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Background Midkine (MK), a heparin-binding protein, participates in multiple cellular processes, such as immunity, cellular growth and apoptosis. Overwhelming evidence indicates that MK plays an important role in various pathological processes, including chronic inflammation, autoimmunity, cancer, and infection. Recent studies demonstrated that MK may be involved in the development of atherosclerosis, yet the mechanism has not been fully explored. Therefore, this study aims to investigate the effect and mechanism of MK on macrophage cholesterol efflux.Methods and Results:Using Oil Red O staining, NBD-cholesterol fluorescence labeling and enzymatic methods, it observed that MK markedly promoted macrophage lipid accumulation. Liquid scintillation counting (LSC) showed that MK decreased cholesterol efflux. Moreover, cell immunofluorescence, western blotting and quantitative real-time polymerase chain reaction (qRT-PCR) showed that MK downregulated ATP-binding membrane cassette transport protein A1 (ABCA1) expression. Functional promotion of ABCA1 expression attenuated the inhibitory effects of MK on cholesterol efflux, which reduced lipid accumulation. Additionally, intervention of adenosine monophosphate activated protein (AMPK)-mammalian target of rapamycin (mTOR) signaling molecule by the AMPK activator, AICAR, increased p-AMPK and ABCA1 expression, decreased p-mTOR expression and promoted cholesterol efflux, resulting in an obvious reduction in intracellular lipid content. Conclusions These data suggest that MK reduces the expression of ABCA1, inhibits the efflux of cholesterol and promotes the accumulation of lipids in RAW264.7 macrophages, and AMPK-mTOR signaling is involved in MK-mediated regulation of cholesterol metabolism in RAW264.7 macrophages.

Early diagnosis and detection of rheumatoid arthritis (RA) activity which is a potential therapeutic target, depends mainly on clinical presentation. However, laboratory tests may contribute to diagnosis and disease activity assessment of RA. This study aims to evaluate the accuracy of serum Midkine as serological marker for RA diagnosis and its activity detection. All patients with RA were recruited during the period from January 2016 to August 2018 in addition to healthy subjects as control. Serum Midkine level was estimated using enzyme immunoassay. The accuracy was determined for serum Midkine against the used American College of Rheumatology/European League Against Rheumatism 2010 classification criteria for RA diagnosis and disease activity score derivative for 28 joints-erythrocyte sedimentation rate (ESR) score for assessment of RA disease activity. A total of 211 of patients with RA (group I) were enrolled in this study with 112 healthy subjects (group II). Patients with RA were divided into two subgroups according to the disease activity; patients with active RA (group IA) and RA in remission (group IB). We detected that the area under curve (AUC) of serum Midkine level (AUC=0.851) was significantly lower than that of rheumatoid factor IgM and anti-cyclic citrullinated peptide IgG for RA diagnosis. However, Midkine presents a significantly higher diagnostic accuracy (AUC=0.939) in detecting RA activity than that offered by C reactive protein (CRP) or ESR. Our study suggested that serum Midkine is a potential serological marker for detection of active inflammatory state with higher diagnostic accuracy than other inflammatory markers as CRP or ESR. Therefore, it can be used as an inflammatory marker for detection of disease activity rather than diagnosis of RA.

Background To determine the role of Midkine (MDK) in non-invasive detection of bladder cancer (Bca) and the relationship with Ki67. Methods Sixty-five Bca patients and 55 non-Bca patients or healthy volunteers were enrolled and voided urine samples were prospectively obtained on the first day of enrollment. Tissue samples were collected by surgery. MDK and Ki67 expressions were analyzed by immunohistochemistry and Western Blot (WB). Specificity and sensitivity of MDK mRNA testing in the detection of Bca were determined by Receiver Operating Characteristic curve (ROC). The relationship between MDK and Ki67 was also assessed. Results MDK was overexpressed in Bca tissues than that in the non-cancer tissues. The specificity and sensitivity for MDK mRNA testing in urine in the identification of Bca was 80% and 72.3%. MDK detected 85.7% of high-grade tumors, 87.5% of muscle-invasive tumors and 79.4% of tumors larger than 3 cm in patients without gross hematuria. Microscopic hematuria may even increase the detection rate of Bca by MDK testing. Furthermore, the correlation of MDK and Ki67 was found positive. Conclusion MDK was overexpressed in Bca tissues and positively correlated with Ki67. MDK might be a potential biomarker for the detection of Bca, especially for those without gross hematuria but with microscopic hematuria.

Midkine levels are related to various diseases, including cardiovascular disease, renal disease and autoimmune disease. The research aimed to investigate the mitigation influence of downregulation of intermediate factors on myocardial hypertrophy induced by angiotensin Ⅱ (Ang), and whether downregulation of midkine could attenuate oxidative stress and autophagy. Induced myocardial hypertrophy of the mice model and treated HL-1 cells with Ang Ⅱ in vitro. The expressions of midkine were increased in the model and HL-1 cells with Ang II treatment. Midkine silence alleviated cardiac hypertrophy induced by Ang II, and inhibited the increases of atrial natriuretic peptide (ANP), Brain natriuretic peptide (BNP) and beta-myosin heavy chain (β-MHC) in the heart of mice. The raises of ANP, BNP and β-MHC in Ang II-induced HL-1 cells were also suppressed after midkine downregulation. Downregulating of midkine inhibited the increases of oxidative stress markers 8-OHdG, superoxide anions and MDA in the heart of mice or in the Ang II-treated HL-1 cells. The raises of LC3B, Atg3, Atg5 and Beclin1 in mice heart and in the Ang II.-induced HL-1 cells were attenuated after midkine silence. These outcomes showed that midkine was upregulated in myocardial hypertrophy mice. Targeting of midkine could alleviate cardiac hypertrophy via attenuation of oxidative stress and autophagy.

Simple Summary Most patients with glioblastoma, the most frequent primary brain tumor in adults, develop resistance to standard first-line treatment combining temozolomide and radiotherapy. Signaling through the hepatocyte growth factor receptor (c-MET) and the midkine (ALK ligand) promotes gliomagenesis and glioma stem cell maintenance, contributing to the resistance of glioma cells to anticancer therapies. This trial reports for the first time that the addition of crizotinib, an ALK, ROS1, and c-MET inhibitor, to standard RT and TMZ is safe and resulted in a promising efficacy for newly diagnosed patients with glioblastoma. Background: MET-signaling and midkine (ALK ligand) promote glioma cell maintenance and resistance against anticancer therapies. ALK and c-MET inhibition with crizotinib have a preclinical therapeutic rationale to be tested in newly diagnosed GBM. Methods: Eligible patients received crizotinib with standard radiotherapy (RT)/temozolomide (TMZ) followed by maintenance with crizotinib. The primary objective was to determine the recommended phase 2 dose (RP2D) in a 3 + 3 dose escalation (DE) strategy and safety evaluation in the expansion cohort (EC). Secondary objectives included progression-free (PFS) and overall survival (OS) and exploratory biomarker analysis. Results: The study enrolled 38 patients. The median age was 52 years (33-76), 44% were male, 44% were MGMT methylated, and three patients had IDH1/2 mutation. In DE, DLTs were reported in 1/6 in the second cohort (250 mg/QD), declaring 250 mg/QD of crizotinib as the RP2D for the EC. In the EC, 9/25 patients (32%) presented grade >= 3 adverse events. The median follow up was 18.7 months (m) and the median PFS was 10.7 m (95% CI, 7.7-13.8), with a 6 m PFS and 12 m PFS of 71.5% and 38.8%, respectively. At the time of this analysis, 1 died without progression and 24 had progressed. The median OS was 22.6 m (95% CI, 14.1-31.1) with a 24 m OS of 44.5%. Molecular biomarkers showed no correlation with efficacy. Conclusions: The addition of crizotinib to standard RT and TMZ for newly diagnosed GBM was safe and the efficacy was encouraging, warranting prospective validation in an adequately powered, randomized controlled study.

In the retina of zebrafish, Müller glia have the ability to reprogram into stem cells capable of regenerating all classes of retinal neurons and restoring visual function. Understanding the cellular and molecular mechanisms controlling the stem cell properties of Müller glia in zebrafish may provide cues to unlock the regenerative potential in the mammalian nervous system. Midkine is a cytokine/growth factor with multiple roles in neural development, tissue repair, and disease., In the retina of zebrafish, Müller glia have the ability to reprogram into stem cells capable of regenerating all classes of retinal neurons and restoring visual function. Understanding the cellular and molecular mechanisms controlling the stem cell properties of Müller glia in zebrafish may provide cues to unlock the regenerative potential in the mammalian nervous system. Midkine is a cytokine/growth factor with multiple roles in neural development, tissue repair, and disease. In midkine-a loss-of-function mutants of both sexes, Müller glia initiate the appropriate reprogramming response to photoreceptor death by increasing expression of stem cell-associated genes, and entering the G1 phase of the cell cycle. However, transition from G1 to S phase is blocked in the absence of Midkine-a, resulting in significantly reduced proliferation and selective failure to regenerate cone photoreceptors. Failing to progress through the cell cycle, Müller glia undergo reactive gliosis, a pathological hallmark in the injured CNS of mammals. Finally, we determined that the Midkine-a receptor, anaplastic lymphoma kinase, is upstream of the HLH regulatory protein, Id2a, and of the retinoblastoma gene, p130, which regulates progression through the cell cycle. These results demonstrate that Midkine-a functions as a core component of the mechanisms that regulate proliferation of stem cells in the injured CNS. SIGNIFICANCE STATEMENT The death of retinal neurons and photoreceptors is a leading cause of vision loss. Regenerating retinal neurons is a therapeutic goal. Zebrafish can regenerate retinal neurons from intrinsic stem cells, Müller glia, and are a powerful model to understand how stem cells might be used therapeutically. Midkine-a, an injury-induced growth factor/cytokine that is expressed by Müller glia following neuronal death, is required for Müller glia to progress through the cell cycle. The absence of Midkine-a suspends proliferation and neuronal regeneration. With cell cycle progression stalled, Müller glia undergo reactive gliosis, a pathological hallmark of the mammalian retina. This work provides a unique insight into mechanisms that control the cell cycle during neuronal regeneration.

Midkine is a heparin-binding growth factor, originally reported as the product of a retinoic acid-responsive gene during embryogenesis, but currently viewed as a multifaceted factor contributing to both normal tissue homeostasis and disease development. Midkine is abnormally expressed at high levels in various human malignancies and acts as a mediator for the acquisition of critical hallmarks of cancer, including cell growth, survival, metastasis, migration, and angiogenesis. Several studies have investigated the role of midkine as a cancer biomarker for the detection, prognosis, and management of cancer, as well as for monitoring the response to cancer treatment. Moreover, several efforts are also being made to elucidate its underlying mechanisms in therapeutic resistance and immunomodulation within the tumor microenvironment. We hereby summarize the current knowledge on midkine expression and function in cancer development and progression, and highlight its promising potential as a cancer biomarker and as a future therapeutic target in personalized cancer medicine.

BACKGROUND Cachexia is responsible for the low quality of life in pancreatic adenocarcinoma (PDAC). The rapid disease progression and patient deterioration seems related to perineural invasion, but the relationship between cachexia and perineural invasion for the evolution of the disease has been rarely studied. As perineural invasion is difficult to be highlighted, a biomarker such as the neurotrophic factor Midkine (MK) which promotes the neuronal differentiation and the cell migration could be helpful. Also, Activin (ACV) has been described as cachexia related to PDAC. However, their role for assessing and predicting the disease course in daily practice is not known. AIM To assess the relationship between perineural invasion and cachexia and their biomarkers, MK and ACV, respectively, and their prognostic value. METHODS This study included prospectively enrolled patients with proven adenocarcinoma and a matched group of controls without any malignancies. Patients with other causes of malnutrition were excluded. The plasma levels of ACV and MK were analyzed using western blotting and were correlated with the clinicopathological features and survival data. These results were validated by immunohistochemical analyses of the pancreatic tumor tissue of the patients included in the study and a supplementary group of surgically resected specimens from patients with a benign disease. RESULTS The study comprised 114 patients with PDAC, 125 controls and a supplementary group of 14 benign pancreatic tissue samples. ACV and MK were both overexpressed more frequently in the plasma of patients with PDAC than in the controls (63% vs 32% for ACV, P < 0.001; 47% vs 16% for MK, P < 0.001), with similar levels in pancreatic tissue the MK protein expression was closely related to the advanced clinical stage (P = 0.006), the presence of metastasis (P = 0.04), perineural invasion (P = 0.03) and diabetes (P = 0.002), but with no influence on survival. No correlation between clinicopathological factors and ACV expression was noted. Cachexia, present in 19% of patients, was unrelated to ACV or MK level. Higher ACV expression was associated with a shorter survival (P = 0.008). CONCLUSION The MK was a biomarker of perineural invasion, associated with tumor stage and diabetes, but without prognostic value as ACV. Cachexia was unrelated to perineural invasion, ACV level or survival.

Glioblastoma (GBM) is the most lethal primary brain tumor with few treatment options. The survival of glioma-initiating cells (GICs) is one of the major factors contributing to treatment failure. GICs frequently produce and respond to their own growth factors that support cell proliferation and survival. In this study, we aimed to identify critical autocrine factors mediating GIC survival and to evaluate the anti-GBM effect of antagonizing these factors. Proteomic analysis was performed using conditioned media from two different patient-derived GBM tumor spheres under a growth factor-depleted status. Then, the antitumor effects of inhibiting an identified autocrine factor were evaluated by bioinformatic analysis and molecular validation. Proteins secreted by sphere-forming GICs promote cell proliferation/survival and detoxify reactive oxygen species (ROS). Among these proteins, we focused on midkine (MDK) as a clinically significant and pathologically relevant autocrine factor. Antagonizing MDK reduced the survival of GBM tumor spheres through the promotion of cell cycle arrest and the consequent apoptotic cell death caused by oxidative stress-induced DNA damage. We also identified PCBP4, a novel molecular predictor of resistance to anti-MDK treatment. Collectively, our results indicate that MDK inhibition is an important therapeutic option by suppressing GIC survival through the induction of ROS-mediated cell cycle arrest and apoptosis., Brain cancer: a key growth factor Targeting the growth factor midkine (MDK) may offer improved treatment for glioblastoma, the most lethal brain cancer. In glioblastoma, the tumor-initiating cells produce their own growth factors, encouraging themselves to keep multiplying, and making glioblastoma very difficult to treat. Do-Hyun Nam and Hyun Ju Kang at the Samsung Medical Center, Seoul, South Korea and coworkers screened the growth factors produced by two glioblastoma samples, then focused on a single cancer-associated factor, MDK. Antagonizing MDK slowed tumor cell growth, and further investigation showed that suppressing MDK restored the susceptibility of tumor cells to DNA damage and the mechanisms that weed out damaged cells. Noting that treatment efficacy varied between tumor samples, the researchers identified a biomarker for sensitivity to MDK treatment. These results point the way to new treatments for this particularly deadly cancer.

The substantial biological heterogeneity of metastatic prostate cancer has hindered the development of personalized therapeutic approaches. Therefore, it is difficult to predict the course of metastatic hormone-sensitive prostate cancer (mHSPC), with some men remaining on first-line androgen deprivation therapy (ADT) for several years while others progress more rapidly. Improving our ability to risk-stratify patients would allow for the optimization of systemic therapies and support the development of stratified prospective clinical trials focused on patients likely to have the greatest potential benefit. Here, we applied a liquid biopsy approach to identify clinically relevant, blood-based prognostic biomarkers in patients with mHSPC. Gene expression indicating the presence of CTCs was greater in CHAARTED high-volume (HV) patients (52% CTChigh) than in low-volume (LV) patients (23% CTChigh; * p = 0.03). HV disease (p = 0.005, q = 0.033) and CTC presence at baseline prior to treatment initiation (p = 0.008, q = 0.033) were found to be independently associated with the risk of nonresponse at 7 months. The pooled gene expression from CTCs of pre-ADT samples found AR, DSG2, KLK3, MDK, and PCA3 as genes predictive of nonresponse. These observations support the utility of liquid biomarker approaches to identify patients with poor initial response. This approach could facilitate more precise treatment intensification in the highest risk patients.

Head-to-head comparison of available commercial antibodies against Midkine by immunoblot (Western blot) andimmunoprecipitation on total cell lysates and conditioned media. Work reported in this report was supported in part by the Emory-Sage-SGC TREAT-AD center established by the National Institutes of Aging under award number U54AG065187.

Lung adenocarcinomas (LUAD) arise from precancerous lesions such as atypical adenomatous hyperplasia, which progress into adenocarcinoma in situ and minimally invasive adenocarcinoma, then finally into invasive adenocarcinoma. The cellular heterogeneity and molecular events underlying this stepwise progression remain unclear. In this study, we perform single-cell RNA sequencing of 268,471 cells collected from 25 patients in four histologic stages of LUAD and compare them to normal cell types. We detect a group of cells closely resembling alveolar type 2 cells (AT2) that emerged during atypical adenomatous hyperplasia and whose transcriptional profile began to diverge from that of AT2 cells as LUAD progressed, taking on feature characteristic of stem-like cells. We identify genes related to energy metabolism and ribosome synthesis that are upregulated in early stages of LUAD and may promote progression. MDK and TIMP1 could be potential biomarkers for understanding LUAD pathogenesis. Our work shed light on the underlying transcriptional signatures of distinct histologic stages of LUAD progression and our findings may facilitate early diagnosis., The origin and progression of lung adenocarcinoma (LUAD) are still poorly understood. Here, the authors analyse LUAD composition and progression in patient samples using single-cell RNA-seq and multiplex imaging, revealing a potential transcriptional divergence from alveolar type 2 cells.

Cell-penetrating peptides (CPPs) have been regarded as potential drug carriers for cancer therapy. However, most well-studied CPPs fail to deliver exogenous drugs efficiently and selectively. In this study, a tumour-targeted CPP with high efficiency derived from heparin-binding domain (HBD) of Midkine (named HMD) was discovered. HMD exhibited higher delivery efficiency than classic CPPs (TAT and R9) and manifested selectivity in tumour cells. Normally, the positive charge is the key factor for the transmembrane activity of CPPs such as TAT and R9. Here, the length of α-helix inside CPP was found also important for in the recognition of heparan sulphate proteoglycans (HSPGs). Subsequently, the introduction of HMD enhanced the inhibitory effect of Momordica antiviral protein of 30 kDa (MAP30) on tumour cells, resulting in a 6.07-fold and 5.42-fold increase in HeLa cells and MGC80-3 cells respectively without enhanced cytotoxicity in normal cells. These results show that HMD possesses high efficiency and good tumour specificity and can be utilised as a promising agent for the tumour-targeted delivery of drug. This study is also a supplement to the existing theories about the biological activities of the α-helix in CPPs.

BackgroundPerineural invasion (PNI) is a prominent characteristic of multiple solid tumors and indicates poor prognosis[1, 2]. A growing body of evidence emphasizes the critical role of competitive endogenous RNA(ceRNA) regulatory networks in various human cancers. However, the complexity and behavior characteristics of the ceRNA network in colon cancer with perineural invasion were still unclear. In this study, we aimed to clarify a midkine(MDK)-related ceRNA regulatory network and identify potential prognostic markers associated with colon cancer with perineural invasion.Material and MethodsWe extract the expression profiles of three RNAs (long non-coding RNAs [lncRNAs], microRNAs [miRNAs], and mRNAs) from The Cancer Genome Atlas (TCGA) database. In order to construct the lncRNA-miRNA-mRNA triple regulatory network in colon cancer with perineural invasion, we performed joint analysis in the MDKhigh and MDKlow expression groups, as well as the colon cancer and paracancerous tissue groups. Kaplan-Meier method was used to plot the Overall survival (OS) curves, and the log-rank test was used for testing. Univariate and multivariate Cox regression analysis were used to determine OS-related characteristics.ResultsKCNQ1OT1-miR-454-3p/miR-204-5p-MAP1B ceRNA network related to the prognosis of colon cancer was obtained through bioinformatics analysis. Importantly, we determined the KCNQ1OT1/MAP1B axis in the ceRNA through correlation analysis, and through Cox regression analysis it seems to be a clinical prognostic model. ConclusionIn conclusion, the current study constructing a ceRNA based KCNQ1OT1/MAP1B axis may be a novel important prognostic factor for the diagnosis and prognosis of colon cancer with perineural invasion.

Midkine (MDK), an extracellular growth factor, regulates signal transduction and cancer progression by interacting with receptors, and it can be internalized into the cytoplasm by endocytosis. However, its intracellular function and signaling regulation remain unclear. Here, we show that intracellular MDK interacts with LKB1 and STRAD to disrupt the LKB1-STRAD-Mo25 complex. Consequently, MDK decreases the activity of LKB1 to dampen both the basal and stress-induced activation of AMPK by glucose starvation or treatment of 2-DG. We also found that MDK accelerates cancer cell proliferation by inhibiting the activation of the LKB1-AMPK axis. In human cancers, compared to other well-known growth factors, MDK expression is most significantly upregulated in cancers, especially in liver, kidney and breast cancers, correlating with clinical outcomes and inversely correlating with PRKAA1 (encoding AMPKα1) expression and phosphorylated AMPK levels. Our study elucidates an inhibitory mechanism for AMPK activation, which is mediated by the intracellular MDK through disrupting the LKB1-STRAD-Mo25 complex.

Background In end-stage renal disease, a high cardiovascular risk profile and endothelial damage prevails. The heparin-binding growth factor midkine stimulates neo-angiogenesis in ischemic diseases, coordinates neutrophil influx, and raises blood pressure through stimulated angiotensin synthesis. Methods We determined changes of midkine serum levels during hemodialysis sessions under the assumption that endothelial cell-derived midkine is released. Periprocedural differences (∆midkine) were calculated and correlated with cardiovacular biomarkers and fluid status (clinical assessment, V. cava collapse, comet tail phenomenon), cardiovascular morbidities, mortality rates. Blood was collected before and after dialysis from hemodialysis patients (n = 171; diabetes: n = 70; hypervolemia: n = 83; both: n = 32). Results Baseline midkine levels were ~ fourfold elevated compared to healthy controls (n = 100). Further, on average a tenfold rise was detected during dialysis, the extent of which was partially related to non-fractionated heparin application (r2 = 0.17). Inter-individual differences were highly reproducible. Hypervolemic patients responded with a less than average rise in midkine levels during dialysis (p p n = 88). In Kaplan Meier survival curves, low delta midkine levels correlated with cardiovascular/overall mortality rates, similar to elevated uPAR levels, whereas other markers (NTproANP, galectin, tenascin-C) were less predictive. Following intervention with successful fluid removal in hypervolemic dialysis patients to optimize fluid homeostasis, midkine values increased (p Conclusion Thus, for dialysis patients inadequate periprocedural midkine upregulation is linked with hypervolemia and associates with cardiovascular events.

This study aimed to investigate the role of cancer-associated fibroblast (CAF)-derived midkine (MK) in cisplatin (DDP) resistance. The primary cultures of CAFs and non-cancer fibroblasts (NFs) were isolated and purified. The DDP-resistant gastric cancer (GC) cells were cultured with CAF-conditioned medium. QRT-PCR and Elisa assays were employed to determine MK expression. The expression of ST7-AS1 was measured by qRT-PCR. The impact of CAFs, MK, and ST7-AS1 silencing on DDP resistance was determined by MTT and Annexin V/PI staining assay. Expression of EMT markers and PI3K/AKT was determined by Western blot and qRT-PCR. The role of MK in DDP resistance was confirmed in a xenograft model. Incubation with CAF-conditioned medium increased the IC50 to DDP. Also, incubation with CAF-conditioned medium increased cell viability, reduced cell apoptosis, and promoted EMT in DDP-resistant GC cells, which were all blocked with MK neutralization antibody treatment. MK increased the DDP resistance and upregulated the expression of ST7-AS1 in DDP-resistant GC cells. Additionally, ST7-AS1 knockdown increased the sensitivity to DDP by inhibiting EMT. Moreover, ST7-AS1 knockdown significantly decreased the phosphorylation of PI3K and AKT, and suppressed EMT, which were restored by MK addition. Finally, MK promoted tumor growth and DDP resistance in a mice model bearing the SGC-7901/DDP xenografts. CAF-derived MK promotes EMT-mediated DDP resistance via upregulation of ST7-AS1 and activation of PI3K/AKT pathway.

Encapsulating the antisense oligonucleotide drug MK-ASODN with nanoliposomes greatly improved its potency and targeting to the heparin-binding growth factor midkine. The disposition and pharmacokinetic (PK) parameters of MK-ASODN nanoliposomes were studied in monkeys and rats, and the human PK parameters were predicted based on preclinical data using a physiologically based pharmacokinetic (PBPK) model. Following intravenous injection, the drug plasma concentration rapidly declined in a multiexponential manner, and the drug was rapidly transferred to tissues from the circulation. The terminal t1/2 in plasma was clearly longer than that of the unmodified antisense nucleic acid drug. According to the AUC,MK-ASODN nanoliposomes were mainly distributed in the kidney, spleen, and liver. . MK-ASODN nanoliposomes were highly plasma protein bound, limiting their urinary excretion. Very little MK-ASODN nanoliposomes were detected in urine or feces. The plasma disposition of MK-ASODN nanoliposomes appeared nonlinear over the studied dose range of 11.5–46 mg kg−1. The monkey PBPK model of MK-ASODN nanoliposomes was well established and successfully extrapolated to predict MK-ASODN nanoliposome PK in humans. These disposition and PK data support further development in phase I clinical studies.

Background The current coronavirus disease 2019 (COVID-19) outbreak caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has emerged in Wuhan, China, and has rapidly become a global challenge, creating major challenges to health systems in almost every country in the world it has turned into a pandemic. COVID-19 poses a risky clinical situation that can range from mild illness to severe respiratory failure, requiring admission to intensive care. Main body It is known that SARS-CoV-2 infection causes a cytokine storm in some critically ill patients. However, more and more evidence showed that there is a dramatic increase in cytokine levels in patients diagnosed with COVID-19. Midkine (MK) is involved in various physiological and pathological processes, which some of them are desired and beneficial such as controlling tissue repair and antimicrobial effects, but some others are harmful such as promoting inflammation, carcinogenesis, and chemoresistance. Also, MK is expressed in inflammatory cells and released by endothelial cells under hypoxic conditions. Conclusions Considering all this information, there are strong data that midkine, an important cytokine known to increase in inflammatory diseases, may be overexpressed in patients who are positive for COVID-19. The overexpression of MK reveals a picture leading to fibrosis and damage in the lung. Therefore, questions arise about how the expression of MK changes in COVID-19 patients and can we use it as an inflammation biomarker or in the treatment protocol in the future.

Interactions between angiogenesis and neurogenesis regulate embryonic brain development. However, a comprehensive understanding of the stages of vascular cell maturation is lacking, especially in the prenatal human brain. Using fluorescence-activated cell sorting, single-cell transcriptomics, and histological and ultrastructural analyses, we show that an ensemble of endothelial and mural cell subtypes tile the brain vasculature during the second trimester. These vascular cells follow distinct developmental trajectories and utilize diverse signaling mechanisms, including collagen, laminin, and midkine, to facilitate cell-cell communication and maturation. Interestingly, our results reveal that tip cells, a subtype of endothelial cells, are highly enriched near the ventricular zone, the site of active neurogenesis. Consistent with these observations, prenatal vascular cells transplanted into cortical organoids exhibit restricted lineage potential that favors tip cells, promotes neurogenesis, and reduces cellular stress. Together, our results uncover important mechanisms into vascular maturation during this critical period of human brain development.

Background: Hepatocellular carcinoma (HCC) is the commonest primary malignant cancer of the liver and the sixth most common cancer in the world. Its incidence is increasing worldwide reaching half million cases each year. The primary marker for HCC is Alpha Feto Protein (AFP) which is not secreted in all cases of HCC and may be normal in as many as 40% of patients with early HCC. Midkine(MK) is a heparin-binding cytokine or growth factor, promoting survival, growth, migration, gene expression and other activities of target cells. MK is over expressed in hepatocellular carcinoma. Objectives: The aim of the study is to evaluate the diagnostic value of MK as a tumor marker of HCC.Patients and Methods: This study was conducted on 85 patients who were classified into three groups: Group I (HCC) group included 45 patients with HCC. Group II (Liver cirrhosis) group included 30 patients without any evidence of hepatic focal lesions as excluded by ultrasonography and AFP estimation. Group III (control group) included 10 normal people. The level of AFP and MK were estimated for all cases together with full clinical assessment liver biochemical profile, viral markers, conventional US and triphasic abdominal CT for HCC cases.Results: Serum AFP median level was significantly (P

Background: Airway smooth muscle cells (ASMCs) produce several cytokines during inflammation, causing changes in extracellular matrix components, leading to airway remodeling. Midkine (MK) promotes the chemotaxis of inflammatory cells and releases proinflammatory factors. Whether Notch and Midkine jointly affect the proliferation and apoptosis of ASMCs is unknown. This research aimed to study the role of MK in ASMCs using an LPS-induced acute lung injury model.Methods: ASMCs were cultured in vitro and divided into five groups according to treatment: control, lipopolysaccharide (LPS), non-target siRNA, MK siRNA, and g-secretase inhibitor LY411575. Cell proliferation was assessed using the Cell Counting Kit-8 assay. Apoptosis was measured by flow cytometry. Changes in the levels of cytokines related to the MK/Notch2 signaling pathway were detected by Western blotting, qPCR, and immunofluorescence.Results: LPS increased the mRNA and protein expression of MK and Notch2. MK silencing and LY411575 reduced this effect. LPS reduced the viability and increased the rate of apoptosis of ASMCs. This effect was attenuated by exogenous MK and enhanced by MK silencing and LY411575 treatment.Conclusions: The MK/Notch2 signaling pathway plays a regulatory role in ASMC proliferation and apoptosis in airway inflammation.

A possibility of repurposing sitagliptin, a well-established antidiabetic drug, for alleviating injury caused by ischemia-reperfusion (IR) is being researched. The aim of this study was to shed some light on the molecular background of the protective activity of sitagliptin during hepatic IR. The expression and/or concentration of inflammation and oxidative stress-involved factors have been determined in rat liver homogenates using quantitative RT-PCR and Luminex® xMAP® technology and markers of nitrative and halogenative stress were quantified using targeted metabolomics (LC-MS/MS). Animals (n = 36) divided into four groups were treated with sitagliptin (5 mg/kg) (S and SIR) or saline solution (C and IR), and the livers from IR and SIR were subjected to ischemia (60 min) and reperfusion (24 h). The midkine expression (by 2.2-fold) and the free 3-nitrotyrosine (by 2.5-fold) and IL-10 (by 2-fold) concentration were significantly higher and the Nox4 expression was lower (by 9.4-fold) in the IR than the C animals. As compared to IR, the SIR animals had a lower expression of interleukin-6 (by 4.2-fold) and midkine (by 2-fold), a lower concentration of 3-nitrotyrosine (by 2.5-fold) and a higher Nox4 (by 2.9-fold) and 3-bromotyrosine (by 1.4-fold). In conclusion, IR disturbs the oxidative, nitrative and halogenative balance and aggravates the inflammatory response in the liver, which can be attenuated by low doses of sitagliptin.

Midkine (MK) is a heparin-binding growth factor, whose role as a biomarker of coronary artery disease, myocardial ischaemia and necrosis has not been well measured. This study quantified serial MK levels in patients undergoing coronary angiography (CA) and identified factors associated with MK. In this single-centre, parallel cohort study, forty patients undergoing CA had arterial samples collected prior, 10 and 20 min after heparin administration. Four groups were examined: 1—stable coronary artery disease (CAD) without percutaneous coronary intervention (PCI); 2—stable CAD for elective PCI; 3—non-ST elevation myocardial infarction (NSTEMI) with or without PCI; 4—ST elevation myocardial infarction (STEMI) with primary PCI. Groups 1, 2 and 4 were heparin naive, allowing assessment of the effects of myocardial necrosis between baseline levels; group 3 had received low-molecular-weight heparin. MK levels were analysed by ELISA. Median MK at baseline did not differ between groups, demonstrating that myocardial ischaemia or necrosis does not affect MK levels. Heparin administration had an immediate effect on median MK at 10 min, showing an average 500-fold increase that is dose-dependent (R2 = 0.35, p = 0.001). Median MK levels remained elevated at 20 min following heparin administration. Multivariate analysis showed that the estimated glomerular filtration rate (eGFR) was the only predictor of elevated baseline MK (p = 0.02). Baseline MK did not correlate with high-sensitivity troponin-I (HsTnI) taken just before CA (p = 0.97), or peak HsTnI during admission (p = 0.74). MK is not a reliable marker of myocardial ischaemia or necrosis. MK increased significantly in all patients following heparin administration in a dose-dependent manner.

Background: Breast cancer (BC) is the most frequently diagnosed life-threatening cancer in women and the second leading cause of cancer death among women worldwide. The present conventional clinicopathological factors remain insufficient to evaluate the substantial prognosis of this disease. Midkine is a heparin-binding growth factor. It is upregulated in many types of cancer. Aim of the work: The aim of this study was to through light on the role of serum midkine level in breast cancer patients and its relation to the conventional tumor marker CA 15-3. Subject and method: This study was conducted on 40 newly diagnosed breast cancer patients (Group I) and 20 apparently healthy control subjects (Group II). Complete history, clinical examination, mammography and histopathological examination of breast cancer with immunohistochemical study were performed. Serum midkine level was assessed by double antibody sandwich assay technique(ELISA) by using human midkine ELISA kit also CA 15-3 level was assessed by using an automatic immune assay analyzer (TOSOH AIA system). Results: The present study revealed a statistically significant difference between breast cancer patients (Group I) and healthy control (Group II) regarding serum midkine level. Serum midkine level showed a statistically significant difference with stage of breast cancer, menopausal status and CA 15-3 serum level. There was no statistically significant difference regarding age, family history of breast cancer, parity, breastfeeding and history of oral contraceptive pills (OCPs) intake. Conclusions: This study showed that midkine might be a diagnostic and prognostic biomarker for breast cancer.

Background: Solitary thyroid nodules are a common clinical problem. None of sonographic features is sufficient to discard or detect malignancy efficiently. Midkine is a novel heparin-binding growth factor, plays critical roles in carcinogenesis. In this study, we aimed to evaluate serum midkine levels in patients with solitary thyroid nodules to predict malignancy. Methods: A total of 100 patients who had solitary thyroid nodules were enrolled in the study. Serum midkine levels were measured. Fine needle aspiration cytology was done to all nodules (25 suspicious/ malignant and 75 benign). Results: Serum midkine levels were significantly higher in patients who had nodules with the following sonographic features; hypoechoic nodules compared to isoechoic and hyperechoic nodules (P=0.024), nodules with microcalcification compared to nodules with macrocalcification or without calcification (P = 0.011), nodules with irregular borders compared to nodules with regular borders (P = 0.014) and nodules more than 2 cm in length than shorter ones (P = 0.011). Serum midkine levels were also higher in nodules with absent halo compared to those with clear halo but with no significant difference (P = 0.660). Also, levels of serum medikine were significantly higher in suspicious/ malignant nodules than in benign nodules (P < 0.001). Conclusion: Serum midkine can predict malignancy in solitary thyroid nodule and also well correlated with sonographic features of thyroid nodules. We suggest that midkine levels may serve as a novel biochemarker in association with sonographic features in evaluation of solitary thyroid nodules.

Prostate cancer (PCa) is the most common cancer in men worldwide. Midkine (MK) is overexpressed in PCa, as well as in tumor-initiating cells termed cancer stem cells (CSCs). Apigenin is a dietary flavone with considerable anti-tumor activities. In this study, we explored the possible therapeutic use of MK silencing, apigenin treatment, and a combination of both on human PCa and prostate cancer stem cells (PCSCs). CD44+CD133+ PC3 and CD44+ LNCaP CSCs were isolated from their parent cell lines. Both MK knockdown and apigenin treatment resulted in loss of cell viability in PCSCs, and these effects were significantly elevated when apigenin was applied with MK silencing. Combined treatment of CD44+CD133+ PC3 cells with apigenin and MK siRNA was also more effective in inducing apoptotic and non-apoptotic cell death when compared with individual applications. Treatment of CD44+ LNCaP cells with apigenin significantly decreased viability, although the combination treatment did not markedly alter the individual therapy. Molecular events underlying cell cycle arrest and inhibition of the survival, proliferation, and migration of CD44+CD133+ PC3 cells were found to be associated with upregulated p21, p27, Bax, Bid, caspase-3, and caspase-8 expression, as well as downregulated p-p38, p-ERK, NF-κB, and PARP. In addition, the combination of apigenin treatment and MK silencing showed better outcomes on the anticancer efficacy of docetaxel in CD44+CD133+ PC3 cells. In conclusion, MK-regulated events are different between PCSCs, and when combined with apigenin plus MK silencing, docetaxel treatment may be a valuable approach for the eradication of PCSCs.