Netrin as a Novel Biomarker and Its Therapeutic Implications in Diabetes Mellitus and Diabetes-Associated Complications
Table 3
The levels of Netrin in cardiovascular (CV) disorders.
CV disorders
Model, method, and interventions
Main findings
References
Coronary artery disease (CAD) and atherosclerosis
A cross-sectional study was conducted in eighteen patients with CAD who underwent elective CABG were included as a test group while fourteen patients who underwent valvular surgery were included as the control group.
Macrophage infiltration was increased in EAT of CAD patients.
The animals received a high cholesterol diet (HCD).
It also showed significantly diminished aortic structural changes associated with atherosclerosis.
Human (h) Netrin-1 (cDNA by adeno-associated virus type 8) was administered to test animals and compared with controls of neomycin resistance (Neo) gene delivery/HCD.
hNetrin-1 delivery was also associated with lower inflammation as compared to the control group.
Hypertension
The DOCA-salt induced hypertension and STZ-induced diabetes in male Sprague-Dawley rats and male c57bl/6 mice were used. After induction of hypertension with administration of DOCA. Blood pressures were measured weekly using the tail-cuff method.
DOCA rats gained less weight and displayed hyperphagia, polydipsia, and polyuria
After 4 weeks of DOCA and after 10 weeks of STZ, rats were anesthetized and a terminal blood sample was collected from the abdominal aorta and level of Netrin-1 was assessed.
The expression of Netrin-1 was substantially elevated in hypertensive rats.
Induction of Netrin-1 protein was localized in renal proximal tubular epithelial cells in both diabetic and hypertensive models.
Increased albumin excretion in urine was seen in both diabetic and hypertensive rats.
Case control study was conducted in 72 women, of which 44 patients were with preeclampsia (PE) and the rest were normal pregnant mothers as a control.
Mean serum Netrin-1 level was remarkably higher in the study group compared to the control group.
The PE group was divided into two subgroups as mild PE () and severe ().
Despite not being statistically significant, serum Netrin-1 expressions were found to be higher in the subgroup of severe than mild PE.
Blood samples were collected from each participant, and a random urine (midstream) sample was collected to assess the serum Netrin levels, and serum Netrin-1 and urinary protein levels were finally evaluated.
It was also noted that pregnant mothers with mild and severe preeclampsia have significant urinary protein excretion than corresponding controls.
Myocardial infraction
Streptozotocin-induced diabetes in male C57BL/6J mice and male Sprague-Dawley rats.
Intramyocardial administration of Netrin-1-MSCs decreased collagen buildup and precludes cardiac hypertrophic remodeling in rats and diabetic mice.
After transplantation, transplanted hearts were assessed using an isolated working heart apparatus after 8 h of ischemia and 24 h of reperfusion. Serum analysis of Netrin-1 and myocardial apoptosis were evaluated by taking tissue samples from cardiac isografts.
Netrin-1 ameliorated myocardial IR injury
Netrin-1 reduced cardiomyocyte apoptosis and leukocyte infiltration.
Netrin-1 generated alternatively activated macrophages through PPARγ activation
Wild-type (WT) C57BL6/J mice were subjected to a 30 min coronary occlusion after adequate anesthesia.
Netrin-1 showed a marked attenuation of ischemia reperfusion- (I/R-) induced myocardial infarction in the tested group.
After a 24 h reperfusion with vehicle (normal saline), Netrin-1, UO126 (MEK1/2 inhibitor), PTIO (nitric oxide/NO scavenger), Netrin-1/UO126, and Netrin-1/PTIO intraventricularly for test and control groups were administered.
Netrin-1 also exhibited to recover cardiac function after ischemia reperfusion.
At the end of each 10 or 30 min of reperfusion, the heart was isolated and the LV was immediately frozen in liquid nitrogen.
This cardioprotective effect of Netrin-1 was found via a DDC-dependent mechanism.
Then various peptides were assessed after taking blood samples using different modalities.
ERK1/2 and NO were required for Netrin-1-mediated cardioprotection activity.
In addition, Netrin-1 exhibited a significant moderation of mitochondrial superoxide production via DCC and ERK1/2.
Netrin-1 besides showed an attenuation of autophagy in post-MI remodeled heart.
Ischemic stroke
Cerebral ischemia was induced in adult male C57BL/6J mice by craniotomy in the left distal middle cerebral artery (dMCA). The carotid arteries were then occluded bilaterally for 20 min and then released.
The level of Netrin-4 was amplified in the ischemic core and colocalized with blood vessels after ischemia.
Exogenous Netrin was infused into the lateral ventricle after induction of ischemia.
Netrin-4 was also expressed in the astrocytic foot processes in the peri-infarct cortex.
Sham-operated mice underwent identical surgery except that the dMCA and the common carotid arteries were not occluded
Intracerebroventricular administration of Netrin-4 was shown to enhance angiogenesis.
After animals were sacrificed, brains were isolated and the tissue corresponding to the ischemic core, peri-infarct cortex, and homologous contralateral cortex was dissected various analysis.
Expression of the putative Netrin-4 receptor DCC, but not UNC5A or UNC5B, was overexpressed in the peri-infarct cortex after induction of stroke.
A prospective study was conducted in 127 patients with ischemic stroke (IS) and 128 normal subjects.
The distribution of genotypes for NTNG1 and rs628117 SNP in both study groups complied.
Among IS patients involved, 28 had cardioembolic stroke, and 99 had large-vessel atherothromboembolic stroke.
The finding showed that rs628117∗G minor allele frequency was markedly higher in patients compared to controls.
Blood and DNA samples were taken and analyzed for the expression of Netrin G1 gene (NTNG1) and rs628117 single-nucleotide polymorphism (SNP).
The carrier of this allele was overexpressed significantly in patients than corresponding controls (83 vs. 62%). The variation in the carriage of the NTNG1 rs628117∗G allele between the patients and controls extended to 98%.
Thus, from this study, it is noted that NTNG1 rs628117 SNP might be a possible risk factor for IS.
Renovascular hypertension was induced in male Sprague-Dawley rats by bilateral renal artery clipping, and 96 rats with stable HTN were chosen.
UNC5H2 expression was substantially overexpressed in NeuN-positive neurons in the ipsilateral VPN after MCAO.
Systolic blood pressure was measured at baseline and weekly.
Exogenous Netrin-1 treatment showed significant improvement of neurological function after MCAO.
Focal infarction was induced in the right dorsolateral cerebral cortex by electrocoagulation of the distal middle cerebral artery (MCA) and right MCA to produce MCA occlusion (MCAO).
Exogenous Netrin-1 administration also displayed a remarkable increment and decrement of the number of neurons and apoptosis, respectively.
Rats with developed permanent MCAO were randomly picked to receive continuous intracerebroventricular infusions of either Netrin-1 or control.
Neurologic evaluation of cell phenotypes Netrin-1, DCC, or UNC5H2 was conducted.
CHF (cardiac hypertrophy)
Pressure overload models (thoracic transverse aortic constriction (TAC)) and culture of neonatal rat cardiomyocytes were performed in wild-type C57BL/6J mice and male Sprague-Dawley neonatal rat pups.
Expression of Netrin-1 reduced in murine hearts following TAC.
Test groups receive recombinant Netrin while the control received vehicles.
Netrin-1 exhibited marked suppression of the cardiac fetal gene expression.
Mice’s in the TAC and sham groups were then sacrificed and their hearts quickly excised, and mRNA levels of Netrin protein and other markers were analyzed.
Netrin-1 was also shown to attenuate the development of cardiac hypertrophy and heart failure.
Besides, Netrin-1 impeded the pressure overload mediated via MEK-ERK1/2 and JNK1/2 signaling pathways.
