Organs Of Mice Research Articles

The new pattern for dual NOTCH pathway involving nuclear transcription and mitochondrial regulation supports therapeutic mechanism of 4-butyl benzophenone derivatives against SIRS

The systemic inflammatory response syndrome (SIRS) represents a self-amplifying cascade of inflammatory reactions and pathophysiological states triggered by infectious or non-infectious factors. The identification of disease targets and differential proteins in the liver (the unique and important immune organ) of SIRS mice treated with the lead compound D1 was conducted using the Genecards database and proteomic analysis, respectively. Subsequently, NOTCH1 was identified as the potential hub target via an intersection analysis between the aforementioned differentially expressed proteins and disease targets. Based on our previous research on the structure-activity relationship, we designed and synthesized a series of SIRS-related derivatives, wherein butyl, halogen, and ester groups were incorporated into benzophenone, aiming at exploring the anti-inflammatory protective action from the perspective of macrophage polarization. Notably, these derivatives exhibited a direct binding capability to the O-glucosylation site (SER496) or its vicinities (such as SER492, VAL485) of NOTCH1 using docking, SPR, DARTS, and CETSA techniques. Mechanistically, derivative D6 exerted anti-inflammatory effects via the dual NOTCH pathway. Firstly, it could inhibit NOTCH1 nuclear transcriptional activity, attenuate the interaction between NICD and RBPJK, concurrently suppress NF-κB and NLRP3 inflammasome (NLRP3, ASC, and cleaved CASP1) activation, and promote NICD (NOTCH1 active fragments) ubiquitination metabolism (the nuclear transcriptional pathway). Secondly, it might possess the ability to increase PGC1α level, subsequently, enhance ATP and MMP levels, mitigate ROS production, increase mitochondrial numbers, and ameliorate mitochondrial inflammatory damage (the mitochondrial pathway). Importantly, the activator Jagged1 could effectively reverse the aforementioned effects, while the inhibitor DAPT exhibited a synergistic effect, suggesting that the nuclear transcriptional regulation and mitochondrial regulation were both in a NOTCH1-dependent manner. Subsequently, it effectively alleviated the inflammatory response and preserved organ function as evidenced by up-regulating M2-type macrophage-related anti-inflammatory cytokines (IL10, TGFβ, CD206, and ARG1) and down-regulating M1-type macrophage-related pro-inflammatory cytokines (NO, IL6, IL18, iNOS, TNFα, CD86, and IL1β). In a word, derivative D6 modulated macrophage polarization and effectively mitigated SIRS by targeting inhibition of the dual NOTCH pathway.

(Invited) Seeing the Sound: An Ultrasound-Mediated Intravascular Light Source for Noninvasive Brain Modulation

Light is used in a wide range of methods in biology and medicine, such as fluorescence imaging, optogenetics, photoactivatable gene editing, photothermal and photodynamic therapies to treat cancers, and photochemotherapy to inactivate viruses in vivo. A critical challenge of applying light in vivo, such as deep-brain optogenetic neuromodulation and photochemotherapy in deep organs, arises from the poor penetration of photons in biological tissue due to scattering and absorption. Therefore, delivering light deep into the body requires invasive procedures, such as the insertion of optical fibers and endoscopes, as well as surgical removal of overlying tissues. The very invasiveness of these procedures also precludes easy repositioning and volume adjustment of the illuminated region in the same subject. To address these challenges, our lab has developed an ultrasound-mediated intravascular light source, leveraging the deep-tissue penetration of focused ultrasound. We capitalized on mechanoluminescent nanotransducers (MLNTs), which are colloidal nanoparticles of mechanoluminescent materials synthesized via a biomineral-inspired suppressed dissolution approach. These MLNTs can be delivered intravenously into blood circulation and emit light locally at the ultrasound focus. Owing to the deep penetration and fast temporal kinetics of ultrasound, we have demonstrated that this method can produce on-demand and dynamically programmable light emission patterns at elevated depths in different organs of live mice with millisecond precision. This ultrasound-mediated intravascular light source has allowed us to perform noninvasive “sono-optogenetic” neuromodulation in live mice, as well as brain-wide “scanning optogenetics” that activate different brain regions of the same mouse brain. Our development of the ultrasound-mediated intravascular light source has been published in PNAS (2019), Science (2020), Science Advances (2022), JACS (2022), JACS (2023), and Nature Protocols (2023).

Heat acclimation alleviates the heat stress-induced impairment of vascular endothelial cells

Heat acclimation (HA) is found to help decrease the incidence of heat-related illnesses such as heat syncope and exertional heat stroke. However, the response of vascular endothelial cells to HA remain to be elucidated. In this study, mouse brain microvascular endothelial cells (bEnd.3), human umbilical vein endothelial cells (HUVEC), and human aortic endothelial cells (HAEC) were selected. The cells were first subjected to HA at 40 ℃ for 2 h per day for 3 days, and then subjected to heat stress at 43 ℃ for 2 h or 4 h. After heat stress, HA-pretreated cells showed a significant increase in cell viability, cell integrity, a decrease in the proportion of S phase cells, cell apoptosis, and cytoskeletal shrinkage compared with the cells without HA pretreatment. Additionally, the expression of VEGF, ICAM-1, iNOS and EPO in HA-pretreated cells significantly increased. We also presented evidence that HA upregulated HSP70 and bcl-2, while downregulated p-p53 and bax. Notably, the suppression of HSP70 expression attenuated the protective role of heat acclimation. Furthermore, HA mitigated injuries in vital organs of mice exposed to heat stress. Conclusively, these findings indicated the HA can increase the vitality of vascular endothelial cells after heat stress, partially restore the function of vascular endothelial cells, and this protective effect may be related to the upregulation of HSP70 expression.

Hyperbranched Polymeric 19F MRI Contrast Agents with Long T2 Relaxation Time Based on β-Cyclodextrin and Phosphorycholine.

19F magnetic resonance imaging (19F MRI) is gaining attention as an emerging diagnostic technology. Effective 19F MRI contrast agents (CAs) for in vivo applications require a long transverse (or spin-spin) relaxation time (T2), short longitudinal (or spin-lattice) relaxation time (T1), high fluorine content, and excellent biocompatibility. Here, we present a novel hyperbranched polymeric 19F MRI CA based on β-cyclodextrin and phosphorylcholine. The influence of the branching degree and fluorine content on T2 was thoroughly investigated. Results demonstrated a maximum fluorine content of 11.85% and a T2 of 612 ms. This hyperbranched polymeric 19F MRI CA exhibited both great biocompatibility against cells and organs of mice and high-performance imaging capabilities both in vitro and in vivo. The research provides positive insights into the synthesis strategies, topological design, and selection of fluorine tags for 19F MRI CAs.

Outer membrane vesicles of Acinetobacter baumannii DS002 carry circular DNA similar to bovine meat and milk factors (BMMFs) and SPHINX 2.36 and probably play a role in interdomain lateral gene transfer.

Several independent studies have demonstrated the existence of replication competent circular DNA molecules of bacterial and viral origin in mammalian cells and tissues. However, studies about their origin and lateral mobility to mammalian cells are scarce. Our work describes the existence of circular DNA, similar to that of DNA molecules identified in mammalian cells, OMVs derived from soil isolate of A. baumannii DS002. Furthermore, the work also provides visual evidence that demonstrates the passage of labeled OMVs to different organs of experimental mice within hours after intravenously administering OMVs into experimental mice. Some of the labeled OMVs have even crossed the membrane of Neuro2A, suggesting the existence of interkingdom horizontal mobility between bacteria and mammals.

Abstract Tu021: Genome-wide CRISPR Screen In Vivo Decodes Monocyte Infiltration Associated With Abdominal Aortic Aneurysm

Introduction: Aortic aneurysm is the second most common aortic disease following atherosclerosis and accounts for the ninth-leading cause of death overall. The inflammatory response has a crucial role in the Abdominal Aortic Aneurysm (AAA) development. The infiltration of monocyte into aortic wall is a hallmark of aortic inflammation and it still requires further understanding of this complicated process. CRISPR screening is a powerful tool to investigate biological process, but it requires large pool of mutant cells and reliable selection procedure, which can usually only be performed in vitro or in xenograft models. To overcome this problem, we developed an unbiased genome-wide CRISPR-Cas Screen for Monocyte Infiltration in vivo (CRISPR-MI) and employed this new method in mouse AAA model to systematically study key genes regulating monocyte infiltration into aortic wall. Hypothesis: Monocyte infiltration is an important process in AAA development and CRISPR-MI could be utilized to study this process in vivo. Methods: To acquire enough monocytes for screen, we used the adoptive transfer method to transplant in vivo differentiated monocytes (bone marrow derived macrophage, BMDM) back into mouse circulation via tail vein injection. We optimized the lentivirus infection protocol, so that sgRNA library delivered by lentivirus can effectively knock out target genes in BMDMs. The BMDMs were infected with sgRNA library before adoptive transfer into AAA-model mice. After transfer, by comparing the sgRNA enrichment in different organs of receipt mice, we could identify key genes inhibiting monocyte infiltration. Results: CRISPR-MI identified novels genes regulating monocyte infiltration into aorta in AAA model, including Trem2 gene. In vitro experiments confirmed that Trem2 knockout increased adhesion molecules and chemokine receptors expression. Conclusions: CRISPR-MI can be used to identify new therapeutical targets for cardiovascular diseases.

Dipeptidylpeptidase-4-targeted activatable fluorescent probes visualize senescent cells.

Senescent cells promote cancer development and progression through chronic inflammation caused by a senescence-associated secretory phenotype (SASP). Although various senotherapeutic strategies targeting senescent cells have been developed for the prevention and treatment of cancers, technology for the invivo detection and evaluation of senescent cell accumulation has not yet been established. Here, we identified activatable fluorescent probes targeting dipeptidylpeptidase-4 (DPP4) as an effective probe for detecting senescent cells through an enzymatic activity-based screening of fluorescent probes. We also determined that these probes were highly, selectively, and rapidly activated in senescent cells during live cell imaging. Furthermore, we successfully visualized senescent cells in the organs of mice using DPP4-targeted probes. These results are expected to lead to the development of a diagnostic technology for noninvasively detecting senescent cells invivo and could play a role in the application of DPP4 prodrugs for senotherapy.

A Study of the Relationship of the Dynamics of Development and Characteristics of Chimerism with Manifestations of Graft-vs.-Host Disease in the Organs of Mice after Allogeneic Transplantation of Whole Bone Marrow

A Study of the Relationship of the Dynamics of Development and Characteristics of Chimerism with Manifestations of Graft-vs.-Host Disease in the Organs of Mice after Allogeneic Transplantation of Whole Bone Marrow

Forskolin improves experimental autoimmune encephalomyelitis in mice probably by inhibiting the calcium and the IL-17-STEAP4 signaling pathway

Multiple sclerosis (MS) is a chronic autoimmune disease in the central nervous system. Forskolin (FSK) is a plant-derived diterpene with excellent immunomodulatory properties and has not been systematically reported for treating MS. This study investigated the therapeutic effects of FSK on cellular and animal MS models and preliminarily explored related mechanisms. The results showed that FSK suppressed the inflammatory response, reduced the expression of STEAP4, and relieved iron deposition in BV-2 cells pretreated by LPS at the cellular level. Meanwhile, at the animal level, FSK treatment halted the progression of experimental autoimmune encephalomyelitis (EAE), alleviated the damage at the lesion sites, reduced the concentration of proinflammatory factors in peripheral blood, and inhibited the immune response of peripheral immune organs in EAE mice. Besides, FSK treatment decreased the expression of STEAP4 in the spinal cord and effectively restored the iron balance in the brain, spinal cord, and serum of EAE mice. Further investigation showed that FSK can reduce IL-17 expression, prevent the differentiation of TH17 cells, and inhibit the calcium signaling pathway. Thus, these results demonstrate that FSK may have the potential to treat MS clinically.

Hematopoietic stem cell gene therapy improves outcomes in a clinically relevant mouse model of multiple sulfatase deficiency

Multiple sulfatase deficiency (MSD) is a severe, lysosomal storage disorder caused by pathogenic variants in the gene SUMF1, encoding the sulfatase modifying factor formylglycine-generating enzyme. Patients with MSD exhibit functional deficiencies in all cellular sulfatases. The inability of sulfatases to break down their substrates leads to progressive and multi-systemic complications in patients, similar to those seen in single-sulfatase disorders such as metachromatic leukodystrophy and mucopolysaccharidoses IIIA. Here, we aimed to determine if hematopoietic stem cell transplant with ex vivo SUMF1 lentiviral gene therapy could improve outcomes in a clinically relevant mouse model of MSD. We first tested our approach in MSD patient-derived cells and found that our SUMF1 lentiviral vector improved protein expression, sulfatase activities, and glycosaminoglycan accumulation. In vivo, we found that our gene therapy approach rescued biochemical deficits, including sulfatase activity and glycosaminoglycan accumulation, in affected organs of MSD mice treated post-symptom onset. In addition, treated mice demonstrated improved neuroinflammation and neurocognitive function. Together, these findings suggest that SUMF1 HSCT-GT can improve both biochemical and functional disease markers in the MSD mouse.

An mpox quadrivalent mRNA vaccine protects mice from lethal vaccinia virus challenge

The outbreak of 2022 monkeypox virus (MPXV) infection in nonendemic regions is a global public health concern. A highly effective and safe MPXV vaccine that is available to the general public is urgently needed to control the mpox pandemic. Here, we developed a multivalent mRNA vaccine candidate, MPXV-1103, which expresses the full-length B6, A35, A29 and M1 proteins with three flexible linkers (G4S1)3 in a single sequence. Compared with the monovalent MPXV mRNA vaccine candidates or the quadrivalent mRNA vaccine from mixtures of the four monovalent MPXV mRNA vaccines, MPXV-1103 elicits a robust humoral response and an MPXV-specific T-cell response and protects mice from lethal vaccinia virus (VACV) challenge, with no live virus detected in the nasal or lungs even at dosages as low as 1 μg. Furthermore, analysis of complete blood counts and photomicrographs of tissue from the main organs of mice vaccinated with MPXV-1103 at doses of 5 μg and 20 μg revealed that two doses of MPXV-1103 did not cause any observable pathological changes in the mice. Collectively, our results suggest that MPXV-1103, with features of high efficacy, safety and a simplified manufacturing process, is a promising vaccine candidate for defending against MPXV infection.

Study of the cyto- and genotoxic activity of water from the Kapshagai reservoir (Kazakhstan) on laboratory mice

Chemical compounds in the environment, which exhibit toxic and genotoxic activity, increase the mutational pressure on biota. This study aimed to investigate the genotoxic, mutagenic, and toxic effects of water from the Ile River and the Kapshagai Reservoir, both sites of active economic activities. Cytogenetic analysis of bone marrow from mice exposed to water samples from the Ile River and the Kapshagai Reservoir revealed a statistically significant increase in aberrant (p<0.05) and polyploid cells (p<0.01), as well as a decrease in the mitotic index (p<0.001), compared to the negative control. The water samples caused statistically significant increases in single- and double-strand DNA breaks in cells across various organs in the experimental mice compared to unexposed animals (p<0.001). These observations suggest the existence of chemical compounds within the water samples from the Kapshagai Reservoir and the Ile River, which exhibit genotoxic, mutagenic, and toxic properties.

Development of radiofluorinated MLN-4760 derivatives for PET imaging of the SARS-CoV-2 entry receptor ACE2.

The angiotensin converting enzyme 2 (ACE2) plays a regulatory role in the cardiovascular system and serves SARS-CoV-2 as an entry receptor. The aim of this study was to synthesize and evaluate radiofluorinated derivatives of the ACE2 inhibitor MLN-4760. [18F]F-MLN-4760 and [18F]F-Aza-MLN-4760 were demonstrated to be suitable for non-invasive imaging of ACE2, potentially enabling a better understanding of its expression dynamics. Computational molecular modeling, based on the structures of human ACE2 (hACE2) and mouse ACE2 (mACE2), revealed that the ACE2-binding modes of F-MLN-4760 and F-Aza-MLN-4760 were similar to that of MLN-4760. Co-crystallization of the hACE2/F-MLN-4760 protein complex was performed for confirmation. Displacement experiments using [3H]MLN-4760 enabled the determination of the binding affinities of the synthesized F-MLN-4760 and F-Aza-MLN-4760 to hACE2 expressed in HEK-ACE2 cells. Aryl trimethylstannane-based and pyridine-based radiofluorination precursors were synthesized and used for the preparation of the respective radiotracers. [18F]F-MLN-4760 and [18F]F-Aza-MLN-4760 were evaluated with regard to the uptake in HEK-ACE2 and HEK-ACE cells and in vitro binding to tissue sections of HEK-ACE2 xenografts and normal organs of mice. Biodistribution and PET/CT imaging studies of [18F]F-MLN-4760 and [18F]F-Aza-MLN-4760 were performed using HEK-ACE2 and HEK-ACE xenografted nude mice. Crystallography data revealed an equal hACE2-binding mode for F-MLN-4760 as previously found for MLN-4760. Moreover, computer-based modeling indicated that similar binding to hACE2 and mACE2 holds true for both, F-MLN-4760 and F-Aza-MLN-4760, as is the case for MLN-4760. The IC50 values were three-fold and seven-fold higher for F-MLN-4760 and F-Aza-MLN-4760, respectively, than for MLN-4760. [18F]F-MLN-4760 and [18F]F-Aza-MLN-4760 were obtained in 1.4 ± 0.3 GBq and 0.5 ± 0.1 GBq activity with > 99% radiochemical purity in a 5.3% and 1.2% radiochemical yield, respectively. Uptake in HEK-ACE2 cells was higher for [18F]F-MLN-4760 (67 ± 9%) than for [18F]F-Aza-MLN-4760 (37 ± 8%) after 3-h incubation while negligible uptake was seen in HEK-ACE cells (< 0.3%). [18F]F-MLN-4760 and [18F]F-Aza-MLN-4760 accumulated specifically in HEK-ACE2 xenografts of mice (13 ± 2% IA/g and 15 ± 2% IA/g at 1h p.i.) with almost no uptake observed in HEK-ACE xenografts (< 0.3% IA/g). This was confirmed by PET/CT imaging, which also visualized unspecific accumulation in the gall bladder and intestinal tract. Both radiotracers showed specific and selective binding to ACE2 in vitro and in vivo. [18F]F-MLN-4760 was, however, obtained in higher yields and the ACE2-binding affinity was superior over that of [18F]F-Aza-MLN-4760. [18F]F-MLN-4760 would, thus, be the candidate of choice for further development in view of its use for PET imaging of ACE2.

Improvement of Immune Function and Redox State in Several Organs of Old and Prematurely Aging Female Mice After a Short Social Interaction With Adults.

Aging is associated with chronic oxidative stress, which contributes to the deterioration of the immune system, increasing morbidity and mortality. A positive social environment permits health maintenance and a slower rate of aging. Improvements in immune function and oxidative stress were shown in peritoneal leukocytes and organs of old mice and adult prematurely aging mice (PAM) after cohabitation with adults or exceptional non-prematurely aging mice (ENPAM), respectively, for 2 months, but adults and ENPAM experienced deterioration. This was solved by shortening the cohabitation time to 15 minutes per day for 2 months, where old mice and PAM maintained immune and redox state improvements in their peritoneal leukocytes, as well as a greater longevity, and adults and ENPAM did not show deterioration. However, it is unknown whether the positive effects of this short cohabitation are reflected in the immunity and redox state of the organs. The aim of the present study was to test whether a cohabitation of 15 minutes per day for 2 months maintains these positive effects in the organs of retired breeder female old mice and PAM and avoids the negative ones in adults and ENPAM. After cohabitation the animals were sacrificed, and the thymus and spleen were extracted to evaluate the immune function. The oxidative state was also analyzed in the spleen, liver, heart, lung, and kidney. The results show that after cohabitation, old mice and PAM improved their immunity and redox state, and adults and ENPAM showed no deterioration. This cohabitation can be suggested to improve health and slow down aging.

Activatable Fluorescent Probe for Studying Drug-Induced Senescence In Vitro and In Vivo.

Aging represents a significant risk factor for compromised tissue function and the development of chronic diseases in the human body. This process is intricately linked to oxidative stress, with HClO serving as a vital reactive oxygen species (ROS) within biological systems due to its strong oxidative properties. Hence, conducting a thorough examination of HClO in the context of aging is crucial for advancing the field of aging biology. In this work, we successfully developed a fluorescent probe, OPD, tailored specifically for detecting HClO in senescent cells and in vivo. Impressively, OPD exhibited a robust reaction with HClO, showcasing outstanding selectivity, sensitivity, and photostability. Notably, OPD effectively identified HClO in senescent cells for the first time, confirming that DOX- and ROS-induced senescent cells exhibited higher HClO levels compared to uninduced normal cells. Additionally, in vivo imaging of zebrafish demonstrated that d-galactose- and ROS-stimulated senescent zebrafish displayed elevated HClO levels compared to normal zebrafish. Furthermore, when applied to mouse tissues and organs, OPD revealed increased fluorescence in the organs of senescent mice compared to their nonsenescent counterparts. Our findings also illustrated the probe's potential for detecting changes in HClO content pre- and post-aging in living mice. Overall, this probe holds immense promise as a valuable tool for in vivo detection of HClO and for studying aging biology in live organisms.

Understanding tissue-resident macrophages unlocks the potential for novel combinatorial strategies in breast cancer.

Tissue-resident macrophages (TRMs) are an integral part of the innate immune system, but their biology is not well understood in the context of cancer. Distinctive resident macrophage populations are identified in different organs in mice using fate mapping studies. They develop from the yolk sac and self-maintain themselves lifelong in specific tissular niches. Similarly, breast-resident macrophages are part of the mammary gland microenvironment. They reside in the breast adipose tissue stroma and close to the ductal epithelium and help in morphogenesis. In breast cancer, TRMs may promote disease progression and metastasis; however, precise mechanisms have not been elucidated. TRMs interact intimately with recruited macrophages, cytotoxic T cells, and other immune cells along with cancer cells, deciding further immunosuppressive or cytotoxic pathways. Moreover, triple-negative breast cancer (TNBC), which is generally associated with poor outcomes, can harbor specific TRM phenotypes. The influence of TRMs on adipose tissue stroma of the mammary gland also contributes to tumor progression. The complex crosstalk between TRMs with T cells, stroma, and breast cancer cells can establish a cascade of downstream events, understanding which can offer new insight for drug discovery and upcoming treatment choices. This review aims to acknowledge the previous research done in this regard while exploring existing research gaps and the future therapeutic potential of TRMs as a combination or single agent in breast cancer.

Assessment of the impact of physical and chemical factors of the production environment on the morphological state of target organs in an animal experiment

The study of the morphological state of target organs of outbred (nonlinear) laboratory mice ICR (CD-1), which were under prolonged dynamic influence of physical and chemical factors of the production environment under model conditions, is of wide research interest, as it allows to assess the impact of these factors at the tissue and cellular level and to identify the presence of pathological changes in relation to the group control that was not exposed to the studied factors of the production environment during the 90-day experiment, which has clinical and practical significance. When assessing the 90-day dynamics (from 0 days – 6 months (background) to 30–60–90 days – 7–8–9 months) of the impact of environmental factors on the morphological state of tissues and organs of outbred (nonlinear) laboratory mice ICR (CD-1), generally accepted and unified methods were used. Animals (weighing 45–50 gr., sexually mature age – 6 months) were divided into 3 experimental groups (vibration exposure, noise exposure, chemical exposure) of 30 individuals each (15 females and 15 males) and 1 control group (15 females and 15 males), kept in standard comfortable conditions, and not exposed to the factors of the production environment. The experiment was conducted in accordance with the rules adopted by the European Convention for the Protection of Animals Used for Experimental Scientific Purposes (Strasbourg, 1986), after approval by the Ethical commission of the Novosibirsk Research Institute of Hygiene of Rospotrebnadzor. Statistical processing of the research materials was carried out using standard Statistica 10.0 application programs. The morphological analysis of the target organs of experimental animals revealed the presence of a complex of pathological changes in the 90-day dynamics of the impact of factors of the production environment, compared with the morphological state of the organs in the control group. The results obtained have clinical and practical significance, as they allow us to justify preventive measures aimed at preventing the negative impact of long-term production factors on the labor contingent. Further study of the morphological state of target organs of ICR laboratory mice exposed to prolonged dynamic exposure to physical and chemical factors of the production environment under model conditions will contribute to the establishment of mechanisms for the development of occupational diseases and the development of scientifically based medical and hygienic measures aimed at preserving the health of the labor contingent in the management of labor longevity.

Responsive β-Diketonate-europium(III) Complex-Based Probe for Time-Gated Luminescence Detection and Imaging of Hydrogen Sulfide In Vitro and In Vivo.

As a crucial biological gasotransmitter, hydrogen sulfide (H2S) plays important roles in many pathological and physiological processes. Highly selective and sensitive detection of H2S is significant for the precise diagnosis and evaluation of diverse diseases. Nevertheless, challenges remain in view of the interference of autofluorescence in organisms and the stronger reactivity of H2S itself. Herein, we report the design and synthesis of a novel H2S-responsive β-diketonate-europium(III) complex-based probe, [Eu(DNB-Npketo)3(terpy)], for background-free time-gated luminescence (TGL) detection and imaging of H2S in autofluorescence-rich biological samples. The probe, consisting of a 2,4-dinitrobenzenesulfonyl (DNB) group coupled to a β-diketonate-europium(III) complex, shows almost no luminescence owing to the existence of intramolecular photoinduced electron transfer. The cleavage of the DNB group by a H2S-triggered reaction results in the recovery of the long-lived luminescence of the Eu3+ complex, allowing the detection of H2S in complicated biological samples to be performed in TGL mode. The probe showed a fast response, high specificity, and high sensitivity toward H2S, which enabled it to be successfully used for the quantitative TGL detection of H2S in tissue homogenates of mouse organs. Additionally, the low cytotoxicity of the probe allowed it to be further used for the TGL imaging of H2S in living cells and mice under different stimuli. All of the results suggested the potential of the probe for the investigation and diagnosis of H2S-related diseases.

The mouse multi-organ proteome from infancy to adulthood

The early-life organ development and maturation shape the fundamental blueprint for later-life phenotype. However, a multi-organ proteome atlas from infancy to adulthood is currently not available. Herein, we present a comprehensive proteomic analysis of ten mouse organs (brain, heart, lung, liver, kidney, spleen, stomach, intestine, muscle and skin) at three crucial developmental stages (1-, 4- and 8-weeks after birth) acquired using data-independent acquisition mass spectrometry. We detect and quantify 11,533 protein groups across the ten organs and obtain 115 age-related differentially expressed protein groups that are co-expressed in all organs from infancy to adulthood. We find that spliceosome proteins prevalently play crucial regulatory roles in the early-life development of multiple organs, and detect organ-specific expression patterns and sexual dimorphism. This multi-organ proteome atlas provides a fundamental resource for understanding the molecular mechanisms underlying early-life organ development and maturation.

The caspase-activated DNase promotes cellular senescence

Cellular senescence is a response to many stressful insults. DNA damage is a consistent feature of senescent cells, but in many cases its source remains unknown. Here, we identify the cellular endonuclease caspase-activated DNase (CAD) as a critical factor in the initiation of senescence. During apoptosis, CAD is activated by caspases and cleaves the genomic DNA of the dying cell. The CAD DNase is also activated by sub-lethal signals in the apoptotic pathway, causing DNA damage in the absence of cell death. We show that sub-lethal signals in the mitochondrial apoptotic pathway induce CAD-dependent senescence. Inducers of cellular senescence, such as oncogenic RAS, type-I interferon, and doxorubicin treatment, also depend on CAD presence for senescence induction. By directly activating CAD experimentally, we demonstrate that its activity is sufficient to induce senescence in human cells. We further investigate the contribution of CAD to senescence in vivo and find substantially reduced signs of senescence in organs of ageing CAD-deficient mice. Our results show that CAD-induced DNA damage in response to various stimuli is an essential contributor to cellular senescence.