Metallothionein Expression Research Articles

Real-Time Fluorescence Visualization of the Dynamic Distribution of Zn2+ Ions during Osteoblast Differentiation.

The differentiation and maturation of osteoblasts are essential for bone formation. Zn2+ plays a crucial role in cell differentiation and is involved in osteogenic differentiation. The concentration and distribution of Zn2+ in the nucleus and cytoplasm indicate the differentiation states of osteoblasts. However, there is an absence of a real-time method for monitoring the dynamic fluctuations of endogenous Zn2+ within the nucleus. Here, a novel Zn2+ fluorescent probe (NTAD-N1) with nuclear membrane permeability was designed and developed, allowing for distribution throughout the entire cell, including the nucleus. The NTAD-N1 probe successfully showed the dynamic distribution and concentration changes of Zn2+ in the nucleus and cytoplasm of preosteoblast MC3T3-E1 during the 21-day differentiation period. The results showed that free Zn2+ increased significantly during differentiation of osteoblasts (2-21 days). Importantly, after 4 days of differentiation, osteoblasts are mainly distributed in the nucleus, which is confirmed by metallothionein expression. Subsequently, the level of free Zn2+ in the cytoplasm remained at a high level, which promoted the increase in alkaline phosphatase activity and inhibited the activity of cis-aconitase in the tricarboxylic acid cycle, resulting in the accumulation of citric acid. This series of events promotes the formation of mineralized nodules. In the process of osteoblast differentiation, the detection time of Zn2+ (≤7 days) is ahead of the late marker of alkaline phosphatase (14 days) and mineralized nodules (14-21 days). This indicates that Zn2+ can be used as a biomarker and an intervention point for early differentiation of osteoblasts.

Folic acid ameliorates high glucose–induced neurotoxicity in human forebrain organoids: Insights from proteomics

AbstractPregestational diabetes (PGDM) has been associated with an elevated risk of congenital abnormalities, particularly those affecting the nervous system. The efficacy of folic acid (FA) supplementation in reducing the incidence of neurodevelopmental damage caused by PGDM has been well documented. However, the exact mechanism is unclear. Here, a human forebrain organoid model, which replicates the three‐dimensional structure of the early fetal neural tissue, was employed to study the neuroprotective effects of FA in PGDM. In this study, the forebrain organoids were cultured at high glucose (HG) concentrations from Days 20 to 40 with or without FA. Immunostaining revealed that the supplementation of FA significantly decreased HG‐induced neuron apoptosis. The proteomics examination suggested HG caused an increase in glial fibrillary acidic protein expression, a marker of astrocytes, leading to the upregulation of metallothionein expression and perturbation of mineral absorption, whereas FA reversed this effect. Proteomics analysis further showed that FA reduced HG‐induced cell migration. Moreover, Western blot analysis verified that FA mitigated HG‐induced apoptosis and cell migration via AMPK/FOXO pathway. Overall, current findings indicate that FA, as a functional food ingredient, has a protective effect on HG‐induced abnormal fetal neurodevelopment.

Validation of Metallothionein Immunohistochemistry as a Highly Sensitive Screening Test for Wilson Disease

Wilson’s disease (WD) is a rare autosomal recessive condition with protean clinical manifestations that results from biallelic ATP7B mutations. However, non-destructive tissue tests to be applied clinically to tissue specimens are not widely available to effectively assess patients for possible WD. Previously, we showed that metallothionein (MTH) immunohistochemistry has a high sensitivity and specificity for WD diagnosis and, thus, represents a potentially powerful diagnostic tool that can be used in routine histologic sections. We sought to validate this finding in a large cohort of bona fide WD patients and to correlate metallothionein expression with other histologic features.We identified 91 cases of WD, which included 28 needle biopsies and 64 explants from 14 centers worldwide. Histologic features were evaluated, and a histopathological pattern was assigned to each case. All cases were evaluated with Masson trichrome and MTH immunohistochemistry (clone UC1MT, Abcam) using previously published technique. Liver tissues from chronic cholestatic diseases (n= 42) were used as controls.The median age of the cohort was 28.5 years. Out of 91 total cases, 83 were positive for MTH immunostain. In the controls, all 42 cases were negative for MTH immunostain. The sensitivity and specificity of MTH immunostain for WD were 91.20% and 100%, respectively.MTH immunohistochemistry is a highly sensitive and specific cost-effective screening tool for WD. It can be used for patients across age groups, varied histologic patterns, and fibrosis stages. This marker could prove to be a valuable tool in the evaluation of patients with possible WD.

Immunoexpression of metallothionein, Ki‐67 and PCNA in dermoid and epidermoid cysts of the oral cavity

AbstractObjectiveTo assess the immunoexpression of metallothionein and cell proliferation markers (Ki‐67 and PCNA) in a series of cases comprising four dermoid cysts and six epidermoid cysts of the oral cavity.Materials and MethodsThe percentages of nuclear and/or cytoplasmic staining in the basal and suprabasal layers of the cysts' epithelial lining were assessed.ResultsThis study included six males and four females, with a mean age of 33.1 years. The floor of the mouth was affected in 40% of the cases. The expression of metallothionein, Ki‐67, and PCNA was observed in all cases examined. For both lesions, the basal layer exhibited higher cytoplasmic and nuclear/cytoplasmic expression of metallothionein. Dermoid cysts exhibited higher expression of Ki‐67 and PCNA compared to epidermoid cysts in both basal and suprabasal layers, with a more pronounced expression in the suprabasal layers.ConclusionsOur results indicate that metallothionein is present in the epithelial lining of both dermoid and epidermoid cysts of the oral cavity. The cell proliferation indices observed in both conditions reflect their benign nature and slow growth.

XBP1 Facilitating NF-κB-p65 Nuclear Translocation Promotes Macrophage-Originated Sterile Inflammation Via Regulating MT2 Transcription in the Ischemia/Reperfusion Liver

Background & AimsXBP1, most conserved transcription factor of endoplasmic reticulum (ER) stress, plays important roles in physiological and pathological settings and has profound effects on disease progression and prognosis, so it’s necessary to investigate XBP1 in macrophage-originated sterile inflammation during liver ischemia/reperfusion injury (IRI). Macrophage XBP1 expression and liver injury are analyzed in patients undergoing ischemia-related hepatectomy. MethodsA myeloid-specific male XBP1-knockout (XBP1M-KO) strain is created for function and mechanism of XBP1 on macrophage-derived sterile inflammation in murine liver IRI with in-vitro parallel research. Macrophages co-cultured with hypoxia-treated hepatocytes are applied to investigate impact of XBP1 in vitro, with analysis of RNA sequencing and databases. ResultsClinically, macrophage XBP1 expression significantly increases in ischemic liver tissues and positively correlates with liver injury after hepatectomy. Less hepatocellular damage is presented in XBP1M-KO mice than in XBP1-proficient (XBP1FL/FL) controls. In vitro, XBP1 deficiency inhibits sterile inflammation and migration in macrophages co-cultured with hypoxia-treated hepatocytes. Analysis of RNA sequencing and databases determines Metallothionein 2 (MT2) as XBP1 target gene, negatively regulated by binding with its promoter. XBP1 deficiency increases MT2 and IKBα expression, but inhibits NF-κB-p65 phosphorylation, markedly neutralizing XBP1M-KO-related benefits by promoting sterile inflammation during liver IRI. ConclusionsXBP1 promotes macrophage-originated sterile inflammation, increases liver IRI by binding to MT2 promoter, and regulates MT2/NF-κB pathway, potentially therapeutic for clinical liver IRI.

Evaluating combined effects of chronic, low-dose exposures of cadmium (CLEC) and hyperglycemia on insulin signaling dysfunction in a hepatocellular model

The pathophysiological effects of chronic heavy metal exposures on human health remains uncertain. In this study, we developed a novel chronic, low-dose exposure of Cadmium (CLEC) model using the hepatocellular cell lines, HepG2 and HUH7. We modulated cell culture conditions to mimic human normoglycemic (5.6 mM) and hyperglycemic (15 mM) states with concomitant cadmium (Cd) exposures for 24 weeks. CLEC cells undergo non-trivial alterations in glucose signaling and metabolic characteristics within our model. We observe elevated baseline reactive oxygen species (ROS) production and decreased 2-NBDG uptake indicative of glucose metabolic dysfunction. Additionally, induction of metallothionein (MT) expression, increased activation of Akt signaling (via phosphorylation) and reduced IRS-2 protein expression are observed in CLEC cells. Cell line specific changes are observed with HepG2 showing a much higher MT gene induction compared to HUH7 cell line which impacts glucose metabolic dysfunction. Hyperglycemic culture conditions (representing type II diabetes) significantly modulate CLEC effects on cells. In conclusion, pathophysiologically relevant models of chronic heavy metal exposures are urgently needed to gain an in-depth, mechanistic understanding of the long-term impacts of toxic metals (e.g., Cd) on human metabolic health.

Blocking Metallothionein-2 Expression by Copper-Doped Carbon Dots Induces Cellular Antioxidant System Collapse for Antitumor Therapy.

The insufficient antioxidant reserves in tumor cells play a critical role in reactive oxygen species (ROS)-mediated therapeutics. Metallothionein-2 (MT-2), an intracellular cysteine-rich protein renowned for its potent antioxidant properties, is intricately involved in tumor development and correlates with a poor prognosis. Consequently, MT-2 emerges as a promising target for tumor therapy. Herein, we present the development of copper-doped carbon dots (Cu-CDs) to target MT-2 to compromise the delicate antioxidant reserves in tumor cells. These Cu-CDs with high tumor accumulation and prolonged body retention can effectively suppress tumor growth by inducing oxidative stress. Transcriptome sequencing unveils a significant decrease in MT-2 expression within the in vivo tumor samples. Further mechanical investigations demonstrate that the antitumor effect of Cu-CDs is intricately linked to apolipoprotein E (ApoE)-mediated downregulation of MT-2 expression and the collapse of the antioxidant system. The robust antitumor efficacy of Cu-CDs provides invaluable insights into developing MT-2-targeted nanomedicine for cancer therapies.

Unique expression and critical role of metallothionein 3 in the control of osteoclastogenesis and osteoporosis

Bone homeostasis is maintained by an intricate balance between osteoclasts and osteoblasts, which becomes disturbed in osteoporosis. Metallothioneins (MTs) are major contributors in cellular zinc regulation. However, the role of MTs in bone cell regulation has remained unexplored. Single-cell RNA sequencing analysis discovered that, unlike the expression of other MT members, the expression of MT3 was unique to osteoclasts among various macrophage populations and was highly upregulated during osteoclast differentiation. This unique MT3 upregulation was validated experimentally and supported by ATAC sequencing data analyses. Downregulation of MT3 by gene knockdown or knockout resulted in excessive osteoclastogenesis and exacerbated bone loss in ovariectomy-induced osteoporosis. Transcriptome sequencing of MT3 knockdown osteoclasts and gene set enrichment analysis indicated that the oxidative stress and redox pathways were enriched, which was verified by MT3-dependent regulation of reactive oxygen species (ROS). In addition, MT3 deficiency increased the transcriptional activity of SP1 in a manner dependent on intracellular zinc levels. This MT3-zinc-SP1 axis was crucial for the control of osteoclasts, as zinc chelation and SP1 knockdown abrogated the promotion of SP1 activity and osteoclastogenesis by MT3 deletion. Moreover, SP1 bound to the NFATc1 promoter, and overexpression of an inactive SP1 mutant negated the effects of MT3 deletion on NFATc1 and osteoclastogenesis. In conclusion, MT3 plays a pivotal role in controlling osteoclastogenesis and bone metabolism via dual axes involving ROS and SP1. The present study demonstrated that MT3 elevation is a potential therapeutic strategy for osteolytic bone disorders, and it established for the first time that MT3 is a crucial bone mass regulator.

Enhancing high-efficient cadmium biosorption of Escherichia coli via cell surface displaying metallothionien CUP1

ABSTRACT Cadmium (Cd) is one of the common heavy metal pollutants in soil, which can induce various diseases and pose a serious threat to human health. Metallothioneins (MTs) are well-known for their excellent metal binding ability due to a high content of cysteine, which has great potential for heavy metal chelation. In this study, we used the Escherichia coli (E. coli) surface display system LPP-OmpA to construct a recombinant plasmid pBSD-LCF encoding LPP-OmpA-CUP1-Flag fusion protein. Then we displayed the metallothionein CUP1 from Saccharomyces cerevisiae on E. coli DH5α surface for Cd removing. The feasibility of surface display of metallothionein CUP1 in recombinant E. coli DH5α (pBSD-LCF) by Lpp-OmpA system was proved by flow cytometry and western blot analysis, and the specificity of the fusion protein in the recombinant strain was also verified. The results showed that the Cd2+ resistance capacity of DH5α (pBSD-LCF) was highly enhanced by about 200%. Fourier-transform infrared spectroscopy showed that sulfhydryl and sulfonyl groups were involved in Cd2+ binding to cell surface of DH5α (pBSD-LCF). Meanwhile, Cd removal rate by DH5α (pBSD-LCF) was promoted to 95.2%. Thus, the recombinant strain E. coli DH5α (pBSD-LCF) can effectively chelate environmental metals, and the cell surface expression of metallothionein on E. coli can provide new ideas and directions for heavy metals remediation.

Copper Is Accumulated as Copper Sulfide Particles, and Not Bound to Glutathione, Phytochelatins or Metallothioneins, in the Marine Alga Ulva compressa (Chlorophyta).

To analyze the mechanism of copper accumulation in the marine alga Ulva compressa, it was cultivated with 10 μM of copper, with 10 μM of copper and increasing concentrations of a sulfide donor (NaHS) for 0 to 7 days, and with 10 μM of copper and a concentration of the sulfide acceptor (hypotaurine) for 5 days. The level of intracellular copper was determined as well as the level of glutathione (GSH) and phytochelatins (PCs) and the expression of metallothioneins (UcMTs). The level of intracellular copper in the algae treated with copper increased at day 1, slightly increased until day 5 and remained unchanged until day 7. The level of copper in the algae cultivated with copper and 100 or 200 μM of NaHS continuously increased until day 7 and the copper level was higher in the algae cultivated with 200 μM of NaHS compared to 100 μM of NaHS. In contrast, the level of intracellular copper decreased in the algae treated with copper and hypotaurine. The level of intracellular copper did not correlate with the level of GSH or with the expression of UcMTs, and PCs were not detected in response to copper, or copper and NaHS. Algae treated with copper and with copper and 200 μM of NaHS for 5 days were visualized by TEM and the elemental composition of electrondense particles was analyzed by EDXS. The algae treated with copper showed electrondense particles containing copper and sulfur, but not nitrogen, and they were mainly located in the chloroplast, but also in the cytoplasm. The algae treated with copper and NaHS showed a higher level of electrondense particles containing copper and sulfur, but not nitrogen, and they were located in the chloroplast, and in the cytoplasm. Thus, copper is accumulated as copper sulfide insoluble particles, and not bound to GSH, PCs or UcMTs, in the marine alga U. compressa.

Reprogramming human urine cells into intestinal organoids with long-term expansion ability and barrier function

Generation of intestinal organoids from human somatic cells by reprogramming would enable intestinal regeneration, disease modeling, and drug screening in a personalized pattern. Here, we report a direct reprogramming protocol for the generation of human urine cells induced intestinal organoids (U-iIOs) under a defined medium. U-iIOs expressed multiple intestinal specific genes and showed resembling gene expression profiles to primary small intestines. U-iIOs can be stably long-term expanded and further differentiated into more mature intestinal lineage cells with high expression of metallothionein and cytochrome P450 (CYP450) genes. These specific molecular features of U-iIOs differ from human pluripotent stem cells derived intestinal organoids (P-iIOs) and intestinal immortalized cell lines. Furthermore, U-iIOs exhibit intestinal barriers indicated by blocking FITC-dextran permeation and uptaking of the specific substrate rhodamine 123. Our study provides a novel platform for patient-specific intestinal organoid generation, which may lead to precision treatment of intestinal diseases and facilitate drug discovery.

Integrated assessment of trace elements in a marine ranching area based on multi-species and multi-level biomarkers: a case study in China’s national-level marine ranching demonstration area

The goal of this study was to evaluate the trace element pollution in a marine ranching area in China based on molecular responses (expression of metallothionein and antioxidant enzyme genes), and biochemical biomarkers (metallothionein content, antioxidant enzyme activities, and malonaldehyde level) in four indicator species. We collected samples of two fish (Lateolabrax maculatus and Sebastes schlegelii), one crustacean (Charybdis japonica), and one gastropod (Rapana venosa) from the western Furong Island marine ranching area and from an adjacent area in March 2022 and measured the trace element content in these indicator species as well as in the seawater and sediment. We found that the bioaccumulation characteristics of trace elements and the response patterns of biomarkers were species specific. Moreover, not every biomarker was significantly correlated with environmental trace element content. We then established two biomarker combinations indicative of trace element pollution in seawater and sediment, respectively, based on the correlation between biomarkers and trace element contents. The selected biomarkers were integrated using integrated biomarker response version 2 (IBRv2). IBRv2 values in the studied marine ranching area were lower than those in the adjacent area. Additionally, these values were consistent with the bioaccumulation of trace elements in the indicator species, the integrated trace element pollution index for seawater, and the potential risk index for sediment. These results show that this multi-biomarker and multi-species IBRv2 approach provided a comprehensive diagnosis of trace element pollution in the marine ranching area. Therefore, its application may be beneficial for marine environmental monitoring and management in view of the ecotoxicological impact of pollutants on organisms.

Effects of Perioperative Zinc Supplementation on Copper Circulating Levels and Expression of Metallothionein and Copper Antioxidant Chaperone-1 in Leukocytes in Patients Undergoing CABG Surgery.

The use of zinc supplement may have a negative effect on copper status. The objective of this study was to evaluate the effect of zinc and vitamin E supplementation on copper and zinc biomarkers in patients undergoing coronary artery bypass graft (CABG) surgery. The study was an add-on project to a previously published randomized controlled trial (NCT05402826) on patients undergoing CABG surgery. Patients in the zinc-vitamin E group (n = 40) received oral zinc (120 mg) and vitamin E (1200 international units) 1 day before surgery, followed by 30 mg of zinc and 200 units of vitamin E per day until 21 days after surgery, while those in the control group (n = 38) received placebo. Plasma levels of copper, ceruloplasmin, superoxide dismutase (SOD) activity, as well as leukocyte gene expression of metallothionein 2A (MT2A) and antioxidant protein 1 (ATOX1), were determined 3 and 21 days after surgery. The plasma copper level in the zinc-vitamin E group was significantly lower than the placebo group on the 3rd postoperative day, but no significant between-group differences were observed on day 21. Plasma ceruloplasmin concentration and SOD activity were not different. Relative mRNA expression of leukocyte MT2A was increased at both times (days 3 and 21 in the zinc-vitamin E group compared to placebo, but ATOX1 expression was not affected. Although the plasma copper level was transiently decreased early after surgery in the zinc-vitamin E group, considering the lack of change in other copper biomarkers, it seems that the use of zinc supplements at the dose used in the present study does not have a significant negative effect on the role of intracellular copper.

Leaching and cytotoxicity of bismuth oxide in ProRoot MTA - A laboratory investigation.

The present study examined the leaching and cytotoxicity of bismuth from ProRoot MTA and aimed to identify whether bismuth leaching was affected by the cement base and the immersion regime used. The leaching profile of bismuth was examined from ProRoot MTA and compared with hydroxyapatite containing 20% bismuth oxide as well as hydroxyapatite and tricalcium silicate to investigate whether bismuth release changed depending on the cement base. Bismuth leaching was determined after 30 and 180 days of ageing immersed in Dulbecco's modified Eagle's medium (DMEM) using mass spectroscopy (ICP-MS). The media were either unchanged or regularly replenished. The pH, surface microstructure and phase changes of aged materials were assessed. Wistar rat femoral bone marrow stromal cells (BMSCs) and cutaneous fibroblasts were isolated, cultured and seeded for cell counting (trypan blue live/dead) after exposure to non-aged, 30- and 180-days-aged samples in regularly replenished DMEM. Aged DMEM in contact with materials was also used to culture BMSCs to investigate the effect of material leachates on the cells. Gene expression analysis was also carried out after direct exposure of cells to non-aged materials. Differences between groups were statistically tested at a significance level of 5%. All materials exhibited alterations after immersion in DMEM and this increased with longer exposure times. The bismuth leached from ProRoot MTA as detected by ICP-MS. Aged ProRoot MTA samples exhibited a black discolouration and surface calcium carbonate deposition. ProRoot MTA influenced cell counts after direct exposure and its 180-days leachates reduced BMSC viability. After direct BMSC contact with non-aged ProRoot MTA an upregulation of metallothionein (MT1 and MT2A) expression and down-regulation of collagen-1a (Col-1a) and bone sialoprotein (BSP) expression was identified. Bismuth leaching was observed throughout 180-days observation period from all materials containing bismuth oxide. This negatively influenced cell viability and gene expression associated with bismuth exposure. This is the first study to report that metallothionein gene expression was influenced by exposure to ProRoot MTA.

Centenarian hippocampus displays high levels of astrocytic metallothioneins.

The hippocampus is a brain area linked to cognition. The mechanisms that maintain cognitive activity in humans are poorly understood. Centenarians display extreme longevity which is generally accompanied by better quality of life, lower cognitive impairment, and reduced incidence of pathologies including neurodegenerative diseases. We performed transcriptomic studies in hippocampus samples from individuals of different ages (centenarians [≥97 years], old, and young) and identified a differential gene expression pattern in centenarians compared to the other two groups. In particular, several isoforms of metallothioneins (MTs) were highly expressed in centenarians. Moreover, we identified that MTs were mainly expressed in astrocytes. Functional studies in human primary astrocytes revealed that MT1 and MT3 are necessary for their homeostasis maintenance. Overall, these results indicate that the expression of MTs specifically in astrocytes is a mechanism for protection during aging.

Histopathology and changes in the expression of metallothioneins, heat shock proteins and inducible nitric oxide synthase in Prochilodus costatus from a neotropical river contaminated by heavy metals

The most recent dam rupture in Brazil released tons of mining tailings into the upper course of the Paraopeba River, affecting this river in an unprecedented way. The present study aimed to evaluate the influence of heavy metals on Prochilodus costatus, an important commercial species in Brazil, four years after the dam colapse. To this end, biomarkers of heavy metals, oxidative stress, and environmental stress were analyzed, and histological analyses of target organs were performed. The results demonstrated critical contamination of fish from the Paraopeba River. Increased expression of Metallothioneins - MTs, Heat Shock Protein - HSP70, and inducible nitric oxide synthase - iNOS, as well as greater rates of histological changes in the liver, spleen, and gonads, were observed in P. costatus. These findings demonstrate that, despite past contamination, the metals present in mining tailings have significantly increased the contamination of the Paraopeba River basin.

Gene-expression profiling of individuals resilient to Alzheimer's disease reveals higher expression of genes related to metallothionein and mitochondrial processes and no changes in the unfolded protein response

Some individuals show a discrepancy between cognition and the amount of neuropathological changes characteristic for Alzheimer’s disease (AD). This phenomenon has been referred to as ‘resilience’. The molecular and cellular underpinnings of resilience remain poorly understood. To obtain an unbiased understanding of the molecular changes underlying resilience, we investigated global changes in gene expression in the superior frontal gyrus of a cohort of cognitively and pathologically well-defined AD patients, resilient individuals and age-matched controls (n = 11–12 per group). 897 genes were significantly altered between AD and control, 1121 between resilient and control and 6 between resilient and AD. Gene set enrichment analysis (GSEA) revealed that the expression of metallothionein (MT) and of genes related to mitochondrial processes was higher in the resilient donors. Weighted gene co-expression network analysis (WGCNA) identified gene modules related to the unfolded protein response, mitochondrial processes and synaptic signaling to be differentially associated with resilience or dementia. As changes in MT, mitochondria, heat shock proteins and the unfolded protein response (UPR) were the most pronounced changes in the GSEA and/or WGCNA, immunohistochemistry was used to further validate these processes. MT was significantly increased in astrocytes in resilient individuals. A higher proportion of the mitochondrial gene MT-CO1 was detected outside the cell body versus inside the cell body in the resilient compared to the control group and there were higher levels of heat shock protein 70 (HSP70) and X-box-binding protein 1 spliced (XBP1s), two proteins related to heat shock proteins and the UPR, in the AD donors. Finally, we show evidence for putative sex-specific alterations in resilience, including gene expression differences related to autophagy in females compared to males. Taken together, these results show possible mechanisms involving MTs, mitochondrial processes and the UPR by which individuals might maintain cognition despite the presence of AD pathology.

The Impact of High Adiposity on Endometrial Progesterone Response and Metallothionein Regulation.

Obesity is a disease with deleterious effects on the female reproductive tract, including the endometrium. We sought to understand the effects of excess adipose on the benign endometrium. A physiologic in vitro coculture system was developed, consisting of multicellular human endometrial organoids, adipose spheroids, and menstrual cycle hormones. Native human endometrial tissue samples women with and without obesity were also analyzed. Academic institution. Benign endometrial tissues from premenopausal women were obtained following written consent. Gene expression, protein expression, chromatin binding, and expression of DNA damage and oxidative damage markers were measured. Under high-adiposity conditions, endometrial organoids downregulated endometrial secretory phase genes, suggestive of an altered progesterone response. Progesterone specifically upregulated the metallothionein (MT) gene family in the epithelial cells of endometrial organoids, while high adiposity significantly downregulated the MT genes. Silencing MT genes in endometrial epithelial cells resulted in increased DNA damage, illustrating the protective role of MTs. Native endometrium from women with obesity displayed increased MT expression and oxidative damage in the stroma and not in the epithelium, indicating the cell-specific impact of obesity on MT genes. Taken together, the in vitro and in vivo systems used here revealed that high adiposity or obesity can alter MT expression by decreasing progesterone response in the epithelial cells and increasing oxidative stress in the stroma.

Zinc and manganese homeostasis closely interact in mammalian cells.

Understanding the homeostatic interactions among essential trace metals is important for explaining their roles in cellular systems. Recent studies in vertebrates suggest that cellular Mn metabolism is related to Zn metabolism in multifarious cellular processes. However, the underlying mechanism remains unclear. In this study, we examined the changes in the expression of proteins involved in cellular Zn and/or Mn homeostatic control and measured the Mn as well as Zn contents and Zn enzyme activities to elucidate the effects of Mn and Zn homeostasis on each other. Mn treatment decreased the expression of the Zn homeostatic proteins metallothionein (MT) and ZNT1 and reduced Zn enzyme activities, which were attributed to the decreased Zn content. Moreover, loss of Mn efflux transport protein decreased MT and ZNT1 expression and Zn enzyme activity without changing extracellular Mn content. This reduction was not observed when supplementing with the same Cu concentrations and in cells lacking Cu efflux proteins. Furthermore, cellular Zn homeostasis was oppositely regulated in cells expressing Zn and Mn importer ZIP8, depending on whether Zn or Mn concentration was elevated in the extracellular milieu. Our results provide novel insights into the intricate interactions between Mn and Zn homeostasis in mammalian cells and facilitate our understanding of the physiopathology of Mn, which may lead to the development of treatment strategies for Mn-related diseases in the future.

Effect of initial periodontal therapy on metallothionein levels in smokers and non-smokers with periodontitis.

The aim of this study was to determine the effect of non-surgical periodontal therapy (NSPT) on mRNA expression of metallothionein (MT) and its levels in serum, saliva and gingival crevicular fluid (GCF) of smokers (S) and non-smokers (NS) with periodontitis (P).A total of 100 participants were included: 48 periodontally healthy (PH) subjects (24 S [PH + S] and 24 NS [PH + NS]) and 52 patients with P (27 S [P + S] and 25 NS [P + NS]). Clinical parameters were recorded, and biofluids (serum, saliva and GCF) and gingival tissue samples were obtained at baseline in all groups and 3months after NSPT in P groups. MT levels in biofluids were determined by ELISA. In gingival tissues, MT-mRNA expression was quantified using real-time PCR. mRNA expression of MT and its levels in biofluids were significantly higher in P + S compared to other groups, and the differences between P + NS and PH + S were non-significant. A significant decrease was observed for MT levels in biofluids, and MT-mRNA expression in periodontitis patients after NSPT. In conclusion, smoking and periodontitis are associated with higher MT expression which decreases after NSPT. MT as an oxidative stress biomarker and its therapeutic role in periodontitis should be investigated in future studies.Clinical trial registration: The study was prospectively registered at Clinical Trials Registry-India (ctri.nic.in) as CTRI/2018/08/015427 on August 23, 2018.