Transgenerational lipid-reducing activity of benzylisoquinoline alkaloids in Caenorhabditis elegans

Bioactivity and mechanism of action of sanguinarine and its derivatives in the past 10 years

Sanguinarine is a quaternary ammonium benzophenanthine alkaloid found in traditional herbs such as Chelidonium, Corydalis, Sanguinarum, and Borovula. It has been proven to possess broad-spectrum biological activities, such as antitumor, anti-inflammatory, antiosteoporosis, neuroprotective, and antipathogenic microorganism activities. In this paper, recent progress on the biological activity and mechanism of action of sanguinarine and its derivatives over the past ten years is reviewed. The results showed that the biological activities of hematarginine and its derivatives are related mainly to the JAK/STAT, PI3K/Akt/mTOR, NF-κB, TGF-β, MAPK and Wnt/β-catenin signaling pathways. The limitations of using sanguinarine in clinical application are also discussed, and the research prospects of this subject are outlined. In general, sanguinarine, a natural medicine, has many pharmacological effects, but its toxicity and safety in clinical application still need to be further studied. This review provides useful information for the development of sanguinarine-based bioactive agents.

A review of transgenerational and multigenerational toxicology in the in vivo model animal Caenorhabditis elegans

A large number of pollutants existing in the environment can last for a long time, and their potential toxic effects can transfer from parents to their offspring. Thus, it is necessary to investigate the toxicity of environmental pollutants across multigenerations and the underlying mechanisms in organisms. Due to its short life cycle and sensitivity to environmental exposures, Caenorhabditis elegans is an important animal model for toxicity assessment of environmental pollutants across multigenerations. In this review, we introduced the transgenerational and multigenerational toxicity caused by various environmental pollutants in C. elegans. Moreover, we discussed the underlying mechanisms for the observed transgenerational and multigenerational toxicity of environmental contaminants in C. elegans.

Histone H3K4me3 modification is a transgenerational epigenetic signal for lipid metabolism in Caenorhabditis elegans

As a major risk factor to human health, obesity presents a massive burden to people and society. Interestingly, the obese status of parents can cause progeny's lipid accumulation through epigenetic inheritance in multiple species. To date, many questions remain as to how lipid accumulation leads to signals that are transmitted across generations. In this study, we establish a nematode model of C. elegans raised on a high-fat diet (HFD) that leads to measurable lipid accumulation, which can transmit the lipid accumulation signal to their multigenerational progeny. Using this model, we find that transcription factors DAF-16/FOXO and SBP-1/SREBP, nuclear receptors NHR-49 and NHR-80, and delta-9 desaturases (fat-5, fat-6, and fat-7) are required for transgenerational lipid accumulation. Additionally, histone H3K4 trimethylation (H3K4me3) marks lipid metabolism genes and increases their transcription response to multigenerational obesogenic effects. In summary, this study establishes an interaction between a network of lipid metabolic genes and chromatin modifications, which work together to achieve transgenerational epigenetic inheritance of obesogenic effects.

Trans-generational effects of copper on nerve damage in Caenorhabditis elegans

The potential toxicity of copper has received great attention for a long time, however, trans-generational effects of copper have not been extensively investigated. Caenorhabditis elegans (C. elegans) was used to evaluate the trans-generational toxicities of copper several physiological endpoints: growth, head thrashes and body bends and degree of neuronal damage. Copper significantly inhibited growth, body bends, head thrashes and caused degeneration of dopaminergic neurons in a concentration-dependent manner in parental worms. Further we found oxidative damage was to underlying the onset of neuron degeneration. In our study copper promoted ROS accumulation, and led to an increased expression of the oxidative stress response-related genes sod-3 and a decreased expression of metal detoxification genes mtl-1 and mtl-2. Moreover, copper increased the fluorescence intensity of the transgenic strain that encodes the antioxidant enzyme SOD-3. Gradually decline in copper-induced impairments were observed in the filial generations without exposure. No growth impairment was shown in F3, the trend of head thrashes recovery gradually appeared in F2 and no growth impairment was shown in F3, the body bends impairment caused by the parental copper exposure was recovery until F4 and no growth impairment was shown in F5. Besides, dopamine neurons revealed damage related to neurobehavioral endpoints, with hereditary effects in the progeny together. In addition, sequencing results suggested that copper exposure could cause epigenetic changes. QRT-PCR results showed that differentially expressed genes can also be passed on to offspring.

Synthetic female gonadal hormones alter neurodevelopmental programming and behavior in F1 offspring

The increased prevalence of neurodevelopmental disorders during the last half-century led us to investigate the potential for intergenerational detrimental neurodevelopmental effects of synthetic female gonadal hormones, typically used in contraceptive pills. We examined 3 separate cohorts of mice over the span of 2 years, a total of 150 female F₀ mice and over 300 male and female rodents from their F₁ progeny. We demonstrate that F₁ male offsprings of female mice previously exposed to the synthetic estrogen 17α-ethinylestradiol (EE2) in combination with the synthetic progestin Norethindrone, exhibit neurodevelopmental and behavioral differences compared to control mice. Because the EE2 + Norethindrone administration resulted in gene expression changes in the exposed F₀ mice ovaries persisting after the end of treatment, it is likely that the synthetic hormone treatment caused changes in the germline cells and that led to altered neurodevelopment in the offsprings. An altered gene expression pattern was discovered in the frontal cortex of male mice from the first offspring (F_1.1) at infancy and an ADHD-like hyperactive locomotor behavior was exhibited in young male mice from the second offspring (F_1.2) of female mice treated with contraceptive pill doses of EE2 + Norethindrone prior to pregnancy. The intergenerational neurodevelopmental effects of EE2 + Norethindrone treatment were sex specific, predominantly affecting males. Our observations in mice support the hypothesis that the use of synthetic contraceptive hormones is a potential environmental factor impacting the prevalence of human neurodevelopmental disorders. Additionally, our results indicate that contraceptive hormone drug safety assessments may need to be extended to F₁ offspring.

Intergenerational reproductive toxicity of chlordecone in male Caenorhabditis elegans

Chlordecone (CLD), also named Kepone, is a synthetic organochlorine pesticide. As one of the common persistent organic pollutants (POPs) in nature, CLD has a profound impact on the environment and human health. The study aims to investigate the reproductive toxicity effects of CLD on male Caenorhabditis elegans and on progeny. L1-stage male nematodes were exposed to the control group (M9 solution) and four dose groups (0.02, 0.2, 2, and 20 μg/L). After exposure for 48 h, the male nematodes were picked to mating experiment and progeny experiment that the number of progeny and the time of observation in male parent and in F1 generation were counted; the number of germ cells and the number of sperm in the meiotic division of male nematodes were counted by staining with dimercaptophenyl hydrazine (DAPI), and the nematode gland area was observed under the bright field of the microscope. In male nematodes, the results showed that a number of progeny were 351.20 ± 31.40, 321.60 ± 24.70, 307.30 ± 19.30, 240.10 ± 27.60, and 227.90 ± 22.70 (P < 0.05); the generation times were 55.80 ± 1.95 h, 56.40 ± 1.60 h, 56.70 ± 0.92 h, 60.80 ± 0.95 h, and 69.60 ± 1.97 h (P < 0.05); relative areas of gonad were (99.80 ± 6.27)%, (93.00 ± 1.70)%, (85.00 ± 1.70)%, (70.70 ± 9.81)%, and (60.00 ± 5.23)% (P < 0.05); DAPI staining results showed the number of germ cells in meiosis area were 191.00 ± 10.97, 181.10 ± 15.56, 177.00 ± 9.20, 147.50 ± 10.56, and 139.30 ± 23.79 (P < 0.05); the sperm numbers were 335.60 ± 21.31, 308.60 ± 19.60, 306.00 ± 11.23, 260.10 ± 27.41, and 255.00 ± 3.72 (P < 0.05). In the F1 generation, the progeny numbers were 328.10 ± 22.28, 167.50 ± 15.30, 150.00 ± 13.65, 131.30 ± 18.40, and 130.20 ± 16.17 (P < 0.05); the generation times were 55.50 ± 2.36, 71.10 ± 0.97, 70.90 ± 0.52, 74.10 ± 2.07, and 73.90 ± 1.35 h (P < 0.05). The groups are grouped in order as M9 solution, 0.02, 0.2, 2, and 20 μg/L. The results revealed that CLD caused decrease in progeny number, relative area of gonad, number of germ cells, and sperm number and prolonged the generation time in the male nematode. In offspring grown up without CLD, the effect of CLD on generation time and sperm number can still be observed on offspring. In conclusion, CLD induces male nematode reproductive toxicity and causes defects in offspring.