Effect of Nano-Titanium Dioxide on Blood-Testis Barrier and MAPK Signaling Pathway in Male Mice

Ghrelin alleviated TiO2 NPs-induced inhibition of endochondral osteogenesis and promoted longitudinal growth of long bones in juvenile rats via Wnt/β-catenin signaling pathway

Titanium dioxide nanoparticles (TiO2 NPs) are widely used in children's daily necessities and foods, and their health hazards to children have attracted particular attention. Childhood is a critical time for accelerated bone growth and development. Current studies revealed that TiO2 NPs exposure causes bone damage in juvenile rats; however, the underlying mechanism is unknown. Ghrelin is a polypeptide hormone that is considered to be a candidate factor for regulating bone growth and development. In this research, 3-week-old juvenile male rats were administered 0, 100 or 200 mg/kg TiO2 NPs and 50 μg/kg ghrelin for 4 weeks to explore the underlying mechanism of TiO2 NPs-induced bone damage, and the protective effect of ghrelin. Our results revealed that TiO2 NPs resulted in decreased synthesis of bone growth-related hormones, disturbed bone metabolism, and destruction of bone structure. Further mechanism studies showed that TiO2 NPs inhibited Wnt/β-catenin pathway, reduced collagen synthesis, inhibited chondrocyte proliferation and differentiation, promoted chondrocyte apoptosis, and inhibited endochondral osteogenesis, ultimately leading to long bone longitudinal growth retardation and osteoporosis. Ghrelin alleviated the negative effects of TiO2 NPs-induced bone growth in juvenile rats by upregulating the Wnt/β-catenin signaling pathway. This study provided a reference for the clinical treatment of growth retardation and idiopathic short stature in juvenile children caused by environmental pollutants.

Inflammation-related miRNAs in obesity, CVD, and NAFLD

Obesity, cardiovascular diseases (CVD), and nonalcoholic fatty liver disease (NAFLD) pose significant worldwide health challenges, characterized by complex interplay among inflammatory pathways that underlie their development. In this review, we examine the contribution of inflammation and associated signaling molecules to the pathogenesis of these conditions, while also emphasizing the significant participation of non-coding RNAs (ncRNAs) in modulating inflammatory pathways. In the context of obesity, aberrant expression patterns of inflammatory-associated miRNAs play a contributory role in adipose tissue inflammation and insulin resistance, thereby exacerbating disturbances in metabolic homeostasis. Similarly, in CVD, dysregulated miRNA expression alters inflammatory reactions, disrupts endothelial function, and induces cardiac remodeling, thereby impacting the advancement of the disease. Moreover, in the context of NAFLD, inflammatory-associated miRNAs are implicated in mediating hepatic inflammation, lipid deposition, and fibrosis, underscoring their candidacy as promising therapeutic targets. Additionally, the competing endogenous RNA (ceRNA) network has emerged as a novel regulatory mechanism in the etiology of CVD, obesity, and NAFLD, wherein ncRNAs assume pivotal roles in facilitating communication across diverse molecular pathways. Moreover, in the concluding section, we underscored the potential efficacy of directing interventions towards inflammatory-related miRNAs utilizing herbal remedies and therapies based on exosome delivery systems as a promising strategy for ameliorating pathologies associated with inflammation in obesity, CVD, and NAFLD.

The ROS Mediates MCUb in Mitochondria-Regulated Apoptosis of TM4 Cells Induced by Titanium Dioxide Nanoparticles

Titanium dioxide nanoparticles (TiO2 NPs) can cause mitochondrial apoptosis of TM4 cells associated with reactive oxygen species (ROS) accumulation and Ca2+ overload, but the relations among these processes remain unclear. This study aimed to evaluate whether the accumulation of ROS caused by TiO2 NPs inhibits MCUb expression, leading to mitochondrial calcium overload and subsequent cell apoptosis through the mitochondrial pathway. TM4 cells were exposed to different concentrations of TiO2 NPs (0, 25, 50, 75, 100 μg/mL) for 24 h. We assessed cell viability, ROS level, MCUb and VDAC1 expression, mitochondrial and cytoplasmic Ca2+ levels, mitochondrial membrane potential (MMP), apoptosis rate, and key proteins related to mitochondrial apoptosis (Bcl-2, Bax, Caspase 3, Caspase 9, p53 and Cyt c). Additionally, the effect of N-acetylcysteine (NAC) on MCUb expression, calcium homeostasis, and cell apoptosis was evaluated. Compared to control group, TiO2 NPs significantly increased ROS level, downregulated MCUb expression, elevated Ca2+ levels in mitochondria and cytoplasm, and enhanced mitochondria-regulated apoptosis, starting from the 50 μg/mL TiO2 NPs group. However, NAC significantly increased MCUb expression, attenuated Ca2+ levels in mitochondria and cytoplasm, and reduced mitochondria-related apoptosis. In conclusion, TiO2 NPs induced ROS accumulation, which inhibited the expression of MCUb. The decreased MCUb level led to Ca2+ overload in mitochondria, causing TM4 cell apoptosis via the mitochondrial pathway. This research elucidates, for the first time, the role of MCUb and its relation with ROS in apoptosis of TM4 cells induced by TiO2 NPs, which supplementing the molecular mechanism of cell apoptosis caused by TiO2 NPs.

ERK/CREB and p38 MAPK/MMP14 Signaling Pathway Influences Spermatogenesis through Regulating the Expression of Junctional Proteins in Eriocheir sinensis Testis

The hemolymph-testis barrier (HTB) is a reproduction barrier in Crustacea, guaranteeing the safe and smooth process of spermatogenesis, which is similar to the blood-testis barrier (BTB) in mammals. The MAPK signaling pathway plays an essential role in spermatogenesis and maintenance of the BTB. However, only a few studies have focused on the influence of MAPK on crustacean reproduction. In the present study, we knocked down and inhibited MAPK in Eriocheir sinensis. Increased defects in spermatogenesis were observed, concurrently with a damaged HTB. Further research revealed that es-MMP14 functions downstream of ERK and p38 MAPK and degrades junctional proteins (Pinin and ZO-1); es-CREB functions in the ERK cascade as a transcription factor of ZO-1. In addition, when es-MMP14 and es-CREB were deleted, the defects in HTB and spermatogenesis aligned with abnormalities in the MAPK. However, JNK impacts the integrity of the HTB by changing the distribution of intercellular junctions. In summary, the MAPK signaling pathway maintains HTB integrity and spermatogenesis through es-MMP14 and es-CREB, which provides insights into the evolution of gene function during barrier evolution.

Titanium dioxide nanoparticles induce apoptosis through ROS-Ca2+-p38/AKT/mTOR pathway in TM4 cells

Titanium dioxide nanoparticles (TiO2 NPs) can cause apoptosis in TM4 cells; however, the underlying mechanism has not been entirely elucidated. The purpose of this study was to investigate the effects of TiO2 NPs on ROS, Ca2+ level, p38/AKT/mTOR pathway, and apoptosis in TM4 cells and to evaluate the role of Ca2+ in p38/AKT/mTOR pathway and apoptosis. After exposure to different concentrations (0, 50, 100, 150, and 200 μg/mL) of TiO2 NPs for 24 h, cell viability, ROS, Ca2+ level, Ca2+-ATPase activity, p38/AKT/mTOR pathway-related proteins, apoptosis rate, and apoptosis-related proteins (Bax, Bcl-2, Caspase 3, Caspase 9, and p53) were detected. The ROS scavenger NAC was used to determine the effect of ROS on Ca2+ level. The Ca2+ chelator BAPTA-AM was used to evaluate the role of Ca2+ in p38/AKT/mTOR pathway and apoptosis. TiO2 NPs significantly inhibited cell viability, increased ROS level, and elevated Ca2+ level while suppressing Ca2+-ATPase activity. TiO2 NPs regulated the p38/AKT/mTOR pathway via increasing p-p38 level and decreasing p-AKT and p-mTOR levels. TiO2 NPs significantly enhanced the apoptosis. NAC attenuated Ca2+ overload and reduction in Ca2+-ATPase activity caused by TiO2 NPs. BAPTA-AM alleviated TiO2 NPs-induced abnormal expression of p38/AKT/mTOR pathway-related proteins. BAPTA-AM assuaged the apoptosis caused by TiO2 NPs. Altogether, this study revealed that TiO2 NPs elevated intracellular Ca2+ level through ROS accumulation. Subsequently, the heightened intracellular Ca2+ level was observed to exert regulation over the p38/AKT/mTOR pathway, ultimately culminating in apoptosis. These results provides a complementary understanding to the mechanism of TiO2 NPs-induced apoptosis in TM4 cells.

Nanomaterials Solutions for Contraception: Concerns, Advances, and Prospects

Preventing unintentional pregnancy is one of the goals of a global public health policy to minimize effects on individuals, families, and society. Various contraceptive formulations with high effectiveness and acceptance, including intrauterine devices, hormonal patches for females, and condoms and vasectomy for males, have been developed and adopted over the last decades. However, distinct breakthroughs of contraceptive techniques have not yet been achieved, while the associated long-term adverse effects are insurmountable, such as endocrine system disorder along with hormone administration, invasive ligation, and slowly restored fertility after removal of intrauterine devices. Spurred by developments of nanomaterials and bionanotechnologies, advanced contraceptives could be fulfilled via nanomaterial solutions with much safer and more controllable and effective approaches to meet various and specific needs for women and men at different reproductive stages. Nanomedicine techniques have been extended to develop contraceptive methods, such as the targeted drug delivery and controlled release of hormone using nanocarriers for females and physical stimulation assisted vasectomy using functional nanomaterials via photothermal treatment or magnetic hyperthermia for males. Nanomaterial solutions for advanced contraceptives offer significantly improved biosafety, noninvasive administration, and controllable reversibility. This review summarizes the nanomaterial solutions to female and male contraceptives including the working mechanisms, clinical concerns, and their merits and demerits. This work also reviewed the nanomaterials that have been adopted in contraceptive applications. In addition, we further discuss safety considerations and future perspectives of nanomaterials in nanostrategy development for next-generation contraceptives. We expect that nanomaterials would potentially replace conventional materials for contraception in the near future.

Melatonin or vitamin C attenuates lead acetate-induced testicular oxidative and inflammatory damage in mice by inhibiting oxidative stress mediated NF-κB signaling

Lead (Pb) acts as an environmental endocrine disruptor and has negative effects in animals; excessive accumulation of lead causes reproductive dysfunction in male animals. Oxidative stress plays a vital role in Pb-induced injury. However, the mechanisms underlying chronic testicular toxicity of Pb remain unclear. In this study, we aimed to determine the effects of lead acetate on reproductive function in male mice, identify the underlying mechanisms, and test counter measures to alleviate the toxic effects. Male mice were dosed with lead acetate (500 mg/L) in free drinking water for 12 weeks, and administered melatonin (5 mg/kg) or vitamin C (500 mg/kg) by intraperitoneal injection. Blood from the eyeball, testicles, and sperm from the caudal epididymis were collected after 12 weeks and analyzed. Pb exposure reduced sperm count and motility, increased sperm malformation (P < 0.01), disrupted testicular morphology and structure, and decreased the expression of steroid hormone synthesis-related enzymes and serum testosterone concentration (P < 0.01). Pb also increased the number of inflammatory cells and the levels of the pro-inflammatory cytokines TNF-α and IL-6 (P < 0.01), and activated NF-κB signaling. Furthermore, the ROS yield and oxidation indicators LPO and MDA were significantly increased (P < 0.01), and the antioxidant indicators T-AOC, SOD, and GSH were significantly reduced (P < 0.01). Treatment with melatonin or vitamin C reversed the effects of lead acetate; vitamin C was more effective in restoring SOD activity (P < 0.01) and enhancing ZO-1 protein levels (P < 0.01). Thus, long-term exposure to lead acetate at low concentrations could adversely affect sperm quality and induce inflammatory damage by oxidative stress mediated NF-κB signaling. Vitamin C could act as a protective agent and improve reproductive dysfunction in male animals after lead accumulation.

M6A transcriptome-wide map of circRNAs identified in the testis of normal and AZ-treated Xenopus laevis

BACKGROUND

Evidence showed that N6-methyladenosine (m6A) is strongly associated with male germline development. However, the role of m6A methylation on circRNAs in amphibians remains unknown. In this study, we conducted m6A sequencing analysis to explore the m6A transcriptome-wide profile of circRNAs in testis tissues of Xenopus laevis (X. laevis) with and without treatment with 100 µg/L atrazine (AZ).

RESULTS

The analysis showed that m6A modification of circRNAs enriched in sense overlapping in testes of X. laevis. We identified the differential m6A modification sites within circRNAs in testes of AZ-exposed X. laevis and compared that with animals from control group. The results showed that a total of 1507 methylated m6A sites was induced by AZ (760 up-methylated and 747 down-methylated). The cross-analysis exhibited a negative correlation of differentially methylated m6A peaks and circRNAs expression level. The Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis indicated that 20 key pathways may be involved in the mechanism of testis damage of AZ-exposed X. laevis.

CONCLUSIONS

These findings indicated that differentially m6A-methylated circRNAs may play important roles in abnormal testis development of AZ-exposed X. laevis. This study is the first report about a map of m6A modification of circRNAs in male X. laevis and provides a basis for further studying on the function and mechanism of m6A methylation of circRNAs in the testis development of amphibian.

TiO2 nanoparticles affect spermatogenesis and adhesion junctions via the ROS-mediated mTOR signalling pathway in Eriocheir sinensis testes

Recent findings found that TiO₂ nanoparticles (TiO₂-NPs) have male reproductive toxicity. However, few reports have studied the toxicity of TiO₂-NPs in crustaceans. In this study, we first chose the freshwater crustacean Eriocheir sinensis (E. sinensis) to explore the male toxicity of TiO₂-NP exposure and the underlying mechanisms. Three nm and 25 nm TiO₂-NPs at a dose of 30 mg/kg bw induced apoptosis and damaged the integrity of the haemolymph-testis-barrier (HTB, a structure similar to the blood-testis-barrier) and the structure of the seminiferous tubule. The 3-nm TiO₂-NPs caused more severe spermatogenesis dysfunction than the 25-nm TiO₂-NPs. We initially confirmed that TiO₂-NP exposure affected the expression patterns of adherens junctions (α-catenin and β-catenin) and induced tubulin disorganization in the testis of E. sinensis. TiO₂-NP exposure caused reactive oxygen species (ROS) generation and an imbalance of mTORC1-mTORC2 (mTORC1/rps6/Akt levels were increased, while mTORC2 activity was not changed). After using the ROS scavenger NAC to inhibit ROS generation, both the mTORC1-mTORC2 imbalance and alterations in AJs were rescued. More importantly, the mTORC1 inhibitor rapamycin abolished mTORC1/rps6/Akt hyperactivation and partially restored the alterations in AJs and tubulin. Collectively, the mTORC1-mTORC2 imbalance induced by TiO₂-NPs was involved in the mechanism of AJ and HTB disruption, resulting in spermatogenesis in E. sinensis.

Es-β-CATENIN affects the hemolymph-testes barrier in Eriocheir sinensis by disrupting cell junctions and cytoskeleton

β-CATENIN is an evolutionarily conserved multifunctional molecule that maintains cell adhesion as a cell junction protein to safeguard the integrity of the mammalian blood-testes barrier, and also regulates cell proliferation and apoptosis as a key signaling molecule in the WNT/β-CATENIN signaling pathway. In the crustacean Eriocheir sinensis, Es-β-CATENIN has been shown to be involved in spermatogenesis, but the testes of E. sinensis have large and well-defined structural differences from those of mammals, and the impact of Es-β-CATENIN in them is still unknown. In the present study, we found that Es-β-CATENIN, Es-α-CATENIN and Es-ZO-1 interact differently in the testes of the crab compared to mammals. In addition, defective Es-β-CATENIN resulted in increased Es-α-CATENIN protein expression levels, distorted and deformed F-ACTIN, and disturbed localization of Es-α-CATENIN and Es-ZO-1, leading to loss of hemolymph-testes barrier integrity and impaired sperm release. In addition to this, we also performed the first molecular cloning and bioinformatics analysis of Es-AXIN in the WNT/β-CATENIN pathway to exclude the effect of the WNT/β-CATENIN pathway on the cytoskeleton. In conclusion, Es-β-CATENIN participates in maintaining the hemolymph-testes barrier in the spermatogenesis of E. sinensis.

Lactoferrin Restores the Deoxynivalenol-Impaired Spermatogenesis and Blood-Testis Barrier Integrity via Improving the Antioxidant Capacity and Modifying the Cell Adhesion and Inflammatory Response

Deoxynivalenol (DON) is among the most prevalent contaminants in cereal crops and has been demonstrated to impair male spermatogenesis and induce oxidative stress, testicular apoptosis, and disruption of the blood-testis barrier (BTB). Lactoferrin (LF) is an iron-binding glycoprotein with multifunctions including anti-inflammation and antioxidation. Thus, this study aimed to investigate the effects of LF on the spermatogenesis and integrity of the BTB in DON-exposed mice. Thirty-two male mice were allotted to four groups for a 35-day feeding period: vehicle (basal diet), DON (12 mg/kg), LF (10 mg/d, p.o.), and DON + LF. The results showed that DON induced vacuolization of the spermatogenic epithelium, broke the adhesion junction between Sertoli cells and spermatids established by N-cadherin and induced testicular oxidative stress. LF administration restored sperm production, attenuated the DON-induced oxidative stress and reduced the breakages in adhesion junction. DON exposure enhanced the protein expression of occludin. Transcriptional profiling of the testis observed a disturbance in the expression profiles of cell adhesion and inflammatory response genes, and LF administration reversed these gene expressions. Furthermore, down-regulated signaling pathways, including the apical junction, TNFα signaling via NF-κB, and TGF-β in the DON group were observed. These were restored by LF. Enrichment analysis between DON + LF group and vehicle also confirmed the absence of these pathways. These findings indicated that LF eliminated the DON-induced detriment to spermatogenesis and cell connections between Sertoli cells and spermatids via improving antioxidant capacity and modifying the inflammatory response and cell adhesion genes.

Nanosized Titanium Dioxide Induced Apoptosis and Abnormal Expression of Blood-Testis Barrier Junction Proteins Through JNK Signaling Pathway in TM4 Cells

Nanosized titanium dioxide (nano-TiO₂) has been widely used in consumer products. It can cross the blood-testis barrier (BTB), and it has adverse effects on the male reproductive system. However, the specific mechanism has not been fully elucidated. The purpose of this study was to understand the role of the JNK signaling pathway in the apoptosis and abnormal expression of BTB junction proteins induced by nano-TiO₂ in TM4 cells. After different concentration of nano-TiO₂ treatments, the cell viability, apoptosis, mitochondrial membrane potential (Δψm), BTB junction proteins (Claudin-11, ZO-1, β-catenin), apoptosis-related proteins (Bax, Bcl-2, cleaved caspase-9, cleaved caspase-3), and phosphorylated (p)-JNK protein were examined. The results showed that cell viability, apoptosis rates, Δψm, and apoptosis-related protein levels changed in a concentration-dependent manner. Cell viability decreased significantly from 100 μg/mL nano-TiO₂ group. Apoptosis rates increased significantly from 150 μg/mL nano-TiO₂ group, and Δψm decreased significantly from 150 μg/mL nano-TiO₂ group. The protein levels of Bax, cleaved caspase-9, and cleaved caspase-3 increased significantly from 150 μg/mL nano-TiO₂ group, and the protein level of Bcl-2 decreased significantly from 100 μg/mL nano-TiO₂ group. The protein level of p-JNK increased significantly from 100 μg/mL nano-TiO₂ group. Abnormal expression of ZO-1 and β-catenin started from 150 μg/mL nano-TiO₂ group, and abnormal expression of Claudin-11 started from 100 μg/mL nano-TiO₂ group. Cells were treated with JNK inhibitor SP100625 to determine whether the changes of the above indicators in the concentration of 150 μg/mL nano-TiO₂ group can be reversed. We found that SP100625 at 20 μM significantly reversed these effects. These results highlighted that nano-TiO₂ could activate the JNK signaling pathway to induce mitochondria-mediated apoptosis and abnormal expression of BTB junction proteins in TM4 cells.

Bibliometric and visual analysis of blood-testis barrier research

Background: Extensive research on the blood-testis barrier has been undertaken in recent years. However, no systematic bibliometric study has been conducted on this subject. Our research aimed to identify the hotspots and frontiers of blood-testis barrier research and to serve as a guide for future scientific research and decision-making in the field.

Methods: Studies on the blood-testis barrier were found in the Web of Science Core Collection. VOSviewer, CiteSpace, and Microsoft Excel were used to conduct the bibliometric and visual analyses.

Results: We found 942 blood-testis barrier studies published in English between 1992 and 2022. The number of annual publications and citations increased significantly between 2011 and 2022, notably in the United States. China and the United States, the US Population Council, Endocrinology, and Cheng C. Yan were the most productive countries, institution, journal, and author, respectively. The study keywords indicated that blood-testis barrier research involves a variety of compositional features (tight junctions, cytoskeleton, adherens junctions), cell types (Sertoli cells, germ cells, Leydig cells, stem cells), reproductive toxicity (cadmium, nanoparticles, bisphenol-a), and relevant mechanisms (spermatogenesis, apoptosis, oxidative stress, dynamics, inflammation, immune privilege).

Conclusion: The composition and molecular processes of the blood-testis barrier as well as the blood-testis barrier in male infertility patients are the primary research hotspots in this field. In addition, future research will likely focus on treatment and the development of novel medications that target signal pathways in oxidative stress and apoptosis to preserve the blood-testis barrier. Further studies must extend to clinical diagnosis and therapy.

Lycopene Alleviates Titanium Dioxide Nanoparticle-Induced Testicular Toxicity by Inhibiting Oxidative Stress and Apoptosis in Mice

PURPOSE

The research was carried out to investigate the possible ameliorative effect of lycopene on TiO₂ NPs-induced male reproductive toxicity and explore the possible mechanism.

METHODS

Ninety-six healthy male Institute of Cancer Research (ICR) mice were equally divided into eight groups (control group, 50 mg/kg TiO₂ NPs group, 5 mg/kg LYC group, 20 mg/kg LYC group, 40 mg/kg LYC group, 50 mg/kg TiO₂ NPs + 5 mg/kg LYC group, 50 mg/kg TiO₂ NPs + 20 mg/kg LYC group, 50 mg/kg TiO₂ NPs + 40 mg/kg LYC group), and the mice were treated by intragastric administration every day for 30 days in this research. Sperm parameters, testicular histopathology, oxidant and antioxidant enzymes, and cell apoptosis-related protein expression in the testicular tissue were analyzed.

RESULTS

The results showed that TiO₂ NPs exposure significantly decreased sperm count and motility, and TiO₂ NPs also increased sperm malformation in the epididymis; these characteristics were improved when co-administration with LYC. Testicular histopathological lesions like disorder of germ cells arrange, detachment, atrophy, and vacuolization were observed after TiO₂ NPs exposure, and these abnormalities were effectively ameliorated by co-administration with LYC. Oxidative stress was induced by TiO₂ NPs exposure as evidenced by increased the level of MDA and decreased the activity of SOD as well as the level of anti-O₂^-, and these alterations were effectively prevented by co-administration with LYC. LYC also alleviated TiO₂ NPs-induced germ cell apoptosis by inhibiting mitochondrial apoptotic pathway, as shown by the upregulation of Bcl-2, the downregulation of Bax, Cleaved Caspase 3, and Cleaved Caspase 9.

CONCLUSION

LYC could ameliorate TiO₂ NPs-induced testicular damage via inhibiting oxidative stress and apoptosis, which could be used to alleviate the testicular toxicity associated with TiO₂ NPs intake.

Hua-Tan-Sheng-Jing Decoction Treats Obesity With Oligoasthenozoospermia by Up-Regulating the PI3K-AKT and Down-Regulating the JNK MAPK Signaling Pathways: At the Crossroad of Obesity and Oligoasthenozoospermia

Background: Oligoasthenozoospermia is the leading cause of male infertility, seriously affecting men's health and increasing the societal medical burden. In recent years, obesity-related oligoasthenozoospermia has attracted increased attention from researchers to find a cure. This study aimed to evaluate the efficacy of Hua-Tan-Sheng-Jing decoction (HTSJD) in treating obesity with oligoasthenozoospermia, determine its active ingredients and identify its mechanism of action. Methods: The ingredients of HTSJD were determined by combining the ultra-performance liquid chromatography with mass spectrometry (UPLC-MS/MS) and systems pharmacology approach. The common pathogenesis of obesity and oligoasthenozoospermia and the potential mechanism of HTSJD against obesity with oligoasthenozoospermia were obtained through target fishing, network construction, and enrichment analyses. Further, molecular docking of the key ingredients with the upstream receptors of the key signaling pathways of the potential mechanism was used to predict their affinity. Finally, high-fat-induced obesity with oligoasthenozoospermia rat model was constructed to determine the effects of HTSJD on semen concentration, sperm motility, body weight, and serum lipid metabolism. The key proteins were validated by immunohistochemistry (IHC). Results: A total of 70 effective components and 847 potential targets of HTSJD (H targets) were identified, of which 743 were common targets related to obesity and oligoasthenozoospermia (O-O targets) mainly enriched in the pathways related to inflammation, oxidative stress and hormone regulation. Finally, 143 common targets (H-O-O targets) for HTSJD against obesity with oligoasthenozoospermia were obtained. Combining the hub genes and the results of Gene Ontology (GO) functional and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis of H-O-O targets, PI3K-AKT and MAPK signaling pathways were identified as the key pathways. Molecular docking results showed that Diosgenin, Kaempferol, Quercetin, Hederagenin, Isorhamnetin may act on the related pathways by docking EGFR, IGF1R and INSR. The animal-based in vivo experiments confirmed that HTSJD improves the sperm quality of high-fat diet-fed rats by reducing their body weight and blood lipid levels, influencing the PI3K-AKT and MAPK signaling pathways and altering the corresponding protein expressions. Conclusion: HTSJD treats obesity with oligoasthenozoospermia by up-regulating the PI3K-AKT signaling pathway and down-regulating the MAPK signaling pathway, which are at the crossroad of obesity and oligoasthenozoospermia.

Effect of Titanium Dioxide and Silver Nanoparticles on Mitochondrial Dynamics in Mouse Testis Tissue

This study was performed to investigate whether the toxicity of nanoparticles (Ag NPs or TiO₂ NPs) affected mitochondrial dynamics (mitochondrial fusion and fission mechanisms) in testicular cells of mice. Animals were assigned into three groups (ten mice per group): control group (distilled water), TiO₂ NP group (5 mg/kg per dose), and Ag NP group (5 mg/kg per dose). NPs were administered intravenously (via tail vein) to mice with 3-day intervals. To determine the possible toxic effect of NPs on mitochondrial dynamics, the expression levels of mitochondrial fission (Drp1)- and fusion (Mfn1, Mfn2, OPA1)-related genes were analyzed. The results showed that both Ag NPs and TiO₂ NPs entered the testis via the blood-testis barier and accumulated in mouse testis tissue. Experiments showed that administration of Ag NPs neither alters testicular weight and testicular index nor causes significant toxic effect on sperm parameters. RT-PCR analysis demonstrated that Ag NP treatment did not disrupt mitochondrial dynamics in testicular cells. Conversely, administration of TiO₂ NPs (anatase, < 25 nm) decreased the sperm motility and the percentages of sperms with swollen tail. Furthermore, RT-PCR and western blot analyses showed that TiO₂ NPs disrupted mitochondrial dynamics by causing excess mitochondrial fission (excess expression of Drp1 gene and DRP1 protein). This is the first report on the toxicity of nanoparticles on mitochondrial dynamics (fusion and fission mechanisms) in testicular cells.

A network pharmacology approach to determine the underlying mechanisms of action of Yishen Tongluo formula for the treatment of oligoasthenozoospermia

Oligoasthenozoospermia is a complex disease caused by a variety of factors, and its incidence is increasing yearly worldwide. Yishen Tongluo formula (YSTLF), created by Professor Sun Zixue, has been used to treat oligoasthenozoospermia in clinical practice for several decades with a good therapeutic effect. However, the chemical and pharmacological profiles of YSTLF remain unclear and need to be elucidated. In this study, a network pharmacology approach was applied to explore the potential mechanisms of YSTLF in oligoasthenozoospermia treatment. All of the compounds in YSTLF were retrieved from the corresponding databases, and the bioactive ingredients were screened according to their oral bioavailability (OB) and drug-likeness (DL). The potential proteins of YSTLF were obtained from the traditional Chinese medicine systems pharmacology (TCMSP) database and the Bioinformatics Analysis Tool for Molecular Mechanism of Traditional Chinese Medicine (BATMAN-TCM) database, while the potential genes of oligoasthenozoospermia were obtained from the GeneCards database and the DisGeNET database. The STRING database was used to construct an interaction network according to the common targets identified by the online tool Venny for YSTLF and oligoasthenozoospermia. The topological characteristics of nodes were visualized and analyzed through Cytoscape. Biological functions and significant pathways were determined and analyzed using the Gene Ontology (GO) knowledgebase, the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Metascape. Finally, the disease-formula-compound-target-pathway network was constructed by Cytoscape. A total of 106 bioactive ingredients and 134 potential targets from YSTLF were associated with oligoasthenozoospermia or considered to be therapeutically relevant. Pathway analysis indicated that the PI3K/Akt, MAPK and apoptosis signaling pathways were significant pathways involved in oligoasthenozoospermia. In conclusion, the current study expounded the pharmacological actions and molecular mechanisms of YSTLF in treating oligoasthenozoospermia from a holistic viewpoint. The potential molecular mechanisms were closely related to antioxidative stress, antiapoptosis and anti-inflammation, with TNF, CCND1, ESR1, NFKBIA, NR3C1, MAPK8, and IL6 being possible targets. This network pharmacology prediction may offer a helpful tool to illustrate the molecular mechanisms of the Chinese herbal compound YSTLF in oligoasthenozoospermia treatment.

Safety assessment of titanium dioxide (E171) as a food additive

The present opinion deals with an updated safety assessment of the food additive titanium dioxide (E 171) based on new relevant scientific evidence considered by the Panel to be reliable, including data obtained with TiO2 nanoparticles (NPs) and data from an extended one-generation reproductive toxicity (EOGRT) study. Less than 50% of constituent particles by number in E 171 have a minimum external dimension < 100 nm. In addition, the Panel noted that constituent particles < 30 nm amounted to less than 1% of particles by number. The Panel therefore considered that studies with TiO2 NPs < 30 nm were of limited relevance to the safety assessment of E 171. The Panel concluded that although gastrointestinal absorption of TiO2 particles is low, they may accumulate in the body. Studies on general and organ toxicity did not indicate adverse effects with either E 171 up to a dose of 1,000 mg/kg body weight (bw) per day or with TiO2 NPs (> 30 nm) up to the highest dose tested of 100 mg/kg bw per day. No effects on reproductive and developmental toxicity were observed up to a dose of 1,000 mg E 171/kg bw per day, the highest dose tested in the EOGRT study. However, observations of potential immunotoxicity and inflammation with E 171 and potential neurotoxicity with TiO2 NPs, together with the potential induction of aberrant crypt foci with E 171, may indicate adverse effects. With respect to genotoxicity, the Panel concluded that TiO2 particles have the potential to induce DNA strand breaks and chromosomal damage, but not gene mutations. No clear correlation was observed between the physico-chemical properties of TiO2 particles and the outcome of either in vitro or in vivo genotoxicity assays. A concern for genotoxicity of TiO2 particles that may be present in E 171 could therefore not be ruled out. Several modes of action for the genotoxicity may operate in parallel and the relative contributions of different molecular mechanisms elicited by TiO2 particles are not known. There was uncertainty as to whether a threshold mode of action could be assumed. In addition, a cut-off value for TiO2 particle size with respect to genotoxicity could not be identified. No appropriately designed study was available to investigate the potential carcinogenic effects of TiO2 NPs. Based on all the evidence available, a concern for genotoxicity could not be ruled out, and given the many uncertainties, the Panel concluded that E 171 can no longer be considered as safe when used as a food additive.