Determination of Optimal Conditions for Zinc-Hyperaccumulation by Saccharomyces cerevisiae FF-10

Jae-Young Cha,Young-Su Cho 한국응용생명화학회 2009 Journal of Applied Biological Chemistry (J. Appl. Vol.52 No.3

Zinc is an essential trace element for many physiological functions in humans and animals. We have previously reported on the isolation of zinc-enriched Saccharomyces cerevisiae FF-10 from the tropical fruit Rambutan (Nephelium lappaceum L.). The present study was undertaken to investigate the influence of the optimal medium composition pertaining to carbon and nitrogen sources, amino acids, minerals, and different zinc compounds on zinc accumulation in FF-10 strain. The highest accumulation of zinc was obtained in a medium containing 2.0%(w/v) glucose, 5.0% yeast extract, and 0.05% ZnSO4 after cultivation at 110 rpm, 30℃ , 72 h. Under these conditions, the 31,932 ppm zinc represented a 93-fold increase over the 339 ppm in the basal medium. The accumulation of zinc in yeast cells increased with the increase of supplemented concentrations (250-4,000 ppm) of zinc powder, zinc sulfate, zinc acetate, and zinc chloride in the culture medium, with the greatest accumulation evident at 4,000 ppm of zinc sulfate, zinc acetate, and zinc chloride. The zinc concentration in the medium strongly influenced FF-10 strain growth. In the presence of medium supplemented with 4,000 ppm zinc chloride, zinc accumulation by FF-10 strain increased by 445-fold to 150,892 ppm. From these results, the beat medium compositions for zinc accumulation in FF-10 yeast were obtained after cultivation with for 72 h in a medium containing 2% glucose, 5% yeast extract, and 0.04% ZnCl2. Zinc is an essential trace element for many physiological functions in humans and animals. We have previously reported on the isolation of zinc-enriched Saccharomyces cerevisiae FF-10 from the tropical fruit Rambutan (Nephelium lappaceum L.). The present study was undertaken to investigate the influence of the optimal medium composition pertaining to carbon and nitrogen sources, amino acids, minerals, and different zinc compounds on zinc accumulation in FF-10 strain. The highest accumulation of zinc was obtained in a medium containing 2.0%(w/v) glucose, 5.0% yeast extract, and 0.05% ZnSO4 after cultivation at 110 rpm, 30℃ , 72 h. Under these conditions, the 31,932 ppm zinc represented a 93-fold increase over the 339 ppm in the basal medium. The accumulation of zinc in yeast cells increased with the increase of supplemented concentrations (250-4,000 ppm) of zinc powder, zinc sulfate, zinc acetate, and zinc chloride in the culture medium, with the greatest accumulation evident at 4,000 ppm of zinc sulfate, zinc acetate, and zinc chloride. The zinc concentration in the medium strongly influenced FF-10 strain growth. In the presence of medium supplemented with 4,000 ppm zinc chloride, zinc accumulation by FF-10 strain increased by 445-fold to 150,892 ppm. From these results, the beat medium compositions for zinc accumulation in FF-10 yeast were obtained after cultivation with for 72 h in a medium containing 2% glucose, 5% yeast extract, and 0.04% ZnCl2.

Vacuolar zinc transporter Zrc1 is required for detoxification of excess intracellular zinc in the human fungal pathogen Cryptococcus neoformans

조민수,Guanggan Hu,Mélissa Caza,Linda C. Horianopoulos,James W. Kronstad,정원희 한국미생물학회 2018 The journal of microbiology Vol.56 No.1

Zinc is an important transition metal in all living organisms and is required for numerous biological processes. However, excess zinc can also be toxic to cells and cause cellular stress. In the model fungus Saccharomyces cerevisiae, a vacuolar zinc transporter, Zrc1, plays important roles in the storage and detoxification of excess intracellular zinc to protect the cell. In this study, we identified an ortholog of the S. cerevisiae ZRC1 gene in the human fungal pathogen Cryptococcus neoformans. Zrc1 was localized in the vacuolar membrane in C. neoformans, and a mutant lacking ZRC1 showed significant growth defects under high-zinc conditions. These results suggested a role for Zrc1 in zinc detoxification. However, contrary to our expectation, the expression of Zrc1 was induced in cells grown in zinc-limited conditions and decreased upon the addition of zinc. These expression patterns were similar to those of Zip1, the high-affinity zinc transporter in the plasma membrane of C. neoformans. Furthermore, we used the zrc1 mutant in a murine model of cryptococcosis to examine whether a mammalian host could inhibit the survival of C. neoformans using zinc toxicity. We found that the mutant showed no difference in virulence compared with the wildtype strain. This result suggests that Zrc1-mediated zinc detoxification is not required for the virulence of C. neoformans, and imply that zinc toxicity may not be an important aspect of the host immune response to the fungus.

Zinc 대사와 관련된 Paneth 세포활성의 변화에 관한 조직화학적 연구

조승묵,김성준,박승국,강태천,원무호,Jo, Seung-Mook,Kim, Sung-Jun,Park, Seung-Kook,Kang, Tae-Cheon,Won, Moo-Ho 한국현미경학회 2000 Applied microscopy Vol.30 No.4

포유류 장생 상피세포의 하나인 파네스세포(Paneth cell)는 여러 가지 금속류를 함유하고 있으며, 생체가 과잉의 이들 금속류에 노출되거나 부족할 때에 장 내강을 통해 제거하거나 흡수함으로써 금속류의 항상성에 기여한다고 알려져 있다. 이번 연구는 이러한 연구보고에 근거하여 금속류중에서 zinc를 실험적으로 과량투여한 후 파네스세포내 zinc의 분포에 어떤 변화가 초래되는 지를 광학 및 전자현미경적 autometallography(AMG)로 관찰함으로써 파네스세포의 zinc와 관련된 세포생물학적 기능을 규명하고자 하였다. Wistar 랫드에 체중 당 20mg의 zinc chloride를 생리식염수 5ml에 녹여 복강주사한 후 2시간에 이르러 0.1 M phosphate buffer(PB)에 녹인 0.5% sodium sulphide-3% glutaraldehyde 흔합액으로 관류고정하였다. 회장(ileum)의 일부를 Dry Ice나 $CO_2$ gas로 얼린 후 cryostat을 이용하여 $20{\mu}m$ 두께의 조직절편을 만들어 및 단계의 AMG법을 시행하였다. 이와는 별도로 EM용으로 선택된 회장절편은 일련의 전자현미경 표본제작과정을 거쳐, 100nm두께의 thin section을 만들어 uranyl-lead 이중염 색 추 전자현미경으로 관찰하였다. Zinc를 투여한 동물에서 관찰된 소견은 생리식염수만을 투여한 대조군의 것과 비교할 때 큰 차이를 보였다. 우선 대조군에서는 파네스세포의 꼭대기(apex)부위에서 낱알모양을 띤 AMG양성반응 구조물(AMG grain)들이 분비과립과 사이토졸(cytosol)에서 관찰되었고, 세포사이공간에서도 적은 양의 grain이 분포하고 있었다. 반면 zinc를 투여한 랫드의 파네스세포에서는 AMG 입자가 이상의 부위에서 훨씬 많은 양의 grain이 분포해 있었으며, 특히 분비과립에서는 가장 높은 농도로 관찰되었다. 더욱이 대조군에서 관찰되지 많았던 장샘의 분비관(Lieberkuhn crypt)및 고유판 혈관의 내에서도 많은 grain이 관찰되었다. 이상의 결과를 요약하면 과량의 zinc에 노출된 생체는 혈관을 경유하여, 파네스세포의 분비과립을 매개로 하여, 장관의 내강쪽으로 과잉의 zinc 를 피내고 있는 모습을 보인다. 따라서 연구자는 파네스세포가 생체내 zinc의 양을 조절하는데 중요한 역할이 있을 것으로 본다. Paneth cells have been suggested to contribute to the elimination of excess metals into the intestinal lumen. The purpose of this study wat to investigate the changes of the zinc pools in rats subjected to functional loading with zinc salt by mean of both light and electron microscopical autometallography (AMG). Wistar rats 4 were administrated with zinc chloride (20 mg/kg body weight) intraperitoneally dissolved in 1 ml distilled water. The control group received 1 ml saline IP. After further one hour the animals were transcardially perfused with 0.4% sodium sulphide dissolved in 0.1 M PB fellowed by 3% glutaraldehyde solution for 10 minutes. Pieces of ileum were frozen with solid $CO_2$ and sectioned on a cryostat. The sections $(20{\mu}m)$ were autometallographically developed. Sections selected for EM were reembedded on top of a blank Epon block, from which ultrathin sections (100 nm) were cut. The ultrathin sections were double stained with uranyl acetate (30 min) and lead citrate (5 min), then examined under electron microscope. Studies of comparable sections from control and zinc loaded animals with the AMG selenium method gave quite different results. The control animals demonstrated a weakly positive staining in the cytoplasm of the Paneth cells. In the electron microscope the AMG silver grains were found to be located in the cytoplasm, while the electron dense secretary granules and other cell organelles were void of staining. Few AMG grains were located at the apical surface of the Paneth cells. In sections from zinc loaded rats, the AMG grains were seen in abundance in the lumen of the Lieberkuhn crypts at light microscopic levels. At EM levels the zinc revealing silver grains were located in the cytoplasm as in the controls, but much more AMG grains were shifted into the secretary granules. Furthermore, profound AMG grains were found in the lumen of the crypts and surrounding vessels. And a few grains were seen in the endothelium. The AMG technique demonstrated a pattern of AMG grains in the Paneth cells that strongly suggests a transport of zinc ions through these cells.

Role of Dietary Zinc as a Nutritional Immunomodulator

Goswami, T.K.,Bhar, R.,Jadhav, S.E.,Joardar, S.N.,Ram, G.C. Asian Australasian Association of Animal Productio 2005 Animal Bioscience Vol.18 No.3

Zinc is ubiquitous in all living cells. Structural and catalytic properties of cellular enzymes are zinc dependent. Zinc deficiency leads to a variety of pathological abnormalities with immune impairment. It is an established fact that nutritional status contributes to overall immune response of individuals. Outcome of zinc deficiency on immune system is so drastic that it is difficult to conceive at the first instance. Zinc supplementation has been advocated to prevent diarrheal disease in children with poor nutritional status. The bioavailability of zinc depends upon its sources. Moreover it varies between monogastrics and ruminants. Controversy still prevails between inorganic and organic sources of zinc with respect to their superiority in bioavailability. Zinc exerts immunostimulatory effects in various laboratory and farm animals. Animals having congenital zinc deficiency diseases like A46 lethal trait usually die due to impairment of the immune system unless treated with zinc. The immune mechanism of zinc and its effect on animals and man are discussed. Zinc has been considered as extremely safe at higher therapeutic doses, but does not provide any beneficial effect but rather may cause immunosuppression. More recently, zinc has been prescribed for immunodeficient hosts, to modulate the immune system so that to a certain extent it can combat against opportunistic pathogens.

Zinc modulation of osterix in MC3T3-E1 cells

Hyun-Ju Seo,Jin Boo Jeong,Young-Eun Cho,In-Sook Kwun 한국영양학회 2020 Journal of Nutrition and Health Vol.53 No.4

Purpose: Zinc is known to be associated with osteoblast proliferation and differentiation. Osterix as zinc-finger transcription factor is also related to osteoblast differentiation and bone formation. In the present study, we aimed to investigate whether zinc modulates osterix gene and protein expression in osteoblastic MC3T3-E1 cells. Methods: MC3T3-E1 cells were cultured in zinc-dependent concentrations (0, 0.5, 1, 5, or 15 μM Zn), along with osteogenic control (normal osteogenic medium) for 1 and 3 days. The gene and protein expression levels of osterix were analyzed by real-time reverse transcription polymerase chain reaction and Western blotting, respectively. Results: Zinc increased osteoblast proliferation in a concentration-dependent manner at day 1 and 3. Similarly, zinc increased the activity of osteoblast marker enzyme alkaline phosphatase in cells and media in a zinc concentration-dependent manner. Moreover, our results showed that the pattern of osterix gene expression by zinc was down-regulated within the low levels of zinc treatments (0.5–1 μM) at day 1, but it was up-regulated after extended culture period at day 3. Osterix protein expression by zinc showed the similar pattern of gene expression, which down-regulated by low zinc levels at day 1 and up-regulated back at day 3 as the early stage of osteoblast differentiation. Conclusion: Our results suggest that zinc modulates osterix gene and protein expression in osteoblasts, particularly in low level of zinc at early stage of osteoblast differentiation period.

Study on Intracellular Zinc Uptake According to Zinc-ligand

Shim, Boo-Im,Kim, Ki-Nam,Kim, Yu-Ri,Lee, Seung-Ho,Lee, Seung-Min,Park, Myung-Gyu,Kim, Meyoung-Kon The Korean Society of Toxicogenomics and Toxicopro 2007 Molecular & cellular toxicology Vol.3 No.4

Zinc plays indispensable roles in metabolism, including cell growth, apoptosis, proliferation and differentiation. Kidneys are target organs for various regulators of mineral metabolism, and play a key role in zinc balance. To investigate the zinc uptake efficiency, we examined the zinc uptake and accumulation level in vivo and in vitro study. Plasma zinc concentration was peaked out at 1 hr after oral zinc administration. The renal zinc level was peaked out at 12 hr after oral zinc administration, and it was the highest in 40 mg/kg Zn-Asp administrated group in comparison with other groups. In addition, the m-RNA expression level of zinc transporter-1 (ZnT-1), zinc transporter-2 (ZnT-2) and high-affinity L-aspartate transporter (EAAT-3) in Zn-Asp administered group were increased compared with control groups and $ZnSO_4$ group. In order to investigate the intracellular zinc uptake mechanism, we performed the in vitro study by using human embryonic kidney cell line, HEK 293. Intracellular zinc level was peaked out at 3 hr after zinc treatment. In the same way, the mRNA expression level of ZnT-1 and EAAT-3 were increased compared with control group. This study showed that Zn-Asp is effective the zinc uptake into the kidney by increasing the zinc transporter expression.

Food sources of zinc and nutritional status with usual dietary zinc intake in Korean toddlers and preschool children

Song SuJin,Shim Jae Eun 한국영양학회 2023 Nutrition Research and Practice Vol.17 No.6

BACKGROUND/OBJECTIVES: This study aimed to evaluate the food sources of zinc and the usual intake of dietary zinc among Korean toddlers and preschool children. SUBJECTS/METHODS: A total of 2,679 children aged 1–5 years was selected from the 2009–2013 Korea National Health and Nutrition Examination Survey (KNHANES) data. Dietary data collected from a single 24-h recall were used to evaluate the food sources of zinc. To estimate usual zinc intake, the distribution obtained from single 24-h recall data in the total sample was adjusted using the ratio of within-to-between-person variance in zinc intake obtained from 2-day 24-h recall sub-sample data of the 2009 KNHANES. The proportion of children with usual zinc intake below the estimated average requirement (EAR) and above the tolerable upper intake level (UL) was assessed. RESULTS: The main sources of zinc in Korean children were grains, dairy products, and meat. The mean usual intakes of zinc among all individuals, those aged 1–2 yrs, and those aged 3–5 yrs were 5.50, 5.01, and 5.83 mg/d, respectively. In all participants, 1.1% of the children consumed zinc below the EAR, whereas 10.7% exceeded the UL. The proportion of children with excessive zinc intake was 25.6% in the 1–2 yrs age group and 0.6% in the 3–5 yrs age group. CONCLUSIONS: According to the current UL, the risk of excessive zinc intake appears to be high among Korean toddlers. Future studies that monitor the health effects of excessive zinc intake are needed to appropriately guide zinc intake in children.

The Efficiency of Zinc-Aspartate Complex on Zinc Uptake in Plasma and Different Organs in Normal SD Rats

Kim, Yu-Ri,Kim, Ki-Nam,Shim, Boo-Im,Lee, Seung-Min,Kim, In-Kyoung,Sohn, Sung-Hwa,Park, Myung-Gyu,Park, Hong-Suk,Kim, Meyoung-Kon The Korean Society of Toxicogenomics and Toxicopro 2007 Molecular & cellular toxicology Vol.3 No.2

Zinc is essential metal and plays a role in a wide variety of physiological and biochemical processes. Prostate gland contains high level of zinc, generally 3-10 folds higher than other organs. Prostatic zinc uptake is resulted from the existence of zinc transporter (ZnT) protein families in membrane. In this study, we investigated the difference of zinc uptake efficiency of zinc-aspartate complex (Zn-Asp) into various organs compared with $ZnSO_4$. We observed that Plasma zinc concentration in both $ZnSO_4$ and Zn-Asp administrated group was increased progressively following administration, and reached a peak level at 2 hr. The increasing pattern of zinc concentration was similar to each groups, however the zinc concentration of Zn-Asp administrated group was higher than that of $ZnSO_4$ administrated group. We found that prostatic zinc level of Zn-Asp administrated group was higher than $ZnSO_4$ administrated group, and was increased approximately $\sim$2.7 fold and $\sim$4.2 fold at 4 and 8 hr after administration. From these observations, we suggest than Zn-Asp has high uptake efficiency of zinc into the prostate gland. Therefore, Zn-Asp is potentially useful treatment of many prostatic diseases.

만성 세균성 전립선염의 백서 모델에서 전립선내 Zinc 주입의 항균 효과

이충범,이윤보,이승주,조용현,조대행 大韓泌尿器科學會 2002 Korean Journal of Urology Vol.43 No.4

Zinc Absorption of Preschool Children

Kim, Young-Seon 한국식품영양학회 2002 韓國食品營養學會誌 Vol.15 No.1

학령전 아동의 zinc absorption, excretion, balance에 대하여 연구한 결과는 다음과 같다. Zinc absorption은 남자아동의 경우 29.7%, 여자 아동의 경우 23.3%, 평균 25.8%로 나타났다. 대상자의 zinc absorption은 zinc intake와는 상관성이 나타나지 않았으며, zinc balance와 유의적 상관 (p<0.01)을 보였다. Zinc balance는 남자 아동의 경우 평균 3.25mg/day, 여자 아동의 경우 1.78mg/day, 평균 2.34mg/day로 1명의 대상자를 제외하고 모두 positive balance를 보였다. Fecal zinc loss는 평균 6.31mg/day, nary zinc loss는 평균 0.16mg/day였다. zinc intake는 fecal zinc loss및 zinc balance에 유의적 영향을 미치는 것으로 나타났으며 (p<0.01), urinary zinc는 intake의 영향을 받지 않았다. 우리나라 학령전 아동의 zinc absorption 및 balance,는 양호한 것으로 나타났다. 그러나 이 방면의 연구 자료가 많지 않아, 성장기 아동을 대상으로 한 zinc nutrition에 대한 구체적이고 지속적인 연구가 필요하다. This study was performed to estimate the zinc absorption, excretion, and balance of preschool children in Pohang and to evaluate the relationship zinc absorption and related variables. To determine the zinc absorption and excretion, duplicate food samples, pooled feces and urine samples were collected for 3 consecutive days in 21 preschool children. The mean fecal and urine excretions were 7.03mg/day and 0.16mg/day for the boys and 5.87mg/day and 0.15mg/day for the girls. Analyzed daily mean zinc intake was 10.45mg/day for the boys and 7.80mg/day for the girls. The mean apparent absorption rate and balance were 29.7% and 3.25mg for the boys and 23.3%, 1.78mg for the girls. Although the mean apparent absorption rate and balance of boys tended to be higher, there was no significant difference between boys and girls. In this study, subjects showed the positive balance except one. Fecal zinc loss reflected dietary zinc (p<0.01), but urinary zinc loss was unaffected by zinc intake. There was a positive relationship between zinc apparent absorption and zinc balance (p<0.01). These results show that the zinc absorption and balance were favorable.