Genetic Variations of the KISS1R Gene in Korean Girls with Central Precocious Puberty

The timing of puberty onset varies greatly among individuals, and much of this variation is modulated by genetic factors. This study aimed to identify the kisspeptin receptor (KISS1R) gene variations and to investigate the associations between these variations and central precocious puberty (CPP). Korean girls with CPP (n = 194) and their healthy controls (n = 99) were included in this study. The entire coding region and the exon-intron boundaries (exon 1 through 5) of the KISS1R gene were directly sequenced. Seven polymorphisms were identified in the KISS1R gene. A missense change c.1091T>A, and an intron variant c.738+64G>T showed significantly higher allele frequencies in CPP patients than in controls (c.1091T>A: 30.7% vs. 22.2%, P = 0.031; c.738+64G>T: 45.6% vs. 35.9%, P = 0.023). The missense variant (c.1091T>A) was a nonsynonymous polymorphism that induces amino acid substitution of p.Leu364His. The haplotype CAGTGTC was detected more frequently in the CPP group (P = 0.042). The sequence variants of the KISS1R gene can be inducible factors in the development of CPP. The association between sequence variants and CPP should be validated by further evidence obtained from larger samples of children with CPP.

Kisspeptin Regulation of Neuronal Activity throughout the Central Nervous System

Kisspeptin signaling at the gonadotropin-releasing hormone (GnRH) neuron is now relatively well characterized and established as being critical for the neural control of fertility. However, kisspeptin fibers and the kisspeptin receptor (KISS1R) are detected throughout the brain suggesting that kisspeptin is involved in regulating the activity of multiple neuronal circuits. We provide here a review of kisspeptin actions on neuronal populations throughout the brain including the magnocellular oxytocin and vasopressin neurons, and cells within the arcuate nucleus, hippocampus, and amygdala. The actions of kisspeptin in these brain regions are compared to its effects upon GnRH neurons. Two major themes arise from this analysis. First, it is apparent that kisspeptin signaling through KISS1R at the GnRH neuron is a unique, extremely potent form or neurotransmission whereas kisspeptin actions through KISS1R in other brain regions exhibit neuromodulatory actions typical of other neuropeptides. Second, it is becoming increasingly likely that kisspeptin acts as a neuromodulator not only through KISS1R but also through other RFamide receptors such as the neuropeptide FF receptors (NPFFRs). We suggest likely locations of kisspeptin signaling through NPFFRs but note that only limited tools are presently available for examining kisspeptin cross-signaling within the RFamide family of neuropeptides.

Correlation of KiSS-1, KiSS-1R and MMP-9 expression to invasion and metastasis of hepatocellular carcinoma and its significance / 中华肝胆外科杂志

Objective To detect the expression of KiSS-1, KiSS-1R and MMP-9 in hepatocellular carcinoma (HCC). To study the correlation of KiSS-1, KiSS-1R and MMP-9 expression with invasion and metastasis of HCC, and to explore the underlying mechanisms. Methods The expression of KiSS-1 , KiSS-1R mRNA in 33 HCC samples, 26 non-neoplastic adjacent liver tissue samples and 13 non-neoplastic distant liver tissue samples were detected by RT-PCR. Tissue chips were constructed by modified manual tools, which contained HCC, non-neoplastic adjacent liver tissues, non-neoplastic distant liver tissues, normal liver tissues and intrahepatic metastasis lesions. The expression of KiSS-1 and MMP-9 protein was determined by tissue chips, immunohistochemistry and semi-quantitative image analysis in 150 HCC, 137 non-neoplastic adjacent liver tissue, 98 non-neoplastic distant liver tissues, 16 normal liver tissues and 37 intrahepatic metastasis lesion samples. Results The results of RT-PCR showed that compared with the non-neoplastic adjacent liver tissues and the non-neoplastic distant liver tissues, the expression of KiSS-1 mRNA in HCC was significantly lower (P＜0.01). The expression of KiSS-1R mRNA did not changed in HCC and non-neoplastic liver tissues (P＞0.05). The expression of KiSS-1 protein was lower in HCC with metastasis and in clinical stage Ⅲ than that in those with non-metastasis, and in clinical stages Ⅰ and Ⅱ . It was also higher in the primary than in the metastasis lesions (P＜0.01, respectively). The expression of MMP-9 was higher in tumors having peplos invasion and metastasis than in those with negative peplos invasion and non-metastasis. It was lower in the primary than the metastasis lesions (P＜0. 01, respectively).Negative correlation between KiSS-1 and MMP-9 expression was found in HCC(r=- 0.340,P＜0.01). Conclusions The imbalance between KiSS-1 and MMP-9 expression might play an important role in enhancing the invasive and metastatic capacity of HCC. Loss of KiSS-1 expression might predict an aggressive clinical behavior and was associated with metastatic potential in HCC.