasizing its neuroendocrine effects and potential therapeutic implications for alleviating cognitive dysfunction associated with disrupted circadian rhythms.

Gastric cancer cells shuttle lactate to induce inflammatory CAF-like phenotype and function in bone marrow-derived mesenchymal stem cells

Metabolic reprogramming, exemplified by the "Warburg effect," is a hallmark of human cancers, leading to lactate buildup in tumors. Bone marrow-derived mesenchymal stem cells (BM-MSCs), key contributors to cancer-associated fibroblasts (CAFs), integrate into gastric cancer stroma through interactions with cancer cells. However, the role of lactate in activating BM-MSCs in this context remains unclear. Herein, exogenous lactate induced a pro-tumorigenic phenotype in BM-MSCs, which was blocked by AZD3965. Gastric cancer cells released more lactate under hypoxia than normoxia. While normoxic gastric cancer cells could educate BM-MSCs, hypoxic cells were more effective. However, the effects of the supernatant from gastric cancer cells in both conditions were significantly reduced by AZD3965. Similarly, prevention of lactate production by oxamic acid sodium significantly reduced the effects observed. Lactate-activated BM-MSCs showed NF-κB signaling activation, increased IL-8 secretion, and no change in TGF-β signaling. These activated BM-MSCs promoted gastric cancer cell migration and invasion through IL-8 secretion and enhanced resistance to CD8 + T cell cytotoxicity by upregulating PD-L1. Collectively, gastric cancer cells induce an iCAF-like phenotype and function in BM-MSCs through a lactate shuttle mechanism, emphasizing the role of metabolic reprogramming in cellular communication that fosters a supportive tumor microenvironment. Targeting lactate-related pathways may provide new therapeutic strategies to hinder BM-MSCs' supportive roles in gastric cancer.

Metabolism dynamics in tropical cockroach during a cold-induced recovery period

BACKGROUND

Insects are poikilothermic organisms, meaning their body heat comes entirely from their surroundings. This influences their metabolism, growth, development, and behavior. Cold tolerance is considered an important factor in determining the geographic distribution of insects. The tropical cockroach Gromphadorhina coquereliana is capable of surviving exposure to cold. To determine the dynamics of metabolic adjustments occurring in the insect body under cold stress, we subjected the cockroach to 4°C for 3 h, followed by recovery periods of 3, 8, and 24 h. We then determined the levels of glycogen, proteins, lipids, amino acids, and carbohydrates. We also measured gene expression and the activity of the main enzymes of metabolic cycles responsible for energy conversion, namely, phosphofructokinase (PFK), hydroxyacyl-CoA dehydrogenase (HADH), and lactic acid dehydrogenase (LDH). All these analyses were conducted in different tissues: hemolymph, fat body, and muscle.

RESULTS

Our results show that in the fat body, protein degradation and an increase in unsaturated fatty acids (UFA) and cholesterol are observed, which likely allows membranes to maintain their functions. The high levels of lactic acid and LDH expression and activity indicate that anaerobic metabolic pathways are triggered. In the hemolymph, cold stress induces an increase in the levels of cryoprotective substances such as amino acids and sugars, which can also be used as a source of energy. On the other hand, muscle metabolism slows down (LDH, HADH), except for an increase in glucose, which may result from the gluconeogenesis process. During the recovery period, increased activity and expression of LDH, PFK, and HADH, as well as increased levels of UFA, lactic acid, glycerol, and TAG, were observed in fat body tissue, while in the hemolymph, increased levels of cryoprotectants still occurred.

CONCLUSIONS

G. coquereliana shows partial freeze tolerance, combining traits of both freeze-intolerant and freeze-tolerant insects. This adaptation helps it survive brief cold periods and suggests an evolutionary move towards complete freeze tolerance. Although cold stress challenges G. coquereliana in maintaining metabolic homeostasis, these insects exhibit deep biochemical adjustments to cope with adverse environmental stressors such as low temperature.

Histone lactylation-augmented IRF4 is implicated in arsenite-induced liver fibrosis via modulating Th17 cell differentiation

Arsenic, a ubiquitous environmental toxicant, has been implicated in causing liver fibrosis through chronic exposure. Histone lactylation is involved in various inflammatory diseases, among which liver fibrosis is included, and is also closely related to the regulation of immune cells. This work focuses on the mechanisms of histone lactylation and Th17 cell differentiation in arsenite-induced liver fibrosis through animal and cellular experiments. Chronic arsenite exposure of mice led to liver fibrosis, elevated glycolysis in liver, and increased lactate levels in both serum and liver, which promoted Th17 cell differentiation of CD4+ T cells and increased IL-17A secretion. Treatment with oxamate, a lactate dehydrogenase inhibitor, suppressed Th17 cell differentiation and alleviated fibrosis in the liver. For HepG2 cells, arsenite exposure enhanced glycolysis and lactate levels, leading to increased global lactylation (Kla), H3K18la, interferon-regulatory factor 4 (IRF4), retinoic acid receptor-related orphan receptor gamma t (RORγt), and IL-17A expression and secretion in co-cultured Jurkat cells. Furthermore, in Jurkat cells, reducing lactate production and transport decreased these protein levels, suppressed Th17 cell differentiation, decreased IL-17A secretion, and ultimately inhibited the activation of hepatic stellate cells (HSCs). These results indicate that lactate derived from hepatocytes promotes Th17 cell differentiation by upregulating IRF4 through H3K18la, thereby enhancing IL-17A secretion and the activation of HSCs, contributing to arsenite-induced liver fibrosis. Our work reveals a new mechanism of histone lactylation in arsenite-induced liver fibrosis and offers a fresh perspective for the development of strategies for prevention and treatment of this condition.

G6PD lactylation is involved in regulating redox balance of boar sperm in low glucose extender

Glucose metabolism is an essential pathway that indirectly supports cellular redox homeostasis by providing reducing equivalents, such as NADPH, particularly in the highly specialized sperm. Sperm exhibit higher progressive motility in low glucose extender. However, the underlying mechanisms remain unclear. The objective of the present study was to investigate effect of low glucose on sperm metabolism and lactylation modification. After 3 h of incubation, low glucose had an effect on the redox state of boar semen in vitro, particularly in terms of the concentration of reactive oxygen species (ROS) and reductive products. Furthermore, glucose-6-phosphate dehydrogenase (G6PD) activity was significantly increased at low glucose condition, accompanied by increased lactate accumulation extracellularly. Meanwhile, protein lactylation levels were enhanced, with G6PD identified as one of lactylation proteins. In conclusion, low glucose incubation induced lactylation of G6PD, resulting in increased enzymatic activity that enhanced the pentose phosphate pathway (PPP), which in turn increased antioxidant capacity and maintained sperm motility in a low glucose environment. The research results provide valuable insights into the adaptation mechanisms of sperm to their environment and offer new perspectives and opportunities for reproductive biology research.

METTL3/YTDHF1 Stabilizes CSRP1 mRNA to Regulate Glycolysis and Promote Acute Myeloid Leukemia Progression

CSRP1 (Cysteine and Glycine-Rich Protein 1) is a protein often overactivated in various cancers, promoting cell proliferation and survival, making it a key factor in cancer development. However, it is worth noting that the effect of this protein on the glycolysis process in Acute Myeloid Leukemia (AML) has not yet been studied. This study aims to investigate the role of the METTL3/YTHDF1 axis in regulating Glycolysis and its impact on AML progression by stabilizing CSRP1 mRNA. We analyzed CSRP1 expression in AML tissues and cell lines using quantitative real-time PCR (qRT-PCR) and Western blotting. Functional assays, including cell viability, colony formation, glycolysis related indicators, were performed to assess the impact of CSRP1 knockdown or overexpression on AML cells. RNA immunoprecipitation (RIP) and RNA stability assays were conducted to elucidate the mechanism of METTL3/YTHDF1-mediated regulation of CSRP1 mRNA. CSRP1 was significantly upregulated in AML tissues and cell lines. Knockdown of CSRP1 inhibited AML cell proliferation and glycolysis. Overexpression of CSRP1 promoted AML cell survival. Mechanistically, METTL3 enhanced CSRP1 mRNA stability via m6A modification, recognized and bound by YTHDF1, preventing mRNA degradation. The METTL3/YTHDF1/ CSRP1 axis plays a critical role in AML progression by regulating glycolysis. Targeting this pathway may provide a novel therapeutic strategy for AML treatment.

Oxidative stress and central metabolism pathways impact epigenetic modulation in inflammation and immune response

Oxidative stress, metabolism, and epigenetics are deeply interconnected processes that collectively influence cellular function, health status, and contribute to disease progression. This review highlights the critical role of metabolic intermediates in epigenetic regulation, focusing on lactate, glutathione (GSH), and S-adenosylmethionine (SAM). Beyond its traditional role in energy metabolism, lactate modulates epigenetic mechanisms, influencing gene expression and cellular adaptation. Meanwhile, GSH and SAM serve as key regulators of DNA methylation and histone post-translational modifications, maintaining epigenetic homeostasis. These processes are tightly controlled by redox balance and oxidative stress, underscoring the intricate interplay between metabolism and epigenetic regulation. GSH depletion disrupts methylation homeostasis, while oxidative post-translational modifications (oxPTMs) on histones-including S-glutathionylation, carbonylation, and nitrosylation-alter chromatin architecture and transcriptional regulation. Additionally, we focus on histone lactylation, particularly its role in regulating innate and adaptive immune responses. We also explore how GSH and oxidative stress influence lactate levels, potentially inducing histone lactylation or S-glutathionylation through S,D-lactoylglutathione (LGSH), thereby impacting epigenetic regulation. By integrating insights into metabolic-epigenetic crosstalk, this review underscores the role of oxidative stress and central metabolic pathways in regulating epigenetic mechanisms, a concept known as "redox epigenetics." Understanding these intricate interactions offers new perspectives for therapeutic strategies aimed at restoring redox homeostasis and metabolic integrity to counteract disturbances in the epigenetic landscape.

TPX2 lactylation is required for the cell cycle regulation and hepatocellular carcinoma progression

Targeting protein for Xklp2 (TPX2) is critical for mitosis and spindle assembly because of its control of Aurora kinase A (AURKA). However, the regulation of TPX2 activity and its subsequent effects on mitosis and cancer progression remain unclear. Here, we show that TPX2 is lactylated at K249 in hepatocellular carcinoma (HCC) tumour tissues and that this process is regulated by the lactylase CBP and the delactylase HDAC1. Lactate reduction via either shRNAs targeting lactate dehydrogenase A or the lactate dehydrogenase A inhibitor GSK2837808A decreases the level of TPX2 lactylation. Importantly, TPX2 lactylation is required for the cell cycle regulation and tumour growth. Mechanistically, TPX2 lactylation disrupts protein phosphatase 1 (PP1) binding to AURKA, enhances AURKA T288 phosphorylation, and facilitates the cell cycle progression. Overall, our study reveals a previously unappreciated role of TPX2 lactylation in regulating cell cycle progression and HCC tumorigenesis, exposing an important correlation between metabolic reprogramming and cell cycle regulation in HCC.

Enhanced detection of glutamate via transverse relaxation encoding with narrowband decoupling in the human brain

PURPOSE

This study aims to improve the detection of glutamate (Glu) concentration and T2 using an enhanced transverse relaxation encoding with narrowband decoupling (TREND) technique.

METHODS

A new editing pulse was designed to simultaneously invert both Glu H3 spins (2.12 ppm and 2.05 ppm) while minimizing the excitation of Glu H4. Additionally, a frequency band was created to invert the lactate (Lac) H2 spin (4.10 ppm) while saturating the NAA aspartyl H2 spin (4.38 ppm). Numerical simulations compared Glu and Lac signals using the original and new editing pulses. In vivo experiments were conducted on healthy participants at 7 T to validate this enhanced TREND technique.

RESULTS

Numerical simulations showed prominently enhanced Glu and Lac resonance signals with the new editing pulse. In vivo spectra showed a 47% ± 14% increase in Glu/Cr peak amplitude ratios with the new editing pulse. Using the enhanced TREND sequence, Glu/Cr concentration ratios in the anterior cingulate cortex were 1.03 ± 0.07 with Cramer-Rao lower bounds (CRLBs) of 1.1% ± 0.1%, and Glu T2 values were 179 ± 18 ms with CRLBs of 1.2% ± 0.1%. The Lac/Cr concentration ratios in the same voxels were 0.05 ± 0.01 with CRLBs of 26% ± 14%, and Lac T2 values were 196 ± 23 ms with CRLBs of 22% ± 15%.

CONCLUSION

The new editing pulse significantly enhanced the detection of Glu and enabled the detection of Lac using TREND for measuring both the concentration and T2 of the markers of oxidative metabolism and glycolysis.

Protective role of coenzyme Q10 against trihexyphenidyl-induced pulmonary toxicity in Wistar rats

BACKGROUND

Trihexyphenidyl (THP), an anticholinergic drug used to manage Parkinson's disease and dystonia, has been associated with oxidative stress and metabolic disturbances, particularly affecting pulmonary function. Long-term exposure to THP may induce lung toxicity through increased oxidative stress, mitochondrial dysfunction, and apoptosis. Coenzyme Q10 (CoQ10), a lipid-soluble antioxidant and mitochondrial cofactor, has been shown to protect against oxidative damage and apoptosis in various models of toxicity. However, its role in mitigating THP-induced pulmonary toxicity remains unexplored. This study investigated the protective effects of CoQ10 against THP-induced pulmonary toxicity in male Wistar rats.

METHODS

Thirty-two adult male Wistar rats (180-200 g) were randomly assigned to four groups (n = 8 per group): (i) Control (vehicle-treated), (ii) THP (1.5 mg/kg), (iii) CoQ10 (10 mg/kg), and (iv) THP + CoQ10. Treatments were administered orally once daily for 21 days. Body weight was recorded at baseline and endpoint. At the end of treatment, rats were euthanized, and lungs were excised, weighed, and processed for biochemical and histological analyses. Oxidative stress markers were assessed, including catalase (CAT), glutathione peroxidase (GPx), superoxide dismutase (SOD), reduced glutathione (GSH), and malondialdehyde (MDA). Metabolic enzymes such as lactate dehydrogenase (LDH) and pyruvate dehydrogenase (PDH) were measured. Angiotensin-converting enzyme (ACE) activity was evaluated to assess vascular function, while caspase-3 levels were determined as an apoptotic marker. Histopathological examination of lung tissues was performed using hematoxylin and eosin staining.

RESULTS

THP administration resulted in significant weight loss, increased lung weight, oxidative stress (decreased CAT, GPx, SOD, and GSH; increased MDA), and metabolic alterations (elevated LDH, PDH, lactate, and pyruvate). ACE activity was reduced, and caspase-3 was elevated, indicating apoptosis. CoQ10 co-administration mitigated these effects, restoring antioxidant enzyme activity, metabolic balance, and ACE levels while reducing MDA and caspase-3 expression. Histological analysis confirmed that CoQ10 ameliorated THP-induced pulmonary damage.

CONCLUSION

CoQ10 demonstrated significant protective effects against THP-induced oxidative stress, metabolic disturbances, and apoptosis, likely due to its antioxidant and anti-inflammatory properties. These findings suggest CoQ10 as a potential therapeutic agent for THP-induced pulmonary toxicity, warranting further research.

CLINICAL TRIAL NUMBER

Not applicable.

Parasympathetic pathway in melatonin regulation exogenous melatonin alleviates abnormal glucose metabolism in the breast muscle under long-term light exposure through the parasympathetic pathway

INTRODUCTION

Human beings and animals have been exposed to long-term artificial lighting environments to induce glucose metabolism disorder. Melatonin (MT) is involved in the regulation of glucolipid metabolism, and can prevent skeletal muscle wasting as well as sarcopenia-associated diseases. However, the effect of exogenous MT on skeletal muscle glucose metabolism and the involvement of the parasympathetic pathway have not been clarified.

OBJECTIVES

To investigate the role of parasympathetic regulatory pathway in the mediating the effects of exogenous MT on skeletal muscle glucose metabolism following long-term light exposure.

METHODS

This study established rapid growth period broiler models, while characterized muscle histological analysis, glucose metabolism indexes and related genes expression through parasympathetic activation, exogenous MT administration and exogenous MT with parasympathetic inhibition experiments.

RESULTS

Long-term light exposure inhibited muscle glycogen synthesis, promoted muscle glycogen decomposition, increased anaerobic glycolysis, decreased aerobic respiration and induced the injury in breast muscle. Parasympathetic activation and exogenous MT caused a marked improvement in muscle glycogen accumulation, aerobic glycolysis and the injury in breast muscle. The exogenous MT beneficial functions were alleviated by parasympathetic inhibition. Furthermore, parasympathetic activation and exogenous MT administration protected cecal microbiota homeostasis, by improving stability of the gut microbiota community and increasing the relative abundance of Lactobacillus. Lactobacillus abundance was positively associated with muscle glycogen accumulation.

CONCLUSION

Taken together, this study highlighted the role of the novel parasympathetic regulatory pathway in the effects of exogenous MT in maintaining glucose metabolism homeostasis and restoring the damage in skeletal muscle with long-term light exposure. The results indicate that gut microbiota are involved in the MT-parasympathetic regulatory network. This study filles the gap in autonomic nervous-endocrine regulation under long light exposure, and provides a new insight to alleviate long light exposure-induced glucose metabolism disorders to improve the growth and health of humans and animals.

M2 macrophage-derived exosome facilitates aerobic glycolysis and osteogenic differentiation of hPDLSCs by regulating TRIM26-induced PKM ubiquitination

BACKGROUND

Our previous findings revealed that exosomes derived from M2-polarized macrophages enhance the osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs), and identified key microRNAs (miRNAs) using high-throughput miRNA sequencing. Therefore, the present study aimed to elucidate the role and underlying molecular mechanism by which exosomes derived from M2 macrophages mediate the osteogenic differentiation of hPDLSCs.

METHODS

Following lentiviral-mediated modulation of miR-6879-5p in both hPDLSCs and M2 macrophage-derived exosomes, RT-qPCR, western blotting, and Alizarin Red staining were applied to assess alterations in osteogenic markers, including ALP, OCN, Collagen I, and RUNX2, as well as mineralized nodule formation in hPDLSCs. Immunoprecipitation-mass spectrometry (IP-MS) was employed to identify proteins interacting with miR-6879-5p target genes in hPDLSCs.

RESULTS

Knockdown of miR-6879-5p in the exosomes reduced the expression of osteogenic markers and inhibited calcified nodule formation in hPDLSCs. Overexpression of TRIM26 attenuated the osteogenic differentiation of hPDLSCs, an effect that was reversed by miR-6879-5p overexpression. IP-MS identified 410 TRIM26-interacting proteins in hPDLSCs. These proteins were associated with ubiquitination, aerobic glycolysis, and amino acid metabolism. The hub proteins in the TRIM26-associated PPI network included RPL and RPS family proteins, as well as glycolysis-associated proteins. CO-IP confirmed an interaction between TRIM26 and PKM, and showed that TRIM26 increased PKM ubiquitination. Overexpression of PKM rescued TRIM26-mediated suppression of osteogenic marker expression and mineralized nodule formation in hPDLSCs.

CONCLUSION

miR-6879-5p carried by M2 macrophage-derived exosomes promotes osteogenic differentiation and aerobic glycolysis in hPDLSCs via modulating TRIM26-mediated ubiquitination of PKM.

Targeting TYROBP to influence the immune microenvironment and osteogenic differentiation of mesenchymal stem cells

Background

Lactate, as an end product of glycolysis, plays an important role in cellular metabolism and signal transduction, and recent studies have shown that it is closely related to cellular differentiation, but its potential role in osteogenic differentiation has not yet been fully investigated.

Methods

We obtained two datasets containing human mesenchymal stem cells and human osteoblasts, GSE12266 and GSE18043 , from the GEO database, which contained a total of 14 samples with sequencing data, and searched for lactate metabolism-related genes from the Genecards database. Ten differentially expressed core genes related to lactate metabolism were identified by differential expression analysis, protein interaction network analysis, and correlation expression analysis, and determined to play a key role in osteogenic differentiation. The effects of hub genes on the immune microenvironment of osteogenic differentiation were explored by enrichment analysis and immune infiltration analysis, and the significant effects of the key gene TYRO Protein Tyrosine Kinase-Binding Protein(TYROBP) on the characterization of bone marrow mesenchymal stem cells (BMSCs) were experimentally verified, and it was determined by drug sensitivity analysis that TYROBP may be a regulatory target of certain drugs affecting osteogenic differentiation.

Result

We successfully screened 10 differentially expressed hub genes related to lactate metabolism, and their area under the curve AUC values for predicting osteogenic differentiation were all highly favorable. Enrichment analysis showed that lactate metabolism may affect osteoblast differentiation through immune infiltration, and the immune infiltration results confirmed the strong association between hub genes and osteoblast immune infiltration status. It was verified that decreasing TYROBP expression promoted cell viability, proliferation and migration ability of BMSCs. Drug sensitivity analysis showed that TYROBP may be a major regulator of drug-induced MSC differentiation.

Conclusion

Our study reveals the critical role of lactate metabolism in osteoblast differentiation, identifies the role of the key gene TYROBP in the regulation of BMSCs, and provides new insights for studies related to the regulation of osteoblast differentiation.

Lactate Is a Major Promotor of Breast Cancer Cell Aggressiveness

Background: Lactate dehydrogenase (LDH) activity, producing high levels of lactate from pyruvate in cancer cells, is often associated with poor patient prognosis. We previously showed enhanced LDH/lactate levels in estrogen receptor (ER) compared to ER + breast cancer cells; lactate or pyruvate supplementation to ER + cells significantly enhanced their motile ability, while LDHB gene knockout (KO) or treatment with LDH inhibitors reduced the motility of the highly aggressive ER breast cancer cells. Aims: To investigate the molecular mechanisms by which lactate, LDHB KO, or treatment with LDH inhibitors can modulate the motile capabilities of breast cancer cell lines. Methods: KO experiments were performed using siRNA, and global expression was determined by proteomic profiling with Proteome Profiler Human XL Oncology arrays, Western blot, and immunofluorescence. Results: Lactate supplementation to ER + breast cancer cells enhanced expression of vimentin, N-cadherin, and snail, while reducing the expression of JAM-A, E-cadherin, and nectin-4. This expression profile was reversed with LDHB KO in ER cells. LDHB KO, or treatment with LDH inhibitors in ER cells, also reduced the expression of IL-6, IL-8, and MMP-2. The expressions of other markers such as PECAM-1, CCL20, and ENPP-2 were differentially modulated with LDH B KO in de novo ER cells (MDA-MB-231) vs. those that had ER knockout (pII). Conclusions: Our data show a novel role for lactate in modulating the EMT status in breast cancer cells and highlight the important role of lactate in breast cancer motility in part through modulating EMT status and the expression profile of cytokines, adhesion molecules, MMP-2, and nectin-4.

Supervised Machine Learning Models for Predicting Sepsis-Associated Liver Injury in Patients With Sepsis: Development and Validation Study Based on a Multicenter Cohort Study

BACKGROUND

Sepsis-associated liver injury (SALI) is a severe complication of sepsis that contributes to increased mortality and morbidity. Early identification of SALI can improve patient outcomes; however, sepsis heterogeneity makes timely diagnosis challenging. Traditional diagnostic tools are often limited, and machine learning techniques offer promising solutions for predicting adverse outcomes in patients with sepsis.

OBJECTIVE

This study aims to develop an explainable machine learning model, incorporating stacking techniques, to predict the occurrence of liver injury in patients with sepsis and provide decision support for early intervention and personalized treatment strategies.

METHODS

This retrospective multicenter cohort study adhered to the TRIPOD+AI (Transparent Reporting of a Multivariable Prediction Model for Individual Prognosis or Diagnosis, Extended for Artificial Intelligence) guidelines. Data from 8834 patients with sepsis in the Medical Information Mart for Intensive Care IV (MIMIC-IV) database were used for training and internal validation, while data from 4236 patients in the eICU-Collaborative Research Database (eICU-CRD) database were used for external validation. SALI was defined as an international normalized ratio >1.5 and total bilirubin >2 mg/dL within 1 week of intensive care unit admission. Nine machine learning models-decision tree, random forest (RF), extreme gradient boosting (XGBoost), light gradient boosting machine (LightGBM), support vector machine, elastic net, logistic regression, multilayer perceptron, and k-nearest neighbors-were trained. A stacking ensemble model, using LightGBM, XGBoost, and RF as base learners and Lasso regression as the meta-model, was optimized via 10-fold cross-validation. Hyperparameters were tuned using grid search and Bayesian optimization. Model performance was evaluated using accuracy, balanced accuracy, Brier score, detection prevalence, F1-score, Jaccard index, κ coefficient, Matthews correlation coefficient, negative predictive value, positive predictive value, precision, recall, area under the receiver operating characteristic curve (ROC-AUC), precision-recall AUC, and decision curve analysis. Shapley additive explanations (SHAP) values were used to quantify feature importance.

RESULTS

In the training set, LightGBM, XGBoost, and RF demonstrated the best performance among all models, with ROC-AUCs of 0.9977, 0.9311, and 0.9847, respectively. These models exhibited minimal variance in cross-validation, with tightly clustered ROC-AUC and precision-recall area under the curve distributions. In the internal validation set, LightGBM (ROC-AUC 0.8401) and XGBoost (ROC-AUC 0.8403) outperformed all other models, while RF achieved an ROC-AUC of 0.8193. In the external validation set, LightGBM (ROC-AUC 0.7077), XGBoost (ROC-AUC 0.7169), and RF (ROC-AUC 0.7081) maintained strong performance, although with slight decreases in ROC-AUC compared with the training set. The stacking model achieved ROC-AUCs of 0.995, 0.838, and 0.721 in the training, internal validation, and external validation sets, respectively. Key predictors-total bilirubin, lactate, prothrombin time, and mechanical ventilation status-were consistently identified across models, with SHAP analysis highlighting their significant contributions to the model's predictions.

CONCLUSIONS

The stacking ensemble model developed in this study yields accurate and robust predictions of SALI in patients with sepsis, demonstrating potential clinical utility for early intervention and personalized treatment strategies.

NCAPD3 contributes to lung cancer progression through modulated lactate-induced histone lactylation and MEK/ERK/LDHA axis

Lung cancer (LC) is one of the most common malignant tumors globally. Non-SMC condensin II complex subunit D3 (NCAPD3) has been involved in the progression of many kinds of tumors. However, the effects of NCAPD3 in LC remain unclear. NCAPD3 expression was investigated by the Ualcan database and using Western blot. The effect of NCAPD3 on prognosis was explored via the Kaplan-Meier plotter database. Cell viability, colony formation, apoptosis, and Transwell assays, and in vivo tumorigenesis were performed to reveal the biological roles of NCAPD3. Glycolysis was assessed via measurement of glucose consumption, extracellular acidification rate (ECAR), lactate production, and ATP levels. The deeper mechanisms of NCAPD3 were investigated by Western blot and rescue experiments. Upregulation of NCAPD3 levels in LC tissues was found in Ualcan and significantly associated with poor prognosis. The expression of NCAPD3 was up-regulated in LC cell lines compared to BEAS-2B cells. Knockdown and overexpression experiments suggested that proliferation, apoptosis, migration, invasion, and glycolysis were regulated by NCAPD3 via the MEK/ERK/LDHA pathway. Additionally, NCAPD3 knockdown inhibited tumor growth in vivo. Mechanistically, NCAPD3 overexpression-mediated activation of the MEK/ERK/LDHA pathway and proliferation, Glucose uptake, and glycolysis were attenuated by MEK inhibitor U0126. Also, histone lactylation helps in tumorigenesis by promoting NCAPD3 expression. Taken together, our results revealed that histone lactylation of NCAPD3 promoted proliferation, migration, invasion, and glycolysis through modulating the MEK/ERK/LDHA signaling pathway in LC, which highlights a novel understanding of NCAPD3 in LC.

Solid/Liquid/Gas Three-Phase Interface Enzymatic Reaction-Based Lactate Biosensor with Simultaneously High Sensitivity and Wide Linear Range

Electrochemical lactate biosensors with simultaneously high sensitivity and wide linear detection range are desirable for health monitoring. Nevertheless, the low oxygen level in biological fluids compromises oxidase enzymatic kinetics, which consequently results in a narrow linear detection range and/or low sensitivity. In this study, we addressed this issue by fabricating a solid/liquid/gas three-phase enzyme electrode with sufficiently high oxygen levels in the local reaction zone and much enhanced oxidase enzymatic kinetics. The three-phase enzyme electrode was fabricated by successively immobilizing H2O2 electrocatalyst and lactate oxidase (LOx) on a superhydrophobic porous carbon substrate. Owing to the much-enhanced oxidase enzymatic kinetics, the linear detection upper limit of the three-phase lactate biosensor was increased up to 40 mM, about 57-fold higher than that of the conventional two-phase system (0.7 mM), while a sensitivity as high as 22.28 μA mM-1 cm-2 was maintained. Moreover, a sweat lactate sensing device was fabricated based on the three-phase enzyme electrode and utilized for lactate detection in undiluted sweat during exercise. This three-phase enzyme electrode with both high sensitivity and wide linear range provides a new approach for the development of high-performance lactate sensing systems.

Metabolic Effects of Cellular Necrosis Caused by Exfoliative Toxin C (ExhC) from Mammaliicoccus sciuri

Exfoliative toxins (ETs) are glutamyl endopeptidases (GEPs) belonging to the chymotrypsin-like serine protease family (CLSPs), and they play crucial roles in diverse skin diseases. Specifically, exfoliative toxin C (ExhC), expressed by Mammaliicoccus sciuri, is an atypical CLSP and has been classified as a moonlighting protein due to its ability to induce necrosis in specific cell lines, inhibit the phagocytic activity of macrophages, and cause skin exfoliation in pigs and mice. The latter function is attributed to the high specificity of ExhC for porcine and murine desmoglein-1, a cadherin that contributes to cell-cell adhesion within the epidermis. Although the amino acid residues responsible for ExhC-induced necrosis have been identified, the specific cellular metabolic pathways leading to cell death remain unclear. Herein, we employed nuclear magnetic resonance (NMR) and mass spectrometry (MS) to explore the metabolic pathways affected by the necrotic activity of ExhC in the BHK-21 cell line. The metabolic profile of cells exposed to subtoxic doses of ExhC revealed significant alterations in oxidative stress protection, energy production, and gene expression pathways. The data demonstrate the potential mechanisms of action of ExhC and highlight that this toxin causes cellular damage, even at low concentrations.

Where do doctors disagree? Characterizing Decision Points for Safe Reinforcement Learning in Choosing Vasopressor Treatment

In clinical settings, domain experts sometimes disagree on optimal treatment actions. These "decision points" must be comprehensively characterized, as they offer opportunities for Artificial Intelligence (AI) to provide statistically informed recommendations. To address this, we introduce a pipeline to investigate "decision regions", clusters of decision points, by training classifiers for prediction and applying clustering techniques to the classifier's embedding space. Our methodology includes: a robustness analysis confirming the topological stability of decision regions across diverse design parameters; an empirical study using the MIMIC-III database, focusing on the binary decision to administer vasopressors to hypotensive patients in the ICU; and an expert-validated summary of the decision regions' statistical attributes with novel clinical interpretations. We demonstrate that the topology of these decision regions remains stable across various design choices, reinforcing the reliability of our findings and generalizability of our approach. We encourage future work to extend this approach to other medical datasets.

Stimuli-Responsive Polymeric Nanoprobes for Bioimaging of Cancer Metastasis

Stimuli-responsive polymeric nanoprobes as a type of nanoscale probe can respond to the tumor microenvironment via specific stimuli inside tumors, such as pH, hypoxia, glutathione (GSH), enzymes, aberrant receptors, and high ATP concentration. The ingenious design of the nanoprobes can improve the specificity and sensitivity to distinguish the slight differences between normal tissues and tumors. Thus, the tiny tumor metastasis can be detected by bioimaging of the stimuli-responsive polymeric nanoprobes. This review summarizes the progress and applications of polymeric nanoprobes in the bioimaging of tumor metastasis. The design strategies for the nanoprobes targeting tumor tissues are discussed according to the stimulus types, including tumor pH, hypoxia, glutathione, enzymes, aberrant receptor, and ATP. Moreover, the challenges currently faced in this field are also discussed. This review will provide valuable insights for the design and optimization of stimuli-responsive polymeric nanoprobes to accelerate the development of bioimaging for tumor metastasis and promote the clinical translation.

Advances in the Fabrication of Polycaprolactone-Based Composite Scaffolds for Bone Tissue Engineering: From Chemical Composition to Scaffold Architecture

Thermoplastic polymer-based materials, which feature essential biological properties and opportunities to implement the cutting-edge additive manufacturing technologies aimed at obtaining high-precision 3D models, have attracted intense interest for porous and bioresorbable bone tissue implants development. Among the wide range of materials, polycaprolactone was found to provide a balance between the biodegradation rate and biocompatibility with various tissues. Recent advances in the fabrication of polymer-polymer and polymer-inorganic composites have opened new ways to improve biological and mechanical outcomes and expanded the range of applications for bone and cartilage restoration, including the development of conductive composites for electrostimulation. While the chemical composition of the manufactured scaffolds played a vital role in their general biological performance and biocompatibility with bone tissue, the micropattern and roughness of the surface were shown to be additional stimuli for stem cell differentiation. More challenges came from the fabrication technique suitable for the proposed scaffold design. Here we summarize the key challenges and advances in fabrication and approaches to the optimization of certain chemical, morphological, or geometrical parameters of polycaprolactone-based scaffolds for bone tissue engineering applications.

Propranolol accelerates adipogenesis and inhibits endothelium differentiation of HemSCs via suppressing HK2 mediated glycolysis

BACKGROUND

As the first-line treatment for hemangioma (IH), the mechanism of propranolol (PRN) remains unclear. In clinical practice, challenges such as PRN resistance and rebound after discontinuation of PRN are frequently encountered. Hence, this research seeks to investigate the mechanisms underlying PRN-induced regression of IH.

METHODS

Hexokinase 2 (HK2) expression was assessed via immunohistochemistry and double-labeling staining. Glycolysis in hemangioma-derived stem cells (HemSCs) was evaluated by measuring glucose uptake, lactate, and ATP production. Peroxisome proliferator-activated receptor Gamma (PPARγ) and vascular endothelial cadherin (VE-cadherin) levels were analyzed using Western blot and qPCR. PRN-treated HemSCs were examined for adipogenic differentiation via Oil Red O and BODIPY staining.

RESULTS

Our results demonstrate that PRN inhibits HemSCs proliferation and endothelial differentiation while promoting adipogenesis by suppressing glycolysis. This effect occurs through HK2 downregulation, likely mediated by PI3K-Akt pathway inhibition. Notably, HK2 expression was significantly lower in CD133+ cells from involutive hemangiomas versus proliferative lesions.

CONCLUSIONS

This study presents the first evidence for the essential role of glycolysis in regulating the proliferation and differentiation of HemSCs, while the efficiency of PRN may be associated with the inhibition of HK2-mediated glycolysis in HemSCs by suppressing the activities of PI3K-Akt pathway.

IMPACT

Glycolysis level is high in HemSCs. Glycolysis is required in propranolol perturbated the HemSCs differentiation. PRN could inhibit glycolysis of HemSCs through down-regulation of HK2 expression. PRN suppressed endothelial differentiation and accelerated adipogenesis of HemSCs. PRN down-regulated HK2 expression through restrained the PI3k-Akt pathway. Schematic of treatment mechanism of PRN in IH. HK2 is highly expressed in HemSCs. PRN may be associated with the inhibition of HK2-mediated glycolysis in HemSCs by suppressing the activities of PI3K-Akt pathway which finally promotes regression of IH.

Effects of a synthetic cannabinoid, 5F-MDMB-PICA, on metabolites and glutamatergic transporters in U87 cell line

Brian metabolic pathways have been impaired in animals exposed to drugs of abuse. The misuse of cannabinoids is associated with neuronal death and synaptic plasticity. Astrocytic glutamate transporters are therapeutic targets in several preclinical models of substance use disorders. Abused drugs could impair metabolic pathways in animal models, particularly those involving astrocytes, where glutamate transporters are critical regulators of neurotransmission. We here aimed to evaluate the metabolomic profile of a human glioblastoma cell line following exposure a synthetic cannabinoid, 5F-MDMB-PICA (5F-M-P), using an in vitro cell model (U87, glioblastoma astrocytic origin cell line). Additionally, we evaluated the effects of 5F-M-P on the expression of astrocytic glutamate transporters. After treatments, the cells were collected for metabolomic study using gas chromatography-mass spectrometry, and protein expression study using western blotting assay. 5F-M-P, especially at a concentration of 100 μM, altered the abundance of numerous metabolites. Enrichment analysis identified that specific signaling pathways were involved in the effects of 5F-M-P on metabolites, including the glutamate neurotransmission pathway. Additionally, 5F-M-P at 200 μM reduced the expression of glutamate transporter-1 and glutamate-aspartate co-transporter. Therefore, 5F-M-P exposure altered key metabolic pathways in astrocytes including glutamatergic pathways, an effect associated with reduced astrocytic glutamate transporter expression.

The integrated single-cell analysis interpret the lactate metabolism-driven immune suppression in triple-negative breast cancer

BACKGROUND

Individuals with triple-negative breast cancer (TNBC) exhibit elevated lactate levels, which offers a valuable lead for investigating the molecular mechanisms underlying the tumor microenvironment (TME) and identifying more efficacious treatments.

METHODS

TNBC samples were classified based on lactate-associated genes. A single-cell transcriptomic approach was employed to examine functional differences across cells with varying lactate metabolism. Immunohistochemistry was used to explore the relationship between lactate metabolism and the CXCL12/CXCR4 signaling axis. In addition, utilizing machine learning techniques, we constructed a prognostic model based on lactic acid phenotype genes.

RESULTS

Lactate-associated gene-based stratification revealed increased immune cell infiltration and immune checkpoint expression in Lactate Cluster 1. Elevated lactate metabolism scores were observed in both cancer-associated fibroblasts (CAFs) and malignant cells. CAFs with high lactate metabolism exhibited immune suppression through the CXCL12/CXCR4 axis. Immunohistochemistry confirmed elevated LDHA, LDHB, CXCL12, and CXCR4 levels in the high lactate group.

CONCLUSION

This study elucidates the complex interplay between lactate and immune cells in TNBC and highlights the CXCL12/CXCR4 axis as a key pathway through which lactate mediates immune suppression, offering new insights into metabolic regulation within the TME. Furthermore, we developed a prognostic model based on lactate metabolism phenotype genes to predict the prognosis of TNBC patients and guide immunotherapy.

Lactate and lactylation in liver diseases: energy metabolism, inflammatory immunity and tumor microenvironment

Liver diseases pose a significant threat to human health. Lactate, a byproduct of glycolysis, serves various biological functions, including acting as an energy source, a signaling molecule, and a substrate for lactylation. Lactylation is a novel lactate-dependent post-translational modification that plays a role in tumor proliferation, the regulation of immune cell function, and the modulation of gene expression. In this paper, we summarize the roles of lactate and lactylation in energy metabolism, inflammatory immunity, and the tumor microenvironment, while also elucidating recent research advancements regarding lactate and lactylation in the context of hepatic fibrosis, non-alcoholic fatty liver disease, and hepatocellular carcinoma. Furthermore, lactate and lactylation are proposed as promising new targets for the treatment of liver diseases.

Identification and analysis of diagnostic markers related to lactate metabolism in myocardial infarction

Lactate metabolism is implicated in myocardial infarction (MI), yet the underlying mechanisms are not fully understood. Identifying lactate metabolism-related genes (LMRGs) could uncover new diagnostic and therapeutic targets for MI. We conducted a bioinformatics analysis on GeneCards database to identify 498 LMRGs and intersected them with differentially expressed genes (DEGs) from MI samples, yielding 17 key genes. We utilized consensus clustering and weighted gene co-expression network analysis (WGCNA) to refine our gene list to 981 candidate genes. Machine learning algorithms identified three biomarkers: OLIG1, LIN52, and RLBP1, associated with 'ribosome' and 'carbon metabolism' pathways. Enrichment analyses and immune microenvironment assessments were performed, and networks including drug-gene interactions and kinase-transcription factor (TF)-mRNA-miRNA were constructed to explore the functions and potential therapeutic implications of these genes. The three biomarkers showed significant correlations with immune cell types, with OLIG1 having the highest positive correlation with monocytes and the highest negative correlation with neutrophils. The drug-gene network revealed potential interactions such as methapyrilene with LIN52 and 'bisphenol A' with RLBP1. The kinase-TF-mRNA-miRNA network comprised 209 nodes and 470 edges, indicating complex regulatory mechanisms. Our study identified three key biomarkers, OLIG1, LIN52, and RLBP1, in lactate metabolism associated with MI, providing insights into potential diagnostic markers and therapeutic targets. These findings warrant further investigation into the molecular mechanisms of these biomarkers in MI.

Association Between Lactate-to-Albumin Ratio and 28-Day All-Cause Mortality in Critical Care Patients with COPD: Can Both Arterial and Peripheral Venous Lactate Serve as Predictors?

Background

Lactate-to-albumin ratio (LAR) has been reported as a useful predictor for multiple critical illnesses. However, the association between LAR and mortality in patients with chronic obstructive pulmonary disease (COPD) remains unclear. This study aims to clarify the correlation between LAR and 28-day all-cause mortality in patients with COPD and to investigate whether LAR calculated using arterial lactate (AL) or peripheral venous lactate (PVL) can serve as predictive indicators.

Methods

A total of 1428 patients from the Medical Information Mart for Intensive Care (MIMIC) IV database (version 2.2) and 2467 patients from the eICU Collaborative Research Database (eICU-CRD, version 2.0) were included in this study. Propensity score matching (PSM) method was conducted to control confounders. Cox proportional hazards model, Kaplan-Meier survival method, subgroup analysis and receiver operating characteristic (ROC) analysis were performed to assess the predictive ability of LAR. To verify our hypothesis, data from the two databases were analyzed individually.

Results

After adjusting for covariates, LAR calculated using either AL (MIMIC IV, HR = 1.254, 95% CI, 1.013-1.552, P = 0.038) or PVL (eICU-CRD, HR = 1.442, 95% CI, 1.272-1.634, P < 0.001) was independently associated with 28-day all-cause mortality in COPD patients. Kaplan-Meier analysis showed that patients with higher LAR value had significantly higher all-cause mortality (all P < 0.05). This association was consistent across subgroup analyses. In addition, the ROC analysis suggested that LAR calculated using PVL may have better predictive performance compared to using AL.

Conclusion

LAR calculated using both AL and PVL can independently predict the 28-day all-cause mortality after ICU admission in patients with COPD and higher level of LAR is related to higher mortality risk.

Super-Enhancer-Driven LncRNA UNC5B-AS1 Inhibits Inflammatory Phenotypic Transition in Pulmonary Artery Smooth Muscle Cells via Lactylation

BACKGROUND

The phenotypic transition of pulmonary artery smooth muscle cells (PASMCs) is a central pathological alteration in pulmonary artery remodeling, contributing to pulmonary hypertension. Super-enhancers (SEs), characterized by histone modifications and the binding of coactivators, drive the expression of prominent genes that define cellular identity. However, the specific role of SEs, particularly SE-driven long noncoding RNAs, in hypoxia-induced phenotypic plasticity of PASMCs remains unclear.

METHODS

In this study, the long noncoding RNA UNC5B antisense RNA 1 (UNC5B-AS1) regulated by SEs was screened in hypoxic PASMCs using RNA sequencing and H3K27ac (histone 3 lysine 27 acetylation) chromatin immunoprecipitation sequencing. Overexpression or knockdown of UNC5B-AS1 in vitro was performed to elucidate its role in pulmonary hypertension pathogenesis. A serotype 5 adenovirus-associated virus carrying a conserved functional fragment of UNC5B-AS1 was used to treat pulmonary hypertension in vivo.

RESULTS

We identified UNC5B-AS1 as an SE-driven long noncoding RNA transcriptionally activated by the transcription factor FOXP3 (forkhead box protein P3), which regulates phenotypic transition in PASMCs. Notably, we demonstrated that UNC5B-AS1 interacts with key glycolytic enzymes in the cytoplasm and likely serves as a molecular scaffold for LRPPRC (leucine-rich PPR motif-containing protein) and oxidative respiratory chain complex IV in mitochondria. Consequently, the deficiency of UNC5B-AS1 in PASMCs promotes the lactylation of promoter regions within inflammatory genes, including those of IL (interleukin)-1β, IL-6, and TNF-α (tumor necrosis factor-α), under hypoxic conditions, ultimately leading to inflammatory phenotypic transition of PASMCs.

CONCLUSIONS

Our findings identify SE-driven UNC5B-AS1 as a novel regulatory factor in the hypoxia-induced phenotypic transition of PASMCs and suggest that overexpression of UNC5B-AS1 may represent a promising therapeutic strategy for pulmonary hypertension.

Development and validation a nomogram to predict long-term mortality risks of PRISm and mild-to-moderate COPD based on NHANES 2007-2012

Chronic Obstructive Pulmonary Disease (COPD) can be prevented in the pre-clinical and early stages. However, very limited prediction models of COPD focus on Preserved Ratio Impaired spirometry (PRISm) and early stages. To fill this gap, this study aimed to develop and validate a nomogram to predict long-term mortality risks of PRISm and early COPD. We obtained data of participants in the US National Health and Nutrition Examination Surveys 2007-2012 and the available mortality follow-up data from the date of survey participation to Dec 31, 2019. The study population (n = 1043) was randomly divided into training and validation datasets at a ratio of 7:3. The cox proportional hazards model was applied to select significant prognostic risk factors of COPD in the training dataset. Besides, the predictive power and clinical usage value were assessed by the area under time dependent receiver operating characteristic curve (time-dependent AUROC), calibration curves and decision curve analysis (DCA). Moreover, directed acyclic graph (DAG) was utilized to plot causal associations between risk factors and mortality. We developed an accurate and easy to use nomogram using six predictors (age, passive smoking, alkaline phosphotase, gamma glutamyl transferase, lactate dehydrogenase, potassium). The nomogram had satisfactory predictive performance, as the time-dependent AUROC with 95% confidence interval (CI) at 7.5 years was 0.78 (0.69-0.84) and 0.80 (0.67, 0.87) in the training and validation datasets, respectively. The calibration curves and DCA also showed that the nomogram had good clinical usage value. Compared with the low-risk groups, the Hazard Ratio in the high-risk group was 2.25 (95% CI 1.29-3.94) in the validation datasets, respectively. DAG shown that there had directly associations of passive smoking and lactate dehydrogenase with all-cause mortality. The nomogram has the potential to identify high-risk populations in the pre-clinical and early stages of COPD.

Lactic acid metabolism: gynecological cancer's Achilles' heel

Lactic acid is significantly expressed in many cancers, including gynecological cancer, and has become a key regulator of the proliferation, development, metastasis and invasion of these cancers. In clinical and experimental studies, the level of lactic acid in gynecological cancer is closely related to metastasis and invasion, tumor recurrence and poor prognosis. Lactic acid can regulate the internal metabolic pathway of gynecological cancer cells and drive the autonomous role of non-cancer cells in gynecological cancer. In addition to being used as a source of energy metabolism by gynecological cancer cells, lactic acid can also be transported from cancer cells to neighboring cancer cells, stroma and vascular endothelial cells (ECs) to further guide metabolic reprogramming. Lactic acid is also involved in promoting inflammation and angiogenesis in gynecologic tumors. Therefore, we reviewed the mechanisms and recent advances in the production and transport of lactic acid in gynecological cancer. These advances and evidence suggest that targeted lactic acid metabolism is a promising cancer treatment.

The metabolic dialogue between intratumoural microbes and cancer: implications for immunotherapy

The tumour microenvironment (TME) exerts a profound influence on cancer progression and treatment outcomes. Recent investigations have elucidated the crucial role of intratumoural microbiota and their metabolites in shaping the TME and modulating anti-tumour immunity. This review critically assesses the influence of intratumoural microbial metabolites on the TME and cancer immunotherapy. We systematically analyse how microbial-derived glucose, amino acid, and lipid metabolites modulate immune cell function, cytokine secretion, and tumour growth. The roles of specific metabolites, including lactate, short-chain fatty acids, bile acids, and tryptophan derivatives, are comprehensively examined in regulating immune responses and tumour progression. Furthermore, we investigate the potential of these metabolites to augment the efficacy of cancer immunotherapies, with particular emphasis on immune checkpoint inhibitors. By delineating the mechanisms through which microbial metabolites influence the TME, this review provides insights into novel microbiome-based therapeutic strategies, thereby highlighting a promising frontier in personalised cancer medicine.

The roles of protein S-nitrosylation in regulating the growth and development of plants: A review

The free radical nitric oxide (NO) is an important redox-related signaling molecule modulating wide range of biological processes in all living plants. The transfer of NO bioactivity could be executed chiefly through a prototypic, redox-based post-translational modification, S-nitrosylation that covalently adds NO moiety to a reactive cysteine thiol of a target protein to form an S-nitrosothiol. Protein S-nitrosylation is recently emerged as an evolutionarily conserved and important mechanism regulating multiple aspects of plant growth and development. Here, we review the recent progress of S-nitrosylated proteins in the modulation of various plant development processes, including seed germination and aging, root development, seedling growth, flowering and fruit ripening and postharvest fruit quality. More importantly, the detailed function mechanism of proteins S-nitrosylation and key challenges in this field are also highlighted.

Versatile PLGA-Based Drug Delivery Systems for Tumor Immunotherapy

Tumor immunotherapy, which utilizes the immune system to fight cancer, represents a revolutionary method for cancer treatment. Poly (lactic-co-glycolic acid) (PLGA) copolymer has emerged as a promising material for tumor immunotherapy due to its biocompatibility, biodegradability, and versatility in drug delivery. By tuning the size, shape, and surface properties of PLGA-based systems, researchers have improved their ability to align with the requirements for diverse tumor immunotherapy modalities. In this review, the basic properties of the PLGA materials are first introduced and further the principal forms of the PLGA systems for controlled release are summarized and delivery applications are targeted. In addition, recent advances in the use of PLGA delivery systems are highlighted to enhance antitumor immune responses in terms of tumor vaccines, immunogenic cell death-mediated immune responses, tumor microenvironment modulation, and combination immunotherapies. Finally, prospects for the future research and clinical translation of PLGA materials are proposed.

SLC4A7 suppresses lung adenocarcinoma oncogenesis by reducing lactate transport and protein lactylation

Lactate and protein lactylation serve a key role in tumor pathogenesis. Solute carrier 4A7 (SLC4A7), a key transporter, participates in cellular acid homeostasis. However, its impact on lactate transport and protein lactylation in solid tumors, particularly lung adenocarcinoma (LUAD), remains largely unexplored. In the present study, lactylome analysis, Transwell and wound healing assay, animal experiments were conducted to validate functional regulation mediated by SLC4A7 in LUAD. SLC4A7 inhibited tumor progression, including metastasis, invasion and proliferation. Mechanistically, SLC4A7 decreased both intracellular and extracellular lactate accumulation and inhibited overall protein lactylation, as confirmed by lactylome analysis. Analyzing the lactylome revealed that SLC4A7 suppressed lysine lactylation of numerous genes like HSP90AA1 and pathways such as focal adhesion associated with carcinogenesis. Additionally, low expression levels of SLC4A7 in LUAD cancer stem cells were validated using tumor tissue samples from patients with LUAD. Moreover, the inhibitory role of SLC4A7 in regulating tumor stemness was verified. Collectively, the present results uncovered the inhibitory effect exerted by SLC4A7 on tumor progression via its regulation of lactate transport, protein lactylation and stemness properties. Targeting SLC4A7 may hold promise as a novel therapeutic strategy for LUAD.

Multilayer cascade-response nanoplatforms as metabolic symbiotic disruptors to reprogram the immunosuppressive microenvironment

Nanomedicine is extensively utilized in tumor treatment, however, the restricted permeability of nanomaterials within tumor tissues, along with the inherent metabolic complexity of these tissues, have hindered effective control of tumor progression. Hypoxic and normoxic tumor cells utilize monocarboxylic acid transporters (MCTs) for the rapid reutilization of lactate, facilitating accelerated tumor growth. Here, cascade-response nanoplatforms (NPs) with contrast-enhanced ultrasound imaging (CEUI) capability had been established, incorporating basigin siRNA internally and featuring hyaluronidase (HAase) and γ-glutamyltranspeptidase (GGT)-responsive lipid coatings externally (GHB NPs). The GHB NPs took advantage of GGT-responsive HAase release to facilitate deep tumor penetration. Furthermore, ultrasound (US) irradiation decreased the expression of glycolysis-related proteins through the modulation of the β-catenin/c-Myc pathway, and US irradiation induced mitochondrial damage, leading to a low-energy state in tumor cells. On this basis, GHB NPs was paired with US stimulation to provide a combination therapy that disturbed tumor cell metabolic symbiosis and remodeled the immunosuppressive tumor microenvironment. This study formulates an effective therapeutic approach for metabolic-immunotherapy, potentially offering a viable candidate for tumor treatment.

Cardiac energy metabolism in diabetes: emerging therapeutic targets and clinical implications

Patients with diabetes are at an increased risk for developing diabetic cardiomyopathy and other cardiovascular complications. Alterations in cardiac energy metabolism in patients with diabetes, including an increase in mitochondrial fatty acid oxidation and a decrease in glucose oxidation, are important contributing factors to this increase in cardiovascular disease. A switch from glucose oxidation to fatty acid oxidation not only decreases cardiac efficiency due to increased oxygen consumption but it can also increase reactive oxygen species production, increase lipotoxicity, and redirect glucose into other metabolic pathways that, combined, can lead to heart dysfunction. Currently, there is a lack of therapeutics available to treat diabetes-induced heart failure that specifically target cardiac energy metabolism. However, it is becoming apparent that part of the benefit of existing agents such as GLP-1 receptor agonists and sodium-glucose cotransporter 2 inhibitors may be related to their effects on cardiac energy metabolism. In addition, direct approaches aimed at inhibiting cardiac fatty acid oxidation or increasing glucose oxidation hold future promise as potential therapeutic approaches to treat diabetes-induced cardiovascular disease.

Activation of hepatic alcohol metabolism by enzymatic porcine placenta hydrolysate in rats

Alcohol consumption causes severe liver damage and oxidative stress. This study investigated the hepatoprotective effects of enzymatic porcine placenta hydrolysate (EPPH) in Sprague-Dawley rats under acute alcohol administration. EPPH significantly reduced plasma ethanol and acetaldehyde levels in a dose-dependent manner. Furthermore, EPPH decreased the hepatic levels of malondialdehyde and thiobarbituric acid reactive substances and suppressed Cyp2e1 mRNA expression. EPPH decreased the plasma alanine transaminase and aspartate transaminase levels and increased the hepatic NAD+/NADH ratio. Hepatic transcriptome analysis revealed the significant regulation of key genes involved in inflammation, alcohol response, and apoptosis. Phosphokinase array analysis demonstrated that EPPH reduced phosphorylation of CASP9, BAX, TP53, and CHK2, thereby facilitating reactive oxygen species removal and suppressing apoptosis. Additionally, qPCR confirmed EPPH reduced Bax and Caspase9 mRNA levels, while immunoblotting showed decreased phosphorylation of TP53 and CHK2. These findings suggest that EPPH improves hepatic alcohol metabolism and reduces alcohol-induced hepatotoxicity.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-025-01822-1.

Lactylation and Ischemic Stroke: Research Progress and Potential Relationship

Ischemic stroke is caused by interrupted cerebral blood flow and is a leading cause of mortality and disability worldwide. Significant advancements have been achieved in comprehending the pathophysiology of stroke and the fundamental mechanisms responsible for ischemic damage. Lactylation, as a newly discovered post-translational modification, has been reported to participate in several physiological and pathological processes. However, research on lactylation and ischemic stroke is scarce. This review summarized the current function of protein lactylation in other diseases or normal physiological processes and explored their potential link with the pathophysiological process and the reparative mechanism of ischemic stroke. We proposed that neuroinflammation, regulation of metabolism, regulation of messenger RNA translation, angiogenesis, and neurogenesis might be the bridge linking lactylation and ischemic stroke. Our study provided a novel perspective for comprehending the role of protein lactylation in the pathophysiological processes underlying ischemic stroke. Lactylation might be a promising target in drug development of ischemic stroke.

Zonated Copper-Driven Breast Cancer Progression Countered by a Copper-Depleting Nanoagent for Immune and Metabolic Reprogramming

While studies of various carcinomas have reported aberrant metal metabolism, much remains unknown regarding their spatial accumulation and regulatory impacts in tumors. Here, elevated copper levels are detected in breast cancer tumors from patients and animal models, specifically exhibiting a zonate spatial pattern. Spatially resolved multiomics analyses reveal that copper zonation drives a tumor metabolic preference for oxidative phosphorylation (OXPHOS) over glycolysis and promotes tumor metastatic and immune-desert phenotypes. Then, a copper-depleting nanoagent is developed based on copper chelator tetrathiomolybdate (TM)-loaded hybridized bacterial outer membrane vesicles (hOMVs) from both Akkermansia muciniphila bacteria and CD326-targeting peptide-engineered Escherichia coli (TM@CD326hOMV). Systemic administration of TM@CD326hOMV reduces the labile copper level in tumors and inhibits both tumor growth and metastatic phenotypes, specifically through metabolic reprograming of OXPHOS toward glycolysis and restoration of antitumor immunity responses involving natural killer cells, CD4+ T cells, and cytotoxic CD8+ T cells in tumors. Assessing survival in murine breast cancer models, a combination of TM@CD326hOMV and a checkpoint blockade agent outperforms monotherapies. Notably, a copper-rich diet undermines the therapeutic efficacy of TM@CD326hOMV. Beyond demonstrating an effective nanoagent for treating breast cancer, this study deepens the understanding of how the pattern of copper accumulation in tumors affects pathophysiology and immunity.

Chlorogenic Acid Improves High-Fat Diet-Induced Skeletal Muscle Metabolic Disorders by Regulating Mitochondrial Function and Lactate Metabolism

Mitochondria are pivotal in sustaining skeletal muscle and the systemic metabolic balance. Chlorogenic acid (CA) is a common dietary antioxidant known for its ability to modulate metabolic homeostasis. This study aimed to investigate the impact of CA on high-fat diet (HFD)-induced mitochondrial dysfunction and metabolic disorder in skeletal muscle. C57BL/6J mice fed with a HFD were treated with CA for 12 weeks. The study assessed the overall glycolipid metabolic status, exercise performance, muscle fiber type, and antioxidant capacity of skeletal muscle in HFD-fed mice treated with CA. Results showed that CA reduced fat accumulation, improved exercise capacity, and enhanced mitochondrial performance in HFD-fed mice. Untargeted metabolomics analysis revealed that lactate metabolism and mitochondrial fatty acid oxidation (FAO) responded positively to CA intervention. Molecular mechanisms demonstrated that CA intervention improved mitochondrial biogenesis and function, promoting FAO and oxidative phosphorylation in mitochondria and ultimately reducing fat deposition in skeletal muscle induced by HFD feeding. Mechanistically, CA decreased HFD-induced lactate production and protein lactylation in skeletal muscle, highlighting the importance of the LDHA-lactate axis in mitochondrial function improvement by CA. Therefore, this study provides additional insights supporting the potential of CA as a natural dietary supplement for metabolic syndrome and associated disorders.

The role of protein lactylation in brain health and disease: current advances and future directions

Lactate, the end product of glycolysis, plays a crucial role in cellular signaling and metabolism. The discovery of lactylation, a novel post-translational modification, has uncovered the role of lactate in regulating diseases, especially in the brain. Lactylation connects genetic encoding with protein function, thereby influencing key biological processes. Increasing evidence supports lactate-mediated lactylation as a critical modulator in neurological disorders. This review offers an overview of lactate metabolism and lactylation, highlighting recent advances in understanding the regulatory enzymes of lactylation and their role in the central nervous system. We investigate the impact of lactylation on brain dysfunctions, including neurodegenerative diseases, cerebrovascular disorders, neuroinflammation, brain tumors, and psychiatric conditions. Moreover, we highlight the therapeutic potential of targeting lactylation in treating brain disorders and outline key research gaps and future directions needed to advance this promising field.

The metabolic underpinnings of sebaceous lipogenesis

Sebaceous glands synthesize and secrete sebum, a mélange of lipids and other cellular products that safeguards the mammalian integument. Differentiating sebocytes delaminate from the basal membrane and dislodge towards the gland's middle, where they eventually undergo a poorly understood death mode in which the whole cell becomes a secretion product (holocrine secretion). Supported by recent transcriptomics data, this review examines the idea that peripheral sebocytes have a remarkable ability to draw nutrients from the blood and become committed to unrestrainedly invest all available resources into synthetic processes for accomplishing sebum synthesis, thereby exploiting core metabolic fluxes as glycogen turnover, glutamine-directed anaplerosis, the pentose phosphate pathway and de novo lipogenesis. Finally, we propose that metabolic-driven processes are an important mechanistic component of holocrine secretion. A deeper understanding of these metabolic adaptations could indicate novel strategies for modulating sebum synthesis, a key pathogenic factor in acne and other skin diseases.

Assessing Bottlenose Dolphins' (Tursiops truncatus) Health Status Through Functional Muscle Analysis, and Oxidative and Metabolic Stress Evaluation: A Preliminary Study

Oxidative stress (OS) occurs when there is an imbalance between the production of reactive oxygen species (ROS) and the body's antioxidant defenses, causing damage to lipids, proteins, and DNA. In marine mammals, physiological adaptation to aquatic life conditions, such as prolonged and repeated dives resulting in cycles of hypoxia followed by reperfusion, is associated with increased production of ROS. This study examines the relationship between oxidative stress, muscular stress, and metabolic damage in the blood serum of eleven captive bottlenose dolphins (Tursiops truncatus), six males and five females. This relationship is investigated using oxidative stress markers (d-ROMs, OXY, and Oxidative Stress index, OSi) and biochemical parameter measurements, including glucose (GLU), aspartate aminotransferase (AST), creatine kinase (CK), and lactate dehydrogenase (LDH). Pearson's sex correlation was performed, and males exhibited significantly higher pro-oxidant levels than females, suggesting a potential protective role of female hormones. Also, a positive correlation between pro-oxidants and antioxidants has been observed in relation to age, as older dolphins produced more ROS but also exhibited higher antioxidant capacity, likely to compensate for oxidative damage. Results show no significant correlation between biochemical parameters and oxidative stress markers. However, a moderately positive correlation between LDH and antioxidant (OXY) capacity was observed (r = 0.458), suggesting a possible association between tissue turnover and antioxidant defenses. The results indicate that the biochemical markers analyzed are not strong predictors of oxidative stress in bottlenose dolphins. However, the correlation between LDH and antioxidant capacity suggests that tissue turnover may affect antioxidant defenses. This is a preliminary study, and further research is needed to clarify these relationships in order to better understand physiological adaptations in dolphins and their implications for management, health, and welfare.

Proteomic Analysis and 2-Hydroxyisobutyrylation Profiling in Metabolic Syndrome Induced Restenosis

Restenosis is the primary complication following stenting for coronary and peripheral arterial disease, posing an ongoing clinical challenge. Metabolic syndrome (MetS), characterized by metabolic disturbances, has been identified as an independent predictor for postoperative restenosis in coronary and carotid arteries, potentially due to endothelial dysfunction and augmented oxidative stress in cells, while its specific regulatory mechanism is still largely unknown. Lysine 2-hydroxyisobutyrylation (Khib), a recently identified posttranslational modification, plays a crucial role in transcriptional regulation and cellular metabolism. However, there is a lack of comprehensive analysis of the proteome and Khib modifications within restenotic vessels in the context of MetS, as well as in the understanding of the associated pathophysiology. In this study, we observed a significant upregulation of Khib in restenotic arteries induced by MetS, confirmed by animal and cellular experiments. Further, using high-throughput liquid chromatography-mass spectrometry, we catalogued 15,558 Khib sites across 2568 proteins, implicating a multitude of biological functions. Analysis revealed 2007 Khib sites on 1002 proteins with considerable differential modifications which are present within the cytoplasm and nucleus. Interestingly, proteins located in the mitochondria, endoplasmic reticulum, and cell membrane also exhibit distinct expression and modification profiles to varying extents that related to vascular smooth muscle contraction, platelet activation, and the PI3K-Akt signaling pathway. Notably, the level of COL1A1 protein detected in the protein-protein interaction pathway network and the level of Khib modification are diametrically opposed, suggesting a significant role in the disease's pathogenesis. This study provides the first comprehensive proteomic and Khib modification overview of MetS-related in-stent restenosis vasculature, offering key insights to inform novel therapeutic approaches for restenosis mitigation.

Neuroadaptation in neurodegenerative diseases: compensatory mechanisms and therapeutic approaches

Progressive neuronal loss is a hallmark of neurodegenerative diseases including Alzheimer's, Parkinson's, Huntington's, and Amyotrophic Lateral Sclerosis (ALS), which cause cognitive and motor impairment. Delaying the onset and course of symptoms is largely dependent on neuroadaptation, the brain's ability to restructure in response to damage. The molecular, cellular, and systemic processes that underlie neuroadaptation are examined in this study. These mechanisms include gliosis, neurogenesis, synaptic plasticity, and changes in neurotrophic factors. Axonal sprouting, dendritic remodelling, and compensatory alterations in neurotransmitter systems are important adaptations observed in NDDs; nevertheless, these processes may shift to maladaptive plasticity, which would aid in the advancement of the illness. Amyloid and tau pathology-induced synaptic alterations in Alzheimer's disease emphasize compensatory network reconfiguration. Dopamine depletion causes a major remodelling of the basal ganglia in Parkinson's disease, and non-dopaminergic systems compensate. Both ALS and Huntington's disease rely on motor circuit rearrangement and transcriptional dysregulation to slow down functional deterioration. Neuroadaptation is, however, constrained by oxidative stress, compromised autophagy, and neuroinflammation, particularly in elderly populations. The goal of emerging therapy strategies is to improve neuroadaptation by pharmacologically modifying neurotrophic factors, neuroinflammation, and synaptic plasticity. Neurostimulation, cognitive training, and physical rehabilitation are instances of non-pharmacological therapies that support neuroplasticity. Restoring compensating systems may be possible with the use of stem cell techniques and new gene treatments. The goal of future research is to combine biomarkers and individualized medicines to maximize neuroadaptive responses and decrease the course of illness. In order to reduce neurodegeneration and enhance patient outcomes, this review highlights the dual function of neuroadaptation in NDDs and its potential as a therapeutic target.

Probiotics promote cellular wound healing responses by modulating the PI3K and TGF-β/Smad signaling pathways

BACKGROUND

Skin wound healing represents a dynamic and intricate biological process involving the coordinated efforts of various cellular and molecular components to restore tissue integrity and functionality. Among the myriads of cellular events orchestrating wound closure, fibroblast migration and the regulation of fibrosis play pivotal roles in determining the outcome of wound healing. In recent years, probiotic therapy has emerged as a promising strategy for modulating wound healing and fibrosis. Here, we aim to investigate the effect of bacterial probiotics on cell migration and anti-fibrotic response of human dermal fibroblast (HDFs).

METHODS

Probiotic mixture BioK was co-cultured with HDFs in vitro to assess its impact on fibroblast migration, gene expression, and protein production associated with important processes in wound healing. Gene expression was investigated by transcriptomic analysis and confirmed by RT-qPCR. Protein levels of the identified genes were evaluated by ELISA. The role of lactic acid, produced by BioK, in mediating pH-related effects on fibroblast activity was further examined.

RESULTS

We observed that BioK effectively promoted HDFs migration in vitro, which was found to be related to the up-regulation of genes involved in the phosphoinositide 3-kinase (PI3K) signaling pathways such as Paxillin, PI3K, PKC and ITG-β1. Interestingly, we also found that BioK down-regulated the expression of Nox-4, α-SMA and Col-I in TGF-Smad signaling pathways, which are involved in the differentiation of fibroblasts to myofibroblasts, and extracellular matrix type I collagen production, demonstrating its potential in reducing formation of fibrosis and scars. One of the acting factors for such down-regulation was identified to be BioK-produced lactic acid, which is known to lower the surrounding pH and to play a major role in fibroblast activity and wound healing.

CONCLUSIONS

This study demonstrates BioK's beneficial effects on fibroblast migration and its potential to mitigate fibrosis through pH modulation and pathway-specific gene regulation. These findings enhance our understanding of probiotic action on wound healing and offer promising therapeutic insights for the reduction of scar formation.

CLINICAL TRIAL NUMBER

Not applicable.