Sperm flagellar 2 (SPEF2) is essential for sperm flagellar assembly in humans.

Spermiogenesis is a complex and tightly regulated process, consisting of acrosomal biogenesis, condensation of chromatin, flagellar assembly, and disposal of extra cytoplasm. Previous studies have reported that sperm flagellar 2 (SPEF2) deficiency causes severe asthenoteratozoospermia owing to spermiogenesis failure, but the underlying molecular mechanism in humans remains unclear. Here, we performed proteomic analysis on spermatozoa from three SPEF2 mutant patients to study the functional role of SPEF2 during sperm tail development. A total of 1262 differentially expressed proteins were detected, including 486 upregulated and 776 downregulated. The constructed heat map of the differentially expressed proteins showed similar trends. Among these, the expression of proteins related to flagellar assembly, including SPEF2, sperm associated antigen 6 (SPAG6), dynein light chain tctex-type 1 (DYNLT1), radial spoke head component 1 (RSPH1), translocase of outer mitochondrial membrane 20 (TOM20), EF-hand domain containing 1 (EFHC1), meiosis-specific nuclear structural 1 (MNS1) and intraflagellar transport 20 (IFT20), was verified by western blot. Functional clustering analysis indicated that these differentially expressed proteins were specifically enriched for terms such as spermatid development and flagellar assembly. Furthermore, we showed that SPEF2 interacts with radial spoke head component 9 (RSPH9) and IFT20 in vitro, which are well-studied components of radial spokes or intra-flagellar transport and are essential for flagellar assembly. These results provide a rich resource for further investigation into the molecular mechanism underlying the role that SPEF2 plays in sperm tail development and could provide a theoretical basis for gene therapy in SPEF2 mutant patients in the future.

News on alginate recovery by forward osmosis: Reverse solute diffusion is useful.

The water content in the recycled alginate solutions from aerobic granular sludge was nearly 100%. Forward osmosis (FO) has become an innovative dewatering technology. In this study, the FO concentration of sodium alginate (SA) was investigated using calcium chloride as a draw solute. The reverse solute flux (RSF) of calcium ions in FO had a beneficial effect, contrary to the findings of previous literature. The properties of the concentrated substances formed on the FO membrane on the feed side were analyzed by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy, verifying that calcium alginate (Ca-Alg), which can be used as a recycled material, was formed on the FO membrane on the feed side owing to the interaction between SA and permeable calcium ions. Water flux increased significantly with the increase in calcium chloride concentration, while the concentration of SA had little influence on the water flux in FO. Based on this discovery, we propose a novel method for the concentration and recovery of alginate, in which the RSF of calcium ions is utilized for recovering Ca-Alg by FO, with calcium chloride as a draw solute.

Separation of trace pharmaceuticals individually and in combination via forward osmosis.

With a high rejection coefficient for trace pharmaceuticals and personal care products (PPCPs), forward osmosis (FO) membrane separation has become a cutting-edge technology in water treatment owing to its low energy consumption and low membrane fouling. Wastewater contains many types of PPCPs, and one pharmaceutical molecule affects the separation behaviors of other pharmaceuticals in FO. Therefore, simultaneous FO of multiple PPCPs needs to be investigated. In this study, the separation behaviors of four trace pharmaceuticals (ciprofloxacin (CIP), sulfamethoxazole (SMX), acetaminophen (ACP), carbamazepine (CBZ)), individually (termed "single pharmaceuticals") and in combination (termed "binary pharmaceuticals" as two pharmaceuticals were studied simultaneously), during FO were investigated at trace concentrations using ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The results showed that for single pharmaceuticals, the molecular sieve dominates their retention rate-the retention rate increases with increasing Stokes radius of the molecules (29.1 â†’ 94.8% for 0.35 â†’ 0.47 nm). For binary pharmaceuticals, the retention rates of both pharmaceuticals without charge decrease with increasing total molecule number (for ACP + CBZ, 31.4 â†’ 52.1% (ACP), 75.1 â†’ 83.0% (CBZ)). Negatively charged pharmaceuticals are mutually exclusive with the negatively charged FO membrane, resulting in the increase of the retention rate of pharmaceuticals (83.1 â†’ 90.1% (CIP) when CIP + ACP â†’ CIP + SMX). In the presence of a positively charged pharmaceutical, the retention rate of negatively charged pharmaceuticals decreases (85.7 â†’ 80.4% (SMX) when SMX + ACP â†’ SMX + CIP) because the positively charged pharmaceutical neutralizes the negative charge on the FO membrane surface, resulting in the weakening of electrostatic repulsion between the negatively charged pharmaceutical and FO membrane surface. The positively charged molecule attracts the negatively charged molecule, forming a couple of molecules with larger molecule weight and increasing the retention rate of the pharmaceuticals (80.4 â†’ 88.2% (SMX) when pH = 7 â†’ 5 for SMX + CIP). The results suggest that the interactions between pharmaceuticals cannot be ignored in the process of removing PPCPs by FO.