Stem Cell Research & Therapy•2024•DOI: 10.1186/s13287-024-03718-z
Background Studies have shown that chemotherapy and radiotherapy can cause premature ovarian failure and loss of fertility in female cancer patients. Ovarian cortex cryopreservation is a good choice to preserve female fertility before cancer treatment. Following the remission of the disease, the thawed ovarian tissue can be transplanted back and restore fertility of the patient. However, there is a risk to reintroduce cancer cells in the body and leads to the recurrence of cancer. Given the low success rate of current in vitro culture techniques for obtaining mature oocytes from primordial follicles, an artificial ovary with primordial follicles may be a good way to solve this problem. Methods In the study, we established an artificial ovary model based on the participation of mesenchymal stem cells (MSCs) to evaluate the effect of MSCs on follicular development and oocyte maturation. P2.5 mouse ovaries were digested into single cell suspensions and mixed with bone marrow derived mesenchymal stem cells (BM-MSCs) at a 1:1 ratio. The reconstituted ovarian model was then generated by using phytohemagglutinin. The phenotype and mechanism studies were explored by follicle counting, immunohistochemistry, immunofluorescence, in vitro maturation (IVM), in vitro fertilization (IVF), real-time quantitative polymerase chain reaction (RT-PCR), and Terminal-deoxynucleotidyl transferase mediated nick end labeling(TUNEL) assay. Results Our study found that the addition of BM-MSCs to the reconstituted ovary can enhance the survival of oocytes and promote the growth and development of follicles. After transplanting the reconstituted ovaries under kidney capsules of the recipient mice, we observed normal folliculogenesis and oocyte maturation. Interestingly, we found that BM-MSCs did not contribute to the formation of follicles in ovarian aggregation, nor did they undergo proliferation during follicle growth. Instead, the cells were found to be located around growing follicles in the reconstituted ovary. When theca cells were labeled with CYP17a1, we found some overlapped staining with green fluorescent protein(GFP)-labeled BM-MSCs. The results suggest that BM-MSCs may participate in directing the differentiation of theca layer in the reconstituted ovary. Conclusions The presence of BM-MSCs in the artificial ovary was found to promote the survival of ovarian cells, as well as facilitate follicle formation and development. Since the cells didn’t proliferate in the reconstituted ovary, this
Acta Biochimica et Biophysica Sinica•2025•DOI: 10.3724/abbs.2024172
Meiosis, a process unique to germ cells, involves formation and repair of double-stranded nicks in DNA, pairing and segregation of homologous chromosomes, which ultimately achieves recombination of homologous chromosomes. Genetic abnormalities resulted from defects in meiosis are leading causes of infertility in humans. Meiotic sex chromosome inactivation (MSCI) plays a crucial role in the development of male germ cells in mammals, yet its underlying mechanisms remain poorly understood. In this study, we illustrate the predominant presence of a protein known as glucose 6 phosphatase catalyzed 3 (G6PC3) in pachytene spermatocytes, with a high concentration in the sex body (XY body), suggesting its significant involvement in male germ cell development. By employing CRISPR-Cas9 technology, we generate mice deficient in the G6pc3 gene, resulting in complete meiotic arrest at the pachytene stage in spermatocytes and are completely sterile. Additionally, we observe abnormal XY body formation and impaired MSCI in G6pc3-knockout spermatocytes. These findings underscore G6pc3 as a new essential regulator that is essential for meiotic progression. G6PC3 is involved in spermatocyte during male spermatogenesis development by the maintenance of meiosis chromosome silencing.
Acta Biochimica et Biophysica Sinica•2024•DOI: 10.3724/abbs.2024122
The main protease (Mpro) of coronaviruses plays a key role in viral replication, thus serving as a hot target for drug design. PF-00835231 is a promising inhibitor of SARS-CoV-2 Mpro. Here, we report the inhibitory potency of PF-00835231 against SARS-CoV-2 Mpro and seven Mpro mutants (G15S, M49I, Y54C, K90R, P132H, S46F, and V186F) from SARS-CoV-2 variants. The results confirm that PF-00835231 has broad-spectrum inhibition against various coronaviral Mpros. In addition, the crystal structures of SARS-CoV-2 Mpro, SARS-CoV Mpro, MERS-CoV Mpro, and seven SARS-CoV-2 Mpro mutants (G15S, M49I, Y54C, K90R, P132H, S46F, and V186F) in complex with PF-00835231 are solved. A detailed analysis of these structures reveals key determinants essential for inhibition and elucidates the binding modes of different coronaviral Mpros. Given the importance of the main protease for the treatment of coronaviral infection, structural insights into Mpro inhibition by PF-00835231 can accelerate the design of novel antivirals with broad-spectrum efficacy against different human coronaviruses.
Chinese Traditional and Herbal Drugs•2026•DOI: 10.7501/j.issn.0253-2670.2026.16.20261624
The bHLH transcription factor family in Forsythia suspensa was systematically identified and characterized using genomic data, yielding 170 members with complete HLH conserved domains distributed across 14 chromosomes. Protein lengths ranged from 67 to 885 amino acids, with relative molecular masses of 7,910.58 to 98,854.78 and theoretical isoelectric points of 4.71 to 10.44. Phylogenetic analysis classified these factors into 13 subfamilies, with subfamily III being the largest. Cis-acting element analysis revealed multiple light-, hormone-, and stress-responsive elements. Exogenous methyl jasmonate (MeJA) treatment of F. suspensa leaves followed by qRT-PCR within 48 h and correlation with phillygenin content identified FsbHLH26 and FsbHLH139 as likely key regulators of phillygenin biosynthesis and accumulation. These findings provide a foundation for elucidating the molecular mechanisms underlying phillygenin biosynthesis.
Acta Biochimica et Biophysica Sinica•2025•DOI: 10.3724/abbs.2025066
Chromosome congression and spindle assembly are essential for genomic stability, and their dysregulation is linked to tumorigenesis. WDR5, a core component of the MLL methyltransferase complex, directly binds Kif2A to regulate mitotic events, but the structural basis of this interaction remained unresolved. Here, the crystal structure of WDR5 in complex with a Kif2A-derived peptide (residues 114–122) was determined at 1.85 Å resolution. Kif2A engages both the WIN and S7 sites of WDR5 via Arg117 and Ser121; Ser121 forms hydrogen bonds with WDR5 Tyr191 and Lys259, inducing Tyr191 rotation and opening the S7 pocket. Structures of WDR5 with truncated or mutated Kif2A peptides and a WDR5 Y191F variant reveal the dynamic nature of Tyr191. Anti-WDR5 compounds exhibit a similar binding mode at the WIN-S7 site. Mutagenesis combined with isothermal titration calorimetry (ITC) assays underscore the critical roles of Arg117 and Ser121 in mediating Kif2A–WDR5 binding. These findings provide atomic-level insights into the non-canonical mitotic function of the MLL/WDR5 complex and highlight WIN-S7 sites as promising therapeutic targets for diseases associated with chromosomal instability, such as cancers.