Search

Abstract Background About 10% of hematologic malignancies are multiple myeloma (MM), an untreatable cancer. Although lactate and branched-chain amino acids (BCAA) are involved in supporting various tumor growth, it is unknown whether they have any bearing on MM prognosis. Methods MM-related datasets (GSE4581, GSE136337, and TCGA-MM) were acquired from the Gene Expression Omnibus (GEO) database and the Cancer Genome Atlas (TCGA) database. Lactate and BCAA metabolism-related subtypes were acquired separately via the R package “ConsensusClusterPlus” in the GSE4281 dataset. The R package “limma” and Venn diagram were both employed to identify lactate-BCAA metabolism-related genes. Subsequently, a lactate-BCAA metabolism-related prognostic risk model for MM patients was constructed by univariate Cox, Least Absolute Shrinkage and Selection Operator (LASSO), and multivariate Cox regression analyses. The gene set enrichment analysis (GSEA) and R package “clusterProfiler"were applied to explore the biological variations between two groups. Moreover, single-sample gene set enrichment analysis (ssGSEA), Microenvironment Cell Populations-counter (MCPcounte), and xCell techniques were applied to assess tumor microenvironment (TME) scores in MM. Finally, the drug’s IC50 for treating MM was calculated using the “oncoPredict” package, and further drug identification was performed by molecular docking. Results Cluster 1 demonstrated a worse prognosis than cluster 2 in both lactate metabolism-related subtypes and BCAA metabolism-related subtypes. 244 genes were determined to be involved in lactate-BCAA metabolism in MM. The prognostic risk model was constructed by CKS2 and LYZ selected from this group of genes for MM, then the prognostic risk model was also stable in external datasets. For the high-risk group, a total of 13 entries were enriched. 16 entries were enriched to the low-risk group. Immune scores, stromal scores, immune infiltrating cells (except Type 17 T helper cells in ssGSEA algorithm), and 168 drugs’IC50 were statistically different between two groups. Alkylating potentially serves as a new agent for MM treatment. Conclusions CKS2 and LYZ were identified as lactate-BCAA metabolism-related genes in MM, then a novel prognostic risk model was built by using them. In summary, this research may uncover novel characteristic genes signature for the treatment and prognostic of MM.

Abstract Background Elevated lactate results in an acidic tumor microenvironment (TME), which stimulates the progression of esophageal cancer (EC). Tumor‐associated macrophages (TAMs) are an essential component of the TME. However, the regulatory mechanisms of lactate secreted by EC on TAMs and the effects of EC advancement are unclear. Methods Proteins and mRNA expression were determined by western blot and RT‐qPCR. Cell metastasis and growth were assessed by scratch assay, transwell and BrdU assays. Lactate in cells was quantified using a lactate kit. A mouse model was constructed for validation in vivo. Results First, we determined that lactate upgraded the M2‐type polarization marker levels of macrophages. Cell function assays confirmed that lactate‐activated M2 macrophages accelerated EC cell migration and proliferation in vitro. However, the lactate inhibitor – oxamate hampered the level of lactate in TE‐1 cells. Oxamate abolished the facilitation of macrophage polarization by lactate. In addition, we discovered that phosphorylated AKT and phosphorylated ERK was obviously raised in lactate‐stimulated macrophages, and oxamate addition reversed this change, implying that AKT and ERK signaling pathways were involved in macrophage polarization. Response experiments proved that attenuation of AKT/ERK signaling markedly returned the lactate‐induced promotion of EC migration and proliferation by macrophages. Finally, mouse tumor models demonstrated that lactate enhanced EC growth by inducing M2 macrophage polarization. Conclusion EC‐secreted lactate stimulated macrophage M2 polarization via the AKT/ERK pathway thereby boosting the growth of EC.

Background: During the past 20 years, numerous publications have described the usefulness of systolic pressure variation, pulse pressure variation, stroke volume variation, etc., to guide intraoperative fluid administration. However, we still lack robust noninvasive physiological variables to successfully predict the response to fluid loading. Aims and Objectives: The present study was designed to evaluate the utility of plethysmography variability index (PVI) to optimize fluid management during intra-abdominal surgery in cancer patients. Materials and Methods: After the Institutional Ethics Committee approval and consent, 60 patients scheduled for elective lower abdominal cancer surgeries were randomized to receive fluid by either PVI-directed management (2 mL/kg/h) or using central venous pressure (8 mL/kg/h) after standardized technique of general and lumbar epidural anesthesia. The PVI was calculated by measuring changes in the PI during the respiratory cycle (PVI = [(PImax - PImin)/PImax] × 100). Arterial blood samples were taken at the time of incision and after 6 h postoperatively. Instances of intraoperative hypotension and oliguria were recorded. Results: Among the 60 patients enrolled in the study, demographic data, ASA status, duration of surgery, and hemodynamics were found to be comparable. The amount of crystalloid given was significantly lesser in Group P (984.70±51.16) as compared to Group C (2395.27±209.68) (P

Introduction: Pneumonia is a common diagnosis in the emergency department (ED). Some scoring systems such as Confusion, Uremia, Respiratory Rate, Blood Pressure, Age>65 (CURB-65) are used to determine the severity of this disease. We aimed to determine the best scoring system (CURB-65, serum lactate+CURB-65, serum procalcinonin+CURB-65) to predict the severity and 30-day mortality of pneumonia patients admitted to our ED. Methods: This study was planned as a prospective study. 480 community-acquired pneumonia patients admitted to our ED between February 1, 2020, and January 31, 2021, were included. CURB-65 score, CURB-65+lactate levels, and CURB65+procalcitonin levels were evaluated to predict disease severity. Results: A total of 480 pneumonia patients, 281 (58.5%) men and 199 (41.5%) women, with a mean age of 61.7 ± 19.06 years, were included in the study. The sensitivity/specificity pair and cut-off value of CURB-65 for 30-day mortality was 71.9/74.8%. These values were 68.5% and 61.9% for CURB-65+lactate (cut-off = 17.50) and 78.1% and 90.7% for CURB-65+procalcitonin (cut-off = 2.095). Discussion: Infectious diseases such as pneumonia, urinary tract infection, and sepsis are common reasons for ED presentations and may be fatal, especially in the elderly population. In such infectious diseases, it is difficult to predict the prognosis of the patients including discharge, hospitalization service, mortality probability in the EDs those are becoming much more crowded each day and several scoring systems have been improved. In this study, the highest sensitivity and specificity were determined in CURB-65+procalcitonin. Conclusion: CURB-65 is superior to CURB-65+lactate; however, CURB-65+procalcitonin is superior to both in predicting 30-day mortality.

Introduction: Acute liver failure (ALF), although rare in children, is a complex progressive pathology, with multisystem involvement and high mortality. Isolated variables or those included in prognostic scores have been studied, to optimize organ allocation. However, its validation is challenging. This study aimed to assess the accuracy of several biomarkers and scores as predictors of prognosis in pediatric ALF (PALF). Methods: An observational study with retrospective data collection, including all cases of ALF, was defined according to the criteria of the Pediatric Acute Liver Failure Study Group, admitted to a pediatric intensive care unit (PICU) for 28 years. Two groups were defined: spontaneous recovery (SR) and non-SR (NSR) – submitted to liver transplantation (LT) or death at PICU discharge. Results: Fifty-nine patients were included, with a median age of 24 months, and 54% were female. The most frequent etiologies were metabolic (25.4%) and infectious (18.6%); 32.2% were undetermined. SR occurred in 21 patients (35.6%). In NSR group (N = 38, 64.4%), 25 required LT (42.4%) and 19 died (32.2%), 6 (15.7%) of whom after LT. The accuracy to predict NSR was acceptable for lactate at admission (AUC 0.72; 95% CI: 0.57–0.86; p = 0.006), ammonia peak (AUC 0.72; 95% CI: 0.58–0.86; p = 0.006), and INR peak (AUC 0.70; 95% CI: 0.56–0.85; p = 0.01). The cut-off value for lactate at admission was 1.95 mmol/L (sensitivity 78.4% and specificity 61.9%), ammonia peak was 64 μmol/L (sensitivity 100% and specificity 38.1%), and INR peak was 4.8 (sensitivity 61.1% and specificity 76.2%). Lactate on admission was shown to be an independent predictor of NSR on logistic regression model. Two prognostic scores had acceptable discrimination for NSR, LIU (AUC 0.73; 95% CI: 0.59–0.87; p = 0.004) and PRISM (AUC 0.71; 95% CI: 0.56–0.86; p = 0.03). In our study, the PALF delta score (PALF-ds) had lower discrimination capacity (AUC 0.63; 95% CI: 0.47–0.78; p = 0.11). Conclusions: The lactate at admission, an easily obtained parameter, had a similar capacity than the more complex scores, LIU and PRISM, to predict NSR. The prognostic value in our population of the promising dynamic score, PALF-ds, was lower than expected.

Objective To explore the effect of lactate and alkali deficiency on the need for red blood cell transfusion in emergency of patients with traumatic hemorrhagic shock. Methods A total of 126 patients with traumatic hemorrhagic shock in our hospital from January 2019 to December 2021 were retrospectively analyzed, and the 99 cases with effective treatment were divided into two groups according to the outcome of blood transfusion within 24 hours after admission: non-transfusion group (n=36) and transfusion group (n=63). The changes of lactic acid (Lac), alkali deficiency (BE), hemoglobin (Hb), hematocrit (Hct) at admission, hemoglobin (Hb), hematocrit (Hct) 24 hours after admission and the length of stay in ICU were compared between the two groups. The binary logistic regression was used to analyze the risk factors of whether there was a need for blood transfusion at the time of emergency admission. The correlation between individual and combined indicators of each risk factor and the need for blood transfusion were analyzed by the receiver operating curve (ROC). Results The mean level of Lac (2.90±1.82) in the non-transfusion group at admission was lower than that in the transfusion group (5.80±2.83) (P0.05)The maximum AUG of Lac and BE(0.875, 0.766) in predicting the need for emergency red blood cell transfusion in patients with traumatic hemorrhagic shock was significantly better than that of Hb and Hct (0.692, 0.682); the optimal threshold for Lac was >3.6 mmol/L, while the optimal threshold for Hb is ≤106 g/L; the maximum AUG obtained by ROC curve analysis combined with Lac, BE, Hb and Hct was 0.910, which was higher than that of the sole virable. Comparative predictive value using the optimal thresholds of Lac and Hb as indications for transfusion showed that Lac had better predictive value than Hb. Conclusion Lac and be can be instructive for patients with traumatic hemorrhagic shock as to whether they need red blood cell transfusion in an emergency setting, and combination of Lac, BE, Hb and Hct may help to determine the transfusion needs of patients more timely and accurately and optimize the transfusion management of emergency patients.

High-intensity exercise training is one of the effective strategies to improve the performance of athletes to achieve excellent physical fitness. In the meantime, a look at the history of sports immunology reveals the idea of window theory, which has been of great concern. According to the history of exercise immunology, high-intensity exercise training can suppress the immune system leading to respiratory infections. It has recently been shown that high-intensity exercise training has no effect on suppressing the immune system. In this review, a new perspective on the immune system and high-intensity exercise training was presented to readers. Moreover, a new look at the history of high-intensity exercise training and the immune system and recent review studies was provided and some suggestions are offered.

Abstract Background Veno-arterial carbon dioxide tension difference (ΔPCO2) and mixed venous oxygen saturation (SvO2) have been shown to be markers of the adequacy between cardiac output and metabolic needs in critical care patients. However, they have hardly been assessed in trauma patients. We hypothesized that femoral ΔPCO2 (ΔPCO2 fem) and SvO2 (SvO2 fem) could predict the need for red blood cell (RBC) transfusion following severe trauma. Methods We conducted a prospective and observational study in a French level I trauma center. Patients admitted to the trauma room following severe trauma with an Injury Severity Score (ISS) > 15, who had arterial and venous femoral catheters inserted were included. ΔPCO2 fem, SvO2 fem and arterial blood lactate were measured over the first 24 h of admission. Their abilities to predict the transfusion of at least one pack of RBC (pRBCH6) or hemostatic procedure during the first six hours of admission were assessed using receiver operating characteristics curve. Results 59 trauma patients were included in the study. Median ISS was 26 (22–32). 28 patients (47%) received at least one pRBCH6 and 21 patients (35,6%) had a hemostatic procedure performed during the first six hours of admission. At admission, ΔPCO2 fem was 9.1 ± 6.0 mmHg, SvO2 fem 61.5 ± 21.6% and blood lactate was 2.7 ± 1.9 mmol/l. ΔPCO2 fem was significantly higher (11.6 ± 7.1 mmHg vs. 6.8 ± 3.7 mmHg, P = 0.003) and SvO2 fem was significantly lower (50 ± 23 mmHg vs. 71.8 ± 14.1 mmHg, P

The relationship between tumor metabolism and immunity is complex and diverse. To date, the role of tumor-specific metabolic reprogramming in shaping the specific tumor microenvironment in tumor immunotherapy remains unclear. Lactic acid is the main product of glycolysis, and the aerobic glycolysis of tumor cells causes lactic acid to accumulate in the microenvironment. Recent studies have shown that the accumulation of lactic acid in the tumor microenvironment hinders anti-tumor immunity, especially affects the function, differentiation, and metabolism of immune cells, and participates in tumor immune escape, thus promoting tumor. This article reviews the effects of lactate accumulation in the tumor microenvironment on dendritic cells, T cells, NK cells, tumor-associated macrophages, and myeloid-derived suppressor cells. Targeted intervention of lactate production and efflux by tumor cells is expected to become a new strategy for tumor immunotherapy.

Abstract Background Transfer (t)RNA-derived small RNA (tsRNA), generated from precursor or mature tRNA, is a new type of small non-coding RNA (sncRNA) that has recently been shown to play a vital role in human cancers. However, its role in laryngeal squamous cell carcinoma (LSCC) remains unclear. Methods We elucidated the expression profiles of tsRNAs in four paired LSCC and non-neoplastic tissues by sequencing and verified the sequencing data by quantitative real-time PCR (qRT–PCR) of 60 paired samples. The tyrosine-tRNA derivative tRFTyr was identified as a novel oncogene in LSCC for further study. Loss-of-function experiments were performed to evaluate the roles of tRFTyr in tumorigenesis of LSCC. Mechanistic experiments including RNA pull-down, parallel reaction monitoring (PRM) and RNA immunoprecipitation (RIP) were employed to uncover the regulatory mechanism of tRFTyr in LSCC. Results tRFTyr was significantly upregulated in LSCC samples. Functional assays showed that knockdown of tRFTyr significantly suppressed the progression of LSCC. A series of mechanistic studies revealed that tRFTyr could enhance the phosphorylated level of lactate dehydrogenase A (LDHA) by interacting with it. The activity of LDHA was also activated, which induced lactate accumulation in LSCC cells. Conclusions Our data delineated the landscape of tsRNAs in LSCC and identified the oncogenic role of tRFTyr in LSCC. tRFTyr could promote lactate accumulation and tumour progression in LSCC by binding to LDHA. These findings may aid in the development of new diagnostic biomarkers and provide new insights into therapeutic strategies for LSCC.

Abstract Introduction Coronavirus disease 2019 (Covid‐19) following venous thromboembolism (VTE) and blood hyperlactatemia are associated with higher mortality. However, reliable biomarkers for this association remain to be elucidated. This study investigated the associations of VTE risk and blood hyperlactatemia with mortality among critically ill Covid‐19 patients admitted to the intensive care unit (ICU). Methods In this single‐centre retrospective study, we included 171 patients aged ≥18 years with confirmed Covid‐19 admitted to the ICU at a tertiary healthcare clinic in the Eastern region of Saudi Arabia between 1 March 2020 and 31 January 2021. Patients were divided into two groups: survivor and non‐survivor. The survivors have been identified as the patients discharged from the ICU alive. The VTE risk was defined using a Padua prediction score (PPS) >4. The blood lactate concentration (BLC) cut‐off value >2 mmol/L was used to determine the blood hyperlactatemia. Results Multi‐factor Cox analysis showed that PPS >4 and BLC >2 mmol/L were more likely to be significantly associated with higher odds of ICU mortality in critically ill Covid‐19 patients (hazard ratio [HR] = 2.80, 95% confidence interval [CI] = 1.00–8.08, p = 0.050; HR = 3.87, 95% CI = 1.12–13.45, p = 0.033, respectively). The Area under the Curve for VTE and blood hyperlactatemia were 0.62 and 0.85, respectively. Conclusion VTE risk and blood hyperlactatemia have been associated with a higher mortality risk in critically ill Covid‐19 patients who are hospitalized in the ICU in Saudi Arabia. According to our findings, these people needed more effective VTE prevention strategies based on a personalized assessment of their risk of bleeding. Moreover, persons without diabetes and other groups with a high risk of dying from COVID‐19 may be recognized by measuring glucose as having elevated glucose and lactate jointly.

Innate immune cells (monocytes/macrophages, NK) can also develop immune memory, which means that these cells are trained after their first encounter with pathogens so that they exhibit a nonspecific immunological response to the same or another pathogen. Bacilli Calmette–Gu rin (BCG) induces nonspecific innate memory (trained immunity) in innate immune cells. We examined nonspecific innate memory in macrophages of BALB/c mice in response to mycobacteria with or without the RD1 region in the genome. Mice were immunized with BCG vaccine, and peritoneal macrophages were isolated on day 7, and then stimulated with bacterial lipopolysaccharide, CFP-10, or ESAT-6. In addition, mice were immunized with Mycobacterium tuberculosis uro-BCG vaccine (RD1-) and Mycobacterium tuberculosis strain H37Rv (RD1+) subcutaneously or intravenously; peritoneal macrophages were isolated and stimulated with lipopolysaccharide on day 4. Alveolar macrophages were obtained from lung explants of mice infected with Mycobacterium tuberculosis strain H37Rv mice, were expanded to confluence 70-80% and further stimulated with lipopolysaccharide. Lactate, cytokines, and glucose levels were examined in conditioned macrophage medium. Peritoneal macrophages from mice primed with BCG vaccine were shown to increase IL-1b, TNFa, and lactate production in response to CFP-6 and ESAT-10 (p < 0.05). Of note is the fact that lipopolysaccharide also increased production of IL-1b, TNFa, and also increased glucose uptake by peritoneal macrophages primed with BCG vaccine (p < 0.05). Peritoneal macrophages primed with Uro-BCG were shown to increase spontaneous production of IL-1b and decrease spontaneous production of TNFa (p < 0.05). When macrophages were primed by subcutaneous or intravenous administration of Mycobacterium tuberculosis strain H37Rv differentially affected cytokine production, by decreasing IL-1b production and increasing TNFa and IL-10, was observed. In response to lipopolysaccharide, peritoneal macrophages increased IL-1b, TNFa, IL-10 production and glucose consumption (p < 0.05). The mode of priming of macrophages with Mycobacterium tuberculosis strain H37Rv also led to multidirectional levels of cytokine production. Alveolar macrophages were shown to retain trained immunity, as they produced elevated levels of IL-1b, TNFa, and IL-10 (p < 0.05). Thus, mouse macrophages formed a trained immunity phenotype in response to different types of mycobacteria, which persists for a long time after primary contact with the pathogen, particularly in alveolar macrophages.

Abstract Background ARHGAP10 is a tumor‐suppressor gene related to ovarian cancer (OC) progression; however, its specific mechanism is unclear. Aims To investigate the effect of ARHGAP10 on OC cell migration, invasion, and glycolysis. Methods and Results Quantitative real‐time PCR (qRT‐PCR) quantified mRNA and protein expressions of AKT, p‐AKT, HK2, and SMAD4 were tested by Western blot. EdU, Wound healing, and Transwell assay were utilized to evaluate OC cell proliferation, migration, and invasion. We used a Seahorse XF24 Extracellular Flux Analyzer to monitor cellular oxygen consumption rates (OCR) and extracellular acidification rates (ECAR). Chromatin immunoprecipitation (ChIP) was used to analyze the transcriptional regulation of ARHGAP10 by SMAD4. ARHGAP10 expression in OC tissues was detected by immunohistochemistry. Our results showed that ARHGAP10 expression was negatively related to lactate levels in human OC tissues. ARHGAP10 overexpression can inhibit the migration, proliferation, and invasion of OC cells, and this function can be blocked by 2‐Deoxy‐D‐glucose. Moreover, we found that ARHGAP10 expression can be rescued with the AKT inhibitor LY294002. Conclusions This study revealed that the antitumor effects of ARHGAP10 in vivo and in vitro possibly suppress oncogenic glycolysis through the PI3K/AKT/HK2‐regulated glycolysis metabolism pathway.

Abstract The perception regarding lactate has changed over the past decades, and some of its physiological roles have gradually been revealed. However, the effects of exogenous lactate on skeletal muscle synthesis remain unclear. This study aimed to confirm the effects of a 5‐week lactate administration and post‐exercise lactate administration on skeletal muscle synthesis. Thirty‐two Institute of Cancer Research mice were randomly assigned to non‐trained + placebo, non‐trained + lactate, trained + placebo, and trained + lactate groups. Furthermore, 3 g/kg of lactate or an equivalent volume of saline was immediately administered after exercise training (maximum oxygen uptake: 70%). Lactate administration and/or exercise training was performed 5 days/week for 5 weeks. After the experimental period, it was observed that lactate administration tended to elevate skeletal muscle weight, increased protein kinase B (p

ObjectivesThe most frequent cause of kidney damage in systemic lupus erythematosus (SLE) is lupus nephritis (LN), which is also a significant risk factor for morbidity and mortality. Lactate metabolism and protein lactylation might be related to the development of LN. However, there is still a lack of relative research to prove the hypothesis. Hence, this study was conducted to screen the lactate-related biomarkers for LN and analyze the underlying mechanism.MethodsTo identify differentially expressed genes (DEGs) in the training set (GSE32591, GSE127797), we conducted a differential expression analysis (LN samples versus normal samples). Then, module genes were mined using WGCNA concerning LN. The overlapping of DEGs, critical module genes, and lactate-related genes (LRGs) was used to create the lactate-related differentially expressed genes (LR-DEGs). By using a machine-learning algorithm, ROC, and expression levels, biomarkers were discovered. We also carried out an immune infiltration study based on biomarkers and GSEA.ResultsA sum of 1259 DEGs was obtained between LN and normal groups. Then, 3800 module genes in reference to LN were procured. 19 LR-DEGs were screened out by the intersection of DEGs, key module genes, and LRGs. Moreover, 8 pivotal genes were acquired via two machine-learning algorithms. Subsequently, 3 biomarkers related to lactate metabolism were obtained, including COQ2, COQ4, and NDUFV1. And these three biomarkers were enriched in pathways ‘antigen processing and presentation’ and ‘NOD-like receptor signaling pathway’. We found that Macrophages M0 and T cells regulatory (Tregs) were associated with these three biomarkers as well.ConclusionOverall, the results indicated that lactate-related biomarkers COQ2, COQ4, and NDUFV1 were associated with LN, which laid a theoretical foundation for the diagnosis and treatment of LN.

Abstract Malfunction of neutrophil apoptosis and elevated serum lactate levels are the key cellular mechanism of immune suppressive status in septic patients. However, whether increased lactate affects apoptosis of neutrophils and aggravates sepsis development, and the molecular mechanism remain unknown. In this study, first, we analyzed the transcriptional profiles of blood cells in sepsis patients (n = 39) and healthy volunteers (n = 40) to reveal that there is close correlation between the lactate‐related gene expression changes associated with lactate production and immune function in leukocytes, especially in neutrophils. Further, we explored the close relationship between lactate and delayed neutrophil apoptosis in human neutrophils. Programmed cell death 1 legand (PD‐L1) was highly expressed in septic patients compared with healthy volunteers. Then, we indicated that elevated levels of lactate in human neutrophils decreased neutrophil apoptosis (P < .001) by upregulating PD‐L1 expression. Inhibition of monocarboxylate transporter 1 (MCT1) significantly attenuated neutrophil apoptosis caused by lactate (P < .001). We further performed in vivo experiments in sepsis mice model and determined that increased lactate decreased neutrophil apoptosis (P < .05) and reduces mice survival rate (P < .001), which could also be rescued by MCT1 inhibitor (P < .05). This study revealed that elevated level of lactate in sepsis upregulates PD‐L1 expression to decrease apoptosis through MCT1 in neutrophils, which provides new insight into sepsis treatment strategy by reducing lactate accumulation.

Abstract Wearable sensors are establishing themselves as options for real‐time continuous health monitoring in health care and wellness. In particular, the use of flexible interfaces that conform to the skin have attracted considerable interest for the extraction of meaningful pathophysiological information through continuous and painless sampling and analysis of biofluids. In contrast, conventional techniques for biomarkers analysis are difficult to adapt to real‐time portable monitoring due to their invasive sampling protocols, biosample preparation and reagent stabilization. Here a shelf‐stable, non‐invasive, paper‐based colorimetric wearable lactate sensor is reported. This sensor exploits the ability of silk to control the concentration, print, and functionally preserve labile transducing biomolecules in the format of a shelf‐stable digital patch for optical readout. This novel approach overcomes major challenges associated with the commercialization of colorimetric wearable sensors (e.g., enzyme thermal instability, narrow sensing range, low sensitivity, and qualitative response) by showing a combination of unprecedented stability (i.e., up to 2 years in refrigerated conditions), wide sensing range, and high sensitivity. Additionally, real‐time quantitative signal readouts are achieved using machine learning‐driven image analysis enabling physiological status evaluation with a simple smartphone camera.

Background: Cisplatin resistance is one of the major obstacles in non-small cell lung cancer (NSCLC) treatment. Intriguingly, elevated lactate levels were observed in cisplatin-resistant cells, which spurred further investigation into their underlying biological mechanisms. Methods: Lactate levels were measured by lactate detection kit. Cisplatin-resistance NSCLC cells were established using progressive concentration of cisplatin. Cell viability, proliferation, and apoptosis were detected by CCK-8, EdU, and flow cytometry, respectively. Cell proliferation in vivo was determined by immunohistochemistry of Ki67 and apoptotic cells were calculated by the TUNEL. MeRIP-PCR was used to measure FOXO3 m6A levels. The interactions of genes were analyzed via RIP, ChIP, Dual-luciferase reporter, and RNA pull-down, respectively. Results: Elevated lactate levels were observed in both NSCLC patients and cisplatin-resistance cells. Lactate treatment increased cisplatin-resistance cell viability in vitro and promoted tumor growth in vivo. Mechanistically, lactate downregulated FOXO3 by YTHDF2-mediated m6A modification. FOXO3 transcriptionally reduced MAGI1-IT1 expression. FOXO3 overexpression inhibited the lactate-induced promotion of cisplatin resistance in NSCLC, which were reversed by MAGI1-IT1 overexpression. MAGI1-IT1 and IL6R competitively bound miR-664b-3p. FOXO3 overexpression or MAGI1-IT1 knockdown repressed lactate-mediated cisplatin resistance in vivo. Conclusion: Lactate promoted NSCLC cisplatin resistance through regulating FOXO3/MAGI1-IT1/miR-664b-3p/IL6R axis in YTHDF2-mediated m6A modification.

We investigated the effect of growing on lactate instead of glucose in human cardiomyocyte assessing their viability, cell cycle activity, oxidative stress and metabolism by a proteomic and metabolomic approach. In previous studies performed on elite players, we found that adaptation to exercise is characterized by a chronic high plasma level of lactate. Lactate is considered not only an energy source but also a signalling molecule and is referred as “lactormone”; heart is one of the major recipients of exogenous lactate. With this in mind, we used a cardiac cell line AC16 to characterize the lactate metabolic profile and investigate the metabolic flexibility of the heart. Interestingly, our data indicated that cardiomyocytes grown on lactate (72 h) show change in several proteins and metabolites linked to cell hypertrophy and cytoskeleton remodelling. The obtained results could help to understand the effect of this metabolite on heart of high-performance athletes.

Extensive research has confirmed numerous advantages of exercise for promoting brain health. More recent studies have proposed the potential benefits of lactate, the by-product of exercise, in various aspects of brain function and disorders. However, there remains a gap in understanding the effects of lactate dosage and its impact on aged rodents. The present study first examined the long-term effects of three different doses of lactate intervention (2000 mg/kg, 1000 mg/kg, and 500 mg/kg) and high-intensity interval training (HIIT) on aging mice (20–22 months) as the 1st experiment. Subsequently, in the 2nd experiment, we investigated the long-term effects of 500 mg/kg lactate intervention and HIIT on brain neuroplasticity in aged mice (25–27 months).The results of the 1st experiment demonstrated that both HIIT and different doses of lactate intervention (500 mg/kg and 2000 mg/kg) positively impacted the neuroplasticity biomarker VEGF in the hippocampus of aging mice. Subsequently, the 2nd experiment revealed that long-term HIIT significantly improved the performance of mice in open-field, novel object recognition, and passive avoidance tests. However, lactate intervention did not significantly affect these behavioral tests. Moreover, compared to the control group, both HIIT and lactate intervention positively influenced the angiogenesis signaling pathway (p/t-AKT/ENOS/VEGF), mitochondrial biomarker (SDHA), and metabolic protein (p/t-CREB, p/t-HSL, and LDH) in the hippocampus of aged mice. Notably, only lactate intervention significantly elevated the BDNF (PGC-1α, SIRT1, and BDNF) signaling pathway and metabolic content (lactate and pyruvate). In the end, long-term HIIT and lactate intervention failed to change the protein expression of p/t-MTOR, iNOS, nNOS, HIF-1α, SYNAPSIN, SIRT3, NAMPT, CS, FNDC5 and Pan Lactic aid-Lysine in the hippocampus of aged mice.In summary, the present study proved that long-term HIIT and lactate treatment have positive effects on the brain functions of aged mice, suggesting the potential usage of lactate as a therapeutic strategy in neurodegenerative diseases in the elderly population.

Cyanobacteria serve as useful hosts in the production of substances to support a low-carbon society. Specifically, the unicellular cyanobacterium Synechocystis sp. PCC 6803 (Synechocystis 6803) can produce organic acids, such as acetate, lactate, and succinate, as well as hydrogen, under dark, anaerobic conditions. The efficient production of these compounds appears to be closely linked to the regulation of intracellular redox balance. Notably, alterations in intracellular redox balance have been believed to influence the production of organic acids and hydrogen. To achieve these alterations, genetic manipulations involved overexpressing malate dehydrogenase (MDH), knocking out d-lactate dehydrogenase (DDH), or knocking out acetate kinase (AK), which subsequently modified the quantities and ratios of organic acids and hydrogen under dark, anaerobic conditions. Furthermore, the mutants generated displayed changes in the oxidation of reducing powers and the nicotinamide adenine dinucleotide hydrogen (NADH)/NAD+ ratio when compared to the parental wild-type strain. These findings strongly suggest that intracellular redox balance, especially the NADH/NAD+ ratio, plays a pivotal role in the production of organic acids and hydrogen in Synechocystis 6803.

Objective: Serum lactate (LA) and lactate dehydrogenase (LDH) levels have a major impact on the clinical treatment of malignant tumors and critically ill patients. Nevertheless, the assessment of disease severity in oncology patients admitted to the intensive care unit (ICU) remains incomplete when considering the serum LA and LDH levels. This study aimed to investigate the significance of serum LDH and LA levels in assessing disease severity and predicting clinical outcomes in patients with colorectal cancer (CRC) admitted to the ICU. Methods: This retrospective study included patients with CRC who were admitted to the ICU between January 2017 and December 2022. The patients were divided into three groups based on the tumor treatment methods they had received within 3 months before ICU admission: post-chemotherapy group, post-surgery group, and palliative treatment group. The association between serum LA and LDH levels and disease severity and clinical outcomes was analyzed. Results: Of 137 patients with CRC admitted to the ICU were finally studied. Patients in the post-chemotherapy group exhibited higher serum LA and LDH levels compared to those in the other two groups. Additionally, they had higher Acute Physiology and Chronic Health Evaluation (APACHE) II scores, longer ICU length of stay, and a higher 30-day mortality. We found a significant positive correlation between serum LA levels and APACHE II scores as well as ICU length of stay and 30-day mortality. In contrast, we only observed a significant positive correlation between serum LDH levels and disease severity in the post-chemotherapy group, whereas no significant correlation between LDH levels and 30-day mortality in any of the three groups. Conclusion: Our study concludes that elevated serum LA levels, rather than LDH levels, are more effective in assessing disease severity and could be used as predictors for clinical outcomes in patients with CRC admitted to the ICU.