Loss of ESRP1 blocks mouse oocyte development and leads to female infertility.

Alternative splicing (AS) contributes to gene diversification, but the AS program during germline development remains largely undefined. Here, we interrupted pre-mRNA splicing events controlled by epithelial splicing regulatory protein 1 (ESRP1) and found that it induced female infertility in mice. Esrp1 deletion perturbed spindle organization, chromosome alignment and metaphase-to-anaphase transformation in oocytes. The first polar body extrusion was blocked during oocyte meiosis owing to abnormal activation of spindle assembly checkpoint and insufficiency of anaphase-promoting complex/cyclosome in Esrp1-knockout oocytes. Esrp1-knockout hampered follicular development and ovulation; eventually, premature ovarian failure occurred in six-month-old Esrp1-knockout mouse. Using single-cell RNA-seq analysis, 528 aberrant AS events of maternal mRNA transcripts were revealed and were preferentially associated with microtubule cytoskeletal organization. Notably, we found that loss of ESRP1 disturbed a comprehensive set of gene-splicing sites - including those within Trb53bp1, Rac1, Bora, Kif2c, Kif23, Ndel1, Kif3a, Cenpa and Lsm14b - that potentially caused abnormal spindle organization. Collectively, our findings provide the first report elucidating the ESRP1-mediated AS program of maternal mRNA transcripts, which may contribute to oocyte meiosis and female fertility in mice.

[Efficacy and safety of mini-track, mini-nephroscopy and mini-ultrasonic probe percutaneous nephrolithotomy for the treatment of 1.5-2.5 cm kidney stones].

OBJECTIVE: To investigate the efficacy and safety of mini-track, mini-nephroscopy and mini-ultrasonic probe percutaneous nephrolithotomy (3mPCNL) for the treatment of 1.5-2.5 cm kidney stones. METHODS: The perioperative data and postoperative follow-up data of a total of 25 patients with about 1.5-2.5 cm kidney stones who underwent 3mPCNL under ultrasound guidance in Peking University People's Hospital from November 2023 to January 2024 were retrospectively analyzed. During the matching period, the 25 patients with 1.5-2.5 cm kidney stones receiving standard percutaneous nephrolithotomy (sPCNL) were matched one-to-one according to the criterion that the absolute difference of the maximum diameter of stones between the two groups was less than 1 mm. The operative time, renal function changes, postoperative stone-free rate, hemoglobin changes, and complication rate of the two treatments were compared, and then the effectiveness and safety of 3mPCNL were preliminarily analyzed. RESULTS: There were no significant differences in mean age, preoperative median creatinine, preoperative mean hemoglobin, preoperative mean hematocrit, median stone maximum diameter, and median stone CT density between the 3mPCNL group and the sPCNL group. The median operation time in the 3mPCNL group was 60.0 (45.0-110.0) min, with no statistical significance compared with the sPCNL group, and all the patients underwent single-channel operations. The mean hemoglobin after operation in the 3mPCNL group was (115.3±15.5) mmol/L, and there was no significant difference between the preoperative group and the sPCNL group, and the mean hemoglobin decreased significantly between the sPCNL group and the sPCNL group [(9.5±2.2) mmol/L vs. (10.1±1.9) mmol/L]. The mean hematocrit after operation was (28.0±5.2)%, and the difference was statistically significant compared with that before operation (t=2.414, P=0.020). The mean hematocrit drop was not statistically signi-ficant compared with the sPCNL group (2.3% vs. 2.7%). The median serum creatinine in the 3mPCNL group was 74.0 (51.0-118.0) µmol/L after operation, and the difference was statistically significant compared with that before operation (Z=-2.980, P=0.005). The stone-free rate in the 3mPCNL group and the sPCNL group was 96.0% and 97.3%, respectively, and the mean hospital stay was (4.3± 1.4) d and (5.5±2.0) d, respectively, with the statistical significance (t=0.192, P=0.025). After the operation, one patient in sPCNL group had massive hemorrhage after the nephrostomy tube was removed, which was improved after selective renal artery embolization. One patient in the 3mPCNL group developed mild perirenal hematoma, which was improved after conservative treatment, and no complications were observed in the other patients. CONCLUSION: 3mPCNL in the treatment of 1.5-2.5 cm kidney stones can achieve an effective rate comparable to sPCNL, and can achieve the ideal stone-free rate in a shorter operative time with a lower rate of surgery-related complications.

mRBPome capture identifies the RNA-binding protein TRIM71, an essential regulator of spermatogonial differentiation.

Continual spermatogenesis relies on the actions of an undifferentiated spermatogonial population that is composed of stem cells and progenitors. Here, using mouse models, we explored the role of RNA-binding proteins (RBPs) in regulation of the biological activities of this population. Proteins bound to polyadenylated RNAs in primary cultures of undifferentiated spermatogonia were captured with oligo (dT)-conjugated beads after UV-crosslinking and profiled by proteomics (termed mRBPome capture), yielding a putative repertoire of 473 RBPs. From this database, the RBP TRIM71 was identified and found to be expressed by stem and progenitor spermatogonia in prepubertal and adult mouse testes. Tissue-specific deletion of TRIM71 in the male germline led to reduction of the undifferentiated spermatogonial population and a block in transition to the differentiating state. Collectively, these findings demonstrate a key role of the RBP system in regulation of the spermatogenic lineage and may provide clues about the influence of RBPs on the biology of progenitor cell populations in other lineages.

LIN28A binds to meiotic gene transcripts and modulates their translation in male germ cells.

The RNA-binding protein LIN28A is required for maintaining tissue homeostasis, including in the reproductive system, but the underlying mechanisms on how LIN28A regulates germline progenitors remain unclear. Here, we dissected LIN28A-binding targets using high-throughput sequencing of RNAs isolated by crosslinking immunoprecipitation (HITS-CLIP) in the mouse testes. LIN28A preferentially binds to mRNA coding sequence (CDS) or 3'UTR regions at sites enriched with GGAG(A) sequences. Further investigation of Lin28a-null mouse testes indicated that meiosis-associated mRNAs bound by LIN28A were differentially expressed. Next, ribosome profiling revealed that the mRNA levels of these targets were significantly reduced in the polysome fractions, and their protein expression levels decreased, in Lin28a-null mouse testes, even when meiotic arrest in the null mouse testes was not apparent. Collectively, these findings provide a set of LIN28A-regulated target mRNAs, and show that LIN28A binding might be a mechanism through which LIN28A acts to regulate undifferentiated spermatogonia fates and male fertility in mammals.

Synergy between Photoluminescence and Charge Transport Achieved by Finely Tuning Polymeric Backbones for Efficient Light-Emitting Transistor.

The lack of design principle for developing high-performance polymer materials displaying strong fluorescence and high ambipolar charge mobilities limited their performance in organic light-emitting transistors (OLETs), electrically pumped organic laser, and other advanced electronic devices. A series of semiladder polymers by copolymerization of weak acceptors (TPTQ or TPTI) and weak donors (fluorene (F) or carbazole (C)) have been developed for luminescent and charge transporting properties. It was found that enhanced planarity, high crystallinity, and a delicate balance in interchain aggregation obtained in the new copolymer, TPTQ-F, contributed to high ambipolar charge mobilities and photoluminescent quantum yield. TPTQ-F showed excellent performance in solution-processed multilayered OLET devices with an external quantum efficiency (EQE) of 5.3%.

Polaron and Exciton Delocalization in Oligomers of High-Performance Polymer PTB7.

A key characteristic of organic photovoltaic cells is the efficient charge separation in the active layer. Sufficient delocalization of the positive polaron in organic photovoltaics is considered essential for the effective separation of the opposite charges and the suppression of recombination. We use light-induced EPR and ENDOR spectroscopy combined with DFT calculations to determine the electronic structure of the positive polaron in PTB7-type oligomers. Utilizing the superior spectral resolution of high-frequency (130 GHz) D-band EPR, the principal components of the g tensors were determined. Pulsed ENDOR spectroscopy at X-band allowed the measurement of 1H hyperfine coupling constants. A comparison of g tensors and 1H hyperfine coupling constants of the PTB7-type oligomers with the high-performance PTB7 polymer revealed a delocalization of the positive polaron in the polymer over about four monomeric units, corresponding to about 45 Å in length. Our current study thus not only determines the polaron delocalization length in PTB7 but also validates the approach combining EPR/ENDOR spectroscopy with DFT-calculated magnetic resonance parameters. This is of importance in those cases where oligomers of defined length are not easily obtained. In addition, the delocalization of the neutral triplet exciton was also determined in the oligomers and compared with polymer PTB7. The analysis revealed that the neutral triplet exciton is substantially more delocalized than the positive polaron, exceeding 10 monomeric units.

Multivariate analysis of factors for failed continuous bladder irrigation in hemorrhagic cystitis patients after hematopoietic stem cell transplantation.

BACKGROUND: Continuous bladder irrigation (CBI) and proper adjustment of saline irrigation speed are important to avoid CBI failure in hemorrhagic cystitis (HC) patients after allogeneic hematopoietic stem cell transplantation (HSCT). Nevertheless, too fast irrigation speed could take away the patient's much heat, contribute to blood coagulopathy, and increase the nursing workload. Evaluation of risk for CBI failure remains an unmet clinical need. METHODS: The general information, clinical characteristics, and consultation records of HC patients in 1380 patients with hematopoietic stem cell transplantation in our center from 2017 to 2019 were analyzed retrospectively. The receiver operating characteristic (ROC) curve was used to calculate the cutoff point of the continuous variable, and multivariate logistic regression was used to analyze the risk factors affecting CBI failure in HC patients. RESULTS: The incidence of HC after HSCT was 23%. A total of 227 patients with HC above grade 2 were included. Univariate analysis showed that CRP, age, platelet counts, onset time after transplantation, albumin, and hemoglobin were associated with CBI failure in the short-term (P < 0.05). ROC curve and multivariate logistic regression analysis showed that CRP > 8.89 ng/ml (RR = 7.828, 95% CI 2.885-21.244), age < 14.5 years (RR = 9.940, 95% CI 3.219-30.697), and onset time of HC > 37d after transplantation (RR = 7.021, 95% CI 2.204-22.364), were independent risk factors for failure of CBI (P < 0.05). CONCLUSIONS: The study identified CRP > 8.89 ng/ml, age < 14.5 years, and onset time of HC after HSCT > 37d are independent factors for failure of CBI, which could be combined to allow stratification of HC after HSCT patients into low-, intermediate- and high-risk subgroups of CBI failure.

Effects of Intra- and Interchain Interactions on Exciton Dynamics of PTB7 Revealed by Model Oligomers.

Recent studies have shown that molecular aggregation structures in precursor solutions of organic photovoltaic (OPV) polymers have substantial influence on polymer film morphology, exciton and charge carrier transport dynamics, and hence, the resultant device performance. To distinguish photophysical impacts due to increasing π-conjugation from chain lengthening and π-π stacking from single/multi chain aggregation in solution and film, we used oligomers of a well-studied charge transfer polymer PTB7 with different lengths as models to reveal intrinsic photophysical properties of a conjugated segment in the absence of inter-segment aggregation. In comparison with previously studied photophysical properties in polymeric PTB7, we found that oligomer dynamics are dominated by a process of planarization of the conjugated backbone into a quinoidal structure that resembles the self-folded polymer and that, when its emission is isolated, this quinoidal excited state resembling the planar polymer chain exhibits substantial charge transfer character via solvent-dependent emission shifts. Furthermore, the oligomers distinctly lack the long-lived charge separated species characteristic of PTB7, suggesting that the progression from charge transfer character in isolated chains to exciton splitting in neat polymer solution is modulated by the interchain interactions enabled by self-folding.

An Electromechanical Approach to Understanding Binding Configurations in Single-Molecule Devices.

The configuration of the molecule-electrode contact region plays an important role in determining the conductance of a single-molecule junction, and the variety of possible contact configurations have yielded multiple conductance values for a number of molecular families. In this report, we perform simultaneous conductance and electromechanical coupling parameter measurements on a series of oligophenylene-dithiol single-molecule junctions. These molecules show two distinct conductance values, and by examining the conductance changes, the electromechanical coupling, and the changes in the I- V characteristics coupled with a combination of analytical mechanical models and density functional theory (DFT) structure calculations, we are able to determine the most-probable binding configuration in each of the conductance states. We find that the lower-conductance state is likely due to the thiols binding to each electrode at a gold top site, and in the higher-conductance state, the phenylene π orbitals interact with electrodes, drastically modifying the transport behavior. This approach provides an expanded methodology for exploring the relationship between the molecule-electrode contact configuration and molecular conductance.

Zhile Capsule Exerts Antidepressant-Like Effects through Upregulation of the BDNF Signaling Pathway and Neuroprotection.

Major depressive disorder is now becoming a common disease in daily life, and most patients do not have satisfactory treatment outcomes. We herein evaluated the therapeutic effects of Zhile capsule and clarified the molecular mechanism. A rat model of chronic unpredictable mild stress-induced depression was established to assess the antidepressant-like effects of Zhile by using the sucrose preference test, open field test, forced swim test, tail suspension test and HPLC. Systems pharmacology was then performed to unravel the underlying mechanism which was confirmed by western blot, enzyme-linked immunosorbent assay, and qPCR. Zhile alleviated depression-like behaviors by upregulating the cAMP-CREB-BDNF (brain-derived neurotrophic factor) axis to exert neuroprotective effects. It may be beneficial to depressive patients in clinical practice.

Molecular Design towards Controlling Charge Transport.

Organic electronics generally deals with bulk, statistically averaged electrical properties of organic materials. Single-molecule electronic devices can then be viewed as linkers to these bulk properties. However, controlling charge transport in single-molecule systems still remains a formidable task and has prevented proliferation of these systems from research laboratories to household electronics. This Concept article provides a general overview of the recent advances made by our group in the field. We will describe several concepts in designing molecular functions towards controlling charge transport through molecular systems. It should be noted, however, that this Concept article is by no means comprehensive and readers should look elsewhere for a more comprehensive picture of molecular electronics.

Investigations of Thienoacene Molecules for Classical and Entangled Two-Photon Absorption.

Investigations of the optical effects in thienoacene chromophores with different central atoms were performed. These chromophores provide a basis for the comparison of the linear, two-photon, and entangled two-photon properties in organic molecules with varying degrees of dipolar or quadrupolar character. Linear absorption and emission as well as time-dependent density functional theory calculations were performed for the chromophores investigated. Measurements of the classical two-photon absorption (TPA), entangled two-photon absorption (ETPA), as well as entangled two-photon fluorescence were experimentally performed for the four chromophores. Electronic structure calculations were utilized to provide estimates of the classical two-photon absorption coefficients. The results of the measured entangled two-photon cross sections were compared with theoretical estimates for the molecules investigated. It is found that the dipole (transition or permanent) pathway can have an effect on the trends in the entangled photon absorption process in dipolar organic chromophores. This study helps predict the properties of the entangled two-photon effect in chromophores with different dipolar and quadrupolar character.

Molecular Rectification Tuned by Through-Space Gating Effect.

Inspired by transistors and electron transfer in proteins, we designed a group of pyridinoparacyclophane based diodes to study the through-space electronic gating effect on molecular rectification. It was shown that an edge-on gate effectively tunes the rectification ratio of a diode via through-space interaction. Higher rectification ratio was obtained for more electron-rich gating groups. The transition voltage spectroscopy showed that the forward transition voltage is correlated to the Hammett parameter of the gating group. Combining theoretical calculation and experimental data, we proposed that the change in rectification was induced by a shift in HOMO level both spatially and energetically. This design principle based on through-space edge-on gate is demonstrated on molecular wires, switches, and now diodes, showing the potential of molecular design in increasing the complexity of single-molecule electronic devices.

Synthesis of Alternating Donor-Acceptor Ladder-Type Molecules and Investigation of Their Multiple Charge-Transfer Pathways.

We describe the synthesis as well as the optical and charge-transport properties of a series of donor-acceptor (D-A) ladder-type heteroacenes. These molecules are stable, soluble, and contain up to 24 fused rings. Structural analyses indicated that the backbones of S 10r and Se 10r are bent in single crystals. The three 10-ring heteroacenes were functionalized with thiol anchoring groups and used for single-molecular conductance measurements. The highest conductance was observed for molecular wires containing a benzoselenadiazole (BSD) moiety, which exhibits the narrowest band gap. Multiple charge-transport pathways were observed in molecular wires containing either benzothiadiazole (BTD) or BSD. The conductance is a complex function of both energy gap and orbital alignment.

Beyond Molecular Wires: Design Molecular Electronic Functions Based on Dipolar Effect.

As the semiconductor companies officially abandoned the pursuit of Moore's law, the limitation of silicone-based semiconductor electronic devices is approaching. Single molecular devices are considered as a potential solution to overcome the physical barriers caused by quantum interferences because the intermolecular interactions are mainly through weak van der Waals force between molecular building blocks. In this bottom-up approach, components are built from atoms up, allowing great control over the molecular properties. Moreover, single molecular devices are powerful tools to understand quantum physics, reaction mechanism, and electron and charge transfer processes in organic semiconductors and molecules. So far, a great deal of effort is focused on understanding charge transport through organic single-molecular wires. However, to control charge transport, molecular diodes, switches, transistors, and memories are crucial. Significant progress in these topics has been achieved in the past years. The introduction and advances of scanning tunneling microscope break-junction (STM-BJ) techniques have led to more detailed characterization of new molecular structures. The modern organic chemistry provides an efficient access to a variety of functional moieties in single molecular device. These moieties have the potential to be incorporated in miniature circuits or incorporated as parts in molecular machines, bioelectronics devices, and bottom-up molecular devices. In this Account, we discuss progress mainly made in our lab in designing and characterizing organic single-molecular electronic components beyond molecular wires and with varied functions. We have synthesized and demonstrated molecular diodes with p-n junction structures through various scanning probe microscopy techniques. The assembly of the molecular diodes was achieved by using Langmuir-Blodgett technique or thiol/gold self-assembly chemistry with orthogonal protecting groups. We have thoroughly investigated the rectification effect of different types of p-n junction diodes and its modification by structural and external effects. Through a combination of structural modifications, low temperature study, and quantum mechanical calculations, we showed that the origin of the rectification in these molecules can be attributed to the effect of dipolar field. Further studies on charge transport through transition metal complexes and anchoring group effect supported this conclusion. Most recently, a model system of molecular transistor was synthesized and demonstrated by STM-BJ technique. The gating effect in the molecular wire originated from the tuning of the energy levels via dipolar field and can be turned on/off by dipolar field and chemical stimulation. This is the first example of gated charge transport in molecular electronics.

Covalently Bound Clusters of Alpha-Substituted PDI-Rival Electron Acceptors to Fullerene for Organic Solar Cells.

A cluster type of electron acceptor, TPB, bearing four α-perylenediimides (PDIs), was developed, in which the four PDIs form a cross-like molecular conformation while still partially conjugated with the BDT-Th core. The blend TPB:PTB7-Th films show favorable morphology and efficient charge dissociation. The inverted solar cells exhibited the highest PCE of 8.47% with the extraordinarily high Jsc values (>18 mA/cm(2)), comparable with those of the corresponding PC71BM/PTB7-Th-based solar cells.

Rational Design of Porous Conjugated Polymers and Roles of Residual Palladium for Photocatalytic Hydrogen Production.

Developing highly efficient photocatalyts for water splitting is one of the grand challenges in solar energy conversion. Here, we report the rational design and synthesis of porous conjugated polymer (PCP) that photocatalytically generates hydrogen from water splitting. The design mimics natural photosynthetics systems with conjugated polymer component to harvest photons and the transition metal part to facilitate catalytic activities. A series of PCPs have been synthesized with different light harvesting chromophores and transition metal binding bipyridyl (bpy) sites. The photocatalytic activity of these bpy-containing PCPs can be greatly enhanced due to the improved light absorption, better wettability, local ordering structure, and the improved charge separation process. The PCP made of strong and fully conjugated donor chromophore DBD (M4) shows the highest hydrogen production rate at ∼33 µmol/h. The results indicate that copolymerization between a strong electron donor and weak electron acceptor into the same polymer chain is a useful strategy for developing efficient photocatalysts. This study also reveals that the residual palladium in the PCP networks plays a key role for the catalytic performance. The hydrogen generation activity of PCP photocatalyst can be further enhanced to 164 µmol/h with an apparent quantum yield of 1.8% at 350 nm by loading 2 wt % of extra platinum cocatalyst.

Synthesis of Ladder-Type Thienoacenes and Their Electronic and Optical Properties.

A series of ladder-type thienoacenes based on benzo[1,2-b:4,5-b']dithiophene (BDT) have been synthesized and characterized. They were shown to be p-type semiconductors with wide band gaps and able to support multiple stable cationic states. As the conjugation lengthens, these oligomers become more emissive, showing high quantum yields. They were shown to be good two-photon absorbers, exhibiting high two-photon absorption coefficients.

Exceptional Single-Molecule Transport Properties of Ladder-Type Heteroacene Molecular Wires.

A series of ladder-type fused heteroacenes consisting of thiophenes and benzothiophenes were synthesized and functionalized with thiol groups for single-molecule electrical measurements via a scanning tunneling microscopy break-junction method. It was found that this molecular wire system possesses exceptional charge transport properties with weak length dependence. The tunneling decay constant ß was estimated to be 0.088 and 0.047 Å(-1) under 0.1 and 0.5 bias, respectively, which is one of the lowest ß values among other non-metal-containing molecular wires, indicating that a planar ladder structure favors charge transport. Transition voltage spectroscopy showed that the energy barrier decreases as the length of the molecule increases. The general trend of the energy offsets derived from the transition voltage via the Newns-Anderson model agrees well with that of the Fermi/HOMO energy level difference. Nonequilibrium Green's function/density functional theory was used to further investigate the transport process in these molecular wires.

Edge-on gating effect in molecular wires.

This work demonstrates edge-on chemical gating effect in molecular wires utilizing the pyridinoparacyclophane (PC) moiety as the gate. Different substituents with varied electronic demands are attached to the gate to simulate the effect of varying gating voltages similar to that in field-effect transistor (FET). It was observed that the orbital energy level and charge carrier's tunneling barriers can be tuned by changing the gating group from strong electron acceptors to strong electron donors. The single molecule conductance and current-voltage characteristics of this molecular system are truly similar to those expected for an actual single molecular transistor.