SLC39A6/ZIP6 is essential for zinc homeostasis and T-cell development in zebrafish

Cysteine-rich zinc finger proteins and the nuclear factor kappa-B pathway

Inflammation-related disorders, such as autoimmune diseases and cancer, impose a significant global health burden. Zinc finger proteins (ZFs) are ubiquitous metalloproteins which regulate inflammation and many biological signaling pathways related to growth, development, and immune function. Numerous ZFs are involved in the nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB) pathway, associating them with inflammation-related diseases that feature chronically elevated pro-inflammatory cytokines. This review highlights the predominance of ZFs in NFκB-related signaling and summarizes the breadth of functions that these proteins perform. The cysteine-specific post-translational modification (PTM) of persulfidation is also discussed in the context of these cysteine-rich ZFs, including what is known from the few available reports on the functional implications of ZF persulfidation. Persulfidation, mediated by endogenously produced hydrogen sulfide (H2S), has a recently established role in signaling inflammation. This work will summarize the known connections between ZFs and persulfidation and has the potential to inform on the development of related therapies.

ZIP transporters-regulated Zn2+ homeostasis: A novel determinant of human diseases

As an essential trace element for organisms, zinc participates in various physiological processes, such as RNA transcription, DNA replication, cell proliferation, and cell differentiation. The destruction of zinc homeostasis is associated with various diseases. Zinc homeostasis is controlled by the cooperative action of zinc transporter proteins that are responsible for the influx and efflux of zinc. Zinc transporter proteins are mainly categorized into two families: Zrt/Irt-like protein (SLC39A/ZIP) family and zinc transporter (SLC30A/ZNT) family. ZIP transporters contain 14 members, namely ZIP1-14, which can be further divided into four subfamilies. Currently, ZIP transporters-regulated zinc homeostasis is one of the research hotspots. Cumulative evidence suggests that ZIP transporters-regulated zinc homeostasis may cause physiological dysfunction and contribute to the onset and progression of diverse diseases, such as cancers, neurological diseases, and cardiovascular diseases. In this review, we initially discuss the structure and distribution of ZIP transporters. Furthermore, we comprehensively review the latest research progress of ZIP transporters-regulated zinc homeostasis in diseases, providing a new perspective into new therapeutic targets for treating related diseases.

From zinc homeostasis to disease progression: Unveiling the neurodegenerative puzzle

Zinc is a crucial trace element in the human body, playing a role in various physiological processes such as oxidative stress, neurotransmission, protein synthesis, and DNA repair. The zinc transporters (ZnTs) family members are responsible for exporting intracellular zinc, while Zrt- and Irt-like proteins (ZIPs) are involved in importing extracellular zinc. These processes are essential for maintaining cellular zinc homeostasis. Imbalances in zinc metabolism have been linked to the development of neurodegenerative diseases. Disruptions in zinc levels can impact the survival and activity of neurons, thereby contributing to the progression of neurodegenerative diseases through mechanisms like cell apoptosis regulation, protein phase separation, ferroptosis, oxidative stress, and neuroinflammation. Therefore, conducting a systematic review of the regulatory network of zinc and investigating the relationship between zinc dysmetabolism and neurodegenerative diseases can enhance our understanding of the pathogenesis of these diseases. Additionally, it may offer new insights and approaches for the treatment of neurodegenerative diseases.

Transcriptional Regulation and Protein Localization of Zip10, Zip13 and Zip14 Transporters of Freshwater Teleost Yellow Catfish Pelteobagrus fulvidraco Following Zn Exposure in a Heterologous HEK293T Model

Zip family proteins are involved in the control of zinc (Zn) ion homeostasis. The present study cloned the promoters and investigated the transcription responses and protein subcellular localizations of three LIV-1 subfamily members (zip10, zip13, and zip14) from common freshwater teleost yellow catfish, Pelteobagrus fulvidraco, using in vitro cultured HEK293T model cells. The 2278 bp, 1917 bp, and 1989 bp sequences of zip10, zip13, and zip14 promoters, respectively, were subcloned into pGL3-Basic plasmid for promoter activity analysis. The pcDNA3.1 plasmid coding EGFP tagged pfZip10, pfZip13, and pfZip14 were generated for subsequent confocal microscope analysis. Several potential transcription factors' binding sites were predicted within the promoters. In vitro promoter analysis in the HEK293T cells showed that high Zn administration significantly reduced the transcriptional activities of the zip10, zip13, and zip14 promoters. The -2017 bp/-2004 bp MRE in the zip10 promoter, the -360 bp/-345 bp MRE in the zip13 promoter, and the -1457 bp/-1442 bp MRE in the zip14 promoter were functional loci that were involved in the regulation of the three zips. The -606 bp/-594 bp KLF4 binding site in the zip13 promoter was a functional locus responsible for zinc-responsive regulation of zip13. The -1383 bp/-1375 bp STAT3 binding site in the zip14 promoter was a functional locus responsible for zinc-responsive regulation of zip14. Moreover, confocal microscope analysis indicated that zinc incubation significantly reduced the fluorescence intensity of pfZip10-EGFP and pfZip14-EGFP but had no significant influence on pfZip13-EGFP fluorescence intensity. Further investigation found that pfZip10 localizes on cell membranes, pfZip14 colocalized with both cell membranes and lysosome, and pfZip13 colocalized with intracellular ER and Golgi. Our research illustrated the transcription regulation of zip10, zip13, and zip14 from P. fulvidraco under zinc administration, which provided a reference value for the mechanisms involved in Zip-family-mediated control of zinc homeostasis in vertebrates.

Impact of Zinc Transport Mechanisms on Embryonic and Brain Development

The trace element zinc (Zn) binds to over ten percent of proteins in eukaryotic cells. Zn flexible chemistry allows it to regulate the activity of hundreds of enzymes and influence scores of metabolic processes in cells throughout the body. Deficiency of Zn in humans has a profound effect on development and in adults later in life, particularly in the brain, where Zn deficiency is linked to several neurological disorders. In this review, we will summarize the importance of Zn during development through a description of the outcomes of both genetic and early dietary Zn deficiency, focusing on the pathological consequences on the whole body and brain. The epidemiology and the symptomology of Zn deficiency in humans will be described, including the most studied inherited Zn deficiency disease, Acrodermatitis enteropathica. In addition, we will give an overview of the different forms and animal models of Zn deficiency, as well as the 24 Zn transporters, distributed into two families: the ZIPs and the ZnTs, which control the balance of Zn throughout the body. Lastly, we will describe the TRPM7 ion channel, which was recently shown to contribute to intestinal Zn absorption and has its own significant impact on early embryonic development.

Hatching gland development and hatching in zebrafish embryos: A role for zinc and its transporters Zip10 and Znt1a

Zinc transporters of the ZIP (Slc39, importers) and ZnT (Slc30, exporters) protein families have evolutionary conserved roles in biology. The aim of the present study was to explore the role of zinc, and zinc transporters Zip10 and Znt1a in zebrafish hatching gland development and larval hatching. In the study, knockdown of genes for Zip10 and Znt1a in zebrafish embryos was achieved using morpholino-modified oligonucleotides. A partial loss-of-function Znt1a mutant (Znt1a^sa17) allowed comparison with the Znt1a morphant. Free Zn²⁺ in embryos and apoptosis were investigated using fluorescent dyes whereas gene expression was investigated by whole-mount in situ hybridization (WISH). The results showed high levels of free Zn²⁺ in the hatching gland cells (HGC) along with abundant expression of zip10 and znt1a in normal embryo. Knockdown of zip10 reduced free Zn²⁺ in HGC, ceased their normal developmental apoptosis, and resulted in displacement and later disappearance of hatching glands and hatching enzymes he1a and catL1b, and inability to hatch. Conversely, knockdown of znt1a or the Znt1a^sa17 mutation accelerated hatching and coincided with high expression of hatching enzymes and free Zn²⁺ in the HGC. Thus, Zip10 and free Zn²⁺ in the HGC are required both for their development and function. This study also demonstrated the opposite functions of the two zinc transporters, ZIP10 and ZnT1 as well as shedding light on the role of Zn²⁺ in regulation of the human hatching enzyme homologue, ovastacin, which is activated by zinc and cleaves the zona pellucida protein, ZP2, to prevent polyspermy.