Polimorfizmi gena metalotioneina 2A u ljudi i njihova povezanost s bolestima i razinama elemenata u tragu

Human metallothioneins are a superfamily of low molecular weight intracellular proteins, whose synthesis can be induced by essential elements (primarily Zn and Cu), toxic elements and chemical agents, and stress-producing conditions. Of the four known isoforms in the human body MT2 is the most common. The expression of metallothioneins is encoded by a multigene family of linked genes and can be influenced by single nucleotide polymorphisms (SNPs) in these genes. To date, 24 SNPs in the MT2A gene have been identified with the incidence of about 1 % in various population groups, and three of them were shown to affect physiological and pathophysiological processes. This review summarises current knowledge about these three SNPs in the MT2A gene and their associations with element concentrations in the body of healthy and diseased persons. The most investigated SNP is rs28366003 (MT2A −5 A/G). Reports associate it with longevity, cancer (breast, prostate, laryngeal, and in paranasal sinuses), and chronic renal disease. The second most investigated SNP, rs10636 (MT2A +838G/C), is associated with breast cancer, cardiovascular disease, and type 2 diabetes. Both are also associated with several metal/metalloid concentrations in the organism. The third SNP, rs1610216 (MT2A −209A/G), has been studied for association with type 2 diabetes, cardiomyopathy, hyperglycaemia, and Zn concentrations. Metallothionein concentrations and MT2A polymorphisms have a potential to be used as biomarkers of metal exposure and clinical markers of a number of chronic diseases. This potential needs to be studied and verified in a large number of well-defined groups of participants (several hundreds and thousands) with a focus on particular physiological or pathological condition and taking into consideration other contributing factors, such as environmental exposure and individual genetic and epigenetic makeup.Metalotioneini u ljudskom organizmu povezana su skupina niskomolekularnih unutarstaničnih proteina, čiju sintezu mogu pobuditi esencijalni elementi, ponajprije Zn i Cu, toksični elementi i druge kemijske tvari te razni uvjeti koji izazivaju stres u organizmu. Od četiriju poznatih izoformi metalotioneina u ljudskome tijelu, najčešći oblik je MT2. Izražaj metalotioneina kodira skupina povezanih gena i na to mogu utjecati polimorfizmi pojedinačnoga nukleotida u tim genima. Do sada su otkrivena 24 jednonukleotidna polimorfizma u području gena MT2A, s incidencijom od oko 1 % u raznim skupinama stanovništva, a za tri je takva polimorfizma utvrđeno da bi mogli utjecati na fiziološke i patofiziološke procese. U preglednom radu prikazane su dosadašnje spoznaje o trima jednonukleotidnim polimorfizmima u genu MT2A i njihove povezanosti s koncentracijama elemenata u zdravih i bolesnih osoba. Najviše istraživan jednonukleotidni polimorfizam gena MT2A do sada bio je rs28366003 (MT2A −5A/G) i za njega su pokazane povezanosti s duljinom života, nekoliko tipova karcinoma (u dojki, prostati, grkljanu i sinusima) i s bubrežnim bolestima. Za drugi najviše istraživani polimorfizam rs10636 (MT2A +838G/C) nađene su povezanosti s rakom dojke, bolestima srca i krvnih žila te dijabetesom tipa 2. Za obje te vrste polimorfizama nađene su povezanosti i s koncentracijama metala i polumetala u organizmu. U samo nekoliko istraživanja ispitivana je povezanost polimorfizma rs1610216 (MT2A −209A/G) s dijabetesom tipa 2, kardiomiopatijom, hiperglikemijom i koncentracijama Zn. Podatci u literaturi upućuju na moguću praktičnu primjenu nalaza koncentracija metalotioneina i genskih polimorfizama MT2A kao bioloških pokazatelja izloženosti metalima i kliničkih pokazatelja brojnih kroničnih bolesti. Za tu svrhu potrebna su daljnja opsežna istraživanja u velikom broju dobro definiranih skupina ispitanika (nekoliko stotina i tisuća), usredotočenih na određeno fiziološko ili patološko stanje te uzimajući u obzir druge čimbenike, kao što su okolišna izloženost, osobne životne navike te genetičke i epigenetičke značajke

Određivanje elemenata u kosi metodom ICP-MS: odabir odgovarajuće procedure pranja uzorka

Human hair is a biological sample that is, unlike blood, noninvasively collected and can be used in the assessment of element intake. Before analysis, hair samples need to be washed to eliminate external contamination, for which no standard procedure exists. The present study evaluated the efficiency of different processes for washing hair samples (by non-ionic detergent, acids, solvents, and their mixtures), including ultrasonication before ICP-MS element (As, Ca, Cd, Cu, Fe, Hg, Mg, Mn, Mo, Pb, Se, and Zn) analysis. All tested washing procedures using detergent or solvents were satisfactory, while nitric and hydrochloric acid solutions yielded to “released” and lost elements due to damaged hair (visible discolouration and hair impairment). The application of ultrasonication improved washing efficiency up to 10 %, depending on the tested element and washing procedure. This work is licensed under a Creative Commons Attribution 4.0 International License.Ljudska kosa je biološki uzorak koji se, za razliku od krvi, skuplja neinvazivno i može rabiti u procjeni unosa elemenata. Prije analize uzorke kose potrebno je oprati kako bi se odstranila vanjska onečišćenja za što ne postoje standardni postupci. Istraživanjem je procijenjena učinkovitost različitih postupaka pranja uzoraka kose (neionskim detergentom, kiselinama, otapalima i njihovim mješavinama) uključujući primjenu ultrazvuka prije analize elemenata (As, Ca, Cd, Cu, Fe, Hg, Mg, Mn, Mo, Pb, Se, and Zn) metodom ICP-MS. Ispitivani postupci pranja bili su zadovoljavajući, izuzev primjenom dušične i klorovodične kiseline, pri čemu se elementi “otpuštaju” i gube zbog oštećivanja kose (vidljive su promjena boje i pucanje vlasi). Primjena ultrazvuka pospješila je učinkovitost pranja uzoraka do 10 % ovisno o ispitivanom elementu i postupku pranja. Ovo djelo je dano na korištenje pod licencom Creative Commons Imenovanje 4.0 međunarodna

Primjena mezo-2,3-dimerkaptojantarne kiseline u radnika profesionalno izloženih olovu

The aim of this study was to evaluate the efficacy of (DMSA) meso-2,3-dimercaptosuccinic acid treatment in workers with increased lead absorption and no overt symptoms of lead poisoning. Seven occupationally lead exposed male workers with blood lead concentrations (PbB) exceeding 50 µg/100 ml and a positive (EDTA) calcium disodium ethylenediaminetetraacetate lead mobilization test were treated with DMSA for 19 days. Individual doses were 700 mg DMSA, three times a day from day one to five, and twice a day from day six to 19. The treatment intensified urinary lead excretion, most rapidly during the first five days. The increased elimination was followed by a decline of mean PbB to 15% of the pretreatment values. However, 15 days after the treatment, the PbB concentrations rebounded, yet kept below the baseline values and did not exceed 40 µg/100 ml. After repeated EDTA lead mobilization test, urine lead was 23–68% of that before DMSA treatment. It can be concluded that DMSA can effectively reduce chelatable lead in occupationally exposed workers.Svrha ovog istraživanja bila je ustanoviti učinkovitost mezo-2,3-dimerkaptojantarne kiseline (DMSA) u tretiranju radnika s povećanom apsorpcijom olova, a bez znakova trovanja olovom. Danas se DMSA smatra jednim od najboljih kelatirajućih sredstava, koje se pokazalo učinkovitim posebno u djece otrovane olovom. U Hrvatskoj, međutim, do sada još nije bilo primjenjivano. Sedam radnika profesionalno izloženih olovu bilo je tretirano s DMSA. Radnici nisu imali kliničkih simptoma otrovanja olovom, koncentracija olova u krvi bila je viša od 50 µg/100 ml, a mobilizacijski test s kalcij dinatrij etilendiamintetraacetatom (EDTA) bio je pozitivan. Postupak je trajao 19 dana u pojedinačnim dozama od 700 mg DMSA tri puta na dan od prvog do petog dana i dva puta na dan od šestog do devetnaestog dana. Rezultati su pokazali da je izlučivanje olova urinom za vrijeme primjene DMSA bilo povišeno, i to najviše prvih pet dana. Nakon toga se smanjilo do 15% od početne vrijednosti. Koncentracije olova u krvi, međutim, povisile su se 15 dana nakon završetka tretmana, ali nisu premašile vrijednost od 40 µg/100 ml. Nakon ponovljenog testa mobilizacije EDTA-om, olovo u urinu iznosilo je 23–68% od one vrijednosti koja je dobivena prije primjene DMSA. Izlučivanje cinka i bakra urinom bilo je za vrijeme terapije povišeno 2–3 puta, a nije bilo promjena u izlučivanju željeza, kalcija i magnezija. Može se zaključiti da DMSA učinkovito smanjuje koncentracije olova u radnika profesionalno izloženih tom toksičnom metalu

Kadmij i olovo u uzorcima vučje jetre: optimizacija metode razgradnje uzoraka uz pomoć mikrovalova

A microwave-assisted digestion method for the determination of cadmium (Cd) and lead (Pb) by inductively coupled plasma mass spectrometry (ICP-MS) was optimised on certified reference material (CRM) (bovine liver, BCR-185R) and wolf liver samples. Different factors influencing digestion efficiency (temperature, time, composition of the digestion mixture, sample mass) were tested. Validation included linearity (up to 200 μg L-1 for Cd and Pb), detection (0.003 μg L-1 for Cd and 0.035 μg L-1 for Pb), and quantification (0.008 μg L-1 for Cd and 0.081 μg L-1 for Pb) limits. Good agreement between measured and certified values was achieved in all conditions, with recoveries ranging from 94 % to 111 % for Cd and from 95 % to 105 % for Pb. The precision of the method, expressed as relative standard deviation, was up to 3 % for Cd and 8 % for Pb. The best digestion parameters (260 °C, 30 min, 1 mL HNO3+4 mL H2O, 0.1 g of CRM) based on accuracy and precision were applied on two wolf liver samples to evaluate the need for the predigestion step (freeze-drying) and appropriate mass of the sample. Freeze-drying improved precision and minimising the tissue mass to 0.1 g reduced the matrix effect. Using these optimised digestion conditions, we determined Cd and Pb in 40 wolf livers collected in Croatia, and their medians (0.055 μg g-1 and 0.107 μg g-1, respectively) were in the range of previously reported data for the grey wolf.Certifi cirani referenti materijal (CRM) govedskih jetara (BCR-185R) i uzorci vučjih jetara koristili su se za optimizaciju metode razgradnje uzoraka prije mjerenja kadmija (Cd) i olova (Pb) masenom spektrometrijom induktivno spregnute plazme (ICP-MS). Ispitivani su različiti uvjeti koji utječu na učinkovitost razgradnje (temperatura, vrijeme, sastav otopine za razgradnju, masa uzorka). Validacijom je obuhvaćeno ispitivanje linearnosti (do 200 μg L-1 Cd/Pb), granice detekcije (0,003 μg L-1 za Cd, 0.035 μg L-1 za Pb) i kvantifikacije (0,008 μg L-1 za Cd, 0,081 μg L-1 za Pb). Postignuto je dobro slaganje izmjerenih i certificiranih vrijednosti u svim ispitivanim uvjetima uz izračunati raspon iskorištenja 94 % do 111 % za Cd i 95 % do 105 % za Pb. Najveća relativna standardna devijacija, kao mjera preciznosti, iznosila je 3 % za Cd i 8 % za Pb. Najbolji uvjeti za razgradnju (260 °C, 30 min, 1 mL HNO3+4 mL H2O, 0,2 g CRM), izabrani prema točnosti i preciznosti, primijenjeni su na uzorke vučjih jetara pri procjeni odgovarajuće mase uzorka i potrebe za uvođenjem dodatnog koraka prije razgradnje (liofilizacije). Liofilizacija poboljšava preciznost pa je preporučujemo pri pripremi uzoraka tkiva. Također, najmanja masa uzorka izabrana je ne samo zbog bolje preciznosti nego i zbog najmanjeg utjecaja matrice te potrebne količine tkiva. Medijani Cd (0,055 μg g-1) i Pb (0,107 μg g-1 mokre mase) dobiveni analizom 40 uzoraka vučjih jetara skupljenih u Hrvatskoj bili su u rasponu vrijednosti objavljenih u literaturi za sivog vuka

Pre-amplification as a method for improvement of quantitative RT-PCR analysis of circulating miRNAs

Introduction: The assessment of circulating miRNAs is challenging and still limited due to their low concentrations, small size and lack of reference values in human biological samples. Pre-amplification of complementary DNAs may facilitate reliable miRNA quantification. The aim of our study was to evaluate the efficacy of pre-amplification as a step to increase the sensitivity of qPCR analysis for five candidate circulating miRNAs presumably related to toxic metals and cigarette smoke exposure: miR-1537, miR-190b, miR-16, miR-21, and miR-146a. Materials and methods: Candidate miRNAs expression was analysed in plasma samples of 19 mother-newborn pairs. For isolation, transcription, pre-amplification and qPCR quantification kits and protocols by Qiagen (Hilden, Germany) were used. Paired t-test or Wilcoxon rank test were used to compare miRNAs expression levels with and without a pre-amplification step prior to qPCR, separately in maternal and cord plasma. Intraclass correlation (ICC) was calculated as an agreement measure between procedures for each miRNA. Results: Pre-amplification facilitated the detection of all assayed miRNAs with an overall cycle threshold (CT) improvement of 6.6 ± 0.89 (P < 0.05). Excellent ICCs (> 0.90) were found between data for preamplified and not preamplified miR-16, miR-21 and miR-146a. However, these correlations for low expressed miR-190b were moderate (0.79 in maternal; 0.61 in cord plasma) and poor for miR-1537 (0.49 in maternal; no correlation in cord plasma). Conclusion: Pre-amplification is a useful, necessary step in the analysis of miR-1537 and miR-190b as a reliable procedure facilitating extracellular miRNA expression detection in human plasma by real-time PCR quantification

Određivanje kemijskog sastava i antioksidacijskog potencijala plodova jarebike (Sorbus aucuparia L.) porijeklom iz alpsko-dinarskog područja Republike Hrvatske

Research background. The rowan (Sorbus aucuparia L.) is a small tree in the Rosaceae family with characteristic orange-red fruits. The raw fruits can be used for making jams, juices and puree, while the dried fruits are used for teas. In folk medicine, they have been used to prevent scurvy and bleeding or as a diuretic and laxative. The aim of this study is to characterize the proximate chemical composition, antioxidant potential and macro- and trace elements of the rowan fruits for their potential use as a functional food. Experimental approach. The fruits were collected from 12 populations in the Alpine-Dinaric region of Croatia. After collection, the samples were transported to the laboratory, cut into small pieces, placed in plastic containers and stored at -20 °C until analysis. Proximate chemical composition, including ash, water, cellulose, crude fat and crude protein, was determined according to standard methods and total carbohydrates as non-structural carbohydrates. Total phenolic content (TPC) and antioxidant capacity (TAC) were also measured. For multielement analysis, fruits were cleaned from the dust, lyophilised, homogenised and acid-digested in a microwave system. Concentrations of elements were determined using the inductively coupled plasma mass spectrometry. Results and conclusions. The basic constituents in the analysed fruits were (in %): water 76.53, total carbohydrates 17.45, crude proteins 2.98, crude fats 1.49, cellulose 1.07 and ash 1.29. On average, the TPC was 932 mg/100 g and the TAC was (60.1±14.5) % and (4.1±1.2) mmol/100 g, determined by DPPH and FRAP assay, respectively. Mass fractions of elements decreased as follows (in mg/kg): K 2485>Ca 459>P 206, Mg 193>Na 6.29>Fe 3.68>Mn 3.58>Zn 1.11>Cu 0.731>Mo 0.098>Co 0.003>Se 0.001. Compared to the literature, the phenolic and element content of the rowan fruits is similar to that of blueberry and raspberry. The obtained results suggest that rowan fruits have valuable nutritional properties and could be useful for fortification in the food industry. Novelty and scientific contribution. The importance of the obtained results is reflected in filling in the gaps in the literature on the composition of elements, especially on the content of essential macro- and trace elements as well as the antioxidant potential of rowan fruits.Pozadina istraživanja. Jarebika (Sorbus aucuparia L.) je malo stablo iz porodice Rosaceae s karakterističnim narančasto-crvenim plodovima. Od sirovih plodova mogu se pripremati džemovi, sokovi i voćne kaše, a od osušenih čajevi. U narodnoj medicini koristi se za sprječavanje razvoja skorbuta i krvarenja, odnosno kao diuretik i laksativ. Svrha je ovog istraživanja bila odrediti kemijski sastav, antioksidacijski potencijal te udjele mineralnih tvari u plodovima jarebike, radi određivanja mogućnosti njezine upotrebe kao funkcionalne hrane. Eksperimentalni pristup. Plodovi su prikupljeni iz 12 različitih populacija u alpsko-dinarskom području Hrvatske. Uzorci su nakon prikupljanja prevezeni u laboratorij, izrezani na male komadiće, stavljeni u plastične posude i čuvani na -20 °C do daljnjih analiza. Kemijski sastav, uključujući masene udjele pepela, vode, celuloze, masti i proteina, određen je pomoću standardnih metoda, a ukupni ugljikohidrati kao nestrukturni ugljikohidrati. Određeni su i ukupni udjel fenola (TPC) i antioksidacijski potencijal (TAC). Za multielementnu analizu plodovi su očišćeni od prašine, liofilizirani, homogenizirani i razgrađeni u mikrovalnom visokotlačnom reaktoru. Koncentracije elemenata određene su spektrometrijom masa uz induktivno spregnutu plazmu. Rezultati i zaključci. Osnovni sastojci u ispitanim plodovima bili su (u %): voda 76,53; ukupni ugljikohidrati 17,45; proteini 2,98; masti 1,49; celuloza 1,07 i pepeo 1,29. Utvrđen je prosječan udjel TPC od 932 mg/100 g, a DPPH odnosno FRAP metodom TAC od (60,1±14,5) % odnosno (4,1±1,2) mmol/100 g. Maseni udjeli elemenata smanjivali su se prema slijedu (u mg/kg): K 2485>Ca 459>P 206, Mg193>Na 6,29>Fe 3,68>Mn 3,58>Zn 1,11>Cu 0,731>Mo 0,098>Co 0,003>Se 0,001. U usporedbi s literaturom, udjeli fenola i mineralnih tvari u plodovima jarebike bili su slični onima u borovnici i malini. Dobiveni rezultati pokazuju da plodovi jarebike imaju vrijedna hranjiva svojstva i mogu biti koristan dodatak u prehrambenoj industriji. Novina i znanstveni doprinos. Važnost dobivenih rezultata ogleda se u nadopuni literature podacima o sastavu elemenata, naročito udjelu esencijalnih makro i mikroelemenata, kao i antioksidacijskom potencijalu plodova jarebike

Metal(loid) exposure assessment and biomarker responses in captive and free-ranging European brown bear (Ursus arctos)

We investigated the level of five non-essential metal(loid)s (As, Cd, Hg, Tl, Pb) and nine essential metals (Mg, Ca, Mn, Fe, Co, Cu, Zn, Se, Mo) in hair and blood components of captive and free-ranging European brown bear populations in Croatia and Poland. Metal(loid) associations with biomarkers of oxidative stress (superoxide dismutase, SOD ; glutathione- peroxidase, GSH-Px ; malondialdehyde, MDA) and metal exposure (metallothionein, MT) were estimated in this top predatory mammal. Lead was the most abundant non-essential metal(loid) in both blood and hair, with 4 of 35 individuals having blood levels over 100 µg/L. A positive association was found between Pb level and SOD activity in blood. Free-ranging bears had higher blood SOD activity, Mn, Zn and Cd levels, hair Co, Cd, Tl and Pb compared to captive individuals, while the opposite was true for Mg and hair Ca thereby reflecting habitat and diet differences. With increasing age, animals showed lower levels of SOD activity and certain essential metals. Females had higher SOD activity and blood levels of some essential metals than males. Hair showed a higher Fe and Co level when sampled during the growth phase and was not predictive of non- essential metal(loid) blood levels. The established metal(loid) baseline values will enable future risk assessment in both captive and wild European brown bear populations

In female rats, ethylene glycol treatment elevates protein expression of hepatic and renal oxalate transporter sat-1 (Slc26a1) without inducing hyperoxaluria

Aim To investigate whether the sex-dependent expression of hepatic and renal oxalate transporter sat-1 (Slc26a1) changes in a rat model of ethylene glycol (EG)-induced hyperoxaluria. Methods Rats were given tap water (12 males and 12 females; controls) or EG (12 males and 12 females; 0.75% v/v in tap water) for one month. Oxaluric state was confirmed by biochemical parameters in blood plasma, urine, and tissues. Expression of sat-1 and rate-limiting enzymes of oxalate synthesis, alcohol dehydrogenase 1 (Adh1) and hydroxy-acid oxidase 1 (Hao1), was determined by immunocytochemistry (protein) and/or real time reverse transcription polymerase chain reaction (mRNA). Results EG-treated males had significantly higher (in μmol/L; mean ± standard deviation) plasma (59.7 ± 27.2 vs 12.9 ± 4.1, P < 0.001) and urine (3716 ± 1726 vs 241 ± 204, P < 0.001) oxalate levels, and more abundant oxalate crystaluria than controls, while the liver and kidney sat-1 protein and mRNA expression did not differ significantly between these groups. EG-treated females, in comparison with controls had significantly higher (in μmol/L) serum oxalate levels (18.8 ± 2.9 vs 11.6 ± 4.9, P < 0.001), unchanged urine oxalate levels, low oxalate crystaluria, and significantly higher expression (in relative fluorescence units) of the liver (1.59 ± 0.61 vs 0.56 ± 0.39, P = 0.006) and kidney (1.77 ± 0.42 vs 0.69 ± 0.27, P < 0.001) sat-1 protein, but not mRNA. The mRNA expression of Adh1 was femaledominant and that of Hao1 male-dominant, but both were unaffected by EG treatment. Conclusions An increased expression of hepatic and renal oxalate transporting protein sat-1 in EG-treated female rats could protect from hyperoxaluria and oxalate urolithiasis

Metallothionein 2A

Human metallothioneins are a superfamily of low molecular weight intracellular proteins, whose synthesis can be induced by essential elements (primarily Zn and Cu), toxic elements and chemical agents, and stress-producing conditions. Of the four known isoforms in the human body MT2 is the most common. The expression of metallothioneins is encoded by a multigene family of linked genes and can be influenced by single nucleotide polymorphisms (SNPs) in these genes. To date, 24 SNPs in the MT2A gene have been identified with the incidence of about 1 % in various population groups, and three of them were shown to affect physiological and pathophysiological processes. This review summarises current knowledge about these three SNPs in the MT2A gene and their associations with element concentrations in the body of healthy and diseased persons. The most investigated SNP is rs28366003 (MT2A −5 A/G). Reports associate it with longevity, cancer (breast, prostate, laryngeal, and in paranasal sinuses), and chronic renal disease. The second most investigated SNP, rs10636 (MT2A +838G/C), is associated with breast cancer, cardiovascular disease, and type 2 diabetes. Both are also associated with several metal/metalloid concentrations in the organism. The third SNP, rs1610216 (MT2A −209A/G), has been studied for association with type 2 diabetes, cardiomyopathy, hyperglycaemia, and Zn concentrations. Metallothionein concentrations and MT2A polymorphisms have a potential to be used as biomarkers of metal exposure and clinical markers of a number of chronic diseases. This potential needs to be studied and verified in a large number of well-defined groups of participants (several hundreds and thousands) with a focus on particular physiological or pathological condition and taking into consideration other contributing factors, such as environmental exposure and individual genetic and epigenetic makeup.Metalotioneini u ljudskom organizmu povezana su skupina niskomolekularnih unutarstaničnih proteina, čiju sintezu mogu pobuditi esencijalni elementi, ponajprije Zn i Cu, toksični elementi i druge kemijske tvari te razni uvjeti koji izazivaju stres u organizmu. Od četiriju poznatih izoformi metalotioneina u ljudskome tijelu, najčešći oblik je MT2. Izražaj metalotioneina kodira skupina povezanih gena i na to mogu utjecati polimorfizmi pojedinačnoga nukleotida u tim genima. Do sada su otkrivena 24 jednonukleotidna polimorfizma u području gena MT2A, s incidencijom od oko 1 % u raznim skupinama stanovništva, a za tri je takva polimorfizma utvrđeno da bi mogli utjecati na fiziološke i patofiziološke procese. U preglednom radu prikazane su dosadašnje spoznaje o trima jednonukleotidnim polimorfizmima u genu MT2A i njihove povezanosti s koncentracijama elemenata u zdravih i bolesnih osoba. Najviše istraživan jednonukleotidni polimorfizam gena MT2A do sada bio je rs28366003 (MT2A −5A/G) i za njega su pokazane povezanosti s duljinom života, nekoliko tipova karcinoma (u dojki, prostati, grkljanu i sinusima) i s bubrežnim bolestima. Za drugi najviše istraživani polimorfizam rs10636 (MT2A +838G/C) nađene su povezanosti s rakom dojke, bolestima srca i krvnih žila te dijabetesom tipa 2. Za obje te vrste polimorfizama nađene su povezanosti i s koncentracijama metala i polumetala u organizmu. U samo nekoliko istraživanja ispitivana je povezanost polimorfizma rs1610216 (MT2A −209A/G) s dijabetesom tipa 2, kardiomiopatijom, hiperglikemijom i koncentracijama Zn. Podatci u literaturi upućuju na moguću praktičnu primjenu nalaza koncentracija metalotioneina i genskih polimorfizama MT2A kao bioloških pokazatelja izloženosti metalima i kliničkih pokazatelja brojnih kroničnih bolesti. Za tu svrhu potrebna su daljnja opsežna istraživanja u velikom broju dobro definiranih skupina ispitanika (nekoliko stotina i tisuća), usredotočenih na određeno fiziološko ili patološko stanje te uzimajući u obzir druge čimbenike, kao što su okolišna izloženost, osobne životne navike te genetičke i epigenetičke značajke