Dynamic elementomics of single-cell ICP-MS-derived signals in normal and calcium pump PMCA4-deficient mouse epididymal sperm during capacitation.

Currently, clinical analysis of male infertility mainly relies on parameters of semen and sperm cells. However, the high diagnostic failure rates indicate that the current assessment methods are not sufficient and a new approach to evaluating sperm function still needs to be developed. Here we explored the feasibility of single-cell inductively coupled plasma mass spectrometry (sc-ICP-MS)-derived profiles to determine the elemental characteristics in viable capacitated sperm under normal and deficient conditions. To validate the measurements, we used male sterile Pmca4-knockout (KO) mice with impaired calcium clearance, known to be dysregulated due to loss of calcium efflux capacity during sperm capacitation. Consistently, we observed significantly increased calcium intensities in Pmca4-KO sperm upon capacitation stimulation compared with control sperm from the caudaepididymides of wild-type control (WT) mice. More importantly, we explored that the characteristic signatures of calcium intensities in individual spikes derived from sc-ICP-MS was consistent with the dynamics of relative calcium levels in single sperm reported in the literature. Prominent alterations were also observed in the dynamic signatures of sc-ICP-MS-derived profiles of essential elements, particularly the redox-labile elements including copper, iron, manganese, selenium, and zinc in Pmca4-KO sperm compared to WT controls. Therefore, our study demonstrates that elementomics of sc-ICP-MS-derived signals can reveal ionic dysregulation in plasma membrane Ca2+-ATPase isoform 4 protein deficient sperm, and that sc-ICP-MS assay can be applied for functional analysis of viable sperm in functional activities, such as capacitation stimulation. We propose that cell elementomics can be used as an alternative approach to assessing sperm quality and male fertility at the single-cell level.

Growth, mortality, and resource utilization of Gymnocypris chui in Langcuo Lake of Tibetan Plateau, China.

To investigate the growth, mortality, and resource utilization of Gymnocypris chui in Langcuo Lake of Tibetan Plateau, we measured body length and body weight of 389 fish based on four sampling surveys from October 2018 to November 2019. We identified the ages through lapillus. Based on frequency distribution of body length, we estimated the growth and mortality coefficients of G. chui in Langcuo Lake and the utilization status of existing population resources according to the Beverton-Holt dynamic comprehensive model. The results showed that G. chui were mainly composed of individuals aged 2 to 19 years in Langcuo Lake, with a length-body weight relationship equation of W=0.0105L3.042. The von Bertalanffy growth equation revealed that the fish had an asymptotic body length of L∞=37.28 cm, growth coefficient of k=0.160, and theoretical growth starting age of t0=-0.887 a. The total mortality coefficient Z was estimated as 0.48, based on the length-converted catch curve method. According to Pauly's empirical formula, the natural mortality coefficient M was 0.34, fishing mortality coefficient F was 0.14, and exploitation rate E was 0.29, indicating that G. chui resources in Langcuo Lake were not over-exploited. Considering the growth and mortality of G. chui in Langcuo Lake, fishing is appropriate, with a recommended fishing length of Lc=22.37 cm.

Discovery of Novel Schizocommunin Derivatives as Telomeric G-Quadruplex Ligands That Trigger Telomere Dysfunction and the Deoxyribonucleic Acid (DNA) Damage Response.

Telomeric G-quadruplex targeting and telomere maintenance interference are emerging as attractive strategies for anticancer therapies. Here, a novel molecular scaffold is explored for telomeric G-quadruplex targeting. A series of novel schizocommunin derivatives was designed and synthesized as potential telomeric G-quadruplex ligands. The interaction of telomeric G-quadruplex DNA with the derivatives was explored by biophysical assay. The cytotoxicity of the derivatives toward cancer cell lines was evaluated by the methyl thiazolyl tetrazolium (MTT) assay. Among the derivatives, compound 16 showed great stabilization ability toward telomeric G-quadruplex DNA and good cytotoxicity toward cancer cell lines. Further cellular experiments indicated that 16 could induce the formation of telomeric G-quadruplex in cells, triggering a DNA damage response at the telomere and causing telomere dysfunction. These effects ultimately provoked p53-mediated cell cycle arrest and apoptosis, and suppressed tumor growth in a mouse xenograft model. Our work provides a novel scaffold for the development of telomeric G-quadruplex ligands.

Polylactic-co-glycolic acid microspheres containing three neurotrophic factors promote sciatic nerve repair after injury.

A variety of neurotrophic factors have been shown to repair the damaged peripheral nerve. However, in clinical practice, nerve growth factor, neurotrophin-3 and brain-derived neurotrophic factor are all peptides or proteins that may be rapidly deactivated at the focal injury site; their local effective concentration time following a single medication cannot meet the required time for spinal axons to regenerate and cross the glial scar. In this study, we produced polymer sustained-release microspheres based on the polylactic-co-glycolic acid copolymer; the microspheres at 300-µm diameter contained nerve growth factor, neurotrophin-3 and brain-derived neurotrophic factor. Six microspheres were longitudinally implanted into the sciatic nerve at the anastomosis site, serving as the experimental group; while the sciatic nerve in the control group was subjected to the end-to-end anastomosis using 10/0 suture thread. At 6 weeks after implantation, the lower limb activity, weight of triceps surae muscle, sciatic nerve conduction velocity and the maximum amplitude were obviously better in the experimental group than in the control group. Compared with the control group, more regenerating nerve fibers were observed and distributed in a dense and ordered manner with thicker myelin sheaths in the experimental group. More angiogenesis was also visible. Experimental findings indicate that polylactic-co-glycolic acid composite microspheres containing nerve growth factor, neurotrophin-3 and brain-derived neurotrophic factor can promote the restoration of sciatic nerve in rats after injury.

Hydrogen-rich saline injection into the subarachnoid cavity within 2 weeks promotes recovery after acute spinal cord injury.

Hydrogen can relieve tissue-damaging oxidative stress, inflammation and apoptosis. Injection of hydrogen-rich saline is an effective method for transporting molecular hydrogen. We hypothesized that hydrogen-rich saline would promote the repair of spinal cord injury induced by Allen's method in rats. At 0.5, 1, 2, 4, 8, 12 and 24 hours after injury, then once daily for 2 weeks, 0.25 mL/kg hydrogen-rich saline was infused into the subarachnoid space through a catheter. Results at 24 hours, 48 hours, 1 week and 2 weeks after injury showed that hydrogen-rich saline markedly reduced cell death, inflammatory cell infiltration, serum malondialdehyde content, and caspase-3 immunoreactivity, elevated serum superoxide dismutase activity and calcitonin gene-related peptide immunoreactivity, and improved motor function in the hindlimb. The present study confirms that hydrogen-rich saline injected within 2 weeks of injury effectively contributes to the repair of spinal cord injury in the acute stage.