Midkine Research Articles

UCHL1 Overexpression Is Related to the Aggressive Phenotype of Non-small Cell Lung Cancer.

Ubiquitin C-terminal hydrolase L1 (UCHL1), which encodes thiol protease that hydrolyzes a peptide bond at the C-terminal glycine residue of ubiquitin, regulates cell differentiation, proliferation, transcriptional regulation, and numerous other biological processes and may be involved in lung cancer progression. UCHL1 is mainly expressed in the brain and plays a tumor-promoting role in a few cancer types; however, there are limited reports regarding its role in lung cancer. Single-cell RNA (scRNA) sequencing using 10X chromium v3 was performed on a paired normal-appearing and tumor tissue from surgical specimens of a patient who showed unusually rapid progression. To validate clinical implication of the identified biomarkers, immunohistochemical (IHC) analysis was performed on 48 non-small cell lung cancer (NSCLC) tissue specimens, and the correlation with clinical parameters was evaluated. We identified 500 genes overexpressed in tumor tissue compared to those in normal tissue. Among them, UCHL1, brain expressed X-linked 3 (BEX3), and midkine (MDK), which are associated with tumor growth and progression, exhibited a 1.5-fold increase in expression compared to that in normal tissue. IHC analysis of NSCLC tissues showed that only UCHL1 was specifically overexpressed. Additionally, in 48 NSCLC specimens, UCHL1 was specifically upregulated in the cytoplasm and nuclear membrane of tumor cells. Multivariable logistic analysis identified several factors, including smoking, tumor size, and high-grade dysplasia, to be typically associated with UCHL1 overexpression. Survival analyses using The Cancer Genome Atlas (TCGA) datasets revealed that UCHL1 overexpression is substantially associated with poor survival outcomes. Furthermore, a strong association was observed between UCHL1 expression and the clinicopathological features of patients with NSCLC. UCHL1 overexpression was associated with smoking, tumor size, and high-grade dysplasia, which are typically associated with a poor prognosis and survival outcome. These findings suggest that UCHL1 may serve as an effective biomarker of NSCLC.

The estrogen response in fibroblasts promotes ovarian metastases of gastric cancer

Younger premenopausal women are more prone to developing ovarian metastases (OM) of gastric cancer (GC) than metastases of other organs; however, the molecular mechanisms remain unclear. Here we perform single-cell RNA sequencing on 45 tumor samples from 18 GC patients with OM. Interestingly, fibroblasts in OM of GC express high levels of estrogen receptor (ER) and midkine (MDK), interacting with tumor cells through activating ER-MDK-LRP1 (low-density lipoprotein receptor-related protein 1) signaling axis. Functional experiments demonstrate that estrogen stimulation induces MDK secretion by ovarian fibroblasts, and binding of MDK to LRP1 increases GC cell migration and invasion. Furthermore, in vivo, estrogen stimulation remarkably augments ovarian engraftment and metastasis of LRP1+ GC cells. Collectively, our findings reveal that ER+ ovarian fibroblasts secrete MDK under estrogen influence, driving OM of GC via the MDK-LRP1 axis. Our study holds the potential to catalyze innovative therapeutic strategies aimed at intercepting and managing OM in GC.

Aging alters the expression of trophic factors and tight junction proteins in the mouse choroid plexus

BackgroundThe choroid plexus (CP) is an understudied tissue in the central nervous system and is primarily implicated in cerebrospinal fluid (CSF) production. CP also produces numerous neurotrophic factors (NTF) which circulate to different brain regions. Regulation of NTFs in the CP during natural aging is largely unknown. Here, we investigated the age and gender-specific transcription of NTFs along with the changes in the tight junctional proteins (TJPs) and the water channel protein Aquaporin (AQP1).MethodsMale and female mice were used for our study. Age-related transcriptional changes were analyzed using quantitative PCR at three different time points: mature adult, middle-aged, and aged. Transcriptional changes during aging were further confirmed with digital droplet PCR. Additionally, we used immunohistochemical analysis (IHC) for the evaluation of in vivo protein expression. We further investigated the cellular phenotype of these NTFS, TJP, and water channel proteins in the mouse CP by co-labeling them with the classical vascular marker, Isolectin B4, and epithelial cell marker, Plectin.ResultsAging significantly altered NTF gene expression in the CP. Brain-derived neurotrophic factor (BDNF), Midkine (MDK), VGF, Insulin-like growth factor (IGF1), IGF2, Klotho (KL), Erythropoietin (EPO), and its receptor (EPOR) were reduced in the aged CP of males and females. Vascular endothelial growth factor (VEGF) transcription was gender-specific; in males, gene expression was unchanged in the aged CP, while females showed an age-dependent reduction. Age-dependent changes in VEGF localization were evident, from vasculature to epithelial cells. IGF2 and klotho localized in the basolateral membrane of the CP and showed an age-dependent reduction in epithelial cells. Water channel protein AQP1 localized in the tip of epithelial cells and showed an age-related reduction in mRNA and protein levels. TJP’s JAM, CLAUDIN1, CLAUDIN2 and CLAUDIN5 were reduced in aged mice.ConclusionsOur study highlights transcriptional level changes in the CP during aging. The age-related transcriptional changes exhibit similarities as well as gene-specific differences in the CP of males and females. Altered transcription of the water channel protein AQP1 and TJPs could be involved in reduced CSF production during aging. Importantly, reduction in the neurotrophic factors and longevity factor Klotho can play a role in regulating brain aging.Graphical

Polymer-locking fusogenic liposomes for glioblastoma-targeted siRNA delivery and CRISPR-Cas gene editing.

In patients with glioblastoma (GBM), upregulated midkine (MDK) limits the survival benefits conferred by temozolomide (TMZ). RNA interference (RNAi) and CRISPR-Cas9 gene editing technology are attractive approaches for regulating MDK expression. However, delivering these biologics to GBM tissue is challenging. Here we demonstrate a polymer-locking fusogenic liposome (Plofsome) that can be transported across the blood-brain barrier (BBB) and deliver short interfering RNA or CRISPR-Cas9 ribonucleoprotein complexes into the cytoplasm of GBM cells. Plofsome is designed by integrating a 'lock' into the fusogenic liposome using a traceless reactive oxygen species (ROS)-cleavable linker so that fusion occurs only after crossing the BBB and entering the GBM tissue with high ROS levels. Our results showed that MDK suppression by Plofsomes significantly reduced TMZ resistance and inhibited GBM growth in orthotopic brain tumour models. Importantly, Plofsomes are effective only at tumour sites and not in normal tissues, which improves the safety of combined RNAi and CRISPR-Cas9 therapeutics.

Targeting Bmi1 for Enhancing Anoikis Sensitivity and Inhibiting Metastasis in Colorectal Cancer.

Patients diagnosed with advanced metastatic colorectal cancer (CRC) confront a bleak prognosis characterized by low survival rates. Anoikis, the programmed apoptosis resistance exhibited by metastatic cancer cells, is a crucial factor in this scenario. We employed bulk flow cytometry and RT-qPCR assays, conducted in vivo experiments with mice and zebrafish, and analyzed patient tissues to examine the effects of the B cell-specific Moloney murine leukemia virus insertion site 1 (Bmi1)-midkine (MDK) axis on the cellular response to anoikis. Bmi1 is pivotal in tumorigenesis. This study elucidated the involvement of Bmi1 in conferring anoikis resistance in CRC and explored its downstream targets associated with metastasis. Elevated levels of Bmi1 expression correlated with distant metastasis in CRC. Suppression of Bmi1 significantly diminished the metastatic potential of CRC cells. Inhibition of Bmi1 led to an increase in the proportion of apoptotic SW620 cells detached from the matrix. This effect was further enhanced by the addition of irinotecan, a topoisomerase I inhibitor. Furthermore, Bmi1 was found to synergize with MDK in modulating CRC viability, with consistent expression patterns observed in in vivo models and clinical tissue specimens. In summary, Bmi1 acted as a regulator of CRC metastatic capability by conferring anoikis resistance. Additionally, it collaborated with MDK to facilitate invasion and distant metastasis. Targeting Bmi1 may offer a promising adjunctive therapeutic strategy when administering traditional chemotherapy regimens to patients with advanced CRC.

Over-expression of KRT17 and MDK genes at mRNA levels in urine-exfoliated cells is associated with early non-invasive diagnosis of non-muscle-invasive bladder cancer

IntroductionCurrent diagnostic approaches for bladder cancer (BLCA) are often invasive or lack the required sensitivity and specificity. This underscores the need for an early non-invasive diagnostic test for BLCA. This work aimed to explore the potential of molecular markers in urine-exfoliated cells for the diagnosis of non-muscle-invasive bladder cancer (NMIBC). Materials and methodsUrine specimens (n = 140) were collected from NMIBC patients (n = 68) and control subjects (31 healthy volunteers and 41 non-cancer patients with common urological diseases [CUD]. Total RNA was extracted from the cells isolated from urine specimens. mRNA expression of selected genes: CDC20, KRT15, FOXM1, CXCR2, UPK1B, MDK, KRT20, and KRT17 was determined using RT-qPCR. The receiver operating characteristic (ROC) curve was then plotted to obtain the area under the curve (AUC), specificity, and sensitivity of the urinary mRNA markers. ResultsThe expression of CDC20, MDK, UPK1B, FOXM1, KRT17, and KRT20 was up-regulated in samples obtained from low- and high-grade pathological grades of NMIBC compared to that measured in healthy subjects. Notably, MDK and KRT17 mRNA levels in the low- and high-grade cases were substantially higher than in normal and CUD groups. The AUC of the KRT17 and MDK combination in diagnosing NMIBC was 0.92, surpassing that of single genes. The sensitivity and specificity of the KRT17 and MDK combination were 74% and 94%, respectively. In diagnosing low-grade from healthy and CUD groups, analysis of the KRT17 and MDK combination yielded AUCs of 0.94 and 0.95, respectively, with sensitivities of 85% and 97%, and specificities of 93% and 85%. ConclusionThe findings of this study revealed that KRT17 and MDK together are potential urine-based biomarkers for early diagnosis of NMIBC.

Midkine: A Cancer Biomarker Candidate and Innovative Therapeutic Approaches.

Midkine (MDK) is a protein that contributes to both physiological and pathological processes. Several studies provide insight into the different roles of MDK in development, tissue repair, neural plasticity, and health and disease processes. This research further examined how MDK contributed to conditions, including neurological diseases, inflammation, and ischaemia. Furthermore, MDK overexpression has been reported in many kinds of cancer and MDK is recognized as a malignancy marker. MDK stimulates pro-tumor activity by regulating a number of signaling pathways, which increase cancer cell proliferation, survival, metastasis, and treatment resistance. However, studies have shown that MDK also functions as a molecule that regulates drug resistance. Several cancer therapy techniques have been suggested to modify MDK function, including antibody-based therapies, oligonucleotides, oncolytic viruses, and small compounds. Further research and experimentation will be required to establish the therapeutic relevance and efficacy of these treatments. This review focuses on the role of MDK in cancer biology, as well as its multiple different roles in health and disease processes.

Targeting the CDK7-MDK axis to suppresses irinotecan resistance in colorectal cancer

AimsColorectal cancer (CRC) remains a major global health issue, with metastatic cases presenting poor prognosis despite advances in chemotherapy and targeted therapy. Irinotecan, a key drug for advanced CRC treatment, faces challenges owing to the development of resistance. This study aimed to understand the mechanisms underlying irinotecan resistance in colorectal cancer. Main methodsWe created a cell line resistant to irinotecan using HT29 cells. These resistant cells were utilized to investigate the role of the CDK7-MDK axis. We employed bulk RNA sequencing, conducted in vivo experiments with mice, and analyzed patient tissues to examine the effects of the CDK7-MDK axis on the cellular response to irinotecan. Key findingsOur findings revealed that HT29 cells resistant to irinotecan, a crucial colorectal cancer medication, exhibited significant phenotypic and molecular alterations compared to their parental counterparts, including elevated stem cell characteristics and increased levels of cytokines and drug resistance proteins. Notably, CDK7 expression was substantially higher in these resistant cells, and targeting CDK7 effectively decreased their survival and tumor growth, enhancing irinotecan sensitivity. RNA-seq analysis indicated that suppression of CDK7 in irinotecan-resistant HT29 cells significantly reduced Midkine (MDK) expression. Decreased CDK7 and MDK levels, achieved through siRNA and the CDK7 inhibitor THZ1, enhanced the sensitivity of resistant HT29 cells to irinotecan. SignificanceOur study sheds light on how CDK7 and MDK influence irinotecan resistance in colorectal and highlights the potential of MDK-targeted therapies. We hypothesized that irinotecan sensitivity and overall treatment efficacy would improve by inhibiting MDK. This finding encourages a careful yet proactive investigation of MDK as a therapeutic target to enhance outcomes in colorectal cancer patients.

Midkine Attenuates Aβ Fibril Assembly and AmyloidPlaque Formation.

Proteomic profiling of Alzheimer's disease (AD) brains has identified numerous understudied proteins, including midkine (MDK), that are highly upregulated and correlated with Aβ since the early disease stage, but their roles in disease progression are not fully understood. Here we present that MDK attenuates Aβ assembly and influences amyloid formation in the 5xFAD amyloidosis mouse model. MDK protein mitigates fibril formation of both Aβ40 and Aβ42 peptides in Thioflavin T fluorescence assay, circular dichroism, negative stain electron microscopy, and NMR analysis. Knockout of Mdkgene in 5xFAD increases amyloid formation and microglial activation. Further comprehensive mass spectrometry-based profiling of whole proteome and aggregated proteome in these mouse models indicates significant accumulation of Aβ and Aβ-correlated proteins, along with microglial components. Thus, our structural and mouse model studies reveal a protective role of MDK in counteracting amyloid pathology in Alzheimer's disease.

Midkine promotes renal fibrosis by stabilizing C/EBPβ to facilitate endothelial-mesenchymal transition

Numerous myofibroblasts are arisen from endothelial cells (ECs) through endothelial to mesenchymal transition (EndMT) triggered by TGF-β. However, the mechanism of ECs transforms to a different subtype, or whether there exists an intermediate state of ECs remains unclear. In present study, we demonstrate Midkine (MDK) mainly expressed by CD31 + ACTA2+ECs going through partial EndMT contribute greatly to myofibroblasts by spatial and single-cell transcriptomics. MDK is induced in TGF-β treated ECs, which upregulates C/EBPβ and increases EndMT genes, and these effects could be reversed by siMDK. Mechanistically, MDK promotes the binding ability of C/EBPβ with ACTA2 promoter by stabilizing the C/EBPβ protein. In vivo, knockout of Mdk or conditional knockout of Mdk in ECs reduces EndMT markers and significantly reverses fibrogenesis. In conclusion, our study provides a mechanistic link between the induction of EndMT by TGF-β and MDK, which suggests that blocking MDK provides potential therapeutic strategies for renal fibrosis.

The role of proliferating stem-like plasma cells in relapsed or refractory multiple myeloma: Insights from single-cell RNA sequencing and proteomic analysis.

The management and comprehension of relapsed or refractory multiple myeloma (RRMM) continues to pose a significant challenge. By integrating single-cell RNA sequencing (scRNA-seq) data of 15 patients with plasma cell disorders (PCDs) and proteomic data obtained from mass spectrometry-based analysis of CD138+ plasma cells (PCs) from 144 PCDs patients, we identified a state of malignant PCs characterized by high stemness score and increased proliferation originating from RRMM. This state has been designated as proliferating stem-like plasma cells (PSPCs). NUCKS1 was identified as the gene marker representing the stemness of PSPCs. Comparison of differentially expressed genes among various PC states revealed a significant elevation in LGALS1 expression in PSPCs. Survival analysis on the MMRF CoMMpass dataset and GSE24080 dataset established LGALS1 as a gene associated with unfavourable prognostic implications for multiple myeloma. Ultimately, we discovered three specific ligand-receptor pairs within the midkine (MDK) signalling pathway network that play distinct roles in facilitating efficient cellular communication between PSPCs and the surrounding microenvironment cells. These insights have the potential to contribute to the understanding of molecular mechanism and the development of therapeutic strategies involving the application of stem-like cells in RRMM treatment.

Prognostic and diagnostic effects of high serum midkine levels in patients with hepatocellular carcinoma.

Midkine (MK) is a soluble cytokine, and its serum levels strongly correspond to protein expression levels in tumors. The present study aimed to clarify the clinicopathological and prognostic significance of serum MK (s-MK) in patients with hepatocellular carcinoma (HCC). Serum samples were obtained before surgery from 123 patients with HCC who had undergone surgery between January 2012 and December 2020. The receiver operating characteristic curve revealed that the best cut-off value for s-MK in differentiating HCC from healthy cases was 426 pg/ml. The clinicopathological variables and overall survival of patients were compared between the s-MK-positive group and s-MK-negative group. The sensitivity, specificity and accuracy of s-MK were 82.1, 97.4 and 88.0%, respectively. An s-MK-positive status was significantly associated with the number of tumors (≥2). The positivity rate of s-MK was significantly higher compared with that of α-fetoprotein and protein-induced by vitamin K absence-II. In total, only 28% of the patients were positive for s-MK. The s-MK-positive group showed significantly worse overall survival compared with the s-MK-negative group. Moreover, multivariate analysis revealed that an s-MK-positive status was independently associated with poor prognosis. s-MK was useful in detecting early HCC. The findings of this study indicated that the s-MK-positive status is associated with the number of tumors and can act as an independent prognostic risk factor.

Spatial and single-cell colocalisation analysis reveals MDK-mediated immunosuppressive environment with regulatory T cells in colorectal carcinogenesis

Cell-cell interaction factors that facilitate the progression of adenoma to sporadic colorectal cancer (CRC) remain unclear, thereby hindering patient survival. We performed spatial transcriptomics on five early CRC cases, which included adenoma and carcinoma, and one advanced CRC. To elucidate cell-cell interactions within the tumour microenvironment (TME), we investigated the colocalisation network at single-cell resolution using a deep generative model for colocalisation analysis, combined with a single-cell transcriptome, and assessed the clinical significance in CRC patients. CRC cells colocalised with regulatory T cells (Tregs) at the adenoma-carcinoma interface. At early-stage carcinogenesis, cell-cell interaction inference between colocalised adenoma and cancer epithelial cells and Tregs based on the spatial distribution of single cells highlighted midkine (MDK) as a prominent signalling molecule sent from tumour epithelial cells to Tregs. Interaction between MDK-high CRC cells and SPP1+ macrophages and stromal cells proved to be the mechanism underlying immunosuppression in the TME. Additionally, we identified syndecan4 (SDC4) as a receptor for MDK associated with Treg colocalisation. Finally, clinical analysis using CRC datasets indicated that increased MDK/SDC4 levels correlated with poor overall survival in CRC patients. MDK is involved in the immune tolerance shown by Tregs to tumour growth. MDK-mediated formation of the TME could be a potential target for early diagnosis and treatment of CRC. Japan Society for the Promotion of Science (JSPS) Grant-in-Aid for Science Research; OITA Cancer Research Foundation; AMED under Grant Number; Japan Science and Technology Agency (JST); Takeda Science Foundation; The Princess Takamatsu Cancer Research Fund.

Midkine (MDK) in Hepatocellular Carcinoma: More than a Biomarker.

Midkine (MDK) is a multifunctional secreted protein that can act as a cytokine or growth factor regulating multiple signaling pathways and being implicated in fundamental cellular processes, such as survival, proliferation, and migration. Although its expression in normal adult tissues is barely detectable, MDK serum levels are found to be elevated in several types of cancer, including hepatocellular carcinoma (HCC). In this review, we summarize the findings of recent studies on the role of MDK in HCC diagnosis and progression. Overall, studies show that MDK is a powerful biomarker for HCC early diagnosis, as it can differentiate not only between HCC patients and normal individuals but also between HCC patients and patients with other liver pathologies. It is correlated with high recurrence rates and was shown to be valuable for the diagnosis of early-stage HCC, even in patients negative for α-fetoprotein (AFP), the most commonly used biomarker for HCC diagnosis. A comparison with AFP reveals that MDK is inferior to AFP with regard to specificity but significantly superior with regard to sensitivity, which further indicates the need for using both biomarkers for more effective HCC diagnosis.

Diagnostic value of Midkine and AFP in the detection of hepatocellular carcinoma: A systematic review and meta-analysis.

Hepatocellular carcinoma (HCC) posed significant health problems and deaths. There are various challenges in the management of HCC, including the late detection or diagnosis. The ongoing diagnostic method in HCC also hinders the detection on the early stages of the disease, thus biomarkers need to be explored further for HCC detection. Serum alpha fetoprotein (AFP) and Midkine (MDK) are two proteins which might be the biomarker of choice in the detection of HCC. This meta-analysis aims to analyze the accuracy of Midkine and AFP in the detection of HCC. The systematic review and meta-analysis was conducted by adhering to the Preferred Reporting System for Systematic Review and Meta-Analysis (PRISMA) guidelines. We conduct literature screening and selection followed by quality assessment from various databases such as PubMed, MEDLINE, SpringerLink, ProQuest, EBSCOhost, Cochrane, and EMBASE. The included studies were then extracted and analyzed cumulatively using MedCalc and MetaDTA with forest plot and ROC curve as outcome. 12 studies were included in this study. The AFP biomarker yields sensitivity value of 62.5% (97.5% CI 0.442 - 0.778) and specificity value of 95% (97.5% CI 0.842 - 0.986), while the Midkine biomarker denotes sensitivity value of 91.6% (97.5% CI 0.83 - 0.961) and specificity value of 82.2% (97.5% CI 0.83 - 0.96). Both AFP and MDK are proven to be a good diagnostic tool or biomarker in the detection of HCC. The use of both in combination should provide high quality diagnostic marker for HCC suspected patients. Further studies on this should be conducted.

Sleep apnoea increases biomarkers of immune evasion, lymphangiogenesis and tumour cell aggressiveness in high-risk patients and those with established lung cancer.

Intermittent hypoxaemia and obstructive sleep apnoea (OSA) have been linked to lung cancer through as yet unidentified pathophysiological mechanisms. This study evaluates the effect of OSA on serum levels of biomarkers of immunosurveillance, lymphangiogenesis and intrinsic tumour cell aggressiveness in high-risk individuals screened for lung cancer and patients with established lung cancer. Serum samples from individuals participating in a lung cancer screening cohort (SAILS study) or with newly diagnosed lung cancer (SAIL study) were analysed. All patients underwent home sleep apnoea testing. Soluble levels of programmed cell death-1 (PD-1), programmed cell death ligand-1 (PD-L1), cytotoxic T-lymphocyte antigen-4, midkine (MDK), paraspeckle component-1 (PSPC1), transforming growth factor-β1 (TGF-β1), SMAD3, matrix metalloproteinase-2 and co-stimulus receptor of the tumour necrosis factor family of receptors (CD137) were determined by ELISA. The presence of moderate-to-severe OSA was associated with increased levels of PSPC1, MDK, PD-L1 and PD-1 in screened individuals, and with higher values of PSPC1, TGF-β1, PD-L1 and PD-1 in patients with established lung cancer. The findings correlated with nocturnal intermittent hypoxaemia indices. Moderate-to-severe OSA is associated with increased expression of serum biomarkers of immune evasion, lymphangiogenesis and tumour cell aggressiveness in high-risk individuals screened for lung cancer and those with established disease.

A comparative study of tumor markers and dynamic contrast-enhanced CT and their combined evaluation in the diagnosis of renal cancer patients

The objectives of this study were to investigate the diagnostic efficacy of dynamic contrast-enhanced Computed Tomography (CT) and tumor markers and their combined evaluation in renal cancer patients. A total of eighty male patients with solid renal lesions were selected from our hospital and categorized into two groups based on pathological examination findings: renal cancer group and benign lesion group. A comparison was made between the findings of dynamic contrast-enhanced CT and tumor markers and the diagnostic efficacy of either mono or combined evaluation were compared. Receiver operating characteristic curves were plotted to better analyze and compare different diagnostic techniques. The serum concentrations of carcinoembryonic antigen (CEA), Cytokeratin 19 fragment (CYFRA21-1), midkine (MK) and matrix metalloproteinase 9 (MMP-9) in renal cancer patients were significantly higher than those with benign lesions (p < 0.05). The Receiver Operating Characteristic (ROC) curve analysis demonstrated that the combination of dynamic contrast-enhanced CT and tumor markers had the highest area under the curve. This difference was statistically significant (p < 0.05). The analysis of the overall model quality results revealed that the model values for both single and combination indicators exceeded 0.5, with the combined indicators having the highest value of (0.84). The diagnostic efficacy of dynamic contrast-enhanced CT combined with tumor markers for renal cancer is significantly higher than either the dynamic contrast-enhanced CT or tumor markers alone. The combination of dynamic contrast-enhanced CT and tumor markers has a significant therapeutic benefit in diagnosing renal cancer. We envisage that, this approach can offer valuable guidance for the clinical diagnosis and treatment of renal cancer.

The role of midkine in health and disease.

Midkine (MDK) is a neurotrophic growth factor highly expressed during embryogenesis with important functions related to growth, proliferation, survival, migration, angiogenesis, reproduction, and repair. Recent research has indicated that MDK functions as a key player in autoimmune disorders of the central nervous system (CNS), such as Multiple Sclerosis (MS) and is a promising therapeutic target for the treatment of brain tumors, acute injuries, and other CNS disorders. This review summarizes the modes of action and immunological functions of MDK both in the peripheral immune compartment and in the CNS, particularly in the context of traumatic brain injury, brain tumors, neuroinflammation, and neurodegeneration. Moreover, we discuss the role of MDK as a central mediator of neuro-immune crosstalk, focusing on the interactions between CNS-infiltrating and -resident cells such as astrocytes, microglia, and oligodendrocytes. Finally, we highlight the therapeutic potential of MDK and discuss potential therapeutic approaches for the treatment of neurological disorders.

Machine learning identified MDK score has prognostic value for idiopathic pulmonary fibrosis based on integrated bulk and single cell expression data

Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal lung disease that poses a significant challenge to medical professionals due to its increasing incidence and prevalence coupled with the limited understanding of its underlying molecular mechanisms. In this study, we employed a novel approach by integrating five expression datasets from bulk tissue with single-cell datasets; they underwent pseudotime trajectory analysis, switch gene selection, and cell communication analysis. Utilizing the prognostic information derived from the GSE47460 dataset, we identified 22 differentially expressed switch genes that were correlated with clinical indicators as important genes. Among these genes, we found that the midkine (MDK) gene has the potential to serve as a marker of Idiopathic pulmonary fibrosis because its cellular communicating genes are differentially expressed in the epithelial cells. We then utilized midkine and its cellular communication-related genes to calculate the midkine score. Machine learning models were further constructed through midkine and related genes to predict Idiopathic pulmonary fibrosis disease through the bulk gene expression datasets. The midkine score demonstrated a correlation with clinical indexes, and the machine learning model achieved an AUC of 0.94 and 0.86 in the Idiopathic pulmonary fibrosis classification task based on lung tissue samples and peripheral blood mononuclear cell samples, respectively. Our findings offer valuable insights into the pathogenesis of Idiopathic pulmonary fibrosis, providing new therapeutic directions and target genes for further investigation.

Synthesis and interaction with growth factors of sulfated oligosaccharides containing an anomeric fluorinated tail

Compounds that mimic the biological properties of glycosaminoglycans (GAGs) and can be more easily prepared than the native GAG oligosaccharides are highly demanded. Here, we present the synthesis of sulfated oligosaccharides displaying a perfluorinated aliphatic tag at the reducing end as GAG mimetics. The preparation of these molecules was greatly facilitated by the presence of the fluorinated tail since the reaction intermediates were isolated by simple fluorous solid-phase extraction. Fluorescence polarization competition assays indicated that the synthesized oligosaccharides interacted with two heparin-binding growth factors, midkine (MK) and FGF-2, showing higher binding affinities than the natural oligosaccharides, and can be therefore considered as useful GAG mimetics. Moreover, NMR experiments showed that the 3D structure of these compounds is similar to that of the native sequences, in terms of sugar ring and glycosidic linkage conformations. Finally, we also demonstrated that these derivatives are able to block the MK-stimulating effect on NIH3T3 cells growth.