Hanbing Wang

The comorbidity of chronic pain and attention deficit complicates treatment, as each condition intensifies the other through mechanisms that are not well understood. The locus coeruleus (LC) integrates a variety of somatosensory and emotional inputs and has been implicated in both chronic pain and attention deficit disorders. We hypothesized that the LC and its projections may contribute to the pathophysiology of comorbid chronic pain and attention deficit. We found that in male mice with chronic sciatic nerve constriction injury (CCI), LC neurons were easily activated by mechanical and thermal stimuli. Chemogenetic activation of LC neurons improved hypersensitivity and attention deficit-like behaviors in naive mice, while inhibition of these neurons exacerbated hypersensitivity and attention deficit-like behaviors in CCI mice. Through neuronal tracing, chemogenetics, optogenetics, and electrophysiology, we discovered a monosynaptic dopaminergic pathway from the locus coeruleus to the thalamic reticular nucleus, influencing pain modulation in naive mice. In CCI mice, both projections were enhanced, and activation of these pathways resulted in analgesic and anti-attention deficit-like effects. This study suggests that LC, particularly the LC-thalamic reticular circuit, is crucial in the regulation of comorbid chronic pain and attention deficit.

It is widely recognized that sleep loss harms healthy adults. Microglia-mediated synaptic pruning is active during sleep and contributes to memory consolidation. Here, we established a mouse model of sleep deprivation (SD) using a modified multiple-platform method (MMPM). Using western blotting, immunofluorescence, and Golgi-Cox staining, we found that SD increased microglial capacity for phagocytizing mature synapses and decreased the number of mature synapses, which affected long-term memory consolidation but did not affect working memory after SD. Further, we discovered that pretreatment with the APOE mimic peptide COG1410 could partially rescue SD-induced long-term memory consolidation. Regarding the mechanism, COG1410 alleviated SD-induced abnormal microglial phagocytosis and increased the number of mature synapses. Also, COG1410 promoted M2 polarization of microglia and reduced hippocampal inflammation caused by SD. However, whether the anti-inflammatory effect of COG1410 is related to the regulation of microglial phagocytosis still needs further study. Finally, we downregulated the expression of TREM2 in the hippocampus using small interfering RNA (siRNA), which reduced the protective effect of COG1410 in SD mice. In summary, COG1410 has the potential to prevent SD-induced memory consolidation impairment by maintaining microglial phagocytosis and anti-inflammation in the mouse hippocampus.

Ifferent neurological diseases. Such diversity in astrocyte morphology and function is essential for understanding both normal brain function and the underlying mechanisms of neurological disorders. To investigate this heterogeneity, we developed a novel method for the selective and sparse labeling of astrocytes in various brain regions. This technique utilizes a dual adeno-associated virus system that allows for the expression of Cre recombinase and enhanced green fluorescent protein under the control of the glial fibrillary acidic protein (GfaABC1D) promoter. The system was tested in C57BL/6J mice and successfully labeled astrocytes across multiple brain regions. The method enabled the detailed visualization of individual astrocytes-including their intricate peripheral processes-through three-dimensional reconstructions from confocal microscopy images. Furthermore, the labeling efficiency of this dual adeno-associated virus technology was validated by examining astrocyte function in a spared nerve injury model and through chemogenetic modulation. This innovative approach holds great promise for future research because it enables a more comprehensive understanding of astrocyte variation not only in spared nerve injury but also in a broad spectrum of neurological diseases. The ability to selectively label and study astrocytes in different brain regions provides a powerful tool for exploring the complexities of these essential cells and their roles in physiological and pathological conditions. Astrocytes are the most abundant glial cells in the central nervous system. They perform a diverse array of functions, with a critical role in structural integrity, synapse formation, and neurotransmission. These cells exhibit substantial regional heterogeneity and display variable responses to different neurological diseases. Such diversity in astrocyte morphology and function is essential for understanding both normal brain function and the underlying mechanisms of neurological disorders. To investigate this heterogeneity, we developed a novel method for the selective and sparse labeling of astrocytes in various brain regions. This technique utilizes a dual adeno-associated virus system that allows for the expression of Cre recombinase and enhanced green fluorescent protein under the control of the glial fibrillary acidic protein (GfaABC1D) promoter. The system was tested in C57BL/6J mice and successfully labeled astrocytes across multiple brain regions. The method enabled the detailed visualization of individual astrocytes-including their intricate peripheral processes-through three-dimensional reconstructions from confocal microscopy images. Furthermore, the labeling efficiency of this dual adeno-associated virus technology was validated by examining astrocyte function in a spared nerve injury model and through chemogenetic modulation. This innovative approach holds great promise for future research because it enables a more comprehensive understanding of astrocyte variation not only in spared nerve injury but also in a broad spectrum of neurological diseases. The ability to selectively label and study astrocytes in different brain regions provides a powerful tool for exploring the complexities of these essential cells and their roles in physiological and pathological conditions. © 2025 Neural Regeneration Research...

Introduction: Goat-derived adeno-associated virus (AAV) vectors, such as AAV Go.1, represent a novel platform for gene therapy due to their unique origin and potential advantages in transduction efficiency and immune evasion. However, their therapeutic potential and biological properties remain underexplored.Methods: In this study, we developed a recombinant AAV (rAAV) Go.1 by replacing the goat AAV rep gene with the standard AAV2-rep gene to improve packaging efficiency. We compared the transduction efficiency of rAAV Go.1 with that of AAV5, a closely related serotype with 95% genome similarity, both in vitro and in vivo. Additionally, we assessed immune evasion properties by evaluating resistance to neutralization using sera from rAAV5-immunized mice and human volunteers. To further enhance transduction efficiency, we introduced site-specific mutations in the VP1 unique (VP1u) region and VP1/2 common region.Results: The rep gene modification led to a significantly higher packaging efficiency for rAAV Go.1 compared to the original goat AAV. rAAV Go.1 exhibited markedly higher transduction efficiency than AAV5 in both in vitro and in vivo models. Furthermore, rAAV Go.1 demonstrated a 4-fold increase in resistance to neutralization by sera from rAAV5-immunized mice. A study involving 20 healthy volunteers revealed that high-titer neutralizing antibodies had a more pronounced inhibitory effect on rAAV5 compared to rAAV Go.1. Mutagenesis studies identified key modifications that enhanced viral properties: K32R, K91R, and K122R mutations in the VP1u region significantly improved viral production, while K137R (VP1u) enhanced transduction efficiency in vitro and in vivo.Discussion: Our findings highlight the potential of rAAV Go.1 as an improved gene therapy vector with superior transduction efficiency and enhanced immune evasion. The identified VP1 mutations further optimize viral properties, making rAAV Go.1 a promising candidate for future therapeutic applications.

Numerous studies have demonstrated a positive correlation between sleep disorders and hyperalgesia. These sleep disorders adversely affect the descending pain regulatory system. Researchers have extensively studied the midbrain dopamine system in relation to pain associated with sleep disturbances. Our study shows that chronic sleep deprivation decreases dopamine responses to noxious stimuli within the mouse nucleus accumbens, regulated by dopamine release and intracellular signals. Furthermore, we confirmed that the dopamine D₂ receptors play a critical role in the pain associated with chronic sleep deprivation. Importantly, we revealed that homer1a in D₂ receptor neurons enhances AMPA receptors expression.

The mechanisms underlying the association between sleep deprivation (SD) and hyperalgesia remain incompletely understood. In this study, the Modified Horizontal Platform Method was employed to induce chronic SD. Neuropathic pain was induced using chronic constriction injury of the sciatic nerve. Pain-like behaviors were assessed through measurements of mechanical allodynia and thermal hyperalgesia, while gait analysis was used to evaluate motor function. Immunofluorescence and western blot analyses were conducted to examine the expression of TNF-α, Iba-1, TH, neurons and c-Fos. Apoptosis was assessed using TUNEL staining. To explore anatomical connections, anterograde and retrograde tracer viruses were injected into the superior cervical ganglion (SCG) and the spinal cord, respectively. Local injection of 6-OHDA was used to ablate sympathetic neurons in the SCG, and R-7050 was administrated to block the TNF-α receptor. We found that chronic SD induced hyperalgesia in both normal and neuropathic pain model, accompanied by significant infiltration of microglia in the dorsal horn. TH expression and apoptotic cells were increased in the SCG following chronic SD. Viral tracer results demonstrated the existence of anatomical connections between the SCG and the spinal cord. Ablation of sympathetic innervation improved pain-like behaviors and reduced microglia, without affecting movement. Furthermore, chronic SD led to increased expression of TNF-α in sympathetic neurons, which was associated with heightened SCG activity. Blocking the TNF-α receptor ameliorated pain-like behaviors, decreased microglia, reduced apoptosis, lowered SCG activity. In conclusion, TNF-α enhanced the activity of sympathetic neurons in the SCG, promoting hyperalgesia related to chronic SD. Graphical Abstract

A negative correlation exists between attention and pain. The cognitive impairments linked to pain can significantly impede a patient’s healing process and everyday tasks, particularly for individuals experiencing persistent pain. Furthermore, it has been demonstrated that diversion can effectively decrease pain levels in individuals. The focus of this review is to analyze clinical trials and fundamental investigations regarding alterations in focus and persistent discomfort. Moreover, we investigated the common neuroanatomy associated with attention and pain. Furthermore, we examined the impact of various neuromodulators on the transmission of pain and processes related to attention, while also considering the potential neural mechanisms that contribute to the co-occurrence of pain and attention deficits. Further investigation in this field will enhance our comprehension of patient symptoms and the underlying pathophysiology, ultimately resulting in more objective approaches to treatment.

Background. Painful diabetic neuropathy (PDN) is a frequent and troublesome complication of diabetes, with little effective treatment. PDN is characterized by specific spinal microglia‐mediated neuroinflammation. Insulin‐like growth factor 1 (IGF‐1) primarily derives from microglia in the brain and serves a vital role in averting the microglial transition into the proinflammatory M1 phenotype. Given that epigallocatechin‐3‐gallate (EGCG) is a potent anti‐inflammatory agent that can regulate IGF‐1 signaling, we speculated that EGCG administration might reduce spinal microglia‐related neuroinflammation and combat the development of PDN through IGF‐1/IGF1R signaling. Methods. Type 1 diabetes mellitus (T1DM) was established by a single intraperitoneal (i.p.) injection of streptozotocin (STZ) in mice. The protein expression level of IGF‐1, its receptor IGF1R, interleukin 1β (IL‐1β), tumor necrosis factor‐α (TNF‐α), and inducible nitric oxide synthase (iNOS) was determined by Western blot or immunofluorescence. Results. The spinal IGF‐1 expression markedly decreased along with the presence of pain‐like behaviors, the spinal genesis of neuroinflammation (increased IL‐1β, TNF‐α, and Iba‐1⁺ microglia), and the intensified M1 microglia polarization (increased iNOS⁺Iba‐1⁺ microglia) in diabetic mice. IGF‐1 could colocalize with neurons, astrocytes, and microglia, but only microglial IGF‐1 was repressed in T1DM mice. Furthermore, we found that i.t. administration of mouse recombinant IGF‐1 (rIGF‐1) as well as i.t. or i.p. treatment with EGCG alleviated the diabetes‐induced pain‐like behaviors, reduced neuroinflammation (suppressed IL‐1β, TNF‐α, and Iba‐1⁺ microglia), prevented the M1 microglia polarization (less iNOS⁺Iba‐1⁺ microglia), and restored the microglial IGF‐1 expression. Conclusions. Our data highlighted the importance of maintaining spinal IGF‐1 signaling in treating microglia‐related neuroinflammation in PDN. This study also provides novel insights into the neuroprotective mechanisms of EGCG against neuropathic pain and neuroinflammation through IGF‐1 signaling, indicating that this agent may be a promising treatment for PDN in the clinical setting.

Background: Painful diabetic neuropathy (PDN) is a common and intractable complication of diabetes mellitus, with little effective treatment. PDN has been associated with spinal neuroinflammation characterized by microglial activation. Recently, the triggering receptor expressed on myeloid cells 2 (TREM2), specifically localized on microglia, has been identified as a vital factor in modulating neuroinflammation and microglial phenotypes in neural diseases. Therefore, we hypothesized that spinal TREM2 might contribute to PDN and neuroinflammation by regulating microglial activity and phenotypes.Methods：Type I diabetes mellitus was elicited by a single intraperitoneal administration of streptozotocin (STZ) in mice. The pain behaviors were reflected by paw mechanical withdrawal thresholds (PMWT) and thermal withdrawal latency (PTWL). Results：We demonstrated that up-regulation of microglial TREM2 and amplification of both microglial M1 and M2 response was along with the presence of diabetes-related mechanical allodynia and thermal hypersensitivity. Moreover, we found that overexpression of TREM2 in microglia aggravated the symptom of PDN, amplified microglia M1 response, and suppressed microglia M2 polarization in the lumbar spinal cord of diabetic mice. However, inhibition of TREM2 with anti-TREM2 neutralizing antibodies attenuated mechanical allodynia and thermal hyperalgesia in diabetic mice. Besides, we identified Galectin-3 (GLT-3) as the potential ligand of the TREM2 receptor in facilitating the progression of PDN.Conclusions: TREM2 could be a critical microglial membrane molecule that modulates microglial phenotypes pain hypersensitivity in PDN. GLT-3 might act as a specific ligand to trigger TREM2 signaling in PDN or other neuropathic pain.