Mitigation of benzyl butyl phthalate toxicity in male germ cells with combined treatment of parthenolide, N-acetylcysteine, and 3-methyladenine.

Benzyl butyl phthalate (BBP) is a widely used plasticizer that poses various potential health hazards. Although BBP has been extensively studied, the direct mechanism underlying its toxicity in male germ cells remains unclear. Therefore, we investigated BBP-mediated male germ cell toxicity in GC-1 spermatogonia (spg), a differentiated mouse male germ cell line. This study investigated the impact of BBP on reactive oxygen species (ROS) generation, apoptosis, and autophagy regulation, as well as potential protective measures against BBP-induced toxicity. A marked dose-dependent decrease in GC-1 spg cell proliferation was observed following treatment with BBP at 12.5 µM. Exposure to 50 µM BBP, approximating the IC50 of 53.9 µM, markedly increased cellular ROS generation and instigated apoptosis, as evidenced by augmented protein levels of both intrinsic and extrinsic apoptosis-related markers. An amount of 50 µM BBP induced marked upregulation of autophagy regulator proteins, p38 MAPK, and extracellular signal-regulated kinase and substantially downregulated the phosphorylation of key kinases involved in regulating cell proliferation, including phosphoinositide 3-kinase, protein kinase B, mammalian target of rapamycin (mTOR), c-Jun N-terminal kinase. The triple combination of N-acetylcysteine, parthenolide, and 3-methyladenine markedly restored cell proliferation, decreased BBP-induced apoptosis and autophagy, and restored mTOR phosphorylation. This study provides new insights into BBP-induced male germ cell toxicity and highlights the therapeutic potential of the triple inhibitors in mitigating BBP toxicity.

Iron-(Fe3+) dependent reactivation of telomerase drives colorectal cancers.

Over-consumption of iron-rich red meat and hereditary or genetic iron overload are associated with increased risk of colorectal carcinogenesis, yet the mechanistic basis of how metal-mediated signaling leads to oncogenesis remains enigmatic. Using fresh colorectal cancer (CRC) samples we identify Pirin, an iron sensor, that overcomes a rate-limiting step in oncogenesis, by re-activating the dormant human-reverse-transcriptase (hTERT) subunit of telomerase holoenzyme in an iron-(Fe3+)-dependent-manner and thereby drives CRCs. Chemical genetic screens combined with isothermal-dose response fingerprinting and mass-spectrometry identified a small molecule SP2509, that specifically inhibits Pirin-mediated hTERT reactivation in CRCs by competing with iron-(Fe3+) binding. Our findings, first to document how metal ions reactivate telomerase, provide a molecular mechanism for the well-known association between red meat, and increased incidence of CRCs. Small molecules like SP2509 represent a novel modality to target telomerase that acts as driver of 90% human cancers and is yet to be targeted in clinic.

N-Acetyl-L-cysteine attenuates titanium dioxide nanoparticle (TiO2 NP)-induced autophagy in male germ cells.

Titanium dioxide nanoparticles (TiO2 NPs) are widely used in consumer products, raising concerns about their impact on human health. This study investigates the effects of TiO2 NPs on male germ cells while focusing on cell proliferation inhibition and underlying mechanisms. This was done by utilizing mouse GC-1 spermatogonia cells, an immortalized spermatogonia cell line. TiO2 NPs induced a concentration-dependent proliferation inhibition with increased reactive oxygen species (ROS) generation. Notably, TiO2 NPs induced autophagy and decreased ERK phosphorylation. Treatment with the ROS inhibitor N-Acetyl-l-cysteine (NAC) alleviated TiO2 NPs-induced autophagy, restored ERK phosphorylation, and promoted cell proliferation. These findings call attention to the reproductive risks posed by TiO2 NPs while also highlighting NAC as a possible protective agent against reproductive toxins.

Genome-wide transcriptome analysis reveals that Bisphenol A activates immune responses in skeletal muscle.

Cumulative human exposure to the environmental toxin, bisphenol A (BPA), has raised important health concerns in recent decades. However, the direct genomic regulation of BPA in skeletal muscles and its clinical significance are poorly understood. Therefore, we conducted a genome-wide transcriptome analysis after daily oral administration of BPA at the lowest observed adverse-effect level (LOAEL, 50 mg/kg) in male mice for six weeks to explore the gene-expression regulations in skeletal muscle induced by BPA. The primary Gene Ontology terms linked to BPA-dependent, differentially expressed genes at LOAEL comprised adaptive-immune response, positive regulation of T cell activation, and immune system process. The gene-set enrichment analysis disclosed increased complement-associated genes [complement components 3 (C3) and 4B, complement factor D, complement receptor 2, and immunoglobulin lambda constant 2] in the group administered with BPA, with a false-discovery rate of <0.05. Subsequent validation analysis conducted in BPA-fed animal skeletal muscle tissue and in vitro experiments confirmed that BPA induced immune activation, as evidenced by increased levels of C3 and C4α proteins in mice, C2C12 myoblasts, and mouse skeletal muscle cells. In addition, BPA markedly upregulated the transcription of tumor necrosis factor-α (Tnfα) in C2C12 myoblasts and mouse skeletal muscle cells, which was substantially inhibited by 5z-7-oxozeanol and parthenolide, providing further evidence of BPA-induced inflammation in muscle cells. Our bioinformatics and subsequent animal and in vitro validations demonstrate that BPA can activate inflammation in skeletal muscle, which could be a risk factor underlying chronic muscle weakness and wastage.

Bisphenol Analogs Downregulate the Self-Renewal Potential of Spermatogonial Stem Cells.

PURPOSE: In this study, we investigated the effect of bisphenol-A (BPA) and its major analogs, bisphenol-F (BPF), and bisphenol-S (BPS), on spermatogonial stem cells (SSCs) populations using in vitro SSC culture and in vivo transplantation models. MATERIALS AND METHODS: SSCs enriched from 6- to 8-day-old C57BL/6-eGFP+ male mice testes were treated with varying concentrations of bisphenols for 7 days to examine bisphenol-derived cytotoxicity and changes in SSC characteristics. We utilized flow cytometry, immunocytochemistry, real-time quantitative reverse transcription-PCR, and western blot analysis. The functional alteration of SSCs was further investigated by examining donor SSC-derived spermatogenesis evaluation through in vivo transplantation and subsequent testis analysis. RESULTS: BPF exhibited a similar inhibitory effect on SSCs as BPA, demonstrating a significant decrease in SSC survival, inhibition of proliferation, and induction of apoptosis. On the other hand, while BPS was comparatively weaker than BPA and BPF, it still showed significant SSC cytotoxicity. Importantly, SSCs exposed to BPA, BPF, and BPS exhibited a significant reduction in donor SSC-derived germ cell colonies per total number of cultured cells, indicating that, like BPA, BPF, and BPS can induce a comparable reduction in functional SSCs in the recipient animals. However, the progress of spermatogenesis, as evidenced by histochemistry and the expressions of PCNA and SSC specific markers, collectively indicates that BPA, BPF, and BPS may not adversely affect the spermatogenesis. CONCLUSIONS: Our findings indicate that the major BPA substitutes, BPF and BPS, have significant cytotoxic effects on SSCs, similar to BPA. These effects may lead to a reduction in the functional self-renewal stem cell population and potential impacts on male fertility.

Inhibition of reactive oxygen species generation by N-Acetyl Cysteine can mitigate male germ cell toxicity induced by bisphenol analogs.

The estrogen-like effect of bisphenol A (BPA) disrupting the maintenance of functional male germ cells is associated with male sub-fertility. This study investigated toxicity of male germ cells induced by four bisphenol analogs: BPA, BPAF, BPF, and BPS. The investigation of bisphenol analogs' impact on male germ cells included assessing proliferation, apoptosis induction, and the capacity to generate reactive oxygen species (ROS) in GC-1 spermatogonia (spg) cells, specifically type B spermatogonia. Additionally, the therapeutic potential and protective effects of N-Acetyl Cysteine (NAC) and NF-κB inhibitor parthenolide was evaluated. In comparison to BPA, BPF and BPS, BPAF exhibited the most pronounced adverse effect in GC-1 spg cell proliferation. This effect was characterized by pronounced inhibition of phosphorylation of PI3K, AKT, and mTOR, along with increased release of cytochrome c and subsequent cleavages of caspase 3, caspase 7, and poly (ADP-ribose) polymerase. Both NAC and parthenolide were effective reducing cellular ROS induced by BPAF. However, only NAC demonstrated a substantial recovery in proliferation, accompanied by a significant reduction in cytochrome c release and cleaved PARP. These results suggest that NAC supplementation may play an effective therapeutic role in countering germ cell toxicity induced by environmental pollutants with robust oxidative stress-generating capacity.

Deciphering the mechanisms and interactions of the endocrine disruptor bisphenol A and its analogs with the androgen receptor.

Bisphenol A (BPA) and its various forms used as BPA alternatives in industries are recognized toxic compounds and antiandrogenic endocrine disruptors. These chemicals are widespread in the environment and frequently detected in biological samples. Concerns exist about their impact on hormones, disrupting natural biological processes in humans, together with their negative impacts on the environment and biotic life. This study aims to characterize the interaction between BPA analogs and the androgen receptor (AR) and the effect on the receptor's normal activity. To achieve this goal, molecular docking was conducted with BPA and its analogs and dihydrotestosterone (DHT) as a reference ligand. Four BPA analogs exhibited higher affinity (-10.2 to -8.7 kcal/mol) for AR compared to BPA (-8.6 kcal/mol), displaying distinct interaction patterns. Interestingly, DHT (-11.0 kcal/mol) shared a binding pattern with BPA. ADMET analysis of the top 10 compounds, followed by molecular dynamics simulations, revealed toxicity and dynamic behavior. Experimental studies demonstrated that only BPA disrupts DHT-induced AR dimerization, thereby affecting AR's function due to its binding nature. This similarity to DHT was observed during computational analysis. These findings emphasize the importance of targeted strategies to mitigate BPA toxicity, offering crucial insights for interventions in human health and environmental well-being.

Significant CO2 emission in the shallow inshore waters of the southeastern Yellow Sea in 2020.

This study investigated the carbonate system and air-sea CO2 exchange in the inshore waters along South Korea's western coastline in 2020. Overlooking these waters might introduce significant errors in estimating air-sea CO2 fluxes of the southeastern Yellow Sea, given their interaction with land, offshore regions, and sediments. During periods other than summer, seasonal variations in seawater CO2 partial pressure (pCO2) could be generally explained by thermal effects. Tidal mixing and shallow depths resulted in weaker stratification-induced carbon export compared to offshore regions. However, during summer, inshore waters exhibited high spatial variability in pCO2, ranging from approximately 185 to 1000 µatm. In contrast to offshore waters that modestly absorbed CO2, inshore waters shallower than 20 m emitted ∼100 Gg C yr-1 to the atmosphere. However, considering the high heterogeneity of the study area, additional observations with high spatial and temporal resolution are required to refine estimates of air-sea CO2 exchange.

Diisobutyl phthalate (DiBP)-induced male germ cell toxicity and its alleviation approach.

Diisobutyl phthalate (DiBP) is a commonly used plasticizer in manufacturing consumer and industrial products to improve flexibility and durability. Despite of the numerous studies, however, the direct mechanism underlying the male reproductive damage of DiBP is poorly understood. In this study, we investigated the male germ cell toxicity of DiBP using GC-1 spermatogonia (spg) cells. Our results indicated that DiBP exposure causes oxidative stress and apoptosis in GC-1 spg cells. In addition, DiBP-derived autophagy activation and down-regulation of phosphoinositide 3-kinase (PI3K)-AKT and extracellular signal-regulated kinase (ERK) pathways further inhibited GC-1 spg cell proliferation, indicating that DiBP can instigate male germ cell toxicity by targeting several pathways. Importantly, a combined treatment of parthenolide, N-acetylcysteine, and 3-methyladenine significantly reduced DiBP-induced male germ cell toxicity and restored proliferation. Taken together, the results of this study can provide valuable information to the existing literature by enhancing the understanding of single phthalate DiBP-derived male germ cell toxicity and the therapeutic interventions that can mitigate DiBP damage.

Restoration of PM2.5-induced spermatogonia GC-1 cellular damage by parthenolide via suppression of autophagy and inflammation: An in vitro study.

Particulate matter (PM) generated by environmental and air pollution is known to have detrimental effects on human health. Among these, PM2.5 particles (diameter < 2.5 µm) can breach the alveolar-capillary barrier and disseminate to other organs, posing significant health risks. Numerous studies have shown that PMs can harm various organs, including the reproductive system. Therefore, this study aimed to investigate the harmful effects of PM2.5 on mouse GC-1 spermatogonia cells (GC-1 spg cells) and to verify the ameliorative effects of parthenolide (PTL) treatment on damaged GC-1 spg cells. We observed a significant dose-dependent reduction in cell proliferation after PM2.5 concentration of 2.5 µg/cm2. Additionally, treatment with 20 µg/cm2 PM2.5 concentration significantly increased the expression of autophagy-related proteins ATG7, the ratio of LC3-II/LC3-I, and decreased phosphorylation of PI3K and AKT. Furthermore, PM2.5 exposure augmented inflammation mediator gene expressions, the phosphorylation of the inflammation-related transcription factor NF-κB p65 at Ser536, and ubiquitination. Treatment of PM2.5-exposed GC-1 spg cells with PTL significantly reduced NF-κB p65 phosphorylation and the expression of autophagy-related proteins ATG7 and LC3-II, leading to a statistically significant recovery in cell proliferation. Together, our findings elucidated the detrimental effects of PM2.5 exposure on male germ cells, and the restorative properties of PTL against air pollutants.

Simultaneous quantification of cyanobacteria and Microcystis spp. using real-time PCR.

In order to develop a protocol to quantify cyanobacteria and Microcystis simultaneously, the primers and probe were designed from the conserved regions of 16S rRNA gene sequences of cyanobacteria and Microcystis, respectively. Probe match analysis of the Ribosomal Database Project showed that the primers matched with over 97% of cyanobacterial 16S rRNA genes, indicating these can be used to amplify cyanobacteria specifically. The TaqMan probe, which is located between two primers, matched with 98.2% of sequences in genus GpXI, in which most Microcystis strains are included. The numbers of cyanobacterial genes were estimated with the emission of SYBR Green from the amplicons with two primers, whereas those of Microcystis spp. were measured from the fluorescence of CAL Fluor Gold 540 emitted by exonuclease activity of Taq DNA polymerase in amplification. It is expected that this method enhances the accuracy and reduces the time to count cyanobacteria and potential toxigenic Microcystis spp. in aquatic environmental samples.