Ursonic acid attenuates spermatogenesis in oligozoospermia mice through inhibiting ferroptosis.

Ursonic acid (UNA) is a natural pentacyclic triterpene found in some medicinal plants and foods. The reproductive protective effect of UNA was evaluated in a mouse model of oligozoospermia induced by busulfan (BUS) at 30 mg/kg b.w.. The mice were initially divided into groups with UNA concentrations of 10, 30, 50, 100 mg/kg. Subsequently, based on sperm parameters, the optimal concentration of 50 mg/kg was identified. As a control, an additional group was supplemented with ursolic acid at a concentration of 50 mg/kg. The results indicated that BUS caused the loss of spermatogenic cells in testis, the decrease of sperm in epididymis, the disorder of testicular cytoskeleton, the decrease of serum sex hormones such as testosterone which induced an increase in feedback of androgen receptor and other testosterone-related proteins, the increase of malondialdehyde and reactive oxygen species levels and the increase of ferroptosis in testis while UNA successfully reversed these injuries. High-throughput sequencing revealed that UNA administration significantly upregulated the expression of genes associated with spermatogenesis, such as Tnp1, Tnp2, Prm1, among others. These proteins are crucial in the histone to protamine transition during sperm chromatin remodeling. Network pharmacology analysis reveals a close association between UNA and proteins related to the transformation of histones to protamine. Molecular docking studies reveal that UNA can interact with the ferroptosis-inhibiting gene SLC7A11, thereby modulating ferroptosis. Taken together, UNA alleviated BUS-induced oligozoospermia by regulating hormone secretion, mitigating oxidative stress and promoting recovery of spermatogenesis by inhibiting the ferroptosis.

Analysis of the structure and activity of the promoter regions of the metallothionein genes of the freshwater pearl mussel Hyriopsis schlegelii.

To investigate the regulation of metallothionein genes (HsMTs) of Hyriopsis schlegelii, 1,121-bp and 1,270-bp regions of the HsMT1 and HsMT2 promoters were cloned and analyzed, respectively. The two promoters shared partially conserved features and possessed distinct characteristics such as the number or position of metal response elements (MREs). Further analysis of the HsMT1 and HsMT2 promoters was performed by the reporter assay using the luciferase gene. Both promoters were activated by various metals, and presented different levels of metal ions inducibility in human hepatoblastoma cells. Deletion mutant assays demonstrated that both the longest promoter regions achieved the maximum inducibility, and the metal inducibility was dependent on the presence of the MRE in HsMT1 and the distal MRE in HsMT2. In addition, we cloned a putative metal responsive transcription factor (hereby designated as HsMTF-like) and studied its effect on HsMTs expression in human hepatoblastoma cells. An in vivo assay demonstrated that HsMTF-like activates basal HsMTs transcription level, and the MRE in the HsMTs promoter mediates this activation process. Moreover, this basal transcription level can be further boosted by zinc treatment. In conclusion, the regulation mechanism for MT activation in H. schlegelii should be evolutionarily conserved.

Comparative proteomics analysis of spermary and ovary in Hyriopsis schlegelii.

We provide the first large-scale quantitative proteomics analysis in Hyriopsis schlegelii. To investigate the proteins expressed in the gonads, a quantitative proteomics approach has been utilized to analyze differentially expressed proteins between the spermary and ovary. In this study, we identified and quantified 2416 proteins in the gonads of Hyriopsis schlegelii. Of these, 559 proteins showed significantly different expression between the spermary and ovary. Some specific proteins expressed in either the spermary or ovary were identified in Hyriopsis schlegelii. In addition, a series of proteins related to gametogenesis were also identified. Compared with previous reports, many proteins in Hyriopsis schlegelii identified here have different expression patterns between the spermary and ovary. The special hermaphroditism in Hyriopsis schlegelii may contribute to these inconsistent results. The provided proteomics data could be considered as a starting point for subsequent studies focusing on the proteins involved in sexual gland development and maturity.

Comparative analysis of the complete mitochondrial genomes of three geographical topmouth culter (Culter alburnus) groups and implications for their phylogenetics.

Topmouth culter (C. alburnus) is an important commercial fish in China. We compared the nucleotide variations in the mtDNA genomes among three geographical groups of Culter alburnus: Liangzi Lake, Hubei Province (referred to as LZH); Taihu Lake, Jiangsu Province (TH); and Poyang Lake, Jiangxi Province (PYH). The similarity of whole mtDNA genomes ranged from 0.992 to 0.999. The similarity among 13 protein-coding genes, 2 rRNA genes, and the D-loop sequences was found to range from 0.982 to 0.996. This is useful data for future designing work for making specific molecular marker for distinguishing individuals of C. alburnus from the three geographical groups. An extended termination-associated sequence (ETAS) and several conserved blocks (CSB-F, CSB-E, CSB-D, CSB1, CSB2, and CSB3) were identified in the mtDNA control regions. A phylogenetic analysis shows a monophyletic relationship of the LZF-female and the LZF-male. However, the analysis also showed paraphyletic relationships for the other two geological groups. This result will be useful for the future breeding work of C. alburnus.

Thiophene-Based Double Helices: Syntheses, X-ray Structures, and Chiroptical Properties.

We demonstrate facile and efficient construction of conjugated double helical ladder oligomers from the saddle-shaped cyclooctatetrathiophene (COTh) building blocks. The key step involves deprotonation of tetra[3,4]thienylene (ß,ß-COTh) with n-BuLi which displays remarkably high ipsilateral selectivity. Three racemic double helical ladder oligomers, rac-DH-1, rac-DH-2, and rac-DH-3, containing two, three, and five COTh annelated moieties are efficiently synthesized by diastereoselective coupling of the racemic precursors. The X-ray crystallographic studies of rac-DH-1, rac-DH-2 and rac-DH-3 unambiguously revealed that each double helical scaffold has two single helices intertwined with each other via the C-C single bonds. Following removal of TMS groups, double helical ladder oligomer rac-DH-1-D had sufficient solubility to be resolved via chiral HPLC, thus enabling determination of its chirooptical properties such as CD spectra and optical rotation. (+)-DH-1-D has a large barrier for racemization, with lower limit of ΔG(‡) > 48 kcal mol(-1), which may be compared to DFT-computed barrier of 51 kcal mol(-1). The enantiomers of DH-1-D show 1 order of magnitude stronger chirooptical properties than the carbon-sulfur [7]helicene, as determined by the anisotropy factor g = Δε/ε = -0.039, based on Δεmax = -11 and ε = 2.8 × 10(2) L mol(-1) cm(-1) in cyclohexane at 327 nm.

Molecular characterization and expression of metallothionein from freshwater pearl mussel, Hyriopsis schlegelii.

Two metallothionein genes (HsMT1 and HsMT2) were first identified and described from Hyriopsis schlegelii. The open reading frame of HsMT1 and HsMT2 were 216 and 222 bp, encoding a protein of 71 and 73 amino acid residues. The deduced amino acid sequences showed they contained parts of typical MT characteristics, apart from HsMT2 lacked Cys-Cys motifs. The phylogenetic tree showed HsMT1 shared a high similarity with that of other molluscs, but HsMT2 was split into a distinct group separated from known molluscan MTs. HsMT1 exhibited constitutive expression in all examined tissues and the highest expression occurred in hepatopancreas, however, nearly all HsMT2 was just detected in gonad. After Cd exposure, their mRNA levels presented similar expression patterns. The transgenic bacteria of HsMT1 showed higher tolerance than HsMT2 in Cd environment. It was implied that HsMT1 and HsMT2 were involved in metal response but HsMT2 might have other physiological functions.

Silicon Spiro Double Helicene-like Compounds Based on Dithieno[2,3-b:3',2'-d]thiophene: Syntheses and Crystal Structures.

Silicon spiro carbon-sulfur double helicene-like compounds 1 and rac-2 were synthesized from 2,5-bis-trimethylsilanyldithieno[2,3-b:3',2'-d]thiophene, with total yields of 17% and 7%, respectively. (1)H and (13)C NMR spectra and X-ray crystallographic analysis showed the predicted 4-fold symmetry for 1 and rac-2 and confirmed their spiro double helicene-like spatial configurations. The absorption behavior of compounds 1 and rac-2 was also investigated.

De novo transcriptome sequencing to identify the sex-determination genes in Hyriopsis schlegelii.

This study presents the first analysis of expressed transcripts in the spermary and ovary of Hyriopsis schlegelii (H. schlegelii). A total of 132,055 unigenes were obtained and 31,781 of these genes were annotated. In addition, 19,511 upregulated and 25,911 downregulated unigenes were identified in the spermary. Ten sex-determination genes were selected and further analyzed by real-time PCR. In addition, mammalian genes reported to govern sex-determination pathways, including Sry, Dmrt1, Dmrt2, Sox9, GATA4, and WT1 in males and Wnt4, Rspo1, Foxl2, and ß-catenin in females, were also identified in H. schlegelii. These results suggest that H. schlegelii and mammals use similar gene regulatory mechanisms to control sex determination. Moreover, genes associated with dosage compensation mechanisms, such as Msl1, Msl2, and Msl3, and hermaphrodite phenotypes, such as Tra-1, Tra-2α, Tra-2ß, Fem1A, Fem1B, and Fem1C, were also identified in H. schlegelii. The identification of these genes indicates that diverse regulatory mechanisms regulate sexual polymorphism in H. schlegelii.

Synthesis and characterization of cyclooctatetrathiophenes with different connection sequences.

Based on the selectivity of deprotonation of 5,5'-bistrimethylsilyl-2,3'-bithiophene (4) in the presence of n-BuLi, three new cyclooctatetrathiophenes (COThs), COTh-1, COTh-2, and COTh-3 have been efficiently developed via intermolecular or intramolecular cyclizations. Their crystal structures clearly show that the different connectivity sequence of the thiophene rings in the molecules. The CV data and UV-vis absorbance spectra of COThs are also described. In addition, the time-dependent density functional theory (TDDFT) calculations accurately reproduce experimental observations and afford band assignment.

Small Molecules of Cyclopentadithiophene Derivatives: Effect of Sulfur Atoms Position and Substituted Groups on Their UV-abs Properties.

Thiophene-based organic semiconductors used as the active components have received much attention. Their photoelectric properties can be easily tuned with various substitutions at different positions on molecular structures. Here, we synthesized series cyclopentadithiophene (CDT) derivatives with sulfur atoms at ortho- (o-CDT), meta- (m-CDT) and para-position (p-CDT) of the bridge carbon. These CDT derivatives were substituted by carbonyl/dicyanomethylene at the bridge position and/or by phenyl groups at α position, respectively. Due to the different conjugation extent and the variation of donor-acceptor (D-A) interaction originating from the change of sulfur atom position, diverse absorption spectra were observed. Especially for dicyanomethylene substituted o-CDT with phenyl as substitution group (DPCN-o-CDT), its absorption spectrum covers the whole region of visible light. Combining with the electrochemical behaviors and theoretical calculations, it was found that the sulfur atoms mainly contribute to the molecular conjugation in these CDT derivatives, especially for o-CDT derivatives. For phenyl groups, they primarily act as electron donor in m-CDT derivatives, and chiefly contribute to molecular conjugation in p-CDT derivatives, and simultaneously work as electron donor and conjugation component in o-CDT derivatives, respectively.