Toxic effect of heavy metals on ovarian deformities,apoptotic changes,oxidative stress,and steroid hormones in rainbow trout

BackgroundAs is well known, the pollution in the aquatic environment in which fish grow has a direct impact on aquaculture practices. Pollution in aquatic systems because of multiple adverse effects on fish metabolic processes, especially the reproductive systems.AimThe goal of this study was to assess the severity of pollution impact in two different hatcheries, Verinag hatchery, Site 1 (S1) and Panzath hatchery, Site 2 (S2) in Anantnag region, using histopathological, ultrastructural, oxidative stress, genotoxic, and hormonal analysis in rainbow trout gonad (ovary).M&M: Fish were collected between May 2018 and April 2019 from two locations, Verinag hatchery (S1) and Panzath hatchery (S2), which were affected by heavy metals.ResultsThe histological and ultrastructural examination of rainbow trout ovaries from the Verinag hatchery (S1) revealed normal structure in growing oocytes in rainbow trout at various stages based on morphological features while the fish ovaries in the Panzath hatchery (S2) showed various deformities and irregularly shaped oocytes. The surfaces of some of these oocytes were wrinkled, rough, or distorted. Apoptotic studies revealed that the frequency of apoptotic cells collected from S2 water was significantly increased in ovarian cells (P < 0.05). The activity of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) were found to be increased in fish collected from S1 but decreased in fish collected from S2. In S2 caught fish, malondialdehyde (MDA) levels were found to increase gradually, and the degree of heavy metal stress was positively correlated (p < 0.05). The comet assay was used to determine the induction of DNA damage in ovarian cells. The induction of DNA damage was found to be significantly higher (p < 0.05) in S2 fish specimens compared to fish from S1. On comparing the DNA damage of the rainbow trout from the two sampling sites, it was revealed that the fish is much more sensitive to aquatic contaminants. Regarding steroid hormones, higher levels of progesterone and estrogen were reported in the fish samples collected from S1 as compared to S2 captured fish.ConclusionIn conclusion, the comparative study of fish from two different sites viz. Verinag hatchery (S1) and Panzath hatchery (S2) revealed that S2 sampled fish suffered more heavy metal damage, including cellular deformities, apoptosis, oxidative damage, and altered steroid hormones.     

Triterpenoids from Meehania fargesii with Cytotoxic Activity1

In the investigation of Meehania fargesii, eighteen triterpenoids were isolated and identified, including a previously unknown compound with an 13,27-cycloursane skeleton, using techniques like 1D and 2D NMR, and HR-MS. Furthermore, the cytotoxicity of these compounds were evaluated against HCT116, MCF-7, and AGS cell lines using the CCK-8 method to examine their structure–activity relationship. Remarkably, compounds 13 and 16 exhibited higher cytotoxicity across all three cell lines compared to the positive drug. Western blot analysis revealed that these compounds activated apoptosis in HCT116 cells by promoting the Bax protein and inhibiting the Bcl-2 protein. This suggests that compounds 13 and 16 have potential as apoptosis-inducing agents in HCT116 cells.     

Orotic acid induces apoptotic death in ovarian adult granulosa tumour cells and increases mitochondrial activity in normal ovarian granulosa cells

Orotic acid (OA) is a natural product that acts as a precursor in the pyrimidine nucleotide biosynthesis pathway. Most studies concerning administration of OA focus on its therapeutic effects; however, its effect on tumours is unclear. We aimed to determine whether treatment with OA influences the viability and apoptosis of normal (HGrC1) and tumour-derived (KGN) human ovarian granulosa cells. The effects of OA (10–250 μM) on viability and apoptosis of both cell lines were determined by using alamarBlue and assessing caspase-3/7 activity, respectively. Annexin V binding and loss of membrane integrity were evaluated in KGN cells. The cell cycle and proliferation of HGrC1 cells were assessed by performing flow cytometric and DNA content analyses, respectively. The influence of OA (10 and 100 μM) on cell cycle- and apoptosis-related gene expression was assessed by RT-qPCR in both cell lines. Mitochondrial activity was analysed by JC-1 staining in HGrC1 cells. In KGN cells, OA reduced viability and increased caspase-3/7 activity, but did not affect mRNA expression of Caspase 3, BAX, and BCL2. OA enhanced proliferation and mitochondrial activity in HGrC1 cells without activating apoptosis. This study demonstrates that the anti-cancer properties of OA in ovarian granulosa tumour cells are not related to changes in apoptosis-associated gene expression, but to increased caspase-3/7 activity. Thus, OA is a promising therapeutic agent for ovarian granulosa tumours. Further, our results suggest that differences in basal expression of cell cycle- and apoptosis-related genes between the two cell lines are responsible for their different responses to OA.     

Increased cyclin B1/CDC 2 kinase activity and phosphorylation of Bcl-2 associated with paclitaxel-induced apoptosis in human nasopharyngeal carcinoma cells

Paclitaxel is a potential cancer chemotherapeutic agent for ovary, breast, and head and neck cancers; its effects on nasopharyngeal carcinoma (NPC) have not been reported previously. This study investigated the cytotoxic mechanism of paclitaxel in two NPC cell lines, NPC-TW01 and NPC-TW04. NPC cells treated with pacli-taxel showed convoluted nuclei, condensed chromatin and decreased cellular and nuclear volume, and also exhibited genomic DNA degradation into multiple oligonucleosomal fragments, suggesting that pacli-taxel induced apoptosis in these cells. The effects of paclitaxel on apoptosis-related proteins including Bcl-2, Bax and CDC 2 were also detected. Although the levels of Bcl-2 and Bax were not changed in NPC cells following treatment with 5 nM-1 μM of paclitaxel, phosphorylation of Bcl-2 was significantly observed in the cells treated with 1 μM of paclitaxel for 12 hours. In addition, cyclin B1-associated CDC 2 kinase was highly activated in the NPC cells exposed to paclitaxel even at low (5 nM) concentration, and this result is associated with the finding that low concentration of paclitaxel is able to induce apoptosis in NPC cells.     

The CD95 (Fas/APO-1) receptor is phosphorylatedin vitro andin vivo and constitutively associates with several cellular proteins

Different CD95 (Fas/APO-1) isoforms and phosphory lated CD95 species were identified in human T and B cell lines. We had shown previously that the CD95 intracellular domain (IC), expressed as a glutathione S-transferase (GST) fusion protein in murine L929 fibroblasts, was phosphorylatedin vivo. GST-CD95IC was phosphorylatedin vitro by a kinase present in extracts from the human lymphocytic cell lines Jurkat and MP-1 and from murine L929 cells. Phosphoamino acid analysis indicated that phosphorylation occurred at multiple threonine residues and also at tyrosine (Tyr232 and Tyr291) and serine. Amino acids 191 to 275 of CD95 were sufficient for phosphorylation at threonine, tyrosine and serine and also mediated interaction with a 35 kDa cellular protein. Immuno-precipitation of CD95 and chemical cross-linking revealed CD95-associated proteins of approximately 35, 45 and 75 kDa. GST-CD95IC affinity chromatography detected binding of the 35 and 75 kDa protein species. The 75 kDa species may correspond to the CD95-associated proteins RIP or FAF1 and the 35 kDa protein may represent a TRADD analogue. These data indicate that several cellular proteins interact with CD95, possibly in a multi-protein complex, and that a kinase activity is associated with CD95 not onlyin vitro but alsoin vivo. Therefore, receptor phosphorylation may play a role in CD95 signal transduction. This work was in part supported by a grant from the Health Research Council of New Zealand (to JW).     

Neuronal apoptosis versus necrosis induced by glutamate or free radicals

The type of cell death encountered in neuronal cell cultures exposed to excitatory amino acids — such as glutamate, the major excitatory neurotransmitter in the central nervous system, or free radicals, such as nitric oxide (NO^.) and superoxide anoin (O2^{. –}), which react to form peroxynitrite (ONOO^–) — appears to depend on the intensity of the exposure and may involve two temporarily distinct phases. Following relatively fulminant insults, an initial phase of necrosis — associated with extreme energy depletion — may simply reflect the failure of neurons to carry out the default apoptotic death program used to efficiently dispose of aged or otherwise unwanted cells. Neurons recovering mitochondrial energy potential after an initial fulminant insult or following a more subtle inciting injury may subsequently undergo apoptosis, possibly associated with a factor released from mitochondria that triggers this death program. The maintenance of balanced energy production may be a decisive factor in detemining the degree, type, and progression of neuronal injury caused by excitotoxins and free radicals. Similar events could possibly occur in vivo after ischemia or other insults.     

Ras-mediated cell proliferation and cell death: some clues from the interleukin-2 receptor system

Oncoproteins of the Ras family have been extensively studied because of their implication in human cancer. Their roles have been primarily assigned to the commandment of cell proliferation and suppression of apoptosis, which has also been demonstrated by the involvement of Ras activation in the signal transduction pathways triggered by most cytokine receptors. Nevertheless, the functions of Ras proteins have been extended in the last years by the findings showing that they can also act as promoters or enhancers of apoptosis in various systems and conditions. These considerations have raised the issue as to how the signals delivered by Ras are regulated and translated in terms of cellular responses, suggesting that signal complementation may direct the final fate of cells. As an example, the interleukin-2 receptor system may represent a useful model in which the meaning of Ras signals may be evaluated in terms of interactions with other simultaneous signalling events, since knowledge of the biochemical events triggered by the interaction of interleukin-2 with its cell surface receptor in lymphocytes has allowed the proposal of a complete signalling model arranged in three independent channels, one of which is mediated by Ras.This work was supported by grants from CICYT and Pharmacia-Upjohn.     

Upregulation of Fas-induced apoptosis by interferon-γ accompanied by increased ICE expression in renal cell cancer cells

The integration of Fas/Apo-1 (CD95) by Fas ligand or anti-Fas antibody induces apoptosis, and this system plays a pivotal role for the lysis of target cells by cytotoxic T lymphocytes. Fas-mediated apoptosis is also increased by a prior incubation of Fas-bearing cells with interferon(IFN)-. Interleukin-1- converting enzyme (ICE) and/or CPP32, or other members of ICE family act as direct cell death executors downstream of this mechanism, and a tetrapeptide inhibitor of these cysteine proteases blocks Fas-mediated apoptosis. In this study, we examined the effect of IFN- on Fas-mediated apoptosis in ACHN cells. IFN- augmented apoptosis in a dose dependent manner and reached a plateau at 400 U/ml when exposed for 48 h before the end of culture. The kinetics revealed a significant increase in apoptosis after 24 h. Exposing ACHN cells to IFN- increased pro-ICE expression accompanied with a decrease of pro-CPP32. These results suggest that direct enhancement of ICE expression and/or upregulation of conversion of pro-CPP32 to active form increases Fas-mediated apoptosis by IFN- in ACHN cells.     

原位缺口平移标记断裂DNA技术及其在检测流行性出血热尸检和实验动物组织中细胞凋亡和早期死亡的应用

原位缺口平移技术（ＩＳＮＴ）已被用于检测细胞核中ＤＮＡ断裂鉴别尸检组织中细胞的凋亡和坏死断裂、流行性出血热（ＥＨＦ）组织中存在散在单个细胞变性死亡和灶性梗死样坏死,前者带有细胞凋亡的特征。本文以ＥＨＦ肝脏和实验性病毒感染鼠脑组织为例,应用缺口平移法,在ＤＮＡ聚合酶或Ｋｌｅｎｏｗ酶的作用下,将地高辛标记的ｄＵＴＰ掺入合成到ＤＮＡ的断裂部位,通过碱性磷酸酶标抗地高辛抗体免疫组化法显示细胞ＤＮＡ的断裂,检测和鉴别细胞的凋亡和坏死。为分析死后解剖时间间隔及组织固定时间对该方法的影响,本文选用死后２～１４０ｈ尸检、经常规固定石蜡包埋后存放１０～３５年的标本和在１０％福尔马林固定了１０～３５年之后再进行常规处理的标本。实验时用蛋白酶Ｋ（ＰＫ）消化前后对比并分别在标记反应液中略去ＤＮＡ聚合酶作为阴性对照,用ＤＮＡ酶消化组织人为制造ＤＮＡ缺日作为阳性对照。结果发现,未经ＰＫ消化的组织,仅灶性肝细胞核ＩＳＮＴ标记阳性,经ＰＫ消化后,散在的带有凋亡特征的肝细胞胞核也出现阳性,灶性肝细胞胞核标记染色增强,但无论是蛋白酶消化与否,明确梗死样坏死的肝细胞均不被标记。结果还发现,死后２～２４ｈ内尸检组织和长时间（１０～３４年）存放的石     

Peroxynitrite-Induced Cytotoxicity in PC12 Cells: Evidence for an Apoptotic Mechanism Differentially Modulated by Neurotrophic Factors

Abstract: Peroxynitrite is a powerful oxidant formed by the near-diffusion-limited reaction of nitric oxide with superoxide. Large doses of peroxynitrite (>2 m M ) resulted in rapid cell swelling and necrosis of undifferentiated PC12 cells. However, brief exposure to lower concentrations of peroxynitrite (EC₅₀ = 850 µ M ) initially (3–4 h) caused minimal damage to low-density cultures. By 8 h, cytoplasmic shrinkage with nuclear condensation and fragmentation became increasingly evident. After 24 h, 36% of peroxynitrite-treated cells demonstrated these features associated with apoptosis. In addition, 46% of peroxynitrite-treated cells demonstrated DNA fragmentation (by terminal-deoxynucleotide transferase-mediated dUTP-digoxigenin nick end-labeling) after 7 h, which was inhibited by posttreatment with the endonuclease inhibitor aurintricarboxylic acid. Serum starvation also resulted in apoptosis in control cells (23%), the percentage of which was not altered significantly by peroxynitrite treatment. Although peroxynitrite is known to be toxic to cells, the present study provides a first indication that peroxynitrite induces apoptosis. Furthermore, pretreatment of cells with nerve growth factor or insulin, but not epidermal growth factor, was protective against peroxynitrite-induced apoptosis. However, both acidic and basic fibroblast growth factors greatly increased peroxynitrite-initiated apoptosis, to 63 and 70%, respectively. Thus, specific trophic factors demonstrate differential regulation of peroxynitrite-induced apoptosis in vitro.