Midkine level may be used as a noninvasive biomarker in Crohn’s disease

Overexpression and potential roles of midkine via regulation of vascular endothelial growth factor A in psoriasis

Midkine plays a critical role in angiogenesis by regulating the vascular endothelial growth factor (VEGF) signalling pathway, which is known to be associated with psoriasis pathogenesis. However, research on midkine-psoriasis relationship remains limited. The objective of this study was to detect midkine expression in psoriasis and investigate its potential role in the disease. Midkine expression was measured using immunohistochemistry and ELISA. Effects of midkine on HaCaT cell proliferation, VEGF-A production and signalling pathways were assessed using CCK8, RT-PCR and WB. Scratch and in vitro tube formation tests were used to evaluate the effects of HaCaT-cell-activated midkine on the migration and tube formation of human dermal microvascular endothelial cells. Murine psoriasiform models were injected with midkine recombinant protein and midkine monoclonal antibody to investigate skin lesions, tissue sections and dermal microvessel density. Levels of midkine significantly increased in both lesions and serum of patients with psoriasis. Serum expression of midkine decreased after treatment and a positive correlation was found between midkine and disease severity. Midkine promoted HaCaT cell proliferation and VEGF-A production. The Notch2/HES1/JAK2-STAT5A pathway expression increased after midkine treatment of HaCaT cells. The supernatant of HaCaT cells treated with midkine promoted HMEC-1 migration and angiogenesis in vitro. Recombinant midkine protein exacerbated psoriasiform lesions with increased expressions of VEGF-A and microvessel density, while midkine monoclonal antibody alleviated psoriasis lesions. Midkine may have a significant impact on psoriasis angiogenesis by regulating VEGF-A expression through the Notch2/HES1/JAK2-STAT5A pathway, highlighting a potential therapeutic target for psoriasis treatment.

Evaluation of serum midkine levels and metabolic parameters in patients with hidradenitis suppurativa

The exact pathogenesis of Hidradenitis suppurativa (HS) has not been known yet. Midkine (MK) is a heparin-binding protein that has crucial roles in many processes such as cell proliferation, cell survival, cell migration, anti-apoptotic activity, and also inflammation and angiogenesis. No data exists in the literature on the evaluation of MK in patients with HS. The present study aimed to determine the serum levels of MK and metabolic parameters in patients with HS and to compare them with healthy subjects. Forty-five patients with HS and 45 healthy controls were included. The severity of the disease was assessed with Hurley staging system in the patient group. Levels of MK, C-reactive protein (CRP), lipids, and fasting glucose were measured with the enzyme-linked immunosorbent assay (ELISA) method. MK levels were significantly higher in the patient group (p < 0.05). Moreover, smoking habit, total cholesterol, triglyceride (TG), low-density lipoprotein (LDL) and CRP were significantly higher in the patient group (for all p < 0.05). Correlation analyses revealed that MK value was correlated positively with waist circumference, TG, total cholesterol level and diastolic blood pressure (for all p < 0.05), while negatively correlated with high-density lipoprotein (HDL) level (p = 0.046, r = - 0.219). There was no difference in the MK levels according to the severity of the disease among patients. This is the first preliminary study showing that these patients with HS have higher serum MK levels, which may also be related to autoinflammation, angiogenesis, atherosclerosis and metabolic syndrome risk.

Spermidine-Eugenol Supplement Preserved Inflammation-Challenged Intestinal Cells by Stimulating Autophagy

Increases in non-communicable and auto-immune diseases, with a shared etiology of defective autophagy and chronic inflammation, have motivated research both on natural products in drug discovery fields and on the interrelationship between autophagy and inflammation. Within this framework, the tolerability and protective effects of a wheat-germ spermidine (SPD) and clove eugenol (EUG) combination supplement (SUPPL) were investigated on inflammation status (after the administration of lipopolysaccharide (LPS)) and on autophagy using human Caco-2 and NCM460 cell lines. In comparison to the LPS treatment alone, the SUPPL + LPS significantly attenuated ROS levels and midkine expression in monocultures, as well as occludin expression and mucus production in reconstituted intestinal equivalents. Over a timeline of 2-4 h, the SUPPL and SUPPL + LPS treatments stimulated autophagy LC3-11 steady state expression and turnover, as well as P62 turnover. After completely blocking autophagy with dorsomorphin, inflammatory midkine was significantly reduced in the SUPPL + LPS treatment in a non-autophagy-dependent manner. After a 24 h timeline, preliminary results showed that mitophagy receptor BNIP3L expression was significantly downregulated in the SUPPL + LPS treatment compared to the LPS alone, whereas conventional autophagy protein expression was significantly higher. The SUPPL shows promise in reducing inflammation and increasing autophagy to improve intestinal health.

Multiple pathophysiological roles of midkine in human disease

Midkine (MK) is a low molecular-weight protein that was first identified as the product of a retinoic acid-responsive gene involved in embryonic development. Recent studies have indicated that MK levels are related to various diseases, including cardiovascular disease (CVD), renal disease and autoimmune disease. MK is a growth factor involved in multiple pathophysiological processes, such as inflammation, the repair of damaged tissues and cancer. The pathophysiological roles of MK are diverse. MK enhances the recruitment and migration of inflammatory cells upon inflammation directly and also through induction of chemokines, and contributes to tissue damage. In lung endothelial cells, oxidative stress increased the expression of MK, which induced angiotensin-converting enzyme (ACE) expression and the consequent conversion from Ang I to Ang II, leading to further oxidative stress. MK inhibited cholesterol efflux from macrophages by reducing ATP-binding cassette transporter A1 (ABCA1) expression, which is involved in lipid metabolism, suggesting that MK is an important positive factor involved in inflammation, oxidative stress and lipid metabolism. Furthermore, MK can regulate the expansion, differentiation and activation of T cells as well as B-cell survival; mediate angiogenic and antibacterial activity; and possess anti-apoptotic activity. In this paper, we summarize the pathophysiological roles of MK in human disease.