Tissue-Specific Localization NUCB2/nesfatin-1 in the Liver and Heart of Mouse Fetus

Nesfatin-1 and nesfatin-1-like peptide attenuate hepatocyte lipid accumulation and nucleobindin-1 disruption modulates lipid metabolic pathways

Nesfatin-1 (NESF-1) has been shown to modulate lipid metabolism. We have identified a nesfatin-1-like-peptide (NLP) processed from a related precursor nucleobindin 1 (NUCB1). Here we determined if NLP, like NESF-1, regulates lipid accumulation in vitro, and tested if the disruption of nucb1 gene affects hepatic lipid metabolism genes in mice. Hepatocytes (HepG2/C3A cells) express NLP and NESF-1 and both peptides significantly reduced lipogenic enzyme mRNAs and enhanced beta-oxidation enzyme mRNAs. Lipid contents in oleic acid induced HepG2/C3A cells were attenuated by NESF-1 and NLP. The inhibitory effect on cellular lipid content was blocked by compound C, an inhibitor of AMPK. The disruption of nucb1 gene affected lipid metabolism-related enzyme mRNAs, endogenous nucb2 mRNA and AMPK phosphorylation. The lipid-lowering effects identified here highlights the potential of nucleobindins and peptides processed from them to address lipid disorders, and its possible benefits in metabolic disease management.

Enteroendocrine cells and gut hormones as potential targets in the crossroad of the gut-kidney axis communication

Recent studies suggest that disruptions in intestinal homeostasis, such as changes in gut microbiota composition, infection, and inflammatory-related gut diseases, can be associated with kidney diseases. For instance, genomic investigations highlight how susceptibility genes linked to IgA nephropathy are also correlated with the risk of inflammatory bowel disease. Conversely, investigations demonstrate that the use of short-chain fatty acids, produced through fermentation by intestinal bacteria, protects kidney function in models of acute and chronic kidney diseases. Thus, the dialogue between the gut and kidney seems to be crucial in maintaining their proper function, although the factors governing this crosstalk are still emerging as the field evolves. In recent years, a series of studies have highlighted the significance of enteroendocrine cells (EECs) which are part of the secretory lineage of the gut epithelial cells, as important components in gut-kidney crosstalk. EECs are distributed throughout the epithelial layer and release more than 20 hormones in response to microenvironment stimuli. Interestingly, some of these hormones and/or their pathways such as Glucagon-Like Peptide 1 (GLP-1), GLP-2, gastrin, and somatostatin have been shown to exert renoprotective effects. Therefore, the present review explores the role of EECs and their hormones as regulators of gut-kidney crosstalk and their potential impact on kidney diseases. This comprehensive exploration underscores the substantial contribution of EEC hormones in mediating gut-kidney communication and their promising potential for the treatment of kidney diseases.

Nesfatin-1 peptide protects rat renal epithelial cells against high glucose and H2O2 induced injury via inhibition of oxidative stress, apoptosis, and fibrosis

Nesfatin-1 is a potent polypeptide and plays a crucial role in many physiological functions. Nesfatin-1 levels are reported in both the central nervous system and peripheral organs. However, the expression of nesfatin-1 in the renal system under chronic oxidative stress-induced conditions and the direct effect of nesfatin-1 treatment on stress-induced pathological damage are not reported. Thus, the present study aimed to explore the role of nesfatin-1 in vitro in oxidative stress-induced renal epithelial cells. High glucose (HG) and H2O2 combination were used to induce oxidative stress (OS). MTT, crystal violet, and H and E staining were used to measure cell viability, cytotoxicity, and morphology. FACS analysis and confocal microscopy were used to measure OS and apoptosis. RT-PCR was done for gene expression analysis. Decreased nesfatin-1 expression was observed in renal epithelial cells induced with HG and H2O2 compared to an untreated control (0.16; p < 0.0001). Nesfatin-1 co-treatment with HG and H2O2 attenuated ROS, apoptosis, and fibrosis. SOD, Catalase, and Bcl-2 expression decreased (p < 0.0001) and Caspase-3 and TGF-β1 expression increased in HG and H2O2-induced cells compared to control cells (p < 0.0001). Nesfatin-1 co-treatment attenuated these changes induced by HG and H2O2 (p < 0.0001). Nesfatin-1 expression was decreased in renal epithelial cells under stress-induced conditions. Moreover, nesfatin-1 co-treatment under stress-induced conditions protects the renal epithelial cells via inhibition of oxidative stress, apoptotic, and fibrotic signaling pathways.

Nesfatin-1 attenuates injury in a rat model of myocardial infarction by targeting autophagy, inflammation, and apoptosis

Nesfatin-1 plays an important role in the modulation of heart performance. However, it remains unclear how nesfatin-1 contributes to cell survival in acute myocardial infarction (MI). A rat model of MI was established via ligation of left anterior descending coronary artery (LAD) for 30 min and 20 µg/kg concentration of nesfatin-1 was intraperitoneally infused prior to reperfusion. At 24 h after reperfusion, oxidative stress markers, the expression of caspase3, beclin-1, pro-inflammatory cytokines, and the mRNA levels of Bax and Bcl-2 were evaluated. Results showed that nesfatin-1 markedly restored GSH content and SOD activity as well as reduced MDA levels compared to only the MI group (p < .05). Likewise, nesfatin-1 contributed to cell survival by inhibiting autophagy and apoptosis markers such as caspase3 and Bax (p < .05). Collectively, these findings support the idea that nasfatin-1 can be used as a good candidate to treat MI by targeting oxidative stress, apoptosis, and autophagy.

Downregulation of nesfatin-1 expression in acute kidney injury in vivo in wistar rats and in vitro in cultured cells

AIMS

Acute kidney injury (AKI) is a debilitating condition followed by sudden kidney damage or failure within hours or days of its occurrence. AKI is characterized by rapid increase in serum creatinine/BUN and decrease in urine output. Nesfatin-1 is an endogenous peptide reported to possess anorexic, antioxidant and anti-apoptotic properties. Although few clinical studies have shown altered nesfatin-1 levels in hemodialysis patients, however, there are no reports investigating the distribution and expression pattern of nesfatin-1 in AKI.

MATERIALS AND METHODS

Nesfatin-1 expression was determined in different disease induced models of AKI by immunoblotting, immunofluorescence and RT-PCR. Gene markers of oxidative stress and inflammation were determined by RT-PCR. The expression of different markers of AKI was measured by assay kits and RT-PCR analysis.

KEY FINDINGS

There was a significant increase in serum levels of creatinine and BUN in AKI rats followed by significant increase in KIM-1 in the kidneys. Significant decrease in nesfatin-1 expression along with increased expression of IL-1β, TNF-α and decreased expression of SOD and catalase was observed in doxorubicin and cisplatin induced AKI rats. However, SOD and catalase expression were upregulated in glycerol induced AKI rats. Moreover, in vitro treatment of renal NRK-52E epithelial cells with nesfatin-1 reversed the changes induced by doxorubicin.

SIGNIFICANCE

Our study reports for the first time, nesfatin-1 expression is decreased in kidneys of different models of AKI induced rats as well as cultured NRK-52E renal epithelial cells. Further studies are required to understand the possible molecular mechanism and therapeutic potential of nesfatin-1 in acute kidney injury.

NUCB2: roles in physiology and pathology

Nucleobindin2 (NUCB2) is a member of nucleobindin family which was first found in the nucleus of the hypothalamus, and had a relationship in diet and energy homeostasis. Its location in normal tissues such as stomach and islet further confirms that it plays a vital role in the regulation of physiological functions of the body. Besides, NUCB2 participates in tumorigenesis through activating various signal-pathways, more and more studies indicate that NUCB2 might impact tumor progression by promoting or inhibiting proliferation, apoptosis, autophagy, metastasis, and invasion of tumor cells. In this review, we comprehensively stated NUCB2's expression and functions, and introduced the role of NUCB2 in physiology and pathology and its mechanism. What is more, pointed out the potential direction of future research.

Nucleobindin-2 consists of two structural components: The Zn2+-sensitive N-terminal half, consisting of nesfatin-1 and -2, and the Ca2+-sensitive C-terminal half, consisting of nesfatin-3

Nucleobindin-2 (Nucb2) is a protein that has been suggested to play roles in a variety of biological processes. Nucb2 contains two Ca2+/Mg2+-binding EF-hand domains separated by an acidic amino acid residue-rich region and a leucine zipper. All of these domains are located within the C-terminal half of the protein. At the N-terminal half, Nucb2 also possesses a putative Zn2+-binding motif. In our recent studies, we observed that Nucb2 underwent Ca2+-dependent compaction and formed a mosaic-like structure consisting of intertwined disordered and ordered regions at its C-terminal half. The aim of this study was to investigate the impact of two other potential ligands: Mg2+, which possesses chemical properties similar to those of Ca2+, and Zn2+, for which a putative binding motif was identified. In this study, we demonstrated that the binding of Mg2+ led to oligomerization state changes with no significant secondary or tertiary structural alterations of Nucb2. In contrast, Zn2+ binding had a more pronounced effect on the structure of Nucb2, leading to the local destabilization of its N-terminal half while also inducing changes within its C-terminal half. These structural rearrangements resulted in the oligomerization and/or aggregation of Nucb2 molecules. Taken together, the results of our previous and current research help to elucidate the structure of the Nucb2, which can be divided into two parts: the Zn2+-sensitive N-terminal half (consisting of nesfatin-1 and -2) and the Ca2+-sensitive C-terminal half (consisting of nesfatin-3). These results may also help to open a new discussion regarding the diverse roles that metal cations play in regulating the structure of Nucb2 and the various physiological functions of this protein.

Reversal of Increase in Intestinal Permeability by Mangifera indica Seed Kernel Extract in High-Fat Diet-Induced Obese Mice

Obesity and hyper-intestinal permeability are interconnected. This study is designed to evaluate the ability of Mangifera indica seed kernel extract (MESK) in restoring the intestinal barrier and preventing obesity and associated metabolic complications in a high-fat diet-induced obese mouse model. Four groups of Swiss albino mice: (1) normal diet (ND), (2) high-fat diet (HFD), (3) HFD + Orlistat (100 µg/kg), and (4) HFD + MESK (75 µg/kg), were used to monitor various biochemical parameters associated with metabolic syndrome (glucose, total cholesterol, triglycerides) and body weight in an eight-week-long study. In vivo intestinal permeability was determined by the FITC-dextran method. Interestingly, MESK significantly reduced HFD-induced body weight gain, hepatic lipid accumulation, hepatic fibrosis, hyperglycemia, and dyslipidemia. Additionally, MESK treatment restored the expression of tight junction protein Zonula Occludens-1 (ZO-1) and Claudin-1 and hence prevented increased intestinal permeability induced by a high-fat diet. Moreover, it also increased the expression of potent satiety molecule Nesfatin-1 in the mouse jejunum. Our results, for the first time, establish MESK as a nutraceutical which prevents disruption of the intestinal barrier and thereby intercepts the adverse consequences of compromised intestinal permeability such as obesity, hyperglycemia, dyslipidemia, and systemic inflammation.

NUCB2/nesfatin-1 - Inhibitory effects on food intake, body weight and metabolism

Since its discovery in 2006 by Oh-I and colleagues, NUCB2/nesfatin-1 encoded by nucleobindin-2 (NUCB2) has drawn sustained attention as reflected in over 500 publications. Among those, more than half focused on the alterations of food intake, body weight and metabolism (glucose, fat) induced by nesfatin-1 and/or NUCB2/nesfatin-1. In the current review we discuss the existing literature focusing on NUCB2/nesfatin-1's influence on food intake, body weight and glucose as well as fat metabolism and highlight gaps in knowledge.

Nesfatin-1 in cardiovascular orchestration: From bench to bedside

Since the discovery of Nesfatin-1 in 2006, intensive research was finalized to further and deeper investigate the precise physiological functions of the peptide at both central and peripheral levels, rapidly enriching the knowledge regarding this intriguing molecule. Nesfatin-1 is a hypothalamic peptide generated via the post-translational processing of its precursor Nucleobindin 2, a protein supposed to play a role in many biological processes thanks to its ability to bind calcium and to interact with different intracellular proteins. Nesfatin-1 is mainly known for its anorexic properties, but it also controls water intake and glucose homeostasis. Recent experimental evidences describe the peptide as a possible direct/indirect orchestrator of central and peripheral cardiovascular control. A specific Nesfatin-1 receptor still remains to be identified although numerous studies suggest that the peptide activates extra- and intracellular regulatory pathways by involving several putative binding sites. The present paper was designed to systematically review the latest findings about Nesfatin-1, focusing on its cardiovascular regulatory properties under normal and physiopathological conditions. The hope is to provide the conceptual basis to consider Nesfatin-1 not only as a pleiotropic neuroendocrine molecule, but also as a homeostatic modulator of the cardiovascular function and with a crucial role in cardiovascular diseases.

Single Nucleotide Polymorphisms of NUCB2 and their Genetic Associations with Milk Production Traits in Dairy Cows

We previously used the RNA sequencing technique to detect the hepatic transcriptome of Chinese Holstein cows among the dry period, early lactation, and peak of lactation, and implied that the nucleobindin 2 (NUCB2) gene might be associated with milk production traits due to its expression being significantly increased in early lactation or peak of lactation as compared to dry period (q value < 0.05). Hence, in this study, we detected the single nucleotide polymorphisms (SNPs) of NUCB2 and analyzed their genetic associations with milk yield, fat yield, fat percentage, protein yield, and protein percentage. We re-sequenced the entire coding and 2000 bp of 5′ and 3′ flanking regions of NUCB2 by pooled sequencing, and identified ten SNPs, including one in 5′ flanking region, two in 3′ untranslated region (UTR), and seven in 3′ flanking region. The single-SNP association analysis results showed that the ten SNPs were significantly associated with milk yield, fat yield, fat percentage, protein yield, or protein percentage in the first or second lactation (p values <= 1 × 10⁻⁴ and 0.05). In addition, we estimated the linkage disequilibrium (LD) of the ten SNPs by Haploview 4.2, and found that the SNPs were highly linked in one haplotype block (D′ = 0.98–1.00), and the block was also significantly associated with at least one milk traits in the two lactations (p values: 0.0002–0.047). Further, we predicted the changes of transcription factor binding sites (TFBSs) that are caused by the SNPs in the 5′ flanking region of NUCB2, and considered that g.35735477C>T might affect the expression of NUCB2 by changing the TFBSs for ETS transcription factor 3 (ELF3), caudal type homeobox 2 (CDX2), mammalian C-type LTR TATA box (VTATA), nuclear factor of activated T-cells (NFAT), and v-ets erythroblastosis virus E26 oncogene homolog (ERG) (matrix similarity threshold, MST > 0.85). However, the further study should be performed to verify the regulatory mechanisms of NUCB2 and its polymorphisms on milk traits. Our findings first revealed the genetic effects of NUCB2 on the milk traits in dairy cows, and suggested that the significant SNPs could be used in genomic selection to improve the accuracy of selection for dairy cattle breeding.