Loss of transient receptor potential channel 5 causes obesity and postpartum depression.

Hypothalamic neural circuits regulate instinctive behaviors such as food seeking, the fight/flight response, socialization, and maternal care. Here, we identified microdeletions on chromosome Xq23 disrupting the brain-expressed transient receptor potential (TRP) channel 5 (TRPC5). This family of channels detects sensory stimuli and converts them into electrical signals interpretable by the brain. Male TRPC5 deletion carriers exhibited food seeking, obesity, anxiety, and autism, which were recapitulated in knockin male mice harboring a human loss-of-function TRPC5 mutation. Women carrying TRPC5 deletions had severe postpartum depression. As mothers, female knockin mice exhibited anhedonia and depression-like behavior with impaired care of offspring. Deletion of Trpc5 from oxytocin neurons in the hypothalamic paraventricular nucleus caused obesity in both sexes and postpartum depressive behavior in females, while Trpc5 overexpression in oxytocin neurons in knock-in mice reversed these phenotypes. We demonstrate that TRPC5 plays a pivotal role in mediating innate human behaviors fundamental to survival, including food seeking and maternal care.

Neoadjuvant PARPi or chemotherapy in ovarian cancer informs targeting effector Treg cells for homologous-recombination-deficient tumors.

Homologous recombination deficiency (HRD) is prevalent in cancer, sensitizing tumor cells to poly (ADP-ribose) polymerase (PARP) inhibition. However, the impact of HRD and related therapies on the tumor microenvironment (TME) remains elusive. Our study generates single-cell gene expression and T cell receptor profiles, along with validatory multimodal datasets from >100 high-grade serous ovarian cancer (HGSOC) samples, primarily from a phase II clinical trial (NCT04507841). Neoadjuvant monotherapy with the PARP inhibitor (PARPi) niraparib achieves impressive 62.5% and 73.6% response rates per RECIST v.1.1 and GCIG CA125, respectively. We identify effector regulatory T cells (eTregs) as key responders to HRD and neoadjuvant therapies, co-occurring with other tumor-reactive T cells, particularly terminally exhausted CD8+ T cells (Tex). TME-wide interferon signaling correlates with cancer cells upregulating MHC class II and co-inhibitory ligands, potentially driving Treg and Tex fates. Depleting eTregs in HRD mouse models, with or without PARP inhibition, significantly suppresses tumor growth without observable toxicities, underscoring the potential of eTreg-focused therapeutics for HGSOC and other HRD-related tumors.

A Light-Responsive Neural Circuit Suppresses Feeding.

Light plays an essential role in a variety of physiological processes, including vision, mood, and glucose homeostasis. However, the intricate relationship between light and an animal's feeding behavior has remained elusive. Here, we found that light exposure suppresses food intake, whereas darkness amplifies it in male mice. Interestingly, this phenomenon extends its reach to diurnal male Nile grass rats and healthy humans. We further show that lateral habenula (LHb) neurons in mice respond to light exposure, which in turn activates 5-HT neurons in the dorsal Raphe nucleus (DRN). Activation of the LHb→5-HTDRN circuit in mice blunts darkness-induced hyperphagia, while inhibition of the circuit prevents light-induced anorexia. Together, we discovered a light-responsive neural circuit that relays the environmental light signals to regulate feeding behavior in mice.

TcdB from Hypervirulent Clostridioides difficile Induces Neuronal Loss and Neurotransmitter Alterations in the Intrinsic Enteric Nervous System.

Clostridioides difficile infection (CDI) is a predominant cause of intestinal infections. The intrinsic enteric nervous system (ENS) occupies the intestinal tissue in large numbers and intricately regulates various aspects of intestinal function. Nonetheless, the specific effects of CDI on the intrinsic ENS remain underexplored. Herein, we employed the TcdB variant (TcdB2) derived from hypervirulent C. difficile to elucidate the impact of CDI on neurons located in colonic wall. We found that TcdB2 directly induced dose-dependent cytopathic effects on enteric neurons both in vitro and in adult mice colons. Notably, an increased expression of choline acetyltransferase (ChAT) and neural nitric oxide synthase (nNOS) in colonic neurons prior to the onset of cytopathic changes following treatment with TcdB2 were observed, both in vivo and in vitro. These findings suggest that during CDI, TcdB not only causes neuronal loss but also alters the composition of neurotransmitters in the ENS.

NDP52 SUMOylation contributes to low-dose X-rays-induced cardiac hypertrophy through PINK1/Parkin-mediated mitophagy via MUL1/SUMO2 signalling.

Radiation-induced heart damage caused by low-dose X-rays has a significant impact on tumour patients' prognosis, with cardiac hypertrophy being the most severe noncarcinogenic adverse effect. Our previous study demonstrated that mitophagy activation promoted cardiac hypertrophy, but the underlying mechanisms remained unclear. In the present study, PARL-IN-1 enhanced excessive hypertrophy of cardiomyocytes and exacerbated mitochondrial damage. Isobaric tags for relative and absolute quantification-based quantitative proteomics identified NDP52 as a crucial target mediating cardiac hypertrophy induced by low-dose X-rays. SUMOylation proteomics revealed that the SUMO E3 ligase MUL1 facilitated NDP52 SUMOylation through SUMO2. Co-IP coupled with LC-MS/MS identified a critical lysine residue at position 262 of NDP52 as the key site for SUMO2-mediated SUMOylation of NDP52. The point mutation plasmid NDP52K262R inhibited mitophagy under MUL1 overexpression, as evidenced by inhibition of LC3 interaction with NDP52, PINK1 and LAMP2A. A mitochondrial dissociation study revealed that NDP52K262R inhibited PINK1 targeting to endosomes early endosomal marker (EEA1), late/lysosome endosomal marker (LAMP2A) and recycling endosomal marker (RAB11), and laser confocal microscopy confirmed that NDP52K262R impaired the recruitment of mitochondria to the autophagic pathway through EEA1/RAB11 and ATG3, ATG5, ATG16L1 and STX17, but did not affect mitochondrial delivery to lysosomes via LAMP2A for degradation. In conclusion, our findings suggest that MUL1-mediated SUMOylation of NDP52 plays a crucial role in regulating mitophagy in the context of low-dose X-ray-induced cardiac hypertrophy. Two hundred sixty-second lysine of NDP52 is identified as a key SUMOylation site for low-dose X-ray promoting mitophagy activation and cardiac hypertrophy. Collectively, this study provides novel implications for the development of therapeutic strategies aimed at preventing the progression of cardiac hypertrophy induced by low-dose X-rays.

Proteome Fishing for CRISPR/Cas12a-Based Orthogonal Multiplex Aptamer Sensing.

Detection of serum protein biomarkers is extremely challenging owing to the superior complexity of serum. Here, we report a method of proteome fishing from the serum. It uses a magnetic nanoparticle-protein corona and a multiplexed aptamer panel, which we incubated with the nanoparticle-protein corona for biomarker recognition. To transfer protein biomarker detection to aptamer detection, we established a CRISPR/Cas12a-based orthogonal multiplex aptamer sensing (COMPASS) platform by profiling the aptamers of protein corona with clinical nonsmall cell lung cancer (NSCLC) serum samples. Furthermore, we determined the four out of nine (FOON) panel (including HE4, NSE, AFP, and VEGF165) to be the most cost-effective and accurate panel for COMPASS in NSCLC diagnosis. The diagnostic accuracy of NSCLC by the FOON panel with internal and external cohorts was 95.56% (ROC-AUC = 99.40%) and 89.58% (ROC-AUC = 95.41%), respectively. Our developed COMPASS technology circumvents the otherwise challenging multiplexed serum protein amplification problem and avoids aptamer degradation in serum. Therefore, this novel COMPASS could lead to the development of a facile, cost-effective, intelligent, and high-throughput diagnostic platform for large-cohort cancer screening.

Nanoparticle-Protein Corona-Based Tissue Proteomics for the Aging Mouse Proteome Atlas.

Highly abundant proteins present in biological fluids and tissues significantly interfere with low-abundance protein identification by mass spectrometry (MS), limiting proteomic depth and hindering protein biomarker discovery. Herein, to enhance the coverage of tissue proteomics, we developed a nanoparticle-protein corona (NP-PC)-based method for the aging mouse proteome atlas. Based on this method, we investigated the complexity of life process of 5 major organs, including the heart, liver, spleen, lungs, and kidneys, from 4 groups of mice at different ages. Compared with the conventional strategy, NP-PC-based proteomics significantly increased the number of identified protein groups in the heart (from 3007 to 3927; increase of 30.6%), liver (from 2982 to 4610; increase of 54.6%), spleen (from 5047 to 7351; increase of 45.7%), lungs (from 4984 to 6903; increase of 38.5%), and kidneys (from 3550 to 5739; increase of 61.7%), and we identified a total of 10 104 protein groups. The overall data indicated that 3-week-old mice showed more differences compared with the other three age groups. The proteins of amino acid-related metabolism were increased in aged mice compared with those in the 3-week-old mice. Protein-related infections were increased in the spleen of the aged mice. Interestingly, the spliceosome-related pathway significantly changed from youth to elders in the liver, spleen, and lungs, indicating the vital role of the spliceosome during the aging process. Our established aging mouse organ proteome atlas provides comprehensive insights into understanding the aging process, and it may help in prevention and treatment of age-related diseases.

Analysis of related factors for pathological upgrading of cervical biopsy from CIN3 to cancer after conical resection.

BACKGROUND: To investigate related factors for postoperative pathological upgrading of cervical biopsy to cervical cancer (CC) in patients with cervical intraepithelial neoplasia (CIN)3 after conical resection. METHODS: This retrospective study collected data from patients diagnosed with CIN3 by cervical biopsies at the author's Hospital between January 2012 and December 2022. The primary outcome was the pathological results of patients after conical resection. The pathological findings were categorized into the pathological upgrading group if postoperative pathology indicated CC, while those with normal, inflammatory, or cervical precancerous lesions were classified into the pathological non-upgrading group. The factors associated with upgrading were identified using multivariable logistic regression analysis. RESULTS: Among 511 patients, there were 125 patients in the pathological upgrading group (24.46%). The patients in the upgrading group were younger (47.68 ± 9.46 vs. 52.11 ± 7.02, P < 0.001), showed a lower proportion of menopausal women (38.40% vs. 53.02%, P = 0.0111), a lower proportion of HSIL (40.00% vs. 57.77%, P = 0.001), a higher rate of HPV-16/18 positive (25.60% vs. 17.36%, P = 0.011), a higher rate of contact bleeding (54.40% vs. 21.50%, P < 0.001), lower HDL levels (1.31 ± 0.29 vs. 1.37 ± 0.34 mmol/L, P = 0.002), higher neutrophil counts (median, 3.50 vs. 3.10 × 109/L, P = 0.001), higher red blood cell counts (4.01 ± 0.43 vs. 3.97 ± 0.47 × 1012/L, P = 0.002), higher platelet counts (204.84 ± 61.24 vs. 187.06 ± 73.66 × 109/L, P = 0.012), and a smaller platelet volume (median, 11.50 vs. 11.90 fL, P = 0.002).The multivariable logistic regression analysis showed that age (OR = 0.90, 95% CI: 0.86-0.94, P < 0.001), menopausal (OR = 2.68, 95% CI: 1.38-5.22, P = 0.004), contact bleeding (OR = 4.80, 95% CI: 2.91-7.91, P < 0.001), and mean platelet volume (OR = 0.83, 95% CI: 0.69-0.99, P = 0.038) were independently associated with pathological upgrading from CIN3 to CC after conical resection. CONCLUSION: Age, menopausal, contact bleeding, and mean platelet volume are risk factors of pathological upgrading from CIN3 to CC after conical resection, which could help identify high risk and susceptible patients of pathological upgrading to CC.

Cell life-or-death events in osteoporosis: All roads lead to mitochondrial dynamics.

Mitochondria exhibit heterogeneous shapes and networks within and among cell types and tissues, also in normal or osteoporotic bone tissues with complex cell types. This dynamic characteristic is determined by the high plasticity provided by mitochondrial dynamics and is stemmed from responding to the survival and functional requirements of various bone cells in a specific microenvironments. In contrast, mitochondrial dysfunction, induced by dysregulation of mitochondrial dynamics, may act as a trigger of cell death signals, including common apoptosis and other forms of programmed cell death (PCD). These PCD processes consisting of tightly structured cascade gene expression events, can further influence the bone remodeling by facilitating the death of various bone cells. Mitochondrial dynamics, therefore, drive the bone cells to stand at the crossroads of life and death by integrating external signals and altering metabolism, shape, and signal-response properties of mitochondria. This implies that targeting mitochondrial dynamics displays significant potential in treatment of osteoporosis. Considerable effort has been made in osteoporosis to emphasize the parallel roles of mitochondria in regulating energy metabolism, calcium signal transduction, oxidative stress, inflammation, and cell death. However, the emerging field of mitochondrial dynamics-related PCD is not well understood. Herein, to bridge the gap, we outline the latest knowledge on mitochondrial dynamics regulating bone cell life or death during normal bone remodeling and osteoporosis.

Clinical characteristics of patients with granulomatous lobular mastitis associated with Corynebacterium parakroppenstedtii infection and drug sensitivity analysis of the isolated strains.

BACKGROUND: It is presently considered that Corynebacterium especially Corynebacterium kroppenstedtii (CK) infection, is one of the important causes of granulomatous lobular mastitis (GLM). However, the pathogen of mastitis in the past two years has been identified as a newly discovered Corynebacterium. But it is unclear whether the pathogen associated with the occurrence of GLM is also this bacterium. METHODS: GLM female patients with positive bacterial culture in pus specimens from February 2023 to February 2024 who were identified as CK infection by mass spectrometer were selected as the research objects in this study, and the clinical isolates were identified by 16S rDNA sequencing technology to identify the specific pathogen of GLM-related bacterial infection. Subsequently, the clinical characteristics of the patients were compared with those of GLM patients without bacterial infection during the same period, to explore the effect of this particular type of Corynebacterium infection on disease development in GLM patients. Finally, we tested the minimum inhibitory concentration (MIC) values of antibiotics when inhibiting these separation strains in vitro through the E-Test experiment, to evaluate their medicine sensitivity. RESULTS: A total of 31 GLM patients initially diagnosed with Corynebacterium kroppenstedtii (CK) infection via MALDI-TOF MS were enrolled in the study. However, subsequent 16S rDNA sequencing revealed that 28 isolates (90.32%) were actually identified as the newly recognized Corynebacterium parakroppenstedtii (CPK). This discovery challenges the conventional belief that CK is the primary pathogen of GLM, suggesting instead that CPK is the predominant pathogen associated with GLM bacterial infections. Comparative analysis of the clinical characteristics between the two groups revealed a significantly higher recurrence rate among CPK-infected GLM patients compared to those without CPK infection, along with elevated prolactin levels (P < 0.05). The sensitivity test results indicated high sensitivity of the isolates to vancomycin, linezolid, and rifampicin. CONCLUSION: In conclusion, this study highlights that Corynebacterium kroppenstedtii strains isolated from GLM specimens were Corynebacterium parakroppenstedtii, serving as the primary pathogen closely linked to GLM's occurrence. CPK infection significantly increases the risk of recurrence in GLM patients, with elevated prolactin levels potentially playing a pivotal role in this process. In clinical antimicrobial treatment, antimicrobials other than penicillin and ciprofloxacin may be empirically administered when sensitivity test results are inconclusive.

Salidroside alleviates imiquimod-induced psoriasis by inhibiting GSDMD-driven keratinocyte pyroptosis.

Psoriasis is a common immune-related polygenic inflammatory skin disease. Salidroside (SAL) exerts anti-inflammatory and antioxidant effects and is used to treat skin diseases. However, the specific effects of SAL on psoriasis remain unclear. In this study, we aimed to investigate the efficacy of SAL for psoriasis treatment. Mice were treated with imiquimod (IMQ) to establish an in vivo psoriasis model. Histological analysis was conducted via hematoxylin and eosin staining. Cytokine release was determined via enzyme-linked immunosorbent assay. Additionally, mRNA levels were determined via reverse transcription-quantitative polymerase chain reaction. Protein expression was assessed via Western blotting. Gasdermin D (GSDMD) and Ki-67 expression levels were determined via immunohistochemistry. Caspase 1 and GSDMD expression levels were determined via immunofluorescence assay. Furthermore, macrophage function and keratinocyte pyroptosis were also analyzed via flow cytometry. Cell proliferation was determined using 5-ethynyl-2'deoxyuridine assay. SAL alleviated IMQ-induced psoriasis. IMQ-mediated GSDMD-driven pyroptosis and keratinocyte hyperproliferation promoted M1 macrophage polarization. However, SAL treatment suppressed GSDMD expression, thereby inhibiting keratinocyte proliferation and pyroptosis and promoting M2 macrophage polarization. GSDMD deficiency further promoted the effects of SAL and suppressed psoriasis progression. Overall, our findings suggest that SAL exerts protective effects against psoriasis. Specifically, it exerts anti-inflammatory effects by regulating M2 macrophage polarization and inhibiting keratinocyte pyroptosis-driven proliferation induced by the immune microenvironment in psoriasis.

Adiponectin protects against myocardial ischemia-reperfusion injury: a systematic review and meta-analysis of preclinical animal studies.

BACKGROUND: Myocardial ischemia-reperfusion injury (MIRI) is widespread in the treatment of ischemic heart disease, and its treatment options are currently limited. Adiponectin (APN) is an adipocytokine with cardioprotective properties; however, the mechanisms of APN in MIRI are unclear. Therefore, based on preclinical (animal model) evidence, the cardioprotective effects of APN and the underlying mechanisms were explored. METHODS: The literature was searched for the protective effect of APN on MIRI in six databases until 16 November 2023, and data were extracted according to selection criteria. The outcomes were the size of the myocardial necrosis area and hemodynamics. Markers of oxidation, apoptosis, and inflammation were secondary outcome indicators. The quality evaluation was performed using the animal study evaluation scale recommended by the Systematic Review Center for Laboratory animal Experimentation statement. Stata/MP 14.0 software was used for the summary analysis. RESULTS: In total, 20 papers with 426 animals were included in this study. The pooled analysis revealed that APN significantly reduced myocardial infarct size [weighted mean difference (WMD) = 16.67 (95% confidence interval (CI) = 13.18 to 20.16, P < 0.001)] and improved hemodynamics compared to the MIRI group [Left ventricular end-diastolic pressure: WMD = 5.96 (95% CI = 4.23 to 7.70, P < 0.001); + dP/dtmax: WMD = 1393.59 (95% CI = 972.57 to 1814.60, P < 0.001); -dP/dtmax: WMD = 850.06 (95% CI = 541.22 to 1158.90, P < 0.001); Left ventricular ejection fraction: WMD = 9.96 (95% CI = 7.29 to 12.63, P < 0.001)]. Apoptosis indicators [caspase-3: standardized mean difference (SMD) = 3.86 (95% CI = 2.97 to 4.76, P < 0.001); TUNEL-positive cells: WMD = 13.10 (95% CI = 8.15 to 18.05, P < 0.001)], inflammatory factor levels [TNF-α: SMD = 4.23 (95% CI = 2.48 to 5.98, P < 0.001)], oxidative stress indicators [Superoxide production: SMD = 4.53 (95% CI = 2.39 to 6.67, P < 0.001)], and lactate dehydrogenase levels [SMD = 2.82 (95% CI = 1.60 to 4.04, P < 0.001)] were significantly reduced. However, the superoxide dismutase content was significantly increased [SMD = 1.91 (95% CI = 1.17 to 2.65, P < 0.001)]. CONCLUSION: APN protects against MIRI via anti-inflammatory, antiapoptotic, and antioxidant effects, and this effect is achieved by activating different signaling pathways.

Feasibility of an exercise-nutrition-psychology integrated rehabilitation model based on mobile health and virtual reality for cancer patients: a single-center, single-arm, prospective phase II study.

OBJECTIVE: Explore the feasibility of a mobile health(mHealth) and virtual reality (VR) based nutrition-exercise-psychology integrated rehabilitation model in Chinese cancer patients. METHODS: We recruited cancer patients in the Oncology department of the Affiliated Changzhou No. 2 People's Hospital of Nanjing Medical University from October 2022 to April 2023. The rehabilitation program was provided by a team of medical oncologists, dietitians, psychotherapists, and oncology specialist nurses. Participants received standard anti-cancer therapy and integrated intervention including hospitalized group-based exercise classes, at-home physical activity prescription, behavior change education, oral nutrition supplements, and psychological counseling. An effective intervention course includes two consecutive hospitalization and two periods of home-based rehabilitation (8 weeks). Access the feasibility as well as changes in aspects of physical, nutritional, and psychological status. RESULTS: At the cutoff date of April 2023, the recruitment rate was 75% (123/165). 11.4%patients were lost to follow-up, and 3.25% withdrew halfway. Respectively, the completion rate of nutrition, exercise, and psychology were 85%,55%, and 63%. Nutrition interventions show the highest compliance. The parameters in nutrition, psychology, muscle mass, and quality of life after the rehabilitation showed significant improvements (P < .05). There was no significant statistical difference (P > .05) in handgrip strength and 6-minute walking speed. CONCLUSION: It is feasible to conduct mHealth and VR-based nutrition-exercise-psychology integrated rehabilitation model in Chinese cancer patients. A larger multi-center trial is warranted in the future. TRIAL REGISTRATION: ChiCTR2200065748 Registered 14 November 2022.

Targeting programmed cell death in inflammatory bowel disease through natural products: New insights from molecular mechanisms to targeted therapies.

Inflammatory bowel disease (IBD) is an autoimmune disorder primarily characterized by intestinal inflammation and recurrent ulceration, leading to a compromised intestinal barrier and inflammatory infiltration. This disorder's pathogenesis is mainly attributed to extensive damage or death of intestinal epithelial cells, along with abnormal activation or impaired death regulation of immune cells and the release of various inflammatory factors, which contribute to the inflammatory environment in the intestines. Thus, maintaining intestinal homeostasis hinges on balancing the survival and functionality of various cell types. Programmed cell death (PCD) pathways, including apoptosis, pyroptosis, autophagy, ferroptosis, necroptosis, and neutrophil extracellular traps, are integral in the pathogenesis of IBD by mediating the death of intestinal epithelial and immune cells. Natural products derived from plants, fruits, and vegetables have shown potential in regulating PCD, offering preventive and therapeutic avenues for IBD. This article reviews the role of natural products in IBD treatment by focusing on targeting PCD pathways, opening new avenues for clinical IBD management.

Design and Simulation of High-Performance D-Type Dual-Mode PCF-SPR Refractive Index Sensor Coated with Au-TiO2 Layer.

A novel surface plasmon resonance (SPR) refractive index (RI) sensor based on the D-type dual-mode photonic crystal fiber (PCF) is proposed. The sensor employs a side-polished few-mode PCF that facilitates the transmission of the fundamental and second-order modes, with an integrated microfluidic channel positioned directly above the fiber core. This design minimizes the distance to the analyte and maximizes the interaction between the optical field and the analyte, thereby enhancing the SPR effect and resonance loss for improved sensing performance. Au-TiO2 dual-layer material was coated on the surface of a microfluidic channel to enhance the penetration depth of the core evanescent field and tune the resonance wavelength to the near-infrared band, meeting the special needs of chemical and biomedical detection fields. The finite element method was utilized to systematically investigate the coupling characteristics between various modes and surface plasmon polariton (SPP) modes, as well as the impact of structural parameters on the sensor performance. The results indicate that the LP11b_y mode exhibits greater wavelength sensitivity than the HE11_y mode, with a maximum sensitivity of 33,000 nm/RIU and an average sensitivity of 8272.7 nm/RIU in the RI sensing range of 1.25-1.36, which is higher than the maximum sensitivity of 16,000 nm/RIU and average sensitivity of 5666.7 nm/RIU for the HE11b_y mode. It is believed that the proposed PCF-SPR sensor features both high sensitivity and high resolution, which will become a critical device for wide RI detection in mid-infrared fields.

The ecological utility study on carbon metabolism of cultivated land: A case study of Hubei Province, China.

Exploring the ecological utility of cultivated land's carbon metabolism offers policy insights for ensuring its healthy operation and promote the dual carbon goals (carbon peak and carbon neutrality). We employed ecological network analysis (ENA) and kernel density estimation to conduct an empirical study, taking Hubei Province from 2000 to 2020 as an example. The results revealed apparent negative effects of carbon metabolic flow on regional carbon balance. Specifically, cultivated land conversion into transportation and industrial land contributed significantly to the harmful carbon flow. Ecological relationships showed fierce competition for carbon storage, leading to overall adverse ecological effects. The ecological utility indicated detrimental impacts on the orderly functioning of land-use carbon metabolism. Cultivated land's carbon metabolism will be essential in achieving land-use carbon neutrality. Therefore, territorial spatial low-carbon optimization should be implemented to realize its green and sustainable development.

Polyunsaturated fatty acids promote the rapid fusion of lipid droplets in Caenorhabditis elegans.

Lipid droplets (LDs) are intracellular organelles that dynamically regulate lipids and energy homeostasis in the cell. LDs can grow through either local lipid synthesis or LD fusion. However, how lipids involving in LD fusion for LD growth is largely unknown. Here, we show that genetic mutation of acox-3 (acyl-CoA oxidase), maoc-1 (enoyl-CoA hydratase), dhs-28 (3-hydroxylacyl-CoA dehydrogenase), and daf-22 (3-ketoacyl-CoA thiolase), all involved in the peroxisomal ß-oxidation pathway in Caenorhabditis elegans, led to rapid fusion of adjacent LDs to form giant LDs (gLDs). Mechanistically, we show that dysfunction of peroxisomal ß-oxidation results in the accumulation of long-chain fatty acid-CoA and phosphocholine, which may activate the sterol-binding protein 1/sterol regulatory element-binding protein to promote gLD formation. Furthermore, we found that inactivation of either FAT-2 (delta-12 desaturase) or FAT-3 and FAT-1 (delta-15 desaturase and delta-6 desaturase, respectively) to block the biosynthesis of polyunsaturated fatty acids (PUFAs) with three or more double bonds (n≥3-PUFAs) fully repressed the formation of gLDs; in contrast, dietary supplementation of n≥3-PUFAs or phosphocholine bearing these PUFAs led to recovery of the formation of gLDs in peroxisomal ß-oxidation-defective worms lacking PUFA biosynthesis. Thus, we conclude that n≥3-PUFAs, distinct from other well-known lipids and proteins, promote rapid LD fusion leading to LD growth.

Molecular mechanism of different flower color formation of Cymbidium ensifolium.

Cymbidium ensifolium is one of the national orchids in China, which has high ornamental value with changeable flower colors. To understand the formation mechanism of different flower colors of C. ensifolium, this research conducted transcriptome and metabolome analyses on four different colored sepals of C. ensifolium. Metabolome analysis detected 204 flavonoid metabolites, including 17 polyphenols, 27 anthocyanins, 75 flavones, 34 flavonols, 25 flavonoids, 18 flavanones, and 8 isoflavones. Among them, purple-red and red sepals contain a lot of anthocyanins, including cyanidin, pelargonin, and paeoniflorin, while yellow-green and white sepals have less anthocyanins detected, and their metabolites are mainly flavonols, flavanones and flavonoids. Transcriptome sequencing analysis showed that the expression levels of the anthocyanin biosynthetic enzyme genes in red and purple-red sepals were significantly higher than those in white and yellow-green sepals of C. ensifolium. The experimental results showed that CeF3'H2, CeDFR, CeANS, CeF3H and CeUFGT1 may be the key genes involved in anthocyanin production in C. ensifolium sepals, and CeMYB104 has been proved to play an important role in the flower color formation of C. ensifolium. The results of transformation showed that the CeMYB104 is involved in the synthesis of anthocyanins and can form a purple-red color in the white perianth of Phalaenopsis. These findings provide a theoretical reference to understand the formation mechanism of flower color in C. ensifolium.

Mitochondrial Protease Targeting Chimeras for Mitochondrial Matrix Protein Degradation.

Targeted protein degradation (TPD) is an emerging technique for protein regulation. Currently, all TPD developed in eukaryotic cells relies on either ubiquitin-proteasome or lysosomal systems, thus are powerless against target proteins in membrane organelles lacking proteasomes and lysosomes, such as mitochondria. Here, we developed a mitochondrial protease targeting chimera (MtPTAC) to address this issue. MtPTAC is a bifunctional small molecule that can bind to mitochondrial caseinolytic protease P (ClpP) at one end and target protein at the other. Mechanistically, MtPTAC activates the hydrolase activity of ClpP while simultaneously bringing target proteins into proximity with ClpP. Taking mitochondrial RNA polymerase (POLRMT) as a model protein, we have demonstrated the powerful proteolytic ability and antitumor application prospects of MtPTAC, both in vivo and in vitro. This is the first modularly designed TPD that can specifically hydrolyze target proteins inside mitochondria.

Growth associated protein 43 deficiency promotes podocyte injury by activating the calmodulin/calcineurin pathway under hyperglycemia.

Podocyte injury is a crucial factor in the pathogenesis of diabetic kidney disease (DKD), and finding potential therapeutic interventions that can mitigate podocyte injury holds significant clinical relevance. This study was to elucidate the role of growth associated protein-43(Gap43) in podocyte injury of high glucose (HG). We confirmed the expression of Gap43 in human glomerulus and found that Gap43 expression was downregulated in podocytes of patients with DKD and HG-treated podocytes in vitro. Gap43 knockdown in podocytes promoted podocyte apoptosis, increased migration ability and decreased nephrin expression, while overexpression of Gap43 markedly suppressed HG-induced injury. Moreover, the increased expression and activity of calcineurin (CaN) were also abrogated by overexpression Gap43 in HG. Pretreatment with a typical CaN inhibitor FK506 in Gap43 knockdown podocytes restored the injury. Mechanistically, co-immunoprecipitation experiments suggested that Gap43 could bind to calmodulin (CaM). Pull-down assay further demonstrated that Gap43 and CaM directly interacts with each other via amino acids 30-52 of Gap43 and amino acids 133-197 of CaM. In addition, we also identified Pax5 as potential transcription inhibitor factor mediating Gap43 expression. In conclusion, the study indicated that the Gap43/CaM-CaN pathway may be exploited as a promising therapeutic target for protecting against podocyte injury in high glucose.