CRISPR/Cas9 based gene editing of Frizzled class receptor 6 (FZD6) reveals its role in depressive symptoms through disrupting Wnt/β-catenin signaling pathway

CXCR2 modulates chronic pain comorbid depression in mice by regulating adult neurogenesis in the ventral dentate gyrus

Research shows that chronic pain may induce depression-like behaviors through impairing adult hippocampal neurogenesis (AHN) in the ventral dentate gyrus (DG), whereas restoration of AHN may effectively alleviate depression. The C-X-C motif chemokine receptor 2 (CXCR2) is a chemokine receptor involved in various neural activities of the hippocampus including AHN. In this study we investigated the role of CXCR2 of neural stem cells (NSCs) in the ventral DG in regulating both AHN and depression-like behaviors of mice with chronic neuropathic pain. Chronic neuropathic pain was induced in mice by the spared nerve injury (SNI) surgery; mechanical allodynia and depression-like behaviors were monitored, then mouse DG was collected for analysis. We observed that chronic neuropathic pain significantly decreased the number of immature neurons in the ventral DG by inhibiting the neuronal differentiation of NSCs; specific overexpression of CXCR2 in NSCs by injecting the adeno-associated virus (AAV) into the DG restored adult neurogenesis accompanied by alleviated depression-like behaviors in SNI mice. In contrast, the knockdown of CXCR2 in hippocampal NSCs of naive mice was sufficient to inhibit adult neurogenesis, inducing depression-like behaviors. Moreover, we found that the Wnt3a/β-catenin pathway was downregulated in the ventral DG of SNI mice, which was restored after CXCR2 overexpression or infusing a CXCR2 agonist CXCL1 into the ventral DG. We conclude that CXCR2 expressed in hippocampal NSCs is crucial for regulating adult neurogenesis and chronic pain-induced depression-like behavior, thus representing a new target for the treatment of chronic pain comorbid depression.

Frizzled receptors: gatekeepers of Wnt signaling in development and disease

Frizzled (FZD) receptors are a subset of G-protein-coupled receptors (GPCRs), the largest class of human cell surface receptors and a major target of FDA-approved drugs. Activated by Wnt ligands, FZDs regulate key cellular processes such as proliferation, differentiation, and polarity, positioning them at the intersection of developmental biology and disease, including cancer. Despite their significance, FZD signaling remains incompletely understood, particularly in distinguishing receptor-specific roles across canonical and non-canonical Wnt pathways. Challenges include defining ligand-receptor specificity, elucidating signal transduction mechanisms, and understanding the influence of post translational modifications and the cellular context. Structural dynamics, receptor trafficking, and non-canonical signaling contributions also remain areas of active investigation. Recent advances in structural biology, transcriptomics, and functional genomics are beginning to address these gaps, while emerging therapeutic approaches-such as small-molecule modulators and antibodies-highlight the potential of FZDs as drug targets. This review synthesizes current insights into FZD receptor biology, examines ongoing controversies, and outlines promising directions for future research and therapeutic development.

Syringa oblata Lindl extract alleviated corticosterone-induced depression via the cAMP/PKA-CREB-BDNF pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Syringa oblata Lindl (ZDX) is a plant in the Oleaceae family that is the primary ingredient in the classic Tibetan medicine AKARU sinensis. The plant's stem is used as a medicine, and Tibetan doctors often use it as a sedative, a use with a history of nearly 100 years. Tibetan medicine mainly uses lilac to treat headache, forgetfulness, insomnia, irritability and other symptoms. Depression is a chronic mental disorder characterized by low mood, cognitive impairments, and physical discomfort, and it has become a significant public health issue. Given the limitations of existing treatments, interest in alternative therapies, including herbal medicines, is increasing.

AIM

To elucidate the mechanism of ZDX extract in the treatment of depression.

MATERIALS AND METHODS

A depression-like mouse model was established via the subcutaneous injection of corticosterone (CORT) into the groin, and a model of PC12 cell injury was established via CORT treatment. The antidepressant effect of the ZDX extract was subsequently evaluated via weight measurements, the sucrose preference test (SPT), the forced swimming test (FST), the open field test(OFT), the tail suspension test (TST), HE staining, Nissl staining and ELISA. Moreover, immunofluorescence staining, qRT‒PCR and Western blotting were used to determine whether ZDX extract can regulate the cAMP/PKA-CREB-BDNF pathway to prevent depression and neuronal apoptosis.

RESULTS

ZDX extract significantly improved depression-like behaviours; inhibited decreases in the protein levels of cAMP, PKA, CREB and BDNF; and increased proliferative activity in the hippocampus and cortex. In addition, in vitro, ZDX extract attenuated CORT-induced injury and apoptosis in hippocampal neurons and inhibited CORT-induced decreases in the mRNA expression levels of cAMP, PKA, CREB and BDNF.

CONCLUSIONS

These findings suggest that ZDX extract has potential as a novel antidepressant therapeutic agent, offering a complementary approach to current treatments by targeting multiple pathways involved in the pathogenesis of depression. Further research is warranted to explore the clinical applications of ZDX extract in the treatment of depression.

Curcumin triggers the Wnt/β-catenin pathway and shields neurons from injury caused by intermittent hypoxia

The objective of this study was to explore the molecular basis through which Curcumin (Cur) mitigates neuronal damage caused by obstructive sleep apnea (OSA). HT22 was used to simulate intermittent hypoxia (IH) injury and explore the effect of Cur on these cells. We evaluated the cell viability, cytotoxicity, apoptosis, proliferation, and Wnt/β-catenin (WβC) pathway. IWR-1 was used to block the pathway and investigate the protective mechanism of Cur. We constructed an in vivo model of IH to validate the results of the cellular experiments. IH accelerated apoptosis and cytotoxicity, suppressed proliferation, and decreased the activity of the WβC pathway. Cur can significantly improve cell viability, reduce apoptosis rate and cell toxicity, promote cell proliferation, and up-regulate the WβC. After blocking the WβC pathway, the proliferative effect of Cur was observably weakened. In vivo, IH caused hippocampal damage and inhibited WβC pathway activity in mice, which was ameliorated by Cur treatment. This implies that Cur could be a novel treatment option for neurological impairment brought on by OSA.

Santacruzamate A Alleviates Pain and Pain-Related Adverse Emotions through the Inhibition of Microglial Activation in the Anterior Cingulate Cortex

Chronic pain is a complex disease. It seriously affects patients' quality of life and imposes a significant economic burden on society. Santacruzamate A (SCA) is a natural product isolated from marine cyanobacteria in Panama. In this study, we first demonstrated that SCA could alleviate chronic inflammatory pain, pain-related anxiety, and depression emotions induced by complete Freund's adjuvant in mice while inhibiting microglial activation in the anterior cingulate cortex. Moreover, SCA treatment attenuated lipopolysaccharide (LPS)-induced inflammatory response by downregulating interleukin 1β and 6 (IL-1β and IL-6) and tumor necrosis factor-α (TNF-α) levels in BV2 cells. Furthermore, we found that SCA could bind to soluble epoxide hydrolase (sEH) through molecular docking technology, and the thermal stability of sEH was enhanced after binding of SCA to the sEH protein. Meanwhile, we identified that SCA could reduce the sEH enzyme activity and inhibit sEH protein overexpression in the LPS stimulation model. The results indicated that SCA could alleviate the development of inflammation by inhibiting the enzyme activity and expression of sEH to further reduce chronic inflammatory pain. Our study suggested that SCA could be a potential drug for treating chronic inflammatory pain.