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Dominant missense pathogenic variants in cardiac myosin heavy chain cause hypertrophic cardiomyopathy (HCM), a currently incurable disorder that increases risk for stroke, heart failure and sudden cardiac death. In this study, we assessed two different genetic therapies—an adenine base editor (ABE8e) and a potent Cas9 nuclease delivered by AAV9—to prevent disease in mice carrying the heterozygous HCM pathogenic variant myosin R403Q. One dose of dual-AAV9 vectors, each carrying one half of RNA-guided ABE8e, corrected the pathogenic variant in ≥70% of ventricular cardiomyocytes and maintained durable, normal cardiac structure and function. An additional dose provided more editing in the atria but also increased bystander editing. AAV9 delivery of RNA-guided Cas9 nuclease effectively inactivated the pathogenic allele, albeit with dose-dependent toxicities, necessitating a narrow therapeutic window to maintain health. These preclinical studies demonstrate considerable potential for single-dose genetic therapies to correct or silence pathogenic variants and prevent the development of HCM.

Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus are the main species for yogurt preparation. Glutathione (GSH) can be synthesized by S. thermophilus and plays a crucial role in combating environmental stress. However, the effect of GSH biosynthesis by S. thermophilus on cocultured L. delbrueckii ssp. bulgaricus is still unknown. In this study, a mutant S. thermophilus ΔgshF was constructed by deleting the GSH synthase. The wild strain S. thermophilus ST-1 and ΔgshF mutants were cocultured with L. delbrueckii ssp. bulgaricus ATCC11842 by using Transwell chambers (Guangzhou Shuopu Biotechnology Co., Ltd.), respectively. It was proven that the GSH synthesized by S. thermophilus ST-1 could be absorbed and used by L. delbrueckii ssp. bulgaricus ATCC11842, and promote growth ability and stress tolerance of L. delbrueckii ssp. bulgaricus ATCC11842. The biomass of L. delbrueckii ssp. bulgaricus ATCC11842 cocultured with S. thermophilus ST-1 or ΔgshF (adding exogenous GSH) increased by 1.8 and 1.4 times compared with the biomass of L. delbrueckii ssp. bulgaricus ATCC11842 cocultured with S. thermophilus ΔgshF. Meanwhile, after H

Preconception and prenatal stress impact fetal and infant development, and women of color are disproportionately exposed to sociocultural stressors like discrimination and acculturative stress. However, few studies examine links between mothers’ exposure to these stressors and offspring mental health, or possible mitigating factors. Using linear regression, we tested associations between prenatally assessed maternal acculturative stress and discrimination on infant negative emotionality among 113 Latinx/Hispanic, Asian American, Black, and Multiethnic mothers and their children. Additionally, we tested interactions between stressors and potential pre- and postnatal resilience-promoting factors: community cohesion, social support, communalism, and parenting self-efficacy. Discrimination and acculturative stress were related to more infant negative emotionality at approximately 12 months old (M = 12.6, SD = .75). In contrast, maternal report of parenting self-efficacy when infants were 6 months old was related to lower levels of infant negative emotionality. Further, higher levels of parenting self-efficacy mitigated the relation between acculturative stress and negative emotionality. Preconception and prenatal exposure to sociocultural stress may be a risk factor for poor offspring mental health. Maternal and child health researchers, policymakers, and practitioners should prioritize further understanding these relations, reducing exposure to sociocultural stressors, and promoting resilience.

Although cyclophilins are attractive targets for probing biology and therapeutic intervention, no subtype-selective cyclophilin inhibitors have been described. We discovered novel cyclophilin inhibitors from the in vitro selection of a DNA-templated library of 256,000 drug-like macrocycles for cyclophilin D (CypD) affinity. Iterated macrocycle engineering guided by ten X-ray co-crystal structures yielded potent and selective inhibitors (half maximal inhibitory concentration (IC50) = 10 nM) that bind the active site of CypD and also make novel interactions with non-conserved residues in the S2 pocket, an adjacent exo-site. The resulting macrocycles inhibit CypD activity with 21- to >10,000-fold selectivity over other cyclophilins and inhibit mitochondrial permeability transition pore opening in isolated mitochondria. We further exploited S2 pocket interactions to develop the first cyclophilin E (CypE)-selective inhibitor, which forms a reversible covalent bond with a CypE S2 pocket lysine, and exhibits 30- to >4,000-fold selectivity over other cyclophilins. These findings reveal a strategy to generate isoform-selective small-molecule cyclophilin modulators, advancing their suitability as targets for biological investigation and therapeutic development.

Despite the availability of Cas9 variants with varied protospacer-adjacent motif (PAM) compatibilities, some genomic loci—especially those with pyrimidine-rich PAM sequences—remain inaccessible by high-activity Cas9 proteins. Moreover, broadening PAM sequence compatibility through engineering can increase off-target activity. With directed evolution, we generated four Cas9 variants that together enable targeting of most pyrimidine-rich PAM sequences in the human genome. Using phage-assisted noncontinuous evolution and eVOLVER-supported phage-assisted continuous evolution, we evolved Nme2Cas9, a compact Cas9 variant, into variants that recognize single-nucleotide pyrimidine-PAM sequences. We developed a general selection strategy that requires functional editing with fully specified target protospacers and PAMs. We applied this selection to evolve high-activity variants eNme2-T.1, eNme2-T.2, eNme2-C and eNme2-C.NR. Variants eNme2-T.1 and eNme2-T.2 offer access to N4TN PAM sequences with comparable editing efficiencies as existing variants, while eNme2-C and eNme2-C.NR offer less restrictive PAM requirements, comparable or higher activity in a variety of human cell types and lower off-target activity at N4CN PAM sequences.

This study investigated the effect of initial normal stress on the non-linear hydraulic properties of fractures during shearing. A natural rough fracture is utilised to generate the rough fracture model and a mathematical expression for predicting the normal displacement during shearing is used, after which the validity is verified. Finally, the non-linear flow rate – hydraulic gradient relationships and the empirical functions for Fochheimer coefficients and critical Reynolds number are analysed. The results show that with the increment of initial normal stress, the fractures are closed and the contact area increases, decreasing the permeability. As initial normal stress increases, both the linear and non-linear Fochheimer coefficients increase following power-law relationships with positive exponents. The non-linear Fochheimer coefficient is approximately five orders of magnitude larger than the linear Fochheimer coefficient, which is consistent with the results reported in the literature. Both Fochheimer coefficients and critical Reynolds number are strongly correlated with fracture aperture. The variation in linear Fochheimer coefficient is more robust than the variation in non-linear Fochheimer coefficient against aperture, resulting in that the critical Reynolds number increases with increasing the aperture, which follows a power-law relationship with the correlation coefficient larger than 0·91.

In this article, the non-negative edge consensus problem is addressed for positive networked systems with undirected graphs using state-feedback protocols. In contrast to existing results, the major contributions of this work included: 1) significantly improved criteria of consequentiality and non-negativity, therefore leading to a linear programming approach and 2) necessary and sufficient criteria giving rise to a semidefinite programming approach. Specifically, an improved upper bound is given for the maximum eigenvalue of the Laplacian matrix and the (out-) in-degree of the degree matrix, and an improved consensuability and non-negativevity condition is obtained. The sufficient condition presented only requires the number of edges of a nodal network without the connection topology. Also, with the introduction of slack matrix variables, two equivalent conditions of consensuability and non-negativevity are obtained. In the conditions, the system matrices, controller gain, as well as Lyapunov matrices are separated, which is helpful for parameterization. Based on the results, a semidefinite programming algorithm for the controller is readily developed. Finally, a comprehensive analytical and numerical comparison of three illustrative examples is conducted to show that the proposed results are less conservative than the existing work.

The viral delivery of base editors has been complicated by their size and by the limited packaging capacity of adeno-associated viruses (AAVs). Typically, dual-AAV approaches based on trans-splicing inteins have been used. Here we show that, compared with dual-AAV systems, AAVs with size-optimized genomes incorporating compact adenine base editors (ABEs) enable efficient editing in mice at similar or lower doses. Single-AAV-encoded ABEs retro-orbitally injected in mice led to editing efficiencies in liver (66%), heart (33%) and muscle (22%) tissues that were up to 2.5-fold those of dual-AAV ABE8e, and to a 93% knockdown (on average) of human PCSK9 and of mouse Pcsk9 and Angptl3 in circulation, concomitant with substantial reductions of plasma cholesterol and triglycerides. Moreover, three size-minimized ABE8e variants, each compatible with single-AAV delivery, collectively offer compatibility with protospacer-adjacent motifs for editing approximately 82% of the adenines in the human genome. ABEs encoded within single AAVs will facilitate research and therapeutic applications of base editing by simplifying AAV production and characterization, and by reducing the dose required for the desired level of editing.

This paper investigates the positive consensus problem of multi-agent systems with directed communication topologies where all the agents have identical continuous-time positive linear dynamics. Existing works of such problem mainly focus on the case where the networked communication topologies are of either undirected and incomplete graphs, or strongly connected directed graphs. In stark contrast to them, we study the problem in which the communication topologies of the networked system are described by directed graphs each containing a spanning tree which is a more general and new scenario due to the interplay between the eigenvalues of the Laplacian matrix and the controller gains. Based on the existing results in spectral graph theory and positive linear systems theory, several necessary and sufficient conditions on the positive consensus of the directed multi-agent system are derived through using linear matrix inequality techniques. Then a primal-dual iterative algorithm is developed for computation and finally several numerical simulations are provided to illustrate the effectiveness of the proposed theoretical results.

PurposeIn 2020, racially/ethnically minoritized (REMD) youth faced the "dual pandemics" of COVID-19 and racism, both significant stressors with potential for adverse mental health effects. The current study tested whether short- and long-term trajectories of depressive symptoms from before to during the COVID-19 pandemic differed between REMD adolescents who did and did not endorse exposure to COVID-19-era-related racism (i.e., racism stemming from conditions created or exacerbated by the COVID-19 pandemic).MethodsA community sample of 100 REMD adolescents enrolled in an ongoing longitudinal study of mental health was assessed before and during the COVID-19 pandemic. Participants were 51% girls, mean age= 16, standard deviation= 2.7, and identified as Latinx/Hispanic (48%), Multiethnic (34%), Asian American (12%), and Black (6%).ResultsREMD adolescents' depressive symptoms were elevated during the COVID-19 pandemic compared to pre-pandemic levels, and increases were more pronounced over time for those who endorsed exposure to COVID-19-era-related racism. In general, Asian American participants endorsed racism experiences at the highest rates compared to others, including being called names (42%), people acting suspicious around them (33%), and being verbally threatened (17%). Additionally, more than half of Black and Asian American participants reported worry about experiencing racism related to the COVID-19 pandemic, even if they had not experienced it to date.DiscussionREMD adolescents are at increased risk for depressive symptoms related to converging stressors stemming from the COVID-19 pandemic and pandemic-related racism, which has the potential to widen racial/ethnic mental health disparities faced by the REMD youth.