Chung-Ho Lin

Background Type 2 Diabetes Mellitus (T2DM) is a significant public health burden. Emerging evidence links volatile organic compounds (VOCs), such as benzene to endocrine disruption and metabolic dysfunction. However, the effects of chronic environmentally relevant VOC exposures on metabolic health are still emerging. Objective Building on our previous findings that benzene exposure at smoking levels (50 ppm) induces metabolic impairments in male mice, we investigated the effects of occupationally relevant, below OSHA approved, benzene exposure on metabolic health. Methods Adult male C57BL/6 mice were exposed to 0.9ppm benzene 8 hours a day for 9 weeks. We assessed measures of metabolic homeostasis and conducted RNA and proteome sequencing on insulin-sensitive organs (liver, skeletal muscle, adipose tissue). Results This low-dose exposure caused significant metabolic disruptions, including hyperglycemia, hyperinsulinemia, and insulin resistance. Transcriptomic analysis of liver, skeletal muscle, and adipose tissue identified key changes in metabolic and immune pathways especially in liver. Proteomic analysis of the liver revealed mitochondrial dysfunction as a shared feature, with disruptions in oxidative phosphorylation, mitophagy, and immune activation. Comparative analysis with high-dose (50 ppm) exposure showed both conserved and dose-specific transcriptomic changes in liver, particularly in metabolic and immune responses. Conclusions Our study is the first to comprehensively assess the impacts of occupational benzene exposure on metabolic health, highlighting mitochondrial dysfunction as a central mechanism and the dose-dependent molecular pathways in insulin-sensitive organs driving benzene-induced metabolic imbalance. Our data indicate that current OSHA occupational exposure limits for benzene are insufficient, as they could result in adverse metabolic health in exposed workers, particularly men, following chronic exposure.

Water quality is threatened by numerous pollutants, among which antibiotics are of great concern due to their widespread use and unaltered excretion, leading to water contamination and fostering antibiotic resistance. To comprehensively address sustainable water remediation, herein, the susceptibility to non-thermal plasma degradation of two veterinary antibiotics (Oxytetracycline (OTC) and Lincomycin (LNC)) are compared in an integral approach, including computational analyses, plasma irradiation assays, and a byproduct toxicity assessment. The computational assessment was performed by evaluating the ionization potential (IP) obtained from Density Functional Theory calculations and determining the antibiotics’ susceptible sites for radical attack. Plasma irradiation achieved nearly complete degradation (~100%) of both compounds with the initial concentration of 1 mg L⁻¹, while 60% degradation was observed when the starting concentration was 10 mg L⁻¹. The mineralization rates were 21% and 31% for OTC and LNC, respectively. The degradation profiles followed similar trends, as expected from their comparable IP values. After treatment, the solution exhibited lower biotoxicity compared to the original antibiotics. Therefore, this work represents a step forward in addressing one of the key environmental challenges of our time and encourages further extending the analysis towards the remediation of water polluted with many other organic compounds.

American elderberry ( Sambucus nigra subsp. canadensis ) is a rapidly emerging new perennial crop for Missouri, recognized for its high level of bioactive compounds with significant health benefits, including antibacterial, antiviral, and antioxidant properties. A high-throughput screening assay combined with untargeted metabolomics analysis was utilized on American elderberry juice from 21 genotypes to explore and characterize these bioactive compounds. Our metabolomics study has identified 32 putative bioactive compounds in the American Elderberry juices. An array of high-throughput screening bioassays was conducted to evaluate 1) total antioxidant capacity, 2) activation of antioxidant response elements (ARE), 3) antiviral activity, and 4) antibacterial activity of the putatively identified compounds. Our results revealed that 14 of the 32 American elderberry compounds exhibited strong antioxidant activity. Four compounds (isorhamnetin 3-O-glucoside, kaempferol, quercetin, and naringenin) activated ARE activity and were found to be non-cytotoxic to cells. Notably, six of the 32 compounds demonstrated significant antiviral activity in an in vitro TZM-bl assay against two strains of HIV-1 virus, CXCR4-dependent NL4-3 virus and CCR5-dependent BaL virus. Luteolin showed the most potent anti-HIV activity against the NL4-3 virus (IC ₅₀ = 1.49 µM), followed by isorhamnetin (IC ₅₀ = 1.67 µM). The most potent anti-HIV compound against the BaL virus was myricetin (IC ₅₀ = 1.14 µM), followed by luteolin (IC ₅₀ = 4.38 µM). Additionally, six compounds were found to have antibacterial activity against gram-positive bacteria S. aureus , with cyanidin 3-O-rutinoside having the most potent antibacterial activity in vitro (IC ₅₀ = 2.9 µM), followed by cyanidin 3-O-glucoside (IC ₅₀ = 3.7 µM). These findings support and validate the potential health benefits of compounds found in American elderberry juices and highlight their potential for use in dietary supplements as well as innovative applications in health and medicine.

Atrazine (ATR), a widely used herbicide in the United States, has contaminated ground and surface water. The persistence in the environment, the carcinogenic characteristic, and the endocrine disruption activity of ATR raises public health concerns. To provide a clean source of drinking water, it is imperative to remediate ATR and its metabolites without toxic by-products. A green technology, Bacillus thuringiensis spore-based display system, has been developed to express a high density of enzymes on the spore surface. The B. thuringiensis spore can serve as a bioparticle to deliver enzymes to different environments and enhance the stability and shelf-life of enzymes expressed on their surface. A cluster of enzymes, AtzA, AtzB, AtzC, AtzD, AtzE, and AtzF, found in Pseudomonas sp. strain ADP, remediates ATR to CO ₂ and NH ₃ in the degradation pathway. AtzA-bearing spores were generated, and they successfully demonstrated the capability of converting ATR to its metabolite, hydroxyatrazine (HA) [Hsieh et al. 2020]. In this study, AtzB, a hydroxyatrazine N -ethylaminohydrolase that hydrolyzes HA to N -isopropylammelide (NiPA), was expressed on the Bacillus spores by fusing atzB to the gene encoding the attachment domain of the BclA spore surface nap layer protein. The results showed that 1 mg AtzB-bearing spores degraded 50% of HA to NiPA in water within 12 hours. The K _m and V _max of AtzB-bearing spores with HA as a substrate were 25.28 µM and 1.26 nmole NiPA h ^-1 mg ^-1 spores, respectively. The optimal ratio of 1:2 for AtzA-bearing to AtzB-bearing spores was applied and successfully converted 90% ATR to NiPA in the water after 96 hours of incubation. The surface water with the addition of 34.5 nM (7.5 µg L ^-1 ) of ATR was treated with a combination of AtzA-bearing and AtzB-bearing spores in a 96-hour time course study. Over 80% of applied ATR in surface water was degraded and ATR concentration was below the United States Environmental Protection Agency maximum contaminant level, 13.8 nM (3 µg L ^-1 ) within 24 hours. At the end of 96 hours. ATR in surface water was completely converted to NiPA. We have successfully demonstrated the application of multienzyme bioremediation of ATR using the Bacillus spore-based display system in the surface water in the laboratory.

Glansreginin A has been reported to be an indicator of the quality of walnuts (Juglans spp.). However, bioactive properties of glansreginin A have not been adequately explored. In the present study, we quantified concentrations of glansreginin A in black walnuts (Juglans nigra) using high performance liquid chromatography-tandem mass spectrometry (HPLC–MS/MS) and performed an array of in vitro bioassays to characterize biological activities (e.g., antibacterial, antioxidant, anticancer capacities) of this compound. Results from HPLC–MS/MS analysis indicated that glansreginin A was presented in all 12 black cultivars examined and its contents were variable among black walnut cultivars, ranged from 6.8 mg/kg (Jackson) to 47.0 mg/kg (Hay). Glansreginin A possessed moderate antibacterial activities against Gram-positive pathogens (Staphylococcus aureus and Bacillus anthracis). This compound exhibited no antioxidant activities, did not induce the activity of antioxidant response element signaling pathways, and exerted no antiproliferative effects on tumorigenic alveolar epithelial cells and non-tumorigenic lung fibroblast cells.

Figure: The primary objective of this study was to identify a universal wastewater biomarker for population normalization for SARS-CoV-2 wastewater-based epidemiology (WBE). A total of 2,624 wastewater samples (41 weeks) were collected weekly during May 2021-April 2022 from 64 wastewater facilities across Missouri, U.S. Three wastewater biomarkers, caffeine and its metabolite, paraxanthine, and pepper mild mottle virus (PMMoV), were compared for the population normalization effectiveness for wastewater SARS-CoV-2 surveillance. Paraxanthine had the lowest temporal variation and strongest relationship between population compared to caffeine and PMMoV. This result was confirmed by data from ten different Wisconsin’s WWTPs with gradients in population sizes, indicating paraxanthine is a promising biomarker of the real-time population across a large geographical region. The estimated real-time population was directly compared against the population patterns with human movement mobility data. Of the three biomarkers, population normalization by paraxanthine significantly strengthened the relationship between wastewater SARS-CoV-2 viral load and COVID-19 incidence rate the most (40 out of 61 sewersheds). Caffeine could be a promising population biomarker for regions where no significant exogenous caffeine sources (e.g., discharges from food industries) exist. In contrast, PMMoV showed the highest variability over time, and therefore reduced the strength of the relationship between sewage SARS-CoV-2 viral load and the COVID-19 incidence rate, as compared to wastewater data without population normalization and the population normalized by either recent Census population or the population estimated based on the number of residential connections and average household size for that municipality from the Census. Overall, the findings of this long-term surveillance study concluded that the paraxanthine has the best performance as a biomarker for population normalization for SARS-CoV-2 wastewater-based epidemiology.

In a previous study, photonic-based molecularly imprinted polymers (MIPs) were fabricated using atrazine (ATZ) and its metabolites, desethylatrazine (DEA) and desisopropylatrazine (DIA), as templates in separate matrices. For the purposes of monitoring the abovementioned molecules in natural waters, the effect of natural waters—featuring ionic strength and natural organic matter (NOM) on atrazine MIP—were studied in this work, and the photonic MIP was implemented for monitoring the target molecules in natural water samples collected from land in nearby farms in northeast of Columbia MO. Non-imprinted polymers (NIP) were also fabricated and applied in the experiments as a control test. In presence of NaCl, CaCl₂, and NOM, MIPs presented lower responses by 26%, higher responses by 23%, and higher responses by 35%, respectively. NIPs response in terms of an increase or decrease was consistent with those of MIPs, but only for a lower percentage. MIPs response in natural waters—which were characterized for their physicochemical characteristics such as conductivity, total organic carbon content, etc.—provided a good approximation of the real concentrations obtained from the LCMS instrument; in general, they showed a good concordance, although large discrepancies occurred for some samples, which can be related to reproducibility issues in the manufacturing process or the presence of unknown interfering compounds in the real samples.