Quantitative assessment, molecular docking and novel metabolic pathways reveal the interaction mechanisms between norfloxacin biodegradation and environmental implications.

Norfloxacin (NOR) is widely used in medicine and animal husbandry, but its accumulation in the environment poses a substantial threat to ecological and human health. Traditional physical, chemical, and rudimentary biological methods often fall short in mitigating NOR contamination, necessitating innovative biological approaches. This study proposes an engineered bacterial consortium found in marine sediment as a strategy to enhance NOR degradation through inter-strain co-metabolism of diverse substrates. Strategically supplementing the engineered bacterial consortium with exogenous carbon sources and metal ions boosted the activity of key degradation enzymes like laccase, manganese peroxidase, and dehydrogenase. Iron and amino acids demonstrated synergistic effects, resulting in a remarkable 70.8% reduction in NOR levels. The innovative application of molecular docking elucidated enzyme interactions with NOR, uncovering potential biodegradation mechanisms. Quantitative assessment reinforced the efficiency of NOR degradation within the engineered bacterial consortium. Four metabolic routes are herein proposed: acetylation, defluorination, ring scission, and hydroxylation. Notably, this study discloses distinctive, co-operative metabolic pathways for NOR degradation within the specific microbial community. These findings provide new ways of understanding and investigating the bioremediation potential of NOR contaminants, which may lead to the development of more sustainable and effective environmental management strategies.

Elucidating polyethylene microplastic degradation mechanisms and metabolic pathways via iron-enhanced microbiota dynamics in marine sediments.

The extensive use of plastics has given rise to microplastics, a novel environmental contaminant that has sparked considerable ecological and environmental concerns. Biodegradation offers a more environmentally friendly approach to eliminating microplastics, but their degradation by marine microbial communities has received little attention. In this study, we used iron-enhanced marine sediment to augment the natural bacterial community and facilitate the decomposition of polyethylene (PE) microplastics. The introduction of iron-enhanced sediment engendered an augmented bacterial biofilm formation on the surface of polyethylene (PE), thereby leading to a more pronounced degradation effect. This novel observation has been ascribed to the oxidative stress-induced generation of a variety of oxygenated functional groups, including hydroxyl (-OH), carbonyl (-CO), and ether (-C-O) moieties, within the microplastic substrate. The analysis of succession in the community structure of sediment bacteria during the degradation phase disclosed that Acinetobacter and Pseudomonas emerged as the principal bacterial players in PE degradation. These taxa were directly implicated in oxidative metabolic pathways facilitated by diverse oxidase enzymes under iron-facilitated conditions. The present study highlights bacterial community succession as a new pivotal factor influencing the complex biodegradation dynamics of polyethylene (PE) microplastics. This investigation also reveals, for the first time, a unique degradation pathway for PE microplastics orchestrated by the multifaceted marine sediment microbiota. These novel insights shed light on the unique functional capabilities and internal biochemical mechanisms employed by the marine sediment microbiota in effectively degrading polyethylene microplastics.

Biological upcycling of nickel and sulfate as electrocatalyst from electroplating wastewater.

Upcycling nickel (Ni) to useful catalyst is an appealing route to realize low-carbon treatment of electroplating wastewater and simultaneously recovering Ni resource, but has been restricted by the needs for costly membranes or consumption of large amount of chemicals in the existing upcycling processes. Herein, a biological upcycling route for synchronous recovery of Ni and sulfate as electrocatalysts, with certain amount of ferric salt (Fe3+) added to tune the product composition, is proposed. Efficient biosynthesis of bio-NiFeS nanoparticles from electroplating wastewater was achieved by harnessing the sulfate reduction and metal detoxification ability of Desulfovibrio vulgaris. The optimal bio-NiFeS, after further annealing at 300 °C, served as an efficient oxygen evolution electrocatalyst, achieving a current density of 10 mA·cm-1 at an overpotential of 247 mV and a Tafel slope of 60.2 mV·dec-1. It exhibited comparable electrocatalytic activity with the chemically-synthesized counterparts and outperformed the commercial RuO2. The feasibility of the biological upcycling approach for treating real Ni-containing electroplating wastewater was also demonstrated, achieving 99.5 % Ni2+removal and 41.0 % SO42- removal and enabling low-cost fabrication of electrocatalyst. Our work paves a new path for sustainable treatment of Ni-containing wastewater and may inspire technology innovations in recycling/ removal of various metal ions.

Fructus choerospondiatis: A comprehensive review of its traditional uses, chemical composition, pharmacological activities, and clinical studies.

ETHNOPHARMACOLOGICAL RELEVANCE: Fructus Choerospondiatis is the dried and mature fruit of Choerospondias axillaris (Roxb.) Burtt et Hill. It has been used for a long time in Tibetan and Mongolian medicine, first recorded in the ancient Tibetan medicine book "Medicine Diagnosis of the King of the Moon" in the early 8th century. Fructus Choerospondiatis shows multiple pharmacological activities, especially in treating cardiovascular diseases. AIM OF THIS REVIEW: This paper reviews the progress in research on the botanical characteristics, traditional uses, chemical constituents, pharmacological activity, clinical studies, and quality control of Fructus Choerospondiatis. This review aims to summarize current research and provide a reference for further development and utilization of Fructus Choerospondiatis resources. METHOD: The sources for this review include the Pharmacopeia of the People's Republic of China (2020), theses, and peer-reviewed papers (in both English and Chinese). Theses and papers were downloaded from electronic databases including Web of Science, PubMed, SciFinder, Scholar, Springer, and China National Knowledge Infrastructure.The search terms used were "Choerospondias axillaris", "C. axillaris", "Choerospondias axillaris (Roxb.) Burtt et Hill", "Fructus choerospondiatis", "Guangzao", "Lapsi", and "Lupsi". RESULTS: Fructus Choerospondiatis contains polyphenols, organic acids, amino acids, fatty acids, polysaccharides, and other chemical components. These ingredients contribute to its diverse pharmacological activities such as antioxidant activity, protection against myocardial ischemia-reperfusion injury, anti-myocardial fibrosis, heart rhythm regulation, anti-tumor, liver protection, and immunity enhancement. It also affects the central nervous system, with the ability to repair damaged nerve cells. CONCLUSION: Fructus Choerospondiatis, with its various chemical compositions and pharmacological activities, is a promising medicinal resource. However, it remains under-researched, particularly in pharmacodynamic material basis and quality control. These areas require further exploration by researchers in the future.

Bifidobacterium animalis subsp. lactis LKM512 Alleviates Inflammatory Bowel Disease in Larval Zebrafish by Reshaping Microbiota.

Inflammatory bowel disease (IBD) is a worldwide issue, and the increased incidence has brought a heavy burden to patients and society. Gut microbiota is involved in the pathogenesis of IBD, and targeting the microbiota, such as probiotics, has emerged as a potential therapy for the treatment of IBD. Here, the effect of Bifidobacterium animalis ssp. lactis LKM512 (LKM512), an anti-aging probiotic, on dextran sulfate sodium salt (DSS)-induced IBD in larval zebrafish was determined. Supplementation of LKM512 promoted the survival rate of the larvae, together with increased locomotor activities and body length. In addition, LKM512 treatment enhanced mucus secretion and alleviated intestinal injury, and these results were associated with the upregulation of mucin-related and downregulation of inflammatory markers. Moreover, LKM512 increased the diversity of the microbiota and ameliorated the dysbiosis by increasing the abundance of Bacteroidetes and Firmicutes and reducing the abundance of Proteobacteria. Specifically, the abundance of beneficial bacteria, including the short-chain fatty-acids (SCFAs)-producing genera Lachnospiraceae_NK4A136_group, Muribaculaceae, and Alloprevotella, was increased by LKM512, while the abundance of harmful genera, such as Pseudomonas, Halomonas, and Escherichia-Shigella, was reduced by LKM512. Consistent with these findings, the microbial functions related to metabolism were partly reversed by LKM512, and importantly, fermentation of short-chain fatty acids-related functions were enhanced by LKM512. Therefore, LKM512 might be one potential probiotic for the prevention and treatment of IBD, and further studies that clarify the mechanism of LKM512 would promote the application of LKM512.

Bifidobacterium and Lactobacillus improve inflammatory bowel disease in zebrafish of different ages by regulating the intestinal mucosal barrier and microbiota.

AIMS: Inflammatory bowel disease (IBD) patients are accompanied by impaired intestinal barrier integrity and gut microbiota dysbiosis. Strategies targeting the gut microbiota are potential therapies for preventing and ameliorating IBD. MAIN METHODS: The potential roles of two probiotic stains, Bifidobacterium longum BL986 (BL986) and Lactobacillus casei LC122 (LC122), on intestinal mucosal barrier function and microbiota in IBD zebrafish of different ages were investigated. KEY FINDINGS: BL986 and LC122 treatment promoted the development and increased the microbiota diversity in larval zebrafish. Both probiotic treatment ameliorated mortality, promoted intestinal mucus secretion, and reduced the expression of inflammatory markers, thereby improving intestinal mucosal barrier function in dextran sulfate sodium salt (DSS)-induced ulcerative colitis (UC) and 2,4,6-trinitro-benzenesulfonicacid (TNBS)-induced Crohn's disease (CD) models in zebrafish. Moreover, the composition and function of microbiota were altered in IBD zebrafish, and probiotics treatment displayed prominent microbiota features. BL986 was more potent in the DSS-induced UC model, and increased the abundance of Faecalibaculum and butyric acid levels. LC122 exerted better protection against TNBS-induced CD, and increased the abundance of Enhydrobacter and acetic acid levels. Furthermore, the effect of probiotics was stronger in larval and aged zebrafish. CONCLUSION: The impact of probiotics on IBD might differ from the subtypes of IBD and the age of the zebrafish, suggesting the types of disease and age should be taken into full consideration during the practical usage of probiotics.

Enhanced degradation of bisphenol A: Influence of optimization of removal, kinetic model studies, application of machine learning and microalgae-bacteria consortia.

Bisphenol A (BPA), a typical endocrine disruptor and a contaminant of emerging concern (CECs), has detrimental impacts not only on the environment and ecosystems, but also on human health. Therefore, it is essential to investigate the degrading processes of BPA in order to diminish its persistent effects on ecological environmental safety. With this objective, the present study reports on the effectiveness of biotic/abiotic factors in optimizing BPA removal and evaluates the kinetic models of the biodegradation processes. The results showed that BPA affected chlorophyll a, superoxide dismutase (SOD) and peroxidase (POD) activities, malondialdehyde (MDA) content, and photosystem intrinsic PSII efficiency (Fv/Fm) in the microalga Chlorella pyrenoidosa, which degraded 43.0 % of BPA (8.0 mg L-1) under general experimental conditions. The bacteria consortium AEF21 could remove 55.4 % of BPA (20 mg L-1) under orthogonal test optimization (temperature was 32 °C, pH was 8.0, inoculum was 6.0 %) and the prediction of artificial neural network (ANN) of machine learning (R2 equal to 0.99 in training, test, and validation phase). The microalgae-bacteria consortia have a high removal rate of 57.5 % of BPA (20.0 mg L-1). The kinetic study revealed that the removal processes of BPA by microalgae, bacteria, and microalgae-bacteria consortia all followed the Monod's kinetic model. This work provided a new perspective to apply artificial intelligence to predict the degradation of BPA and to understand the kinetic processes of BPA biodegradation by integrated biological approaches, as well as a novel research strategy to achieve environmental CECs elimination for long-term ecosystem health.

Microbiome profiling of nasal extracellular vesicles in patients with allergic rhinitis.

Background: Nasal microbiota is crucial for the pathogenesis of allergic rhinitis (AR), which has been reported to be different from that of healthy individuals. However, no study has investigated the microbiota in nasal extracellular vesicles (EVs). We aimed to compare the microbiome composition and diversity in EVs between AR patients and healthy controls (HCs) and reveal the potential metabolic mechanisms in AR. Methods: Eosinophil counts and serum immunoglobulin E (IgE) levels were measured in patients with AR (n = 20) and HCs (n = 19). Nasal EVs were identified using transmission electron microscopy and flow cytometry. 16S rRNA sequencing was used to profile the microbial communities. Alpha and beta diversities were analyzed to determine microbial diversity. Taxonomic abundance was analyzed based on the linear discriminant analysis effect size (LEfSe). Microbial metabolic pathways were characterized using Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUst2) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. Results: Eosinophils, total serum IgE, and IgE specific to Dermatophagoides were increased in patients with AR. Alpha diversity in nasal EVs from patients with AR was lower than that in HCs. Beta diversity showed microbiome differences between the AR and HCs groups. The microbial abundance was distinct between AR and HCs at different taxonomic levels. Significantly higher levels of the genera Acetobacter, Mycoplasma, Escherichia, and Halomonas were observed in AR patients than in HCs. Conversely, Zoogloea, Streptococcus, Burkholderia, and Pseudomonas were more abundant in the HCs group than in the AR group. Moreover, 35 microbial metabolic pathways recognized in AR patients and HCs, and 25 pathways were more abundant in the AR group. Conclusion: Patients with AR had distinct microbiota characteristics in nasal EVs compared to that in HCs. The metabolic mechanisms of the microbiota that regulate AR development were also different. These findings show that nasal fluid may reflect the specific pattern of microbiome EVs in patients with AR.

Total body water/fat-free mass ratio as a valuable predictive parameter for mortality in maintenance hemodialysis patients.

Hydration of fat-free mass (FFM), defined as the ratio of total body water (TBW) to FFM (TBW/FFM), is stable at 0.739 in adult mammals. However, an increase in the TBW/FFM ratio is common in hemodialysis (HD) patients. This study aimed to evaluate the determinants of TBW/FFM and investigate its predictive value for the prognosis of all-cause mortality in HD patients. We enrolled patients undergoing maintenance HD between July 2020 and May 2021. All patients were prospectively followed until death, HD dropout, or until the end of the study (November 1, 2021). A forward stepwise multivariable linear regression analyses was performed to test the independent relationship between TBW/FMM and other clinical variables. Receiver operating characteristic (ROC) analysis was used to discriminate the TBW/FFM with respect to 180-day mortality. Of the 106 patients, 42 had elevated TBW/FFM levels. Multiple linear regression analysis revealed that the TBW/FFM ratio was significantly associated with extracellular water (ECW)/TBW (standardized regression coefficient [ß = 1.131, P < .001], phase angle (PhA) [ß = 0.453, P < .001], and sex (ß = 0.440, P < .001). We calculated the ROC curve (AUC) of TBW/FFM, ECW, ECW/TBW, and intracellular water (ICW) to compare the discriminatory capacities of these parameters in predicting 180-day mortality. The AUC for TBW/FFM (AUC = 0.849; 95% CI, 0.745-0.953) exhibited better discriminatory potential than ECW (AUC = 0.562; 0.410-0.714), although it had a similar predictive potential as the ECW/TBW ratio (AUC = 0.831; 0.731-0.932). High TBW/FFM can be used as a valuable prognostic index for predicting all-cause mortality in patients on HD.

Adsorption of Pb2+, Cu2+ and Cd2+ by sulfhydryl modified chitosan beads.

A chitosan-based bead was synthesized by crosslinking as well as sulfhydryl modification reaction and its removal ability of Pb2+, Cu2+ and Cd2+ was investigated. The test results showed that the crystal structure of chitosan was destroyed completely and the specific surface area was greatly increased after modification. The adsorption of Pb2+, Cu2+ and Cd2+ by the beads was carried out at different pH, ionic strength, contact time and initial concentration and the maximum adsorption capacities were 273.7 mg/g, 163.3 mg/g and 183.1 mg/g, respectively. Furthermore, due to the large ion radius of Pb2+, its adsorption was seriously disturbed by other ions in the competitive adsorption process. Finally, the adsorption processes of Pb2+, Cu2+ and Cd2+ were well fitted by the Langmuir isotherm model and the pseudo second-order kinetics model, respectively. Combined with the results of X-ray photoelectron spectroscopy, chemical coordination is the main adsorption mechanism.

Preparation of Chitosan/Calcium Alginate/Bentonite Composite Hydrogel and Its Heavy Metal Ions Adsorption Properties.

In order to avoid the secondary pollution of the toxic residue of chemical crosslinking agent accompanied by chemical hydrogel adsorbent and enhance the adsorption performance of physical hydrogel, chitosan/calcium alginate/bentonite (CTS/CA/BT) composite physical hydrogel was constructed. The formation mechanism and structure of the composite hydrogel were determined by FTIR, XRD and SEM. Adsorption performances of the hydrogel toward Pb2+, Cu2+ and Cd2+ in water under different condition as well as multi-ion competitive sorption were investigated. The adsorption processes were described with the canonical adsorption kinetics and isotherms models. With the utilization of XPS analysis and adsorption thermodynamics analysis, it was found that the adsorptions were spontaneous physico-chemical adsorptions. The results showed that the maximum adsorption capacity of the hydrogel for Pb2+, Cu2+ and Cd2+ reached up to 434.89, 115.30 and 102.38 mg·g-1, respectively, better than those of other physical hydrogels or chitosan/bentonite composite. Moreover, the composite hydrogel improved the collectability of bentonite and showed a good reusability. The modification of bentonite and the formation of hydrogel were completed simultaneously, which greatly simplifies the operation process compared with the prior similar works. These suggest that the CTS/CA/BT composite hydrogel has promising application prospects for removal of heavy metal ions from water.

Establishment of a cell line from swim bladder of the Grass carp (Ctenopharyngodon idellus) for propagation of Grass Carp Reovirus Genotype II.

A cell line was established from swim bladder of the Grass carp (Ctenopharyngodon idellus) (CiSB), which was permissive for infection and propagation of Grass Carp Reovirus (GCRV). CiSB cells displayed optimal growth at 27 °C using M199 medium containing 10% fetal bovine serum and a fibroblastic-like morphology. Karyotype analysis revealed that the average diploid chromosome number was 52 in 58% of cells at passage 60 compared to the wild type Grass carp cells (2n = 48). Infection with GCRV II isolate Hunan1307 was tracked by immunofluorescence and virus titration assay. The virus titer reached 105.2 TCID50/mL on 7th days post infection (dpi). Healthy adult Grass carp that were challenged with the virus propagated onto CiSB cells, displayed the typical symptoms and histopathological changes of Grass carp hemorrhagic disease (GCHD). Therefore, the CiSB cells can be used to propagate GCRV II and serve as a useful tool to study the pathogenesis of GCHD.

Preparation of a novel bio-adsorbent of sodium alginate grafted polyacrylamide/graphene oxide hydrogel for the adsorption of heavy metal ion.

A novel bio-adsorbent named SA-PAM/GO hydrogel composites was synthesized through free radical polymerization. The structure and performance were characterized and analyzed by BET, SEM-EDS, FTIR and TGA. After modification, the BET surface area increased more than tripled, which was consistent with SEM results. Under optimal conditions, the maximum adsorption capacity of Cu2+ and Pb2+ were 68.76 mg/g and 240.69 mg/g, respectively. In addition, the research of kinetics and isotherms displayed that the pseudo-second-order kinetic model and the Langmuir isotherm model fitted the data well. After further research, the different adsorption mechanism including physical adsorption, chemical adsorption and electrostatic interactions were discussed. The chemical adsorption accompanying the ion exchange process was confirmed as the staple adsorption mechanism. Furthermore, the adsorbent still maintained good adsorption capacity after 5 cycles of adsorption-regeneration. Therefore, the SA-PAM/GO hydrogel composites have potential to remove the heavy metal ions from water body effectively.

A regional-scale decomposition of energy-related carbon emission and its decoupling from economic growth in China.

China, known as the largest carbon emitter and the second largest economy worldwide, has continued to put effort into the understandings of the main drivers of carbon emission and their decoupling statuses from its economic growth. Considering the significant differences of natural and social environments in different regions of China, this paper presents a regional-scale decomposition of energy-related carbon emission and its decoupling from economic growth by using the Logarithmic Mean Divisia Index (LMDI) and the Tapio decoupling method. The decoupling results indicate that carbon emissions in all regions show a stable decoupling trend from their economic development, which means that China is now on the right road for achieving a low-carbon economy. However, the decoupling status by the end of 2016 also indicates that most of the regions are still in the states of expansive coupling or weak decoupling, especially in Northwest (NW), which implies that the speed of decarbonization process is still not high enough. The decomposition results show that in all regions except NW, GDP per capita is the most influential factor leading to increasing carbon emissions, while energy intensity is the largest factor in reducing carbon emissions. In NW, both GDP per capita and energy intensity drive the increase in carbon emissions. The results in this paper could benefit China's regional policy-making and national strategies.

Contribution to knowledge of the genus Cuanta Dworakowska, 1993 (Hemiptera: Cicadellidae: Typhlocybinae) with descriptions of three new species.

The leafhopper genus Cuanta Dworakowska, 1993 is recorded from China for the first time. Three species, C. plana, C. curva. and C. centralis spp. nov., are described and illustrated as new to science. A check-list and key to all species of Cuanta are provided.

Effects of varicocele on testosterone, apoptosis and expression of StAR mRNA in rat Leydig cells.

The aim of this study was to explore the effects of varicocele on the morphology and function of Leydig cells in the rat testis. Forty male Sprague-Dawley rats were divided into two groups: the experimental group underwent surgery to create a left varicocele (VC), and the control group underwent a sham operation. Serum testosterone and intratesticular testosterone levels were measured using a radioimmunoassay after 4 and 8 weeks of operation. Leydig cells were studied for apoptosis and expression of steroidogenetic acute regulatory (StAR) protein mRNA levels. Serum testosterone levels declined after 4 and 8 weeks of operation but were not significant (P>0.05). However, the intratesticular testosterone levels after 8 weeks were significantly decreased compared with the control group (P<0.01). The mean apoptosis index of Leydig cells in the experimental group was significantly higher than that in the control group after 4 or 8 weeks (P<0.01). StAR mRNA levels in the Leydig cells of the experimental group were significantly lower compared to those of the control group (P<0.01). Our data show that varicocele did impair Leydig cell function by increasing apoptosis and suppressing the expression of the StAR protein.

Efficacy of maximal androgen blockade versus castration alone in the treatment of advanced prostate cancer: a retrospective clinical experience from a Chinese medical centre.

In this retrospective study, we evaluated and compared the efficacy and toxicities of maximal androgen blockade (MAB) versus castration alone in Chinese patients with advanced prostate cancer. From 1996 to 2004, 608 patients with advanced prostate cancer were included in the study. Patients were retrospectively divided into two groups according to different therapeutic regimens. Of the 608 patients, 300 patients were treated with MAB (castration plus nonsteroidal antiandrogens) and the remaining 308 were treated with castration alone. The 2- and 5-year overall survival rates of these patients were 73.7% and 56%, respectively. Multivariate analysis showed that, in patients with metastatic prostate cancer, MAB was associated with not only the improvement of progression-free survival (PFS) (increased by 10 months) but also a 20.6% reduction in mortality risk compared with castration alone. In contrast, the efficacy of MAB was not superior to castration alone for patients with nonmetastatic prostate cancer. Interestingly, among patients with MAB, those using bicalutamide had a longer PFS than those using flutamide; this was especially so in patients with metastatic prostate cancer. Almost all of the toxicities due to the hormone therapy were mild to moderate and manageable. To conclude, in China, hormone therapies, including MAB and castration alone, have been standard treatments for advanced prostate cancer. For patients with nonmetastatic prostate cancer, castration alone might be adequately practical and efficient. In patients with metastatic prostate cancer, however, MAB has superior efficacy over castration alone. It is clear that MAB should be considered the first-line standard treatment for patients with metastatic prostate cancer.

Multifocal brain metastases in clear cell renal cell carcinoma with complete response to sunitinib.

We report the case of a 70-year-old man who received sunitinib treatment for brain metastatic clear cell renal cell carcinoma. After 6 months of treatment, brain MRI showed complete disappearance of two brain metastases. To the best of our knowledge, this is the first reported case of multifocal brain metastases in renal cell carcinoma with complete response to sunitinib.

[The preparation of StAR gene probe and its expression in mice Leydig cells under stress].

OBJECTIVE: To prepare the cDNA probe of the steroidogenic acute regulatory (StAR) gene, and to investigate the StAR mRNA expression in stressed C57BL/6 mice leydig cells. METHODS: cDNA fragment encoding mouse StAR was amplified by RT-PCR from the total RNA prepared from the testis, and then the RT-PCR product was cloned into pCR2. 1-TOPO vector. After StAR gene cDNA was sequenced, the Dig-labeled cRNA probes for mouse StAR gene were prepared by in vitro transcription from cDNA fragment. With the specific cRNA probes, in situ hybridization analysis was conducted in stressed mice testis and controls. RESULTS: The results demonstrated that StAR mRNA levels were significantly lower in stressed leydig cells than that in controls (P < 0.05). CONCLUSIONS: The decreased StAR mRNA levels induced by stress may result in a reduced production of StAR protein, which compromised the transportation of cholesterol, the substrate for androgen biosynthesis, into mitochondria, resulting in a poor T production in leydig cells and finally a declined T levels.