Autophagy induction by piplartine ameliorates axonal degeneration caused by mutant HSPB1 and HSPB8 in Charcot-Marie-Tooth type 2 neuropathies

HSPB1 [heat shock protein family B (small) member 1] and HSPB8 are essential molecular chaperones for neuronal proteostasis, as they prevent protein aggregation. Mutant HSPB1 and HSPB8 primarily harm peripheral neurons, resulting in axonal Charcot-Marie-Tooth neuropathies (CMT2). Macroautophagy/autophagy is a shared mechanism by which HSPB1 and HSPB8 mutations cause neuronal dysfunction. Autophagosome formation is reduced in mutant HSPB1-induced pluripotent stem-cell-derived motor neurons from CMT type 2F patients. Likewise, the HSPB8K141N knockin mouse model, mimicking CMT type 2 L, exhibits axonal degeneration and muscle atrophy, with SQSTM1/p62-positive deposits. We show here that mouse embryonic fibroblasts isolated from a HSPB8K141N/green fluorescent protein (GFP)-LC3 model have diminished autophagosome production under conditions of MTOR inhibition. To correct the autophagic deficits in the HSPB1 and HSPB8 models, we screened by high-throughput autophagosome quantification the repurposing Spectrum Collection library for molecules that could boost the autophagic activity above the canonical MTOR inhibition. Hit compounds were validated on motor neurons obtained by differentiation of HSPB1P182L and HSPB8K141N patient-derived induced pluripotent stem cells, focusing on autophagy induction as well as neurite network density, axonal degeneration, and mitochondrial morphology. We identified molecules that specifically stimulate autophagosome formation in the HSPB8K141N cells, without affecting autophagy flux. Two top lead compounds induced autophagy and reduced axonal degeneration, thus promoting neuronal network maturation in the CMT2 patient-derived motor neurons. Based on these findings, the phenotypical screen revealed that piplartine rescued autophagy deficiencies in both the HSPB1 and HSPB8 models, demonstrating autophagy induction as an effective therapeutic strategy for CMT neuropathies and other chaperonopathies.

Mitophagy is induced in human engineered heart tissue after simulated ischemia and reperfusion

The paradoxical exacerbation of cellular injury and death during reperfusion remains a problem in the treatment of myocardial infarction. Mitochondrial dysfunction plays a key role in the pathogenesis of myocardial ischemia and reperfusion injury. Dysfunctional mitochondria can be removed by mitophagy, culminating in their degradation within acidic lysosomes. Mitophagy is pivotal in maintaining cardiac homeostasis and emerges as a potential therapeutic target. Here, we employed beating human engineered heart tissue (EHT) to assess mitochondrial dysfunction and mitophagy during ischemia and reperfusion simulation. Our data indicate adverse ultrastructural changes in mitochondrial morphology and impairment of mitochondrial respiration. Furthermore, our pH-sensitive mitophagy reporter EHTs, generated by a CRISPR/Cas9 endogenous knock-in strategy, revealed induced mitophagy flux in EHTs after ischemia and reperfusion simulation. The induced flux required the activity of the protein kinase ULK1, a member of the core autophagy machinery. Our results demonstrate the applicability of the reporter EHTs for mitophagy assessment in a clinically relevant setting. Deciphering mitophagy in the human heart will facilitate development of novel therapeutic strategies.

GPNMB disrupts SNARE complex assembly to maintain bacterial proliferation within macrophages

Xenophagy plays a crucial role in restraining the growth of intracellular bacteria in macrophages. However, the machinery governing autophagosome‒lysosome fusion during bacterial infection remains incompletely understood. Here, we utilize leprosy, an ideal model for exploring the interactions between host defense mechanisms and bacterial infection. We highlight the glycoprotein nonmetastatic melanoma protein B (GPNMB), which is highly expressed in macrophages from lepromatous leprosy (L-Lep) patients and interferes with xenophagy during bacterial infection. Upon infection, GPNMB interacts with autophagosomal-localized STX17, leading to a reduced N-glycosylation level at N296 of GPNMB. This modification promotes the degradation of SNAP29, thus preventing the assembly of the STX17-SNAP29-VAMP8 SNARE complex. Consequently, the fusion of autophagosomes with lysosomes is disrupted, resulting in inhibited cellular autophagic flux. In addition to Mycobacterium leprae, GPNMB deficiency impairs the proliferation of various intracellular bacteria in human macrophages, suggesting a universal role of GPNMB in intracellular bacterial infection. Furthermore, compared with their counterparts, Gpnmbfl/fl Lyz2-Cre mice presented decreased Mycobacterium marinum amplification. Overall, our study reveals a previously unrecognized role of GPNMB in host antibacterial defense and provides insights into its regulatory mechanism in SNARE complex assembly.

Mesenteric Fibrosis in Neuroendocrine Neoplasms: a Systematic Review of New Thoughts on Causation and Potential Treatments

PURPOSE OF REVIEW

Mesenteric fibrosis (MF) is a hallmark of small intestinal neuroendocrine neoplasms (SI-NEN) and is frequently associated with significant morbidity due to related complications such as intestinal obstruction, ischemia, and cachexia.

RECENT FINDINGS

Herein we performed a systematic review to discuss the development of MF in SI-NEN. The pathophysiological mechanisms acknowledged as causative for the development of MF include the major components of the tumor microenvironment, such as fibroblasts, endothelial and immune cells and the extracellular matrix, which are involved in a complex interplay activating several signaling pathways that promote profibrotic factors and induce both a desmoplastic reaction and tumor proliferation. Surgery remains the mainstay of treatment, while several medical management options of MF complicating SI-NEN available present rather limited efficacy. MF is a frequent characteristic of SI-NEN that requires particular attention and targeted management to avoid complications.

The potential of low-intensity pulsed ultrasound to apply the long-term ovary protection from injury induced by 4-vinylcyclohexene diepoxide through inhibiting granulosa cell apoptosis

The potential of low-intensity pulsed ultrasound (LIPUS) in regulating ovarian function has been demonstrated; however, there is a lack of scientific evidence regarding the long-term efficacy of LIPUS in treating ovarian injury and understanding its regulatory mechanisms. In this study, 4-vinylcyclohexene diepoxide (VCD) was used to induce ovarian injury in rats, and LIPUS was applied to target the damaged ovarian tissues. The research aimed to investigate the long-term protective effect of LIPUS against ovum toxicity induced by VCD and elucidate the associated molecular mechanisms. During the experiment, HE staining was employed for observing the morphology and structure of the ovary, while protein sequencing was utilized for identifying and confirming the molecular mechanism through which LIPUS restores the damaged ovarian structure. The long-term effectiveness of LIPUS in protecting against ovarian injury was evaluated through ELISA, estrous cycle monitoring, fertility testing, and behavioral analysis. The results indicated that LIPUS effectively restored the structure of damaged ovaries. Both in vivo and in vitro studies revealed that this protective effect may be attributed to LIPUS inhibiting apoptosis of ovarian granulosa cells (GCs) by regulating Daxx-mediated ASK1/JNK signaling pathway. Subsequent functional tests demonstrated significant improvements in sex hormone secretion and regulation of estrous cycle within 6 cycles following LIPUS treatment. Additionally, there was a notable increase in offspring numbers after mating. Behavioral analysis revealed that LIPUS effectively alleviated menopausal symptoms resulting from ovarian injury including mood fluctuations, cognitive behavior changes, and reduced muscle excitability levels. These findings suggest that beneficial effects of LIPUS may help reduce VCD-induced ovarian damage with long-term efficacy.

Neuromuscular electrical stimulation alleviates stroke-related sarcopenia by promoting satellite cells myogenic differentiation via AMPK-ULK1-Autophagy axis

Background

Stroke-related sarcopenia can result in muscle mass loss and muscle fibers abnormality, significantly affecting muscle function. The clinical management of stroke-related sarcopenia still requires further research and investigation. This study aims to explore a promising therapy to restore muscle function and promote muscle regeneration in stroke-related sarcopenia, providing a new theory for stroke-related sarcopenia treatment.

Methods

Stroke-related sarcopenia rat model was established by using permanent middle cerebral artery occlusion (pMCAO) rat and treated with neuromuscular electrical stimulation (NMES). Electrical stimulation (ES) treatment in vitro was mimicked to test the effect of NMES on muscle regeneration in rat skeletal muscle satellite cells (MuSCs). Catwalk, H&E and Masson's trichrome staining, immunofluorescence, transcriptomic analysis, transmission electron microscopy, MuSCs transfection, autophagy flux detection, quantitative real-time PCR analysis, Co-Immunoprecipitation and Western Blot were used to investigate the role of NMES and its mechanism in stroke-related sarcopenia in vivo.

Results

After NMES treatment, muscle mass and myogenic differentiation were significantly increased in stroke-related sarcopenia rats. The NMES group had more stable gait, neater footprints, higher muscle wet weight, more voluminous morphology and more regenerated muscle fibers. Additionally, ES treatment induced myogenic differentiation in rat MuSCs in vitro. Transcriptomic analysis also showed that "AMPK signaling pathway" was enriched and genes upregulated in ES-treated cells, revealing ES treatment could activate the autophagy in an AMPK-ULK1-dependent mechanism in MuSCs. Besides, it was also founded that infusion of AMPK or ULK1 inhibitor, knockdown of AMPK or ULK1 in MuSCs could block the effect of myotube formation of ES.

Conclusion

NMES not only restores muscle function but also enhances myogenic activity and muscle regeneration via AMPK-ULK1 autophagy in stroke-related sarcopenia rats. Our study provides a promising strategy for the treatment of stroke-related sarcopenia.

The translational potential of this article

This study first demonstrates that NMES alleviates stroke-related sarcopenia by promoting MuSCs differentiation through AMPK-ULK1-autophagy axis. The findings reveal a novel therapeutic mechanism, suggesting that NMES can restore muscle function and enhance regeneration in stroke patients. By combining NMES with MuSCs-based therapies, this approach offers a promising strategy for clinical rehabilitation, potentially improving muscle mass and function in stroke survivors. The translational potential lies in its applicability to non-invasive, cost-effective treatments for sarcopenia, enhancing patients' quality of life.

Omic AI reveals new autophagy regulators from the Atg1 interactome in Saccharomyces cerevisiae

In Saccharomyces cerevisiae, Atg1 is a core autophagy-related (Atg) protein kinase (PK) in regulating macroautophagy/autophagy, by physically interacting with numerous other proteins, or by phosphorylating various substrates. It is unclear how many Atg1-interacting partners and substrates are also involved in regulating autophagy. Here, we conducted transcriptomic, proteomic and phosphoproteomic profiling of Atg1-dependent molecular landscapes during nitrogen starvation-triggered autophagy, and detected 244, 245 and 217 genes to be affected by ATG1 in the autophagic process at mRNA, protein, and phosphorylation levels, respectively. Based on the Atg1 interactome, we developed a novel artificial intelligence (AI) framework, inference of autophagy regulators from multi-omic data (iAMD), and predicted 12 Atg1-interacting partners and 17 substrates to be potentially functional in autophagy. Further experiments validated that Rgd1 and Whi5 are required for bulk autophagy, as well as physical interactions and co-localizations with Atg1 during autophagy. In particular, we demonstrated that 2 phosphorylation sites (p-sites), pS78 and pS149 of Whi5, are phosphorylated by Atg1 to regulate the formation of Atg1 puncta during autophagy initiation. A working model was illustrated to emphasize the importance of the Atg1-centered network in yeast autophagy. In addition, iAMD was extended to accurately predict Atg proteins and autophagy regulators from other PK interactomes, indicating a high transferability of the method. Taken together, we not only revealed new autophagy regulators from the Atg1 interactome, but also provided a useful resource for further analysis of yeast autophagy.

Sequences and Structures of Viral Proteins Linked to the Genomes (VPg) of RNA Viruses

In the mid-1970s, it was revealed that the 5' end of the RNA genome of poliovirus (PV) was covalently linked to a peptide called VPg (viral protein, genome-linked). Subsequently, VPgs have been found attached to many other viruses and even phages. This review summarizes the patterns of physicochemical properties that are conserved within the VPgs of plus-strand RNA viruses where short-peptide VPgs have been identified. Mutagenesis and structural data indicate the importance of a 5 aa conserved motif at the N-termini of picornaviral VPgs (around the tyrosine 3 residue, which forms a covalent bond to UMP and the RNA). Hidden Markov models have been used to find motifs and VPgs in additional genera of picornaviruses, as well as dicistroviruses in insects and comoviruses in plants. These latter VPgs are bound to the RNA termina through linkages to serine or threonine. The role of free VPg and VPgpU needs clarification, especially in light of multiple genome copies in many of the viruses. Lysine and other positively charged side chains are hallmarks of VPgs. These may contribute to interactions with the viral RNA, polymerase, membranes and cellular proteins. The larger protein VPgs from potyviruses and noroviruses/caliciviruses may also show some areas of similar properties to these small peptides.

Dopamine Receptor D3 Induces Transient, mTORC1-Dependent Autophagy That Becomes Persistent, AMPK-Mediated, and Neuroprotective in Experimental Models of Huntington's Disease

Huntington disease's (HD) is a neurodegenerative disorder caused by the expansion of a polyglutamine region (PolyQ) within the huntingtin protein (HTT). Mutated huntingtin (mHTT) is cytotoxic, particularly for striatal medium spiny neurons (MSNs), whose degeneration is the hallmark of HD. Autophagy inducers currently available promote the clearance of toxic proteins. However, due to their low selectivity and the possibility that prolonged autophagy hampers essential processes in unaffected cells, researchers have questioned their benefits in neurodegenerative diseases. Since MSNs express dopamine receptors D2 (DRD2) and D3 (DRD3) and DRD2/DRD3 agonists may activate autophagy, here, we explored how healthy and mHTT-challenged cells respond to prolonged DRD2/DRD3 agonist treatment. Autophagy activation and its effects on mHTT/polyQ clearance were studied in R6/1 mice (a genetic model of HD), their wild-type littermates, and DRD2- and DRD3-HEK cells expressing a pathogenic (Q74) and a non-pathogenic (Q23) polyQ fragment of mHTT treated with the DRD2/DRD3 agonist pramipexole. Two forms of DRD3-mediated autophagy were found: a transient mTORC1-dependent in WT mice and Q23-DRD3-HEK cells and a persistent AMPK-ULK1-activated in R6/1 mice and Q74-DRD3-HEK cells. This also promoted a robust clearance of soluble mHTT/polyQ and neuroprotection in striatal neurons and DRD3-HEK cells. The findings indicate that DRD3-induced autophagy may be a safe, disease-modifying intervention in HD patients.

Well-Differentiated Jejunoileal Neuroendocrine Tumors and Corresponding Liver Metastases: Mesenteric Fibrogenesis and Extramural Vascular Invasion in Tumor Progression

BACKGROUND

Patients with jejunoileal neuroendocrine tumors (JINETs) can live for many years despite liver metastases. Evidence suggests that tumor heterogeneity is prognostically important, hence the selection of Ki67 hotspots for tumor grading. According to the stepwise metastasis model, clonal hotspots should predominate in the metastases. However, an alternative view holds that the polyclonality of metastases is consistent with origin from genetically heterogeneous clusters of disseminated cells. The shortcomings of Ki67 grading are also being recognized, thus renewing the search for other prognostic parameters.

METHODS

A 20-year retrospective study that paired JINETs and hepatic metastases was conducted by analyzing them for various parameters.

RESULTS

There were 43 patients (mean follow-up of 7.234 years); 14 were dead due to the disease, 22 were alive with the disease, and 7 were alive with no evidence of the disease. Most JI NETs (22/30) were grade 1, eight were grade 2, and none were grade 3. Tumor grades for both the primaries and liver metastases were not prognostic (p-values = 0.1260 and 0.2566, respectively). Seventeen of the 41 JI NETs showed mesenteric fibrogenesis (MF), and 18 had EMVI, with a high level of agreement between these parameters (92.68%) (kappa value 0.85), and both were strongly associated with poor outcomes.

CONCLUSIONS

JINETs and their liver metastases tend to have low proliferation rates. However, an important mechanism in the metastatic cascade appears to be mesenteric fibrogenesis. It encases vessels, which enhances extramural vascular invasion, thereby conveying clusters of tumor cells to the liver. This supports the polyclonal nature of tumor progression rather than origin from hotspot aberrant clones.

Sinapic Acid Ameliorates Cadmium-Induced Hepatotoxicity: Modulation of Oxidative Stress, Inflammation, and Apoptosis

Background/Objectives: Cadmium (Cd) is a harmful metal commonly used in industry. Numerous clinical diseases, including osteomalacia, testicular damage, renal and hepatic failure, and pulmonary edema, are associated with Cd exposure. The current study evaluated the protective effect of Sinapic acid (SA) against Cd-induced hepatotoxicity by investigating different mechanistic pathways interfering with Cd-related liver injury. Methods: Forty rats were randomly assigned to four groups as follows; group 1 served as negative control and received saline, group 2 received saline for 14 days and CdCl2 (3.5 mg/kg IP) as a single dose on day 14, groups 3 and 4 were treated with SA (20, 40 mg/kg PO), respectively, for 14 days and injected with CdCl2 (3.5 mg/kg IP) on day 14. Serum was collected to evaluate liver function. Liver samples were collected for histopathological examination and the assessment of markers related to oxidative stress, inflammation, and apoptosis. Results: Acute Cd administration elevated liver enzymes and induced pathological changes in liver specimens, with the concurrent release of inflammatory markers and reduced antioxidant capabilities. Pretreatment with SA improved liver function and Cd-induced histopathological changes and elevated the activities of antioxidant enzymes. SA ameliorated inflammation, as evidenced by decreased expression of NF-κB, TNF-α, TLR-4, and COX-2, iNOS, and IL-1β levels along with suppression of mTOR, JNK, ERK, BAX, and Bcl-2. Conclusions: The present data suggest that SA represents a promising protective agent against Cd-induced hepatic injury by attenuating oxidative stress, inflammation, and apoptosis.

An Insight into Neuronal Processing of Ghrelin: Effects of a Bioactive Ghrelin Derivative on Proteolytic Pathways and Mitophagy

Protein homeostasis (proteostasis) is preserved by an orchestrated network of molecular mechanisms that regulate protein synthesis, folding, and degradation, ensuring cellular integrity and function. Proteostasis declines with age and is related to pathologies such as neurodegenerative diseases and cardiac disorders, which are accompanied by the accumulation of toxic protein aggregates. In this context, therapeutic strategies enhancing the two primary degradative systems involved in the cellular clearance of those abnormal proteins, namely ubiquitin-proteasome system and autophagy-lysosomal pathway, represent a promising approach to counteract the collapse of proteostasis in such pathological conditions. In this work, we explored the processing of ghrelin, a pleiotropic peptide hormone linked to energy metabolism and higher brain functions, which is reported to modulate the protein degradative mechanisms. According to our data, ghrelin is processed by serine hydrolases secreted into the conditioned medium of SH-SY5Y neuroblastoma cell line, commonly used in neurotoxicology and neuroscience research. Ghrelin processing leads to the formation of a shorter peptide (ghrelin(1-11)) that stimulates both the cell proteasome system and autophagy-lysosomal pathway, encompassing the selective autophagy of mitochondria. Our findings suggest that ghrelin processing may contribute to the maintenance of neuronal proteostasis.

Cu(OH)2 nanopesticide induced liver dysfunction in mice by targeting lipoylated tricarboxylic acid cycle proteins via ferredoxin 1

Copper hydroxide [Cu(OH)2] nanopesticide is an emerging agrochemical known for its ability to mitigate bacterial and fungal damage to host organisms. However, its environmental exposure and potential toxicological effects have garnered significant attention. The liver is regarded as the primary organ for copper storage and utilization within the body. Here, the potential hepatic dyshomeostasis and metabolic dysfunction resulting from exposure to Cu(OH)2 nanopesticide for a month were investigated using the C57BL/6 mouse model. The findings demonstrated that Cu(OH)2 nanopesticide induced damage to the core functions of the mouse liver, evidenced by an impaired tissue microstructure, attenuated biochemical function, as well as disturbed bile acid synthesis and energy metabolism. The regulatory manner of Cu(OH)2 nanopesticide on the lipoylated proteins in the tricarboxylic acid (TCA) cycle by targeting ferredoxin 1 (FDX1) and its associated lipoic acid and iron-sulfur pathways, also shared genetic characteristics with the recently identified cuproptosis mechanism, providing a deeper understanding of the hepatoxic effects induced by this copper nanopesticide. These findings contribute valuable data for evaluating the hepatotoxicity of Cu(OH)2 nanopesticide, and further research into the molecular mechanisms is anticipated to enhance the identification of therapeutic targets for hepatic diseases related to copper metabolism.

Effects of tianeptine on mTORC1-mediated neuronal autophagy in primary rat hippocampal neurons under nutrient deprivation

The aim of this study was to investigate the effects of the antidepressant tianeptine on the mechanistic target of rapamycin complex 1(mTORC1)-mediated autophagy pathway in primary hippocampal neurons exposed to B27-deprived conditions. When primary hippocampal neurons were treated with tianeptine at doses of 1, 10, 50, and 100 µM for 3 days under B27-deprived conditions, we observed that it activated autophagy and increased the formation of autophagosomes through the upregulation of autophagic proteins, including autophagy-activating kinase 1 (ULK1), Beclin 1, LC3B-II/I, and p62. And at a concentration of 100 µM tianeptine, the decrease in mTORC1 phosphorylation induced by B27 deprivation was significantly reversed. Changes in the expression of autophagic proteins induced by B27 deprivation were reversed by tianeptine treatment in a concentration-dependent manner, and tianeptine significantly reduced the increase in LC3B membrane number induced by B27 deprivation, an effect that was blocked by pretreatment with rapamycin. In conclusion, tianeptine attenuated the activity of mTORC1-mediated autophagy in primary rat hippocampal neurons under B27-deprived conditions. These results may suggest a novel mechanism by which tianeptine may affect autophagy in neurons.

Effects of bacterial fertilizer and soil amendment on Spuriopinella brachycarpa (Kom.) Kitag. growth and soil microbiota

Introduction

Spuriopinella brachycarpa (Kom.) Kitag. is a nutritious wild vegetable, but its quality deteriorates during artificial cultivation due to soil condition alterations. Microbial fertilizers and soil amendments hold promise for improving cultivation outcomes, yet their combined effects remain under - explored.

Methods

A field experiment was conducted with seven treatments, including a control (CK) and six combinations of Trichoderma harzianum, Bacillus subtilis, and earthworm polysaccharide. Plant samples were analyzed for yield, quality, and root architecture, while soil samples were tested for fertility and microbial community characteristics.

Results

Treatments T3 (dual bacterial fertilizers) and T6 (dual bacterial fertilizers + soil amendment) significantly enhanced yield, nutritional quality, and root development. T6 also maintained high soil fertility and optimized the soil microbial community in terms of richness, diversity, and beneficial species abundance.

Discussion

The positive effects of T3 and T6 are likely due to the synergy between the bacterial fertilizers and the soil amendment, which improves nutrient cycling, soil structure, and microbial functions. However, the study has limitations, such as the need for long - term research and more in - depth exploration of microbial functions.

Extracellular matrix mechanical cues (dys)regulate metabolic redox homeostasis due to impaired autophagic flux

BACKGROUND

Extracellular matrix (ECM) stiffness is increasingly recognized as a critical regulator of cellular behaviour, governing processes such as proliferation, differentiation, and metabolism. Neurodegenerative diseases are characterized by mitochondrial dysfunction, oxidative stress, impaired autophagy, and progressive softening of the brain tissue, yet research into how mechanical cues influence cellular metabolism in this context remains scarce.

MATERIALS AND METHODS

In this study, we evaluated the long-term effects of brain-compliant, soft ECM on mitochondrial bioenergetics, redox balance, and autophagic capacity in human neuroblastoma (SH-SY5Y) and mouse hippocampal (HT22) cell lines, as well as primary mouse neurons.

RESULTS

We observed that prolonged exposure to soft ECM does not impact cell proliferative capacity of neuronal cells but results in mitochondrial bioenergetic dysfunction, redox imbalance, and disrupted autophagic flux. These findings were consistently validated across both human and mouse neuronal cells. Our data indicate a decreased maximal autophagic capacity in cells exposed to long-term soft ECM, potentially due to an imbalance in autophagosome formation and degradation, as demonstrated by decreased LC3 II levels following chloroquine-induced autophagic flux inhibition. This impairment in autophagy was coupled with increased cellular oxidative stress, further indicating metabolic alterations.

CONCLUSIONS

These findings emphasize the critical role of ECM stiffness in regulating neuronal cell metabolism and suggest that prolonged exposure to soft ECM may mimic key aspects of neurodegenerative disease pathology, thereby enhancing the physiological relevance of in vitro models. This study underscores the necessity for further research into ECM mechanics as a contributing factor in neurodegenerative disease progression and as a potential target for therapeutic strategies.

SLC7A11 is an unconventional H+ transporter in lysosomes

Lysosomes maintain an acidic pH of 4.5-5.0, optimal for macromolecular degradation. Whereas proton influx is produced by a V-type H+ ATPase, proton efflux is mediated by a fast H+ leak through TMEM175 channels, as well as an unidentified slow pathway. A candidate screen on an orphan lysosome membrane protein (OLMP) library enabled us to discover that SLC7A11, the protein target of the ferroptosis-inducing compound erastin, mediates a slow lysosomal H+ leak through downward flux of cystine and glutamate, two H+ equivalents with uniquely large but opposite concentration gradients across lysosomal membranes. SLC7A11 deficiency or inhibition caused lysosomal over-acidification, reduced degradation, accumulation of storage materials, and ferroptosis, as well as facilitated α-synuclein aggregation in neurons. Correction of abnormal lysosomal acidity restored lysosome homeostasis and prevented ferroptosis. These studies have revealed an unconventional H+ transport conduit that is integral to lysosomal flux of protonatable metabolites to regulate lysosome function, ferroptosis, and Parkinson's disease (PD) pathology.

Diallyl Disulfide Reduces Ethyl Carbamate-Induced Cytotoxicity and Apoptosis in Intestinal and Hepatic Cells

Epidemiological studies indicate that lifestyle and dietary habits are associated with an increasing cancer incidence. Consuming fermented foods and alcoholic beverages and smoking can expose humans to ethyl carbamate (EC), a probable human carcinogen classified as group 2A by the International Agency for Research on Cancer (IARC). Increasing the intake of bioactive compounds can reduce EC-induced toxicity. Diallyl disulfide (DADS), found in garlic, may protect against damage induced by chemical agents and natural compounds. Here, the potential protective effect of DADS against EC was investigated by evaluating EC-induced cytotoxicity, DNA damage, apoptosis, and reactive oxygen species production in colorectal adenocarcinoma (Caco-2) and hepatocarcinoma (HepG2) cells. To this end, resazurin, comet, and annexin V-FITC staining assays and CM-H2DCFDA markers were used to evaluate the effect on Caco-2 and HepG2 cells of protocols combining DADS (10-120 μM) and EC (80 mM). The protocols were as follows: (i) cells pretreated with DADS for 2 h and exposed to EC for 24 h; (ii) cells pretreated with DADS for 24 h and exposed to EC for 24 h; (iii) cells simultaneously exposed to DADS and EC for 24 h; (iv) cells exposed to EC for 24 h and treated with DADS for 2 h. EC induced cytotoxicity and apoptosis in Caco-2 and HepG2 cells and oxidative damage in Caco-2 cells. Combined exposure to DADS and EC for 24 h decreased EC-mediated cytotoxicity and apoptosis in both Caco-2 and HepG2 cells. These findings encourage further studies on the mechanisms of action of the combined DADS and EC.

RNA Methylation and Transcriptome Analysis Reveal Key Regulatory Pathways Related to Cadmium-Induced Liver Damage

Cadmium (Cd) is a prevalent environmental and industrial contaminant that causes significant damage to liver function. However, the role of m6A methylation─a critical epigenetic modification─in Cd-induced liver injury remains poorly understood. This study aimed to investigate the effects of m6A methylation in Cd-induced liver damage. A mouse model of Cd-induced liver injury was established, and exposure to CdCl2 (20 mg/kg) for 90 days resulted in reduced m6A methylation levels. Using methylated RNA immunoprecipitation sequencing (MeRIP-seq) and RNA sequencing (RNA-Seq), we characterized the m6A methylation profiles in both control and Cd-exposed groups. A total of 8355 unique m6A peaks and 1,101 unique m6A-modified genes were identified. Among these, 673 genes exhibited differential m6A methylated modifications, including 463 hyper-methylated and 210 hypo-methylated genes. Conjoint analysis of MeRIP-seq and RNA-Seq data unveiled genes that showed both differential methylation and expression. These genes were significantly enriched in the AGE-RAGE and PI3K-Akt signaling pathway. Through bioinformatics screening, five key genes (Il-1β, Ccl2, Tlr2, Itgax, and Ccr2) were identified, and expression validation indicated that Itgax and Ccr2 may play pivotal roles in Cd-induced liver injury. Notably, elevated expression of methyltransferase-like 14 (METTL14) was observed in both in vivo and in vitro models. Inhibition of Mettl14 can regulate Cd-induced liver inflammation through m6A-dependent regulation of Ccr2 expression. Collectively, our findings highlight the crucial role of Mettl14 and Ccr2 in Cd-induced liver injury, providing novel insights into the epigenetic mechanisms underlying liver diseases and potential biomarkers for diagnosis and therapy.

Promising roles of vitamin D receptor and APRO family proteins for the development of cancer stem cells targeted malignant tumor therapy

Malignant tumors are heterogeneous diseases characterized by uncontrolled cell proliferation, invasion, metastasis, and/or recurrence of their malignancies. In particular, cancer stem cells (CSCs) within these tumors might be responsible for the property of invasiveness and/or therapies-resistance. CSCs are a self-renewing, awfully tumorigenic subpopulation of cancer cells, which are notorious for strong chemoresistance and are frequently responsible the aggravated invasion, metastasis, and/or recurrence. Developing targeting therapies against CSCs, therefore, may be deliberated a more encouraging mission for the greater cancer therapy. Innovation for a more potent anti-CSC treatment has been required as soon as possible. Interestingly, vitamin D could modulate the inflammatory condition of the tumor microenvironment (TME) by successfully affecting CSCs, which has an imperative role in determining the malignant phenotype of CSCs. In addition, vitamin D may also contribute to the regulation of the malignant behaviors of CSCs. Consistently, vitamin D could have potential applications for the significant inhibition of several tumor growths within various cancer therapies. The biological significance of vitamin D for CSCs regulation may be involved in the function of APRO family proteins. Therefore, vitamin D could be one of the innovative therapeutic modalities for the development of novel CSCs related tumor therapies.

Outcome of Debulking the Mesenteric Mass in Symptomatic Patients with Locally Advanced Small Intestine Neuroendocrine Tumors

BACKGROUND

Approximately 10% of patients with small intestine neuroendocrine neoplasms (SI-NENs) present with locally advanced, unresectable symptomatic disease. The present study analyzed the results of debulking of the mesenteric mass in such patients.

METHODS

Patients operated on for locally advanced SI-NEN disease were identified from the prospective database of the ENETS Center of Excellence Marburg based on the review of imaging results and operative notes. "Locally advanced" was defined as mesenteric disease involving the mesenteric root above the level of the horizontal part of the duodenum and/or extending into the retroperitoneum. Patient characteristics, operations, and outcomes were retrospectively analyzed.

RESULTS

29 of 202 (14%) operated SI-NEN patients (79% male) operated on, with a median age of 63 (46-78) years, had symptomatic locally advanced disease and presented with either abdominal pain (76%) and/or symptoms of obstruction (38%). Imaging revealed a mesenteric mass >10 mm above the level of the pars descendens duodeni in 15 (52%) patients, with tumor-related obstruction of the superior mesenteric vein in 17 (59%) patients. Fourteen (48%) patients had had previous surgery with primary tumor resection (n = 10) or diagnostic or bypass procedures (n = 4). Debulking of the mesenteric mass with (n = 26) or without (n = 2) bowel resection was performed 28 patients; the remaining patient underwent only resection of the ischemic bowel. Median operating time was 262 (156-411) minutes. Four (14%) patients had clinically relevant postoperative complications; one patient died perioperatively. A total of 27/29 (93%) patients reported improvement in preoperative abdominal symptoms. After a median follow-up of 28 (1-142) months, 21 (72%) patients were alive with disease.

CONCLUSIONS

Debulking of the mesenteric mass in locally advanced symptomatic SI-NENs is a challenging procedure, but most patients benefit in terms of bowel symptoms.

Methylmercury Chloride Exposure Affects Oocyte Maturation Through AMPK/mTOR-Mediated Mitochondrial Autophagy

Mercury, a prevalent heavy metal, negatively impacts oocyte maturation. However, the exact mechanism by which methylmercury chloride (MMC) affects this process remains elusive. The present study found that MMC administration triggered meiotic failure in oocytes by disrupting cumulus cell expansion, leading to compromised spindle apparatus and altered chromosomal architecture, which are crucial for oocyte development. This disruption is characterized by abnormal microtubule organization and defective chromosome alignment. Additionally, MMC exposure caused oxidative stress-induced apoptosis due to mitochondrial dysfunction, as indicated by decreased mitochondrial membrane potential, mitochondrial content, mitochondrial DNA copy number, and adenosine triphosphate levels. Proteomic analysis identified 97 differentially expressed proteins, including P62, an autophagy marker. Our results confirmed that MMC induced autophagy, particularly through the hyperactivation of the mitochondrial autophagy to remove damaged and normal mitochondria. The mitochondrial reactive oxygen species (ROS) scavenger Mito-TEMPO alleviated oxidative stress and mitochondrial autophagy levels, suggesting that mitochondrial ROS initiates this autophagic response. Notably, MMC activates mitochondrial autophagy via the monophosphate-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) signal pathway due to mitochondrial dysfunction. In vivo studies in mice revealed that MMC exposure decreased reproductive performance, attributed to excessive mitochondrial autophagy leading to reduced oocyte quality. Overall, these findings demonstrate that MMC exposure impairs oocyte maturation via the hyperactivation of mitochondrial autophagy induced by mitochondrial dysfunction.

The presence of a fat layer after neoadjuvant chemotherapy as an indicator of prognosis in osteosarcoma

Objective

This study aimed to evaluate the potential of magnetic resonance imaging (MRI) to monitor the response in patients with osteosarcoma receiving chemotherapy and to assess the correlation between the presence of a fat layer surrounding the tumor after neoadjuvant chemotherapy and prognosis.

Methods

In total, 28 patients with osteosarcoma were included in this retrospective study. All patients underwent chemotherapy and surgery. MRI scans of the patients were evaluated before and after neoadjuvant chemotherapy. The prognostic factors included histological response and alkaline phosphatase (ALP) level. Relapse and survival at follow-up were defined as patient outcomes. The log-rank test was used to compare these factors with various MRI characteristics (e.g. change in maximum lesion length before and after chemotherapy, change in maximum edema, and fat layer presence after chemotherapy).

Results

The median time of follow-up was 64.3 ± 41.5 months. The 3- and 5-year event-free survival rates were 75.0% and 67.9%, respectively. ALP levels after chemotherapy were associated with tumor necrosis (p = 0.01). Change in maximum lesion length [p = 0.044; odds ratio (OR) = 0.035; confidence interval (CI): 0.01-0.911] was a predictor of survival. Changes in edema on T2-weighted sequences (p = 0.979; OR = 0.989, CI: 0.437-2.242) were not significant. The presence of a fat layer (p = 0.013; OR = 0.000; confidence CI: 0.000-0.018) predicted good event-free survival.

Conclusions

The presence of a fat layer correlated with good prognosis in patients with osteosarcoma. MRI characteristics in the early stages could help to inform decision-making about treatment strategy.

Autophagy in adult stem cell homeostasis, aging, and disease therapy

Autophagy is a crucial cellular process that facilitates the degradation of damaged organelles and protein aggregates, and the recycling of cellular components for the energy production and macromolecule synthesis. It plays an indispensable role in maintaining cellular homeostasis. Over recent decades, research has increasingly focused on the role of autophagy in regulating adult stem cells (SCs). Studies suggest that autophagy modulates various cellular processes and states of adult SCs, including quiescence, proliferation, self-renewal, and differentiation. The primary role of autophagy in these contexts is to sustain homeostasis, withstand stressors, and supply energy. Notably, the dysfunction of adult SCs during aging is correlated with a decline in autophagic activity, suggesting that autophagy is also involved in SC- and aging-associated disorders. Given the diverse cellular processes mediated by autophagy and the intricate mechanisms governing adult SCs, further research is essential to elucidate both universal and cell type-specific regulatory pathways of autophagy. This review discusses the role of autophagy in regulating adult SCs during quiescence, proliferation, self-renewal, and differentiation. Additionally, it summarizes the relationship between SC aging and autophagy, providing therapeutical insights into treating and ameliorating aging-associated diseases and cancers, and ultimately promoting longevity.

GRAMD1B is a regulator of lipid homeostasis, autophagic flux and phosphorylated tau

Lipid dyshomeostasis and tau pathology are present in frontotemporal lobar degeneration (FTLD) and Alzheimer's disease (AD). However, the relationship between lipid dyshomeostasis and tau pathology remains unclear. We report that GRAM Domain Containing 1B (GRAMD1B), a nonvesicular cholesterol transporter, is increased in excitatory neurons of human neural organoids (HNOs) with the MAPT R406W mutation. Human FTLD, AD cases, and PS19 tau mice also have increased GRAMD1B expression. We show that overexpression of GRAMD1B increases levels of free cholesterol, lipid droplets, and impairs autophagy flux. Modulating GRAMD1B in iPSC-derived neurons also alters key autophagy-related components such as PI3K, phospho-AKT, and p62, as well as phosphorylated tau, and CDK5R1. Blocking GRAMD1B function decreases free cholesterol and lipid droplets. Knocking down GRAMD1B additionally reduces phosphorylated tau, and CDK5R1 expression. Our findings elucidate the role of GRAMD1B in the nervous system and highlight its relevance to FTLD and AD.

Steroid Signaling in Autophagy

Autophagy is a conserved cellular process essential for homeostasis and development that plays a central role in the degradation and recycling of cellular components. Recent studies reveal bidirectional interactions between autophagy and steroid-hormone signaling. Steroids are signaling molecules synthesized from cholesterol that regulate key physiological and developmental processes - including autophagic activity. Conversely, other work demonstrates that autophagy regulates steroid production by controlling the availability of precursor sterol substrate. Insights from Drosophila and mammalian models provide compelling evidence for the conservation of these mechanisms across species. In this review we explore how steroid hormones modulate autophagy in diverse tissues and contexts, such as metabolism and disease, and discuss advances in our understanding of autophagy's regulatory role in steroid hormone production. We examine the implications of these interactions for health and disease and offer perspectives on the potential for harnessing this functionality for addressing cholesterol-related disorders.

Menin-MLL1 complex cooperates with NF-Y to promote HCC survival

Identification of new therapeutic targets in hepatocellular carcinoma (HCC) remains critical. Chromatin regulating complexes are frequently mutated or aberrantly expressed in HCC, suggesting dysregulation of chromatin environments is a key feature driving liver cancer. To investigate whether the altered chromatin state in HCC cells could be targeted, we designed and utilized an epigenome-focused CRISPR library that targets genes involved in chromatin regulation. This focused approach allowed us to test multiple HCC cell lines in both 2D and 3D growth conditions, which revealed striking differences in the essentiality of genes involved in ubiquitination and multiple chromatin regulators vital for HCC cell survival in 2D but whose loss promoted growth in 3D. We found the core subunits of the menin-MLL1 complex among the strongest essential genes for HCC survival in all screens and thoroughly characterized the mechanism through which the menin-MLL1 complex promotes HCC cell growth. Inhibition of the menin-MLL1 interaction led to global changes in occupancy of the complex with concomitant decreases in H3K4me3 and expression of genes involved in PI3K/AKT/mTOR signaling pathway. Menin inhibition affected chromatin accessibility in HCC cells, revealing that increased chromatin accessibility at sites not bound by menin-MLL1 was associated with the recruitment of the pioneer transcription factor complex NF-Y. A CRISPR/Cas9 screen of chromatin regulators in the presence of menin inhibitor SNDX-5613 revealed a significantly increased cell death when combined with NFYB knockout. Together these data show that menin-MLL1 is necessary for HCC cell survival and cooperates with NF-Y to regulate oncogenic gene transcription.

Roles of anoikis in hepatocellular carcinoma therapy and the assessment of anoikis-regulatory molecules as therapeutic targets

As the fourth leading cause of death from cancer and the sixth most common neoplasm in the world, hepatocellular carcinoma (HCC) is responsible for ninety percent of all primary liver cancers. There are four mechanisms that contribute to the spread of cancer: the separation of cells from the primary neoplasm, their survivability during metastasis, extravasation, and the development of secondary tumors at remote locations. In addition to its role in the development of a scaffold for cell adhesion, the extracellular matrix (ECM) also plays a role in the stimulation of signal transduction and the regulation of essential cellular mechanisms, including proliferation, migration, differentiation, and viability. The disruption of cell-ECM interactions and the ensuing separation of cells from the primary ECM trigger anoikis, a form of programmed cell death. One of the most effective factors in suppressing anoikis is ECM receptors from the integrin family. Cell migration, proliferation, and survival are primarily governed by the formation of physical connections with the cytoskeleton and the conveyance of signals between cells and the ECM via integrin receptors.

The role of autophagy in ischemic brain injury

Ischemic brain injury occurs in many clinical settings, including stroke, cardiac arrest, hypovolemic shock, cardiac surgery, cerebral edema, and cerebral vasospasm. Decades of work have revealed many important mechanisms related to ischemic brain injury. However, there remain significant gaps in the scientific knowledge to reconcile many ischemic brain injury events. Brain ischemia leads to protein misfolding and aggregation, and damages almost all types of subcellular organelles including mitochondria, endoplasmic reticulum, Golgi apparatus, lysosomes, etc. Irreparably damaged organelles and insoluble protein aggregates are normally removed by autophagy. The build-up of common autophagic components, such as LC3, p62, and ubiquitinated proteins, are generally observed in brain tissue samples in animal models of both global and focal brain ischemia, but the interpretation of the role of these autophagy-related changes in ischemic brain injury in the literature has been controversial. Many pathological events or mechanisms underlying dysfunctional autophagy after brain ischemia remain unknown. This review aims to provide an update of the current knowledge and future research directions regarding the critical role of dysfunctional autophagy in ischemic brain injury.

Low extracellular pH protects cancer cells from ammonia toxicity

Ammonia is a natural waste product of cellular metabolism which, through its lysosomotropic ability, can have detrimental effects on various cellular functions. Increased levels of ammonia were recently detected in the interstitial fluid of various tumours, substantiating that high ammonia concentrations are a pathophysiological condition in the tumour microenvironment, alongside hypoxia and acidosis. Since little is known about how cancer cells respond to elevated levels of ammonia in the tumour microenvironment, we investigated how a panel of cancer cell lines derived from solid tumours behaved when exposed to increasing concentrations of ammonia. We found that ammonia represses cell growth, induces genome instability, and inhibits lysosome-mediated proteolysis in a dose-dependent manner. Unexpectedly, we also found that small fluctuations in the pH of the extracellular environment, had a significant impact on the cytotoxic effects of ammonia. In summary, our data show that the balance of pH and ammonia within the interstitial fluids of cancerous tumours significantly impacts the behaviour and fate of cells residing in the tumour microenvironment.

Advancements in Osteosarcoma Therapy: Overcoming Chemotherapy Resistance and Exploring Novel Pharmacological Strategies

Osteosarcoma is recognized as the most prevalent primary bone malignancy, primarily affecting children and adolescents. It is characterized by its aggressive behavior and high metastatic potential, which often leads to poor patient outcomes. Despite advancements in surgical techniques and chemotherapy regimens, the prognosis for patients with osteosarcoma remains unsatisfactory, with survival rates plateauing over the past few decades. A significant barrier to effective treatment is the development of chemotherapy resistance, which complicates the management of the disease and contributes to high rates of recurrence. This review article aims to provide a comprehensive overview of recent advancements in osteosarcoma therapy, particularly in overcoming chemotherapy resistance. We begin by discussing the current standard treatment modalities, including surgical resection and conventional chemotherapy agents such as methotrexate, doxorubicin, and cisplatin. While these approaches have been foundational in managing osteosarcoma, they are often limited by adverse effects and variability in efficacy among patients. To address these challenges, we explore novel pharmacological strategies that aim to enhance treatment outcomes. This includes targeted therapies focusing on specific molecular alterations in osteosarcoma cells and immunotherapeutic approaches designed to harness the body's immune system against tumors. Additionally, we review innovative drug delivery systems that aim to improve the bioavailability and efficacy of existing treatments while minimizing toxicity. The review also assesses the mechanisms underlying chemotherapy resistance, such as drug efflux mechanisms, altered metabolism, and enhanced DNA repair pathways. By synthesizing current research findings, we aim to highlight the potential of new therapeutic agents and strategies for overcoming these resistance mechanisms. Ultimately, this article seeks to inform future research directions and clinical practices, underscoring the need for continued innovation in treating osteosarcoma to improve patient outcomes and survival rates.

A non-fluorescent immunohistochemistry method for measuring autophagy flux using MAP1LC3/LC3 and SQSTM1 as core markers

Macroautophagy/autophagy is a crucial cellular process for degrading and recycling damaged proteins and organelles, playing a significant role in diseases such as cancer and neurodegeneration. Evaluating autophagy flux, which tracks autophagosome formation, maturation, and degradation, is essential for understanding disease mechanisms. Current fluorescence-based methods are resource-intensive, requiring advanced equipment and expertise, limiting their use in clinical laboratories. Here, we introduce a non-fluorescent immunohistochemistry (IHC) method using MAP1LC3/LC3 and SQSTM1 as core markers for autophagy flux assessment. LC3 levels reflect autophagosome formation, whereas SQSTM1 degradation and a decrease in the number of its puncta indicate active flux (i.e., lysosomal turnover). We optimized chromogenic detection using diaminobenzidine (DAB) staining and developed a scoring system based on puncta number and the percentage of stained cells. This accessible, cost-effective method enables reliable autophagy quantification using a standard light microscope, bridging the gap between experimental research and clinical diagnostics. Our protocol allows accurate autophagy evaluation in fixed tissues, offering practical applications in biomedical research and clinical pathology assessment.

High throughput screening assay for the identification of ATF4 and TFEB activating compounds

Macrophages act to defend against infection, but can fail to completely prevent bacterial replication and dissemination in an immunocompetent host. Recent studies have shown that activation of a host transcription factor, TFEB, a regulator of lysosomal biogenesis, could restrict intramacrophage replication of the human pathogen Mycobacterium tuberculosis and synergize with suboptimal levels of the antibiotic rifampin to reduce bacterial loads. Currently available small molecule TFEB activators lack selectivity and potency, but could be potentially useful in a variety of pathological conditions with suboptimal lysosomal activity. TFEB nuclear translocation and activation depend on its phosphorylation status which is controlled by multiple cellular pathways. We devised a whole cell, high throughput screening assay to identify small molecules that activate TFEB by establishing a stably transfected HEK293T reporter cell line for ATF4, a basic leucine zipper transcription factor induced by stress response and activated in parallel to TFEB. We optimized its use in vitro using compounds that target endoplasmic reticulum stress and intracellular calcium signaling. We report results from screening the commercially available LOPAC library and the Selleck Chemicals library modified to include only FDA-approved drugs and clinical research compounds. We identified twenty-one compounds across six clinical use categories that activate ATF4, and confirmed that two proteasome inhibitors promote TFEB activation. The results of this study provide an assay that could be used to screen for small molecules that activate ATF4 and TFEB and a potential list of compounds identified as activators of the ATF4 transcription factor in response to cellular stress.

Prognostic value of clinical parameters and exosomal lncRNA NEAT1_1 in MEN1-related non-functioning pancreatic neuroendocrine tumors

Non-functioning pancreatic neuroendocrine tumors (NF-pNETs) significantly contribute to the premature death of multiple endocrine neoplasia type 1 (MEN1) patients. Reliable prognostic markers are not yet available. MicroRNAs (miRNA) and long-non-coding (lnc) RNAs, transported by extracellular vesicles, are emerging as new prognostic tools. This study aimed to analyze the clinical characteristics, the exosomal-miRNA 451 (exo-miR451) and the lnc-RNA nuclear paraspeckle assembly transcript 1 (NEAT1_1, 3.7 kB) in the mild and aggressive courses of MEN1-NFpNET disease. Patient characteristics were assessed regarding an aggressive course of disease. In addition, exo-miR451 and exo-lnc-NEAT1_1 expression levels were quantified in serum by RT-qPCR and correlated with clinical data. Immunohistochemistry results of STAT3 (signal transducer and activator of transcription 3), regulated by NEAT1, were performed in NF-pNET tissue and correlated with exo-lnc-NEAT1_1 expression. Among 66 MEN1 patients with NF-pNETs, 13 (20%) had an aggressive disease course. No significant differences in patient characteristics were observed between those with aggressive (n = 13) and mild (n = 53) disease (all p > .5). Exosomal miRNA-451 was dysregulated in 55% (n = 23) of cases, showing a trend toward higher upregulation in the aggressive group (36% vs. 19%), although this difference was not statistically significant (p = .215). Exo-NEAT1_1 was overexpressed in 42% (16/38) of patients, without significant differences between groups (p = .0523). However, exo-NEAT1_1 expression strongly correlated with STAT3 immunohistochemical staining (p = .001). Although no prognostic marker could be identified, we show for the first time that the STAT3-NEAT1 pathway plays a role in MEN1-associated NF-pNET tumorigenesis.

USP4 depletion-driven RAB7A ubiquitylation impairs autophagosome-lysosome fusion and aggravates periodontitis

Periodontitis, a prevalent and chronic inflammatory disease, is intricately linked with macroautophagy/autophagy, which has a dual role in maintaining periodontal homeostasis. Despite its importance, the precise interplay between autophagy and periodontitis pathogenesis remains to be fully elucidated. In this study, our investigation revealed that the ubiquitination of RAB7A, mediated by reduced levels of the deubiquitinating enzyme USP4 (ubiquitin specific peptidase 4), disrupts normal lysosomal trafficking and autophagosome-lysosome fusion, thereby contributing significantly to periodontitis progression. Specifically, through genomic and histological analysis of clinical gingival samples, we observed a decreased RAB7A expression and impaired autophagic activity in periodontitis. This was further substantiated through experimental periodontitis mice, where RAB7A inactivation was shown to directly affect autophagy efficiency and drive periodontitis progression. Next, we explored the function of active RAB7A to promote lysosomal trafficking dynamics and autophagosome-lysosome fusion, which was inhibited by RAB7A ubiquitination in macrophages stimulated by Porphyromonas gingivalis (P. g.), one of the keystone pathogens of periodontitis. Last, by proteomics analysis, we revealed that the ubiquitination of RAB7A was mediated by USP4 and validated that upregulation of USP4 could attenuate periodontitis in vivo. In conclusion, these findings highlight the interaction between USP4 and RAB7A as a promising target for therapeutic intervention in managing periodontal diseases.Abbreviation: 3-MA: 3-methyladenine; Baf A1:bafilomycin A1; BECN1: beclin 1, autophagy related; CEJ-ABC: cementoenamel junctionto alveolar bone crest; IL1B/IL-1β: interleukin 1 beta; KD:knockdown; LPS: lipopolysaccharide; MOI: multiplicity of infection;OE: overexpression; P.g.: Porphyromonasgingivalis; RILP: Rabinteracting lysosomal protein; ScRNA-seq: single-cell RNA sequencing; SQSTM1/p62: sequestosome 1; S.s.: Streptococcus sanguinis; USP4:ubiquitin specific peptidase 4.

Cellular senescence and glaucoma

Cellular senescence, a characteristic feature of the aging process, is induced by diverse stressors. In recent years, glaucoma has emerged as a blinding ocular disease intricately linked to cellular senescence. The principal pathways implicated are oxidative stress, mitochondrial dysfunction, DNA damage, autophagy impairment, and the secretion of various senescence- associated secretory phenotype factors. Research on glaucoma-associated cellular senescence predominantly centers around the increased resistance of the aqueous humor outflow pathway, which is attributed to the senescence of the trabecular meshwork and Schlemm's canal. Additionally, it focuses on the mechanisms underlying retinal ganglion cell senescence in glaucoma and the corresponding intervention measures. Given that cell senescence represents an irreversible phase preceding cell death, an in-depth investigation into its mechanisms in the pathogenesis and progression of glaucoma, particularly by specifically blocking the signal transduction of cell senescence, holds the potential to decrease the outflow resistance of aqueous humor. This, in turn, could provide a novel avenue for safeguarding the optic nerve in glaucoma.

Characterisation of autophagy induction by the thiopurine drugs azathioprine, mercaptopurine and thioguanine in THP-1 macrophages

Activating autophagy may be therapeutically beneficial, and we have previously shown that azathioprine (AZA), an immunomodulatory drug, induces autophagy. Here, we evaluated the induction of autophagy by the thiopurines AZA, mercaptopurine (6-MP) and thioguanine (6-TG) in THP-1 macrophages and investigated the mechanism of action in the context of this cellular process. The cytotoxicity of thiopurines was evaluated using an LDH assay. Induction of endogenous LC3 by thiopurines was evaluated using immunostaining. To confirm autophagy activation by thiopurines, a GFP-RFP-LC3 reporter plasmid was used to monitor the maturation of autophagosomes to autolysosomes. Induction of apoptosis by thiopurines was evaluated using Annexin V/PI staining, and ER stress was assessed via RT‒PCR analysis of XBP1 splicing. To gain insight into the mechanism of action of thiopurines, mTORC1 activity and eIF2α-S51 phosphorylation were evaluated by immunoblotting. Thiopurines were not cytotoxic to cells and induced strong time- and concentration-dependent autophagy. Thiopurines activate autophagy with complete progression through the pathway. Induction of autophagy by thiopurines occurred independently of apoptosis and ER stress. Immunoblotting revealed that AZA inhibited mTORC1 activity, and AZA and 6-TG increased eIF2α-S51 phosphorylation. In contrast, 6-MP had a minor effect on either signalling pathway. Thiopurines are strong inducers of autophagy, and autophagy induction should be considered among the mechanisms responsible for patient response to thiopurines.

Ciprofol reduces postoperative glioma recurrence by promoting MAPK11-PML phosphorylation: insights from transcriptomic and proteomic analysis

BACKGROUND

Glioma, the most common malignant tumor of the central nervous system, has a high postoperative recurrence rate. While Ciprofol is widely used as an anesthetic, its therapeutic potential in glioma treatment remains largely unexplored.

METHODS

Glioma T98G cells were treated with varying concentrations of Ciprofol to assess proliferation, invasion, migration, and apoptosis via CCK-8, Transwell, and flow cytometry assays. Proteomic, phosphoproteomic, and transcriptomic analyses were performed to identify molecular targets and pathways. Molecular docking evaluated the binding of Ciprofol to key kinases, and silencing experiments validated their roles. In vivo, glioma mouse models were used to assess postoperative recurrence via tumor size, fluorescence imaging, and histological analysis.

RESULTS

Ciprofol inhibited glioma cell proliferation, invasion, and migration while promoting apoptosis. Proteomic analyses identified MAPK11 and PML as key mediators of Ciprofol's effects. Silencing MAPK11 impaired these effects, while in vivo experiments showed reduced postoperative recurrence via MAPK11-PML phosphorylation.

CONCLUSION

Ciprofol reduces postoperative glioma recurrence by promoting MAPK11-PML phosphorylation, providing novel molecular targets for glioma treatment and suggesting its therapeutic potential beyond anesthesia.

Oxidized protein aggregate lipofuscin impairs cardiomyocyte contractility via late-stage autophagy inhibition

Aging of the heart is accompanied by impairment of cardiac structure and function. At molecular level, autophagy plays a crucial role in preserving cardiac health. Autophagy maintains cellular homeostasis by facilitating balanced degradation of cytoplasmic components including organelles and misfolded or aggregated proteins. The age-related decline in autophagy favors an accumulation of protein aggregates such as lipofuscin particularly in the heart, which is composed primarily of non-proliferating cells. Therefore, this study investigates whether lipofuscin accumulation contributes to age-related functional decline of primary adult cardiomyocytes isolated from C57BL/6J mice and examines the role of autophagic flux in mediating these effects. Results showed an age-associated reduction in cardiomyocyte contraction amplitude and an increase in autofluorescence, indicating the accumulation of lipofuscin with age. In vitro treatment of adult primary cardiomyocytes with artificial lipofuscin increased autofluorescence and decreased both contraction amplitude and cellular autophagic flux. Induction of autophagy with rapamycin mitigated contractile dysfunction in lipofuscin-treated cardiomyocytes, whereas inhibition of autophagic flux revealed stage-dependent effects. Late-stage autophagy inhibition using chloroquine or concanamycin A reduced cardiomyocyte contraction amplitude, whereas early-stage autophagy inhibition via 3-methyladenine did not affect contraction within 24 h. In conclusion, our results indicate that lipofuscin directly impairs cardiomyocyte function by diminishing late-stage autophagic flux. These findings highlight the essential role of the autophagy-lysosomal system in preserving age-related loss of cardiomyocyte function caused by accumulating protein aggregates.

Chaperone mediated autophagy modulates microglia polarization and inflammation via LAMP2A in ischemia induced spinal cord injury

Spinal cord injury (SCI)-induced ischemic delayed paralysis is one of the most serious side effects of aneurysms surgeries. Recent studies prove that the activation of autophagy, including macroautophagy and micro-autophagy pathways, occur during SCI-induced brain neuron damage. However, the role of chaperone mediated autophagy (CMA) during SCI remains to be unveiled. In the present work, rat model of delayed paralysis after aneurysms operation and adenovrius induced LAMP2A knockdown in microglia cells were applied in the present work to investigate the involvement of LAMP2A-mediated CMA in the aneurysm operation related SCI and delayed paralysis. The results showed that LAMP2A was upregulated in the SCI procedure, and contributed to neuron death and pro-inflammation perturbation via inducing iNOS+ polarization in microgila. We additionally observed that knockdown of LAMP2A resulted in the shift of microglia from iNOS+ to ARG1+ phenotype, as well as alleviated neuron damage during SCI. Furthermore, the analysis of BBB score, the result of immunohistological staining, and protein detection confirmed the activation of LAMP2A-mediated CMA activation and its interaction with NF-κB signaling, which leads to neuron death and motor function loss. These results prove that LAMP2A-mediated CMA contributes to the upregulation of pro-inflammatory cytokines and results in cell death in neurons during ischemic delayed paralysis via activating NF-κB signaling. Inhibition of LAMP2A promotes neurons survival during ischemic delayed paralysis.

Mechanism and application of HDAC inhibitors in the treatment of hepatocellular carcinoma

Hepatoma is the sixth most malignant tumor in the world and the second leading cause of cancer death. Among the types of hepatoma, hepatocellular carcinoma (HCC) is the most important pathological type. For patients with early-stage HCC, the curative treatment is tumor resection. However, early diagnosis and treatment of HCC are difficult; the disease progresses rapidly, and the prognosis is poor. Due to the current limited treatment options for advanced HCC, the identification of new targeted agents is critical for the development of novel approaches to HCC treatment. Histone deacetylases (HDACs) is a protease that removes acetyl groups from histone lysine residues in proteins, and it plays an important role in the structural modification of chromosomes and the regulation of gene expression. Abnormally expressed HDACs can promote tumorigenesis by inducing biological processes such as cell proliferation, migration, and apoptosis inhibition. Since HDACs activity is upregulated in HCC, treatment regimens specifically inhibiting various HDACs have shown good efficacy. This article reviews the application of HDAC inhibitors in the treatment of HCC and explains their mechanisms of action. KEY MESSAGES: HDAC network and cellular effects of HDAC inhibitors. Role and mechanism of HDAC inhibitors in HCC. HDAC inhibitor combined with other ways to treat HCC. The side effects of HDACis in the treatment of HCC.

WTAP suppresses STAT3 via m6A methylation to regulate autophagy and inflammation in central nervous system injury

Central nervous system (CNS) repair after injury is a challenging process limited by inflammation and neuronal apoptosis. This study identifies Wilms' tumor 1-associating protein (WTAP) as a pivotal regulator of neuronal protection and repair through m6A methylation of STAT3 mRNA. By employing spinal cord injury (SCI) as a representative model of CNS injury, transcriptomic analyses reveal WTAP as a key mediator of pathways related to neuronal autophagy and inflammation regulation. WTAP enhances neuronal autophagy by suppressing STAT3 expression and activity, which inhibits the NLRP3 inflammatory pathway. Functional studies demonstrate that WTAP knockdown exacerbates neuronal apoptosis, whereas overexpression improves cell viability, autophagy, and motor recovery. In vivo, WTAP promotes SCI repair via m6A-mediated suppression of STAT3 and regulation of the NLRP3 signaling pathway, highlighting its therapeutic potential for CNS injury repair.

Transcription factor EP300 targets SIRT5 to promote autophagy of nucleus pulposus cells and attenuate intervertebral disc degeneration

BACKGROUND

Intervertebral disc degeneration (IVDD) is a prevalent spinal ailment and the leading cause of chronic low back pain. Understanding the exact pathogenesis of IVDD and developing targeted molecular drugs will be important in the future. Autophagy plays a key role in the metabolic processes and in the quality control of proteins in IVDD. However, the role of autophagy in the senescence of nucleus pulposus cell (NPC), the primary cells in the intervertebral disc responsible for maintaining the disc's structure and function, is not yet clear.

METHODS

Gene expression profiling data of human disc tissue were obtained from the Gene Expression Omnibus GSE15227, GSE23130, and GSE70362 datasets. Autophagy-related differentially expressed genes were identified from the Molecular Signatures Database (MSigDB) database. Weighted gene co-expression network analysis (WGCNA), receiver operating characteristic (ROC) curves, and least absolute shrinkage and selection operator (LASSO) regression identified an autophagy-related hub gene that encodes the E1A binding protein EP300 transcription factor in IVDD samples. Potential downstream target genes of EP300 were identified by bioinformatics analysis. The analysis identified sirtuin 5 (SIRT5) as a potential downstream target of EP300. Chromatin immunoprecipitation (ChIP)-qPCR, small interfering RNA (siRNA), and luciferase reporter gene assays were used to verify the interaction of EP300 and SIRT5 in vitro. For in vivo experiments, SIRT5 knockout mice and SIRT5-overexpressing adeno-associated virus serotype 5 (AAV5) were constructed to verify the effect of the EP300-SIRT5 signal axis on the progression of IVDD.

RESULTS

EP300 expression was reduced in the IVDD samples compared with its expression in healthy disc tissue samples. The reduced EP300 expression inhibited the occurrence of autophagy, which promoted NPC senescence. ChIP-qPCR and luciferase reporter gene assays showed that EP300 promoted SIRT5 expression by direct binding to its promoter. Activation of EP300 expression increased SIRT5 expression and significantly improved autophagy for inhibition of NPC senescence. In vivo experiments confirmed that knockdown of EP300 promoted NPC senescence and led to an exacerbation of IVDD, which was reversed by SIRT5 overexpression.

CONCLUSION

Our results provide the first evidence for the importance of EP300 and SIRT5 interactions in promoting IVDD development by inhibiting autophagy during IVDD. The EP300-SIRT5 signaling axis was identified as a promising target for therapy of IVDD based on autophagy genes.

IL-27 aggravates acute hepatic injury by promoting macrophage M1 polarization to induce Caspase-11 mediated Pyroptosis in vitro and in vivo

OBJECTIVES

Our aim was to explore the IL-27 effect in sepsis (SP)-related acute hepatic injury (AHI) as well as its possible mechanism.

MATERIALS AND METHODS

Herein, we utilized both wild-type (WT) and IL-27 receptor (WSX-1)-deficient (IL-27R-/-) mice alongside RAW264.7 cells. Our study established an SP-associated AHI model through the intraperitoneal injections of lipopolysaccharide (LPS) + D-galactosamine (D-G). For examining the IL-27 impact on AHI, mice serum and liver tissue samples were gathered. Inflammatory factor levels in the liver and serum were detected using ELISA and immunohistochemistry. Immunofluorescence and Western blot techniques were employed for the detection of protein expression associated with polarization and pyroptosis in the liver, including iNOS, ARG-1, caspase-11, RAGE, and GSDMD. To further verify the IL-27 effects on macrophage polarization and pyroptosis and explore possible mechanisms involved, we used LPS-triggered RAW264.7 macrophages to assess AMPK/SIRT1 expression after IL-27 intervention. This study utilized Compound C (CC) to block the AMPK/SIRT1 pathway. The inflammatory response level and protein expression related to macrophage polarization and pyroptosis were measured again to reveal IL-27 implication in AHI and determine whether its role is associated with the AMPK/SIRT1 pathway.

RESULTS

The results revealed that IL-27 exacerbated systemic inflammation and liver damage in AHI mice by promoting M1 macrophage polarization, thereby increasing pro-inflammatory phenotype macrophages (M1). This further exacerbated the inflammatory response and pyroptosis in vivo and in vitro. Additionally, IL-27 down-regulated p-AMPK and SIRT1 protein expression while overexpressing macrophage inflammatory mediators including IL-1β/6 and TNFα. Furthermore, IL-27 promoted increased RAGE and caspase-11 protein expression, aggravating macrophage pyroptosis. Employing CC to block the AMPK pathway further aggravated M1 macrophage polarization and pyroptosis in vitro and in vivo, ultimately worsening liver injury.

CONCLUSIONS

Here, IL-27 aggravates AHI by promoting macrophage M1 polarization to induce caspase-11-mediated pyroptosis in vitro and in vivo, which may be linked to the AMPK/SIRT1 signaling pathway.

Cost-effective and simple flow cytometry quantification of receptor-mediated autophagy using fluorescent tagging

Mitophagy, a selective clearance of damaged or superfluous mitochondria via autophagy machinery and lysosomal degradation, is an evolutionarily conserved process essential for various physiological functions, including cellular differentiation and immune responses. Defects in mitophagy are implicated in numerous human diseases, such as neurodegenerative disorders, cancer, and metabolic conditions. Despite significant advancements in mitophagy research over recent decades, novel and robust methodologies are necessary to elucidate its molecular mechanisms comprehensively. In this study, we present a detailed protocol for quantitatively assessing mitophagy through flow cytometry using a mitochondria-targeted fluorescent mitophagy receptor, GFP-BNIP3L/NIX. This method offers a rapid alternative to conventional microscopy or immunoblotting techniques for analyzing mitophagy activity. Additionally, this approach can theoretically be adapted to utilize any fluorescent-tagged selective autophagy receptor, enabling the direct and rapid analysis of various types of receptor-mediated selective autophagy.

Dietary cinnamon promotes longevity and extends healthspan via mTORC1 and autophagy signaling

Cinnamon, renowned for its aromatic flavor, represents one of the most widely used spices worldwide. Cinnamon is also considered beneficial to human health with therapeutic potential for treating various diseases, ranging from diabetes and cancer to neurodegenerative diseases. However, the mechanisms underlying cinnamon's health benefits remain elusive. It is also unclear whether cinnamon has any role in aging. Using C. elegans as a model, here we show that feeding worms cinnamaldehyde (CA), the active ingredient in cinnamon oil, prolongs longevity. CA also promotes stress resistance and reduces β-Amyloid toxicity in a C. elegans model of Alzheimer's disease. Mechanistically, CA exerts its beneficial effects through mTORC1 and autophagy signaling. Interestingly, CA promotes longevity by inducing a dietary restriction-like state without affecting food intake, suggesting CA as a dietary restriction mimetic. In human cells, CA exerts a similar effect on mTORC1 and autophagy signaling, suggesting a conserved mechanism. Our results demonstrate that dietary cinnamon promotes both lifespan and healthspan and does so by regulating mTORC1 and autophagy signaling.

Targeting Dysregulated Epigenetic Modifiers With Kidney-Targeted Nanotherapeutics for Polycystic Kidney Disease

Autosomal dominant polycystic kidney disease (ADPKD) is the most common genetic kidney disease worldwide. The one small molecule drug available to patients, tolvaptan, is associated with off-target side effects and high discontinuation rates, necessitating the development of new therapeutic strategies. Previous work has shown that the epigenome is altered in ADPKD; however, the identification and targeting of dysregulated epigenetic modulators has yet to be explored for human ADPKD therapy. Using cells derived from cysts of ADPKD patients, we tested the gene expression of several epigenetic modulators. We found Brd4 and BMi1 are upregulated and observed that their inhibition using small molecule drugs, AZD-5153 and PTC-209, significantly slowed the proliferation of ADPKD patient cells. To enhance the delivery of AZD-5153 and PTC-209 to renal cells, we loaded the drugs into kidney-targeting micelles (KM) and assessed their therapeutic effects in vitro. Combining AZD-5153 and PTC-209 in KMs had a synergistic effect on reducing the proliferation in ADPKD patient cells and in a 3D PKD cyst model. These findings were also consistent in murine in vitro models using Pkd1 null renal proximal tubule cells. In summary, we demonstrate Brd4 and BMi1 as novel targets in ADPKD and targeting the epigenome using kidney nanomedicine as a novel therapeutic strategy in ADPKD.

Modulation of AMPK/mTOR Autophagic Pathway Using Dapagliflozin Protects Against Cadmium-Induced Testicular and Renal Injury in Rats

Cadmium is a widely distributed heavy metal found in the environment that poses serious hazards to human health. Dapagliflozin (DAPA), a sodium-glucose co-transporter 2 (SGLT-2) inhibitor, exhibited antioxidant, antiapoptotic, and anti-inflammatory properties. Our data assessed the effect of DAPA against Cd-triggered renal and testicular impairment in rats, as well as the underlying mechanisms. Cd (30 mg/kg) and DAPA (5 and 10 mg/kg) were administrated by oral gavage to rats and continued for 21 days. DAPA attenuated Cd-triggered renal and testicular injury as shown by diminishing serum creatinine, BUN, and urinary total protein concentration in addition to increasing creatinine clearance, urinary creatinine, and serum testosterone. Moreover, it diminished renal and testicular histopathological alterations induced by Cd. DAPA stimulated the impaired autophagy flux as seen by significantly elevating the p-AMPK/total AMPK, decreasing p-mTOR/total mTOR ratios, and diminishing p62 & LC3 protein levels. Additionally, DAPA significantly lowered MDA content, increased GSH level and SOD activity. Moreover, it augmented the cytoprotective Nrf2/HO-1 signaling pathway. Furthermore, it attenuated renal and testicular apoptotic cell death via decreasing caspase-3 expression. Conclusion: Boosting autophagic events and combating oxidative stress and apoptosis by DAPA were engaged in alleviating Cd-induced renal and testicular impairment. This was accomplished by modulating the AMPK/mTOR and enhancing the Nrf2/HO-1 pathways.

RNF144A inhibits autophagy by targeting BECN1 for degradation during L. monocytogenes infection

Listeria monocytogenes (L. monocytogenes, Lm) is widely used in the laboratory as an infection model for the research on pathogenesis and host defense against gram-positive intracellular bacteria. Macroautophagy (called simply "autophagy" hereafter), is important in the host defense against pathogens, such as bacteria, viruses, and parasites. BECN1 plays a pivotal role in the initiation of autophagy and accumulating evidence indicates that post-translational modifications of BECN1 provide multiple strategies for autophagy regulation. In this study, we demonstrated that the RING1-IBR-RING2 (RBR) family member RNF144A (ring finger protein 144A), which was induced by Lm infection, promoted Lm infection in an autophagy-dependent but STING1-independent pattern. rnf144a deficiency in mice protected mice from Lm infection with inhibited innate immune responses. Interestingly, RNF144A decreased Lm-induced autophagosome accumulation. Mechanistic investigation indicated that RNF144A interacted with BECN1 and promoted its K48-linked ubiquitination, leading to the subsequent proteasome-dependent degradation of BECN1 and reduced autophagosome accumulation. Further study demonstrated that RNF144A promoted the ubiquitination of BECN1 at K117 and K427, and these two ubiquitination sites were essential to the role of BECN1 in autophagy and Lm infection. Thus, our findings suggested a new regulator in intracellular bacterial infection and autophagy, which may contribute to our understanding of host defense against intracellular bacterial infection via autophagy.Abbreviations: ATG3: autophagy related 3; ATG5: autophagy related 5; ATG7: autophagy related 7; ATG10: autophagy related 10; ATG12: autophagy related 12; ATG16L1: autophagy related 16 like 1; Baf A1: bafilomycin A1; BECN1: beclin 1; BMDC: bone marrow-derived dendritic cell; BMDM: bone marrow-derived macrophage; CFUs: colony-forming units; CHX: cycloheximide; CQ: chloroquine; CXCL10/IP-10: C-X-C motif chemokine ligand 10; EBSS: Earle's balanced salt solution; ELISA: enzyme-linked immunosorbent assay; IFIT1/ISG56: interferon induced protein with tetratricopeptide repeats 1; IFNB/IFN-β: interferon beta; IL6: interleukin 6; IRF3, interferon regulatory factor 3; Lm: L. monocytogenes; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MEF: mouse embryonic fibroblast; MOI: multiplicity of infection; PLA: proximity ligation assay; PMA: phorbol myristate acetate; PMA-THP1, PMA-differentiated THP1; PMs: peritoneal macrophages; PTMs: posttranslational modifications; RBR: RING1-IBR-RING2; RNF144A: ring finger protein 144A; STING1, stimulator of interferon response cGAMP interactor 1; TBK1, TANK binding kinase 1; TNF/TNF-α: tumor necrosis factor.

Heterozygous Men1(+/T) Knockout Mice Do Not Develop Bronchopulmonary Neuroendocrine Hyperplasia or Neoplasia but Bronchial Adenocarcinoma

INTRODUCTION

Bronchopulmonary Neuroendocrine Neoplasms (NEN) occur in 2-7% of patients with multiple endocrine neoplasia type 1 (MEN1). Precursor lesions have been identified for MEN1-related pancreatic, duodenal, and gastric NEN. The aim of the current study using a MEN1 mouse model was to define the precursor lesions of bronchopulmonary NEN and evaluate the potential prophylactic antitumor effects of somatostatin analogues in a transgenic MEN1 mouse model.

METHODS

Fifteen mice, germline heterozygous for Men1(+/T), were treated with subcutaneous injections of lanreotide autogel (Somatuline Autogel®, IPSEN Pharma), while 15 mice were treated with subcutaneous injections of physiologic sodium chloride as the control group. Five mice from each group were euthanized after 12, 15, and 18 months, respectively. The complete lungs were resected and evaluated after hematoxylin and eosin staining and immunohistochemistry for synaptophysin and chromogranin A.

RESULTS

In the lungs of the 30 evaluated mice, whether treated or placebo treated, no bronchopulmonary neuroendocrine cell hyperplasia nor neuroendocrine neoplasia was detected through histopathology. However, pulmonary adenocarcinoma developed in 2 (13%) of the 15 untreated mice and in 1 (7%) of the 15 lanreotide-treated mice.

CONCLUSIONS

Heterozygous Men1(+/T) knockout mice do not develop bronchopulmonary NEN or precursor lesions, but pulmonary adenocarcinoma. This surprising result needs to be investigated in more detail.