Prokineticin 2 as a potential biomarker for the diagnosis of Kawasaki disease

Possible therapeutic effects of PROK2 in testicular ischemia/reperfusion injury: A preclinical study in Wistar albino rats

This study aimed to investigate the therapeutic effects of PROK2 on oxidative stress, inflammatory response, and tissue damage caused by ischaemia/reperfusion (I/R) in testicular tissue. A total of 48 prepubertal male Wistar albino rats were divided into four groups: sham, testicular torsion/detorsion (TTD), testicular torsion + PROK2 + detorsion (TT + PROK2 + TD), and testicular torsion/detorsion + PROK2 (TTD + PROK2) (n = 12). Testicular torsion/detorsion surgeries (2 hours of torsion followed by 24 hours of detorsion) were performed on all groups except the sham group. The TT + PROK2 + TD group received a single dose of PROK2 (60 nmol/kg) intraperitoneally 30 minutes before the end of torsion, while the TTD + PROK2 group received a single dose of PROK2 (60 nmol/kg) at the beginning of detorsion. Subsequently, biochemical parameters (serum testosterone level, total antioxidant capacity (TAS), total oxidant capacity (TOS), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) levels in testicular tissue), as well as histopathological and immunohistochemical changes, were evaluated. In TTD, a significant decrease was observed in testosterone and TAS levels, while there was an increase in TOS, TNF-α, and IL-6 levels. PROK2 treatment reduced inflammatory parameters and enhanced antioxidant parameters and testosterone levels. Additionally, a low Johnsen's score and spermatogonia count in the TTD group improved with PROK2 treatment. We concluded that PROK2, by exhibiting antioxidative and anti-inflammatory properties, may have a therapeutic effect on I/R-induced tissue damage in testicular tissue.

The association of serum CHI3L1 levels with the presence of Kawasaki disease

Chitinase 3-like protein 1(CHI3L1) has been found to be a biomarker for inflammatory diseases, but the diagnostic value of Kawasaki disease (KD) is not investigated. A total of 180 subjects, including 80 KD patients, 70 febrile controls and 30 healthy controls were recruited. Serum of CHI3L1 were measured with an enzyme-linked immunosorbent assay. The correlation between CHI3L1 and clinical parameters was assessed by Spearman correlation coefficient. Multiple logistic regression was employed to investigate the association between CHI3L1 and the incidence of KD. The diagnostic power was evaluated with the receiver operating characteristic curve analysis. Serum CHI3L1 levels in the KD group were significantly higher than those in the fever control group and healthy group. Compared with fever patients, both patients with incomplete KD and complete KD had higher serum CHI3L1 levels. Serum CHI3L1 levels were positively associated with white blood cell counts, neutrophils, platelet, erythrocyte sedimentation rate, C-reactive protein, alanine aminotransferase and the incidence of KD, and negatively associated with hemoglobin, aspartate aminotransferase and albumin. High CHI3L1 tertiles was significantly associated with the high incidence of KD in the unadjusted or adjusted models. Analysis of the Receiver operating characteristic curves, it was showed that the area under the curve was 0.908, with sensitivity of 0.838 and specificity of 0.8 for continuous CHI3L1, and was 0.884 for categorical CHI3L1, with sensitivity of 0.938 and specificity of 0.643 to distinguish all types of KD, respectively. CHI3L1 had the AUC of 0.901, with sensitivity of 0.826 and specificity of 0.8, and had the area under curve of 0.952, with sensitivity of 0.818 and specificity of 0.971 to discriminate complete KD and incomplete KD from febrile diseases, respectively. Serum of CHI3L1 may be a novel and reliable biomarker for the diagnosis of KD.

Clinical value of prokineticin 2 in the diagnosis of neonatal necrotizing enterocolitis

BACKGROUND

Necrotizing enterocolitis (NEC) is an inflammatory and necrotizing intestinal emergency that occurs in preterm infants and low birth weight newborns; however, no specific serum biomarkers for the diagnosis of NEC has been identified so far.

METHODS

Serum samples were collected from healthy neonatal controls and patients with NEC newly admitted to the Children's Hospital of Chongqing Medical University. ELISA was used to measure serum PK2 levels, and ROC curve analysis was sued to evaluate the diagnostic efficacy of PK2 and other clinical biomarkers.

RESULTS

Serum PK2 levels in the NEC group (n = 53) were significantly lower than those in the control group (n = 18), but increased to near-normal levels after the postoperative recovery period. The NLR value of NEC group was higher than that of control group (P < 0.05). There was no significant difference in WBC and PLT count between NEC group and control group (P > 0.05). Serum CRP and PCT levels in NEC group were significantly higher than those in control group (P < 0.001 for CRP and P < 0.05 for PCT, respectively). After surgery, serum CRP, NLR and PCT levels were lower than before surgery, while serum PK2 levels were higher than before surgery (P < 0.05). The areas under the ROC curve (AUC) of PK2, PCT and CRP for the diagnosis of NEC were 0.837, 0.662 and 0.552, respectively. The AUC of PK2 combined with PCT, PK2 combined with CRP, and PK2 combined with PCT and CRP were 0.908, 0.854 and 0.981, respectively. PK2 exhibited the highest diagnostic efficacy for NEC.

CONCLUSION

PK2 has higher diagnostic efficacy than PCT and CRP in the diagnosis of NEC; the combination of PK2 and PCT or CRP can significantly improve its diagnostic efficiency, especially when the three are combined at the same time.

Prokineticin 2 is a catabolic regulator of osteoarthritic cartilage destruction in mouse

BACKGROUND

Our preliminary study indicates that the multi-functional protein, prokineticin 2 (Prok2), is upregulated in osteoarthritic (OA) chondrocytes as a target of the hypoxia-inducible factor (HIF)-2α. This study aims to elucidate the potential roles of Prok2 in OA.

METHODS

Prok2 expression was assessed through microarray analysis in chondrocytes and confirmed via immunostaining in OA cartilage. Experimental OA was induced through destabilization of the medial meniscus (DMM). Functions of Prok2 were assessed by adenoviral overexpression, intra-articular (IA) injection of recombinant Prok2 (rProk2), and knockdown of Prok2 in joint tissues. We also explored the potential utility of Prok2 as an OA biomarker using enzyme-linked immunosorbent assay (ELISA).

RESULTS

HIF-2α upregulated Prok2, one of the prokineticin signaling components, in OA chondrocytes of mice and humans. Adenoviral overexpression of Prok2 in chondrocytes and cartilage explants, as well as the application of rProk2, led to an upregulation of matrix metalloproteinase (MMP)3 and MMP13. Consistently, the overexpression of Prok2 in joint tissues or IA injection of rProk2 exacerbated cartilage destruction and hindpaw mechanical allodynia induced by DMM. However, the knockdown of Prok2 in joint tissues did not significantly affect DMM-induced cartilage destruction. Additionally, despite being a secreted protein, the serum levels of Prok2 in OA mice and human OA patients were found to be below the range detected by ELISA.

CONCLUSION

The upregulation of Prok2 exacerbates OA cartilage destruction and hindpaw mechanical allodynia. However, its knockdown is not sufficient to inhibit experimental OA and Prok2 is not a potential candidate serum biomarker of OA.