Review Article

Alterations in Immune-Related Defensin Alpha 4 (DEFA4) Gene Expression in Health and Disease

Table 2

A list of studies reporting DEFA4 gene expression changes in nervous system-related diseases.

ReferencesDiseasesStudy aimResearch contribution

[77]Schizophrenia (SZ)Gene expression profiles of PBMCs samples were analyzed from 114 SZ and schizoaffective disorder patients versus 80 healthy controls.DEFA4 was found to be one of the 59 genes that were significantly up-regulated in SZ patients and schizoaffective disorder patients versus controls.
Moreover, a significant correlation was revealed between DEFA4 expression and gender; DEFA4 expression was therein higher in males than females.

[78]Bipolar disorder (BD) and schizophrenia (SZ)The proteomics analysis was conducted on saliva samples from 32 SZ patients, 17 patients with BD compared to 31 healthy controls.DEFA4 has been reported as one of the eight proteins that showed elevated levels in SZ and BD patients compared with healthy subjects.

[80]Post-traumatic stress disorder (PTSD)Transcriptome profiles of blood samples from PTSD patients with high IL-6 levels (n = 16) and PTSD patients with normal IL-6 levels (n = 16) were compared with age-matched normal controls (n = 16) (all participants were women).-DEFA4 was observed to be up-regulated in PTSD patients who have elevated levels of IL-6 compared with those who have normal levels of IL-6.
A significant positive correlation was reported between DEFA4 expression and serum IL-6 levels.

[81]Alzheimer’s disease (AD) and mild cognitive impairment (MCI)Gene expression analysis was conducted on blood samples of 200 subjects with a diagnosis of early AD, 400 individuals with MCI, and nearly 200 cognitively normal individuals as the control group.DEFA4 was one of 50 genes that have shown the most significant differences between AD and MCI compared to the control group, wherein DEFA4 was up-regulated in both AD and MCI versus controls.

[82]Parkinson’s disease (PD)To determine the genes involved in PD pathogenesis (both genetic PD or idiopathic PD) next-generation sequencing (RNA-seq) was conducted on blood samples of:
(i) 20 PD patients with the G2019S mutation of the LRRK2 gene.
(ii) 20 asymptomatic carriers of the mutation
(iii) 20 subjects with idiopathic PD
(iv) 20 controls
DEFA4 was one of the 13 common genes that were identified to have significant differential gene expression in G2019S-associated PD and idiopathic PD, wherein DEFA4 was up-regulated in both:
(i) (G2019S-associated PD compared with asymptomatic carriers)
(ii) (between idiopathic PD compared with controls).

[83]Parkinson’s disease (PD)To elucidate the molecular basis underlying PD, transcriptomic analyses were performed on blood samples of 72 PD patients compared to 22 healthy controls.DEFA4 was reported as one of the top 20 aberrantly expressed genes in PD patients, DEFA4 down-regulation was found in PD patients compared to healthy controls.

[92]Multiple sclerosis (MS)Gene expression analysis was conducted on blood samples from patients with MS in remission, relapsing and healthy controls, aiming to understand the molecular mechanisms underlying MS.DEFA4 was one of the genes that up-regulated in females with MS in remission status compared with their controls.

[94]Multiple sclerosis (MS)The study aims to analyze the post-mortem of normal-appearing white matter (NAWM) of MS patients to identify the possible gene expression pathways that affect the disease heterogeneity and HPA axis activity.DEFA4 was one of the top ten genes that strongly connected to the module with a strong positive correlation to both severity of MS and HPA axis activity

[93]Multiple sclerosis (MS)This study aimed to identify the differentially expressed genes in CD4+ T lymphocytes of relapsing-remitting MS patients during relapse after 3–6 days of treatment with IVMP in vivo.11 genes were found to be the most significantly differentially expressed in CD4+ T lymphocytes of patients after treatment with IVMP. DEFA4 was one of seven genes that were highly up-regulated.