GFAP filaments are core elements of the cytoskeleton in astrocytes, shaping cellular processes and influencing central nervous system function and pathology. How these filaments are built at the molecular level has remained unclear. Using cryo-electron microscopy and cryo-electron tomography, we show that GFAP filaments are helical polymers assembled from extended and twisted coiled-coil tetramers that interdigitate to form a complex filament tube. In the filament lumen, the low-complexity head domains aggregate to form a flexible fibre, while the tail domains extend from the surface and facilitate higher-order bundling of the filaments, indicating that both the low-complexity structural regions and the well-ordered coiled-coils of the filament tube contribute to the unique structure of GFAP filaments. Our findings provide molecular insights into the pathogenesis of Alexander Disease, localising multiple deleterious mutations to the critical interlock interaction between successive tetramers emergent in the final filament assembly.

Alexander disease (AxD) is a rare and fatal neurodegenerative disorder caused by dominant mutations in the gfap gene, which encodes glial fibrillary acidic protein (GFAP), a major intermediate filament in astrocytes. As a primary astrogliopathy, AxD is marked by white matter abnormalities, the formation of GFAP-containing Rosenthal fibers, astrocyte dysfunction, and progressive neurodegeneration. While GFAP mutations are known to cause toxic gain-of-function effects, the precise mechanisms by which mutant GFAP drives astrocyte dysfunction and central nervous system pathology remain unclear. To address this, we developed a novel rat model of AxD harboring the R237H mutation in the endogenous gfap locus, which mirrors the R239H mutation commonly associated with early-onset AxD in humans. This model recapitulates key AxD pathologies, including GFAP aggregation, widespread astrogliosis, white matter abnormalities, and motor deficits. Using homozygous mutant rats, we dissected the distinct contributions of mutant GFAP and elevated GFAP expression to astrocyte dysfunction and neurodegeneration. Our findings reveal that AxD pathogenesis results from a synergistic interaction between the toxic gain-of-function properties of mutant GFAP and its elevated expression, which together drive GFAP aggregation, proteostatic stress, and astrocyte dysfunction. These insights provide a deeper understanding of AxD mechanisms and a foundation for developing targeted therapies for this devastating disease.

Astrocytes play a vital role in maintaining central nervous system homeostasis, supporting neuronal function, and responding to injury or disease. Dysfunction in astrocyte activity is increasingly recognized as a key contributor to neurodegenerative disorders, including Alexander disease (AxD), a rare and fatal condition caused by mutations in glial fibrillary acidic protein (GFAP). These mutations result in GFAP aggregation, Rosenthal fiber formation, and progressive astrocyte dysfunction. While in vivo animal models offer a complex cellular environment, both current in vitro and in vivo models face limitations in accurately replicating the intricate cellular context and functions of astrocytes. To address this, we developed a cellular model using primary rat astrocytes derived from wild-type (WT) and AxD model rats to study the functional effects of GFAP mutations. This physiologically relevant system enables detailed investigation of astrocyte-specific mechanisms, including GFAP aggregation, oxidative stress responses, and pathological modifications. For researchers without access to AxD model rats, lentiviral transduction offers an alternative method to introduce AxD-associated GFAP mutations into astrocytes derived from normal rats, thereby broadening the applicability of this approach. Compared with immortalized astrocyte cell lines or in vitro studies using recombinant protein, primary astrocytes better preserve native cellular architecture and molecular profiles, offering a robust platform for studying GFAP dynamics, solubility, and astrocytic responses to stressors such as oxidative damage and pathological modifications. This cellular model bridges the gap between molecular and systemic studies, providing a controlled experimental framework to explore astrocyte dysfunction in AxD. By complementing existing methodologies, primary astrocyte cultures enhance our understanding of AxD pathology and represent a valuable tool for identifying potential therapeutic targets for neurodegenerative diseases.

Glial Fibrillary Acidic Protein (GFAP) is a key intermediate filament protein critical for maintaining the structural integrity and function of astrocytes in the central nervous system. Mutations in GFAP are the root cause of Alexander disease (AxD), a rare and often fatal neurodegenerative disorder characterized by elevation of GFAP levels and accumulation of GFAP in the form of Rosenthal fibers. Here, we outline a comprehensive set of experimental approaches for the biochemical characterization of GFAP and its disease-causing variants. Using optimized expression and advanced purification techniques, we achieved high yields and purity of both wild-type and mutant GFAP proteins. Biochemical assays were employed to evaluate the effects of pathogenic mutations on filament assembly, solubility, and aggregation. Additionally, we explored the role of aberrant posttranslational modifications in GFAP aggregation and their impact on filament properties. This work advances our understanding of GFAP's role in AxD and lays a foundation for developing therapeutic strategies targeting GFAP dysfunction. Furthermore, the methodologies presented here serve as valuable tools for investigating the biochemical consequences of GFAP mutations and advancing interventions for GFAP-related disorders.

Spectrins are ubiquitous cytoskeleton proteins found in all metazoan cells. αII-spectrin, encoded by SPTAN1, is the pivotal protein responsible for organization of the axonal cytoskeleton. Monoallelic SPTAN1 mutations cause various inherited neurological diseases, including spastic paraplegia 91 (SPG91), a type of hereditary spastic paraplegia (HSP). We reported two patients with SPG91 caused by the SPTAN1 mutation c.55 C > T (p.Arg19Trp), who presented with lower limb spasticity and polyneuropathy. An analysis of the patients reported in the literature in addition to the present patients revealed that SPTAN1 p.Arg19Trp was specific for an HSP phenotype, with 35

Glial fibrillary acidic protein (GFAP) is classified as a type III intermediate filament protein predominantly expressed in mature astrocytes. It has the ability to self-assemble into 10 nm filaments in vitro, making it particularly valuable for elucidating the sequences essential for filament assembly. In this study, we created a series of deletion mutants targeting sequences in the N-terminal, C-terminal, and central rod domains to explore the sequences critical for the assembly of GFAP into 10 nm filaments. The impact of these deletions on filament formation was evaluated through in vitro assembly studies and transduction assays conducted with primary astrocytes. Our data revealed that deletions at the carboxy end resulted in abnormalities in either filament diameter calibration or lateral association, whereas deletions at the amino-terminal end significantly disrupted the filament assembly process, particularly restricting filament elongation. Furthermore, we discovered that the filament-forming sequences within the rod domain varied in their contributions to filament assembly and network formation. These findings enhance our understanding of the GFAP assembly process in vitro and provide a detailed mapping of the essential regions required for GFAP assembly. These insights hold significant implications for Alexander disease arising from deletion mutations in GFAP.

Here, we describe pathological events potentially involved in the disease pathogenesis of Alexander disease (AxD). This is a primary genetic disorder of astrocyte caused by dominant gain-of-function mutations in the gene coding for an intermediate filament protein glial fibrillary acidic protein (GFAP). Pathologically, this disease is characterized by the upregulation of GFAP and its accumulation as Rosenthal fibers. Although the genetic basis linking GFAP mutations with Alexander disease has been firmly established, the initiating events that promote GFAP accumulation and the role of Rosenthal fibers (RFs) in the disease process remain unknown. Here, we investigate the hypothesis that disease-associated mutations promote GFAP aggregation through aberrant posttranslational modifications. We found high molecular weight GFAP species in the RFs of AxD brains, indicating abnormal GFAP crosslinking as a prominent pathological feature of this disease. In vitro and cell-based studies demonstrate that cystine-generating mutations promote GFAP crosslinking by cysteine-dependent oxidation, resulting in defective GFAP assembly and decreased filament solubility. Moreover, we found GFAP was ubiquitinated in RFs of AxD patients and rodent models, supporting this modification as a critical factor linked to GFAP aggregation. Finally, we found that arginine could increase the solubility of aggregation-prone mutant GFAP by decreasing its ubiquitination and aggregation. Our study suggests a series of pathogenic events leading to AxD, involving interplay between GFAP aggregation and abnormal modifications by GFAP ubiquitination and oxidation. More important, our findings provide a basis for investigating new strategies to treat AxD by targeting abnormal GFAP modifications.

Nipah virus (NiV) is known to be a highly pathogenic zoonotic virus, which is included in the World Health Organization Research & Development Blueprint list of priority diseases with up to 70% mortality rate. Due to its high pathogenicity and outbreak potency, a therapeutic countermeasure against NiV is urgently needed. As NiV needs to be handled within a Biological Safety Level (BSL) 4 facility, we had developed a safe drug screening platform utilizing a baculovirus expression vector system (BEVS) based on a NiV-induced syncytium formation that could be handled within a BSL-1 facility. To reconstruct the NiV-induced syncytium formation in BEVS, two baculoviruses were generated to express recombinant proteins that are responsible for inducing the syncytium formation, including one baculovirus exhibiting co-expressed NiV fusion protein (NiV-F) and NiV attachment glycoprotein (NiV-G) and another exhibiting human EphrinB2 protein. Interestingly, syncytium formation was observed in infected insect cells when the medium was modified to have a lower pH level and supplemented with cholesterol. Fusion inhibitory properties of several compounds, such as phytochemicals and a polysulfonated naphthylamine compound, were evaluated using this platform. Among these compounds, suramin showed the highest fusion inhibitory activity against NiV-induced syncytium in the baculovirus expression system. Moreover, our in silico results provide a molecular-level glimpse of suramin’s interaction with NiV-G’s central hole and EphrinB2’s G-H loop, which could be the possible reason for its fusion inhibitory activity.

Background: Alzheimer’s disease (AD) is a multifactorial disorder characterized by cognitive decline. Current available therapeutics for AD have limited clinical benefit. Therefore, preventive therapies for interrupting the development of AD are critically needed. Molecules targeting multifunction to interact with various pathlogical components have been considered to improve the therapeutic efficiency of AD. In particular, herbal medicines with multiplicity of actions produce cognitive benefits on AD. Bugu-M is a multi-herbal extract composed of Ganoderma lucidum (Antler form), Nelumbo nucifera Gaertn., Ziziphus jujuba Mill., and Dimocarpus longan, with the ability of its various components to confer resilience to cognitive deficits. Objective: To evaluate the potential of Bugu-M on amyloid-β (Aβ) toxicity and its in vitro mechanisms and on in vivo cognitive function. Methods: We illustrated the effect of Bugu-M on Aβ25–35-evoked toxicity as well as its possible mechanisms to diminish the pathogenesis of AD in rat cortical neurons. For cognitive function studies, 2-month-old female 3×Tg-AD mice were administered 400 mg/kg Bugu-M for 30 days. Behavioral tests were performed to assess the efficacy of Bugu-M on cognitive impairment. Results: In primary cortical neuronal cultures, Bugu-M mitigated Aβ-evoked toxicity by reducing cytoskeletal aberrations and axonal disruption, restoring presynaptic and postsynaptic protein expression, suppressing mitochondrial damage and apoptotic signaling, and reserving neurogenic and neurotrophic factors. Importantly, 30-day administration of Bugu-M effectively prevented development of cognitive impairment in 3-month-old female 3×Tg-AD mice. Conclusion: Bugu-M might be beneficial in delaying the progression of AD, and thus warrants consideration for its preventive potential for AD.

Background: Alzheimer’s disease (AD) is a multifactorial disorder characterized by cognitive decline. Current available therapeutics for AD have limited clinical benefit. Therefore, preventive therapies for interrupting the development of AD are critically needed. Molecules targeting multifunction to interact with various pathlogical components have been considered to improve the therapeutic efficiency of AD. In particular, herbal medicines with multiplicity of actions produce cognitive benefits on AD. Bugu-M is a multi-herbal extract composed of Ganoderma lucidum (Antler form), Nelumbo nucifera Gaertn., Ziziphus jujuba Mill., and Dimocarpus longan, with the ability of its various components to confer resilience to cognitive deficits. Objective: To evaluate the potential of Bugu-M on amyloid-β (Aβ) toxicity and its in vitro mechanisms and on in vivo cognitive function. Methods: We illustrated the effect of Bugu-M on Aβ 25–35 -evoked toxicity as well as its possible mechanisms to diminish the pathogenesis of AD in rat cortical neurons. For cognitive function studies, 2-month-old female 3×Tg-AD mice were administered 400 mg/kg Bugu-M for 30 days. Behavioral tests were performed to assess the efficacy of Bugu-M on cognitive impairment. Results: In primary cortical neuronal cultures, Bugu-M mitigated Aβ-evoked toxicity by reducing cytoskeletal aberrations and axonal disruption, restoring presynaptic and postsynaptic protein expression, suppressing mitochondrial damage and apoptotic signaling, and reserving neurogenic and neurotrophic factors. Importantly, 30-day administration of Bugu-M effectively prevented development of cognitive impairment in 3-month-old female 3×Tg-AD mice. Conclusion: Bugu-M might be beneficial in delaying the progression of AD, and thus warrants consideration for its preventive potential for AD. Keywords Alzheimer’s disease , amyloid-β , axon , cognition , dementia , herbal , mild cognitive impairment , natural product , prevention , synapse

Classical swine fever virus (CSFV) and porcine circovirus type 2 (PCV2) have caused severe diseases in swine populations worldwide. Here, a polycistronic baculovirus vector was developed to express a bivalent vaccine, consisting of the CSFV-E2 and PCV2-Cap protein, and an immunomodulator protein derived from the Flammulina velutipes, FVE-FIP, as well as the selection marker, green fluorescent protein. The simultaneous expression of the CSFV-E2 and PCV2-Cap protein was mediated by the 2A-like sequence derived from the Perina nuda virus (PnV), while the expression of the FVE-FIP was driven by the internal ribosome entry site (IRES) element derived from the Rhophalosipum padi virus (RhPV). The Western blot analysis result suggested that the CSFV-E2, PCV2-Cap, and FVE-FIP protein were successfully co-expressed by the infected Spodoptera frugiperda IPBL-Sf21 (Sf21) cell line. The extracted cell lysate containing all three recombinant proteins was administered to Balb/C mice with or without the supplementation of Freund's adjuvant. The ELISA analysis of the serum collected from all the immunized groups showed detectable antibodies against CSFV-E2 and PCV2-Cap. Furthermore, the immunized group without the adjuvant supplementation demonstrated a similar level of antibodies to the group with adjuvant supplementation, suggesting the efficiency of the FVE-FIP in enhancing the immune response. These results demonstrated the polycistronic baculovirus vector could be employed to develop bivalent vaccines for pigs.

Alexander disease results from gain of function mutations in the gene encoding glial fibrillary acidic protein (GFAP), an intermediate filament protein expressed in astrocytes. At least eight GFAP isoforms have been described, however, the predominant alpha isoform accounts for approximately 90% of GFAP protein in the central nervous system. Here we describe exonic variants identified in three unrelated families with Type II Alexander disease that alter the splicing of GFAP pre-mRNA and result in upregulation of a previously uncharacterized GFAP lambda isoform (NM 001363846.1). Affected members of Family 1 and Family 2 shared the same missense variant, NM 001363846.1:c.1289G>A;p.(Arg430His) while in Family 3 we identified a synonymous variant in the adjacent nucleotide, NM 001363846.1:c.1290C>A;p.(Arg430Arg). Using RNA and protein analysis of brain autopsy samples, and a mini-gene splicing reporter assay, we demonstrate both variants result in upregulation of the lambda isoform. We assessed other GFAP variants in the ClinVar database for predicted aberrant splicing and using the same assay demonstrated significant changes to splicing for two selected variants. Our approach demonstrates the importance of characterizing the effect of GFAP variants on mRNA splicing in order to inform future pathophysiologic and therapeutic study for Alexander disease.

Alexander disease (AxD) is a neurodegenerative astrogliopathy caused by mutation in the glial fibrillary acidic protein (GFAP) gene. A 42-year-old Korean man presented with temporary gait disturbance and psychiatric regression after a minor head trauma in the absence of bulbar symptoms and signs. Magnetic resonance images of the brain and spinal cord showed significant atrophy of the medulla oblongata and the entire spinal cord as well as contrast-enhanced T2 hypointensity in the basal ganglia. DNA sequencing revealed a novel 33-bp in-frame deletion mutation (p.Glu138_Leu148del) within the 1B rod domain of GFAP, which was predicted to be deleterious by PROVEAN analysis. To test whether the deletion mutant is disease-causing, we performed in vitro GFAP assembly and sedimentation assays, and GFAP aggregation assays in human adrenal carcinoma SW13 (Vim−) cells and rat primary astrocytes. All the assays revealed that GFAP p.Glu138_Leu148del is aggregation prone. Based on these findings, we diagnosed the patient with Type II AxD. This is a report that demonstrates the pathogenicity of InDel mutation of GFAP through functional studies. This patient’s atypical presentation as well as the discrepancy between clinical symptoms and radiologic findings may extend the scope of AxD.

Self-monitoring of blood glucose (SMBG) is common in patients with diabetes. The aim of this study was to explore how frequency/behavior of SMBG affect glucose control in patients with type 2 diabetes. This cross-sectional study was conducted at a regional teaching hospital in Taiwan. All participants completed a structured questionnaire about the frequency and behavior of SMBG, and hemoglobulin A1C (A1C) data were recorded from medical records. A total of 382 diabetes outpatients participated in the study. In the patients using insulin injections, A1C was better in patients with SMBG ≥ 28 times than in those with SMBG < 28 times per month (7.82 ± 1.86% vs. 8.33 ± 1.31%, p = 0.025). In the patients not using insulin, A1C was better in patients with SMBG > 14 times than those with SMBG ≤ 14 times per month (7.08 ± 0.23% vs. 7.55 ± 0.08%, p = 0.038). The patients who more frequently reviewed the causes of hypoglycemia and hyperglycemia had a better A1C level (p for linear trend <0.001). Our study suggested that SMBG ≥ 28 and >14 times could improve glycemic control for insulin-requiring and non-insulin-requiring type 2 diabetes patients, respectively. Further exploration of the cause of hyperglycemia or hypoglycemia shown by SMBG could also improve blood glucose control.

Background and Objectives: The aim of this study was to investigate the relationships between obesity-related factors including body mass index (BMI), diabetes or prediabetes, hyperlipidemia, fasting plasma glucose, fasting plasma insulin, homeostasis model assessment-estimated insulin resistance (HOMA-IR), highly sensitive C-reactive protein (hs-CRP) and Graves’ orbitopathy (GO). Materials and Methods: Eighty-four patients with Graves’ disease (GD) (42 without GO and 42 with GO) were enrolled in this cross-sectional cohort study. Gender, age, GD treatment history, height, body weight, waist circumference, smoking status, co-morbidities, levels of free thyroxin, thyroid-stimulating hormone, thyroid-stimulating hormone receptor (TSHR) antibodies, fasting plasma glucose and insulin, and hs-CRP were recorded. The eye condition was evaluated using the consensus statement of the European Group of Graves’ Orbitopathy (EUGOGO) and the NOSPECS classification. Results: In this study, multivariate regression analysis showed that BMI, fasting plasma insulin, and HOMA-IR were associated with the presence of GO after adjusting the age, gender, smoking, TSHR antibodies, and steroid usage (adjusted odd’s ratio (aOR) 1.182, 95% confidence interval (95% CI), 1.003–1.393, p = 0.046; aOR 1.165, 95% CI, 1.001–1.355, p = 0.048; and aOR 1.985, 95% CI, 1.046–3.764, p = 0.036, respectively). In addition, BMI, fasting plasma glucose, fasting plasma insulin, HOMA-IR, and hs-CRP levels were positively correlated with the severity of GO. Conclusions: The findings of this study suggest that obesity-related factors, especially fasting plasma insulin and HOMA-IR, are related to GO. Our study highlighted the importance of obesity-related factors in GO. Obesity-related factors may cause the development of GO or occur simultaneously with GO.

Alexander disease is a primary genetic disorder of astrocytes caused by dominant mutations in the gene encoding glial fibrillary acidic protein (GFAP). How single-amino-acid changes can lead to cytoskeletal catastrophe and brain degeneration remains poorly understood. In this study, we have analyzed 14 missense mutations located in the GFAP rod domain to investigate how these mutations affect in vitro filament assembly. Whereas the internal rod mutants assembled into filaments that were shorter than those of wild type, the rod end mutants formed structures with one or more of several atypical characteristics, including short filament length, irregular width, roughness of filament surface, and filament aggregation. When transduced into primary astrocytes, GFAP mutants with in vitro assembly defects usually formed cytoplasmic aggregates, which were more resistant to biochemical extraction. The resistance of GFAP to solubilization was also observed in brain tissues of patients with Alexander disease, in which a significant proportion of insoluble GFAP were accumulated in Rosenthal fiber fractions. These findings provide clinically relevant evidence that link GFAP assembly defects to disease pathology at the tissue level and suggest that altered filament assembly and properties as a result of GFAP mutation are critical initiating factors for the pathogenesis of Alexander disease.

Alexander disease (AxD) caused by mutations in the coding region of GFAP is a neurodegenerative disease characterized by astrocyte dysfunction, GFAP aggregation, and Rosenthal fiber accumulation. Although how GFAP mutations cause disease is not fully understood, Rosenthal fibers could be induced by forced overexpression of human GFAP and this could be lethal in mice implicate that an increase in GFAP levels is central to AxD pathogenesis. Our recent studies demonstrated that intronic GFAP mutations cause disease by altering GFAP splicing, suggesting that an increase in GFAP isoform expression could lead to protein aggregation and astrocyte dysfunction that typify AxD. Here we test this hypothesis by establishing primary astrocyte cultures from transgenic mice overexpressing human GFAP. We found that GFAP-δ and GFAP-κ were disproportionately increased in transgenic astrocytes and both were enriched in Rosenthal fibers of human AxD brains. In vitro assembly studies showed that while the major isoform GFAP-α self-assembled into typical 10-nm filaments, minor isoforms including GFAP-δ, -κ, and -λ were assembly-compromised and aggregation prone. Lentiviral transduction showed that expression of these minor GFAP isoforms decreased filament solubility and increased GFAP stability, leading to the formation of Rosenthal fibers-like aggregates that also disrupted the endogenous intermediate filament networks. The aggregate-bearing astrocytes lost their normal morphology and glutamate buffering capacity, which had a toxic effect on neighboring neurons. In conclusion, our findings provide evidence that links elevated GFAP isoform expression with GFAP aggregation and impaired glutamate transport, and suggest a potential non-cell-autonomous mechanism underlying neurodegeneration through astrocyte dysfunction.

Alexander disease (AxD) is a devastating leukodystrophy caused by gain-of-function mutations in GFAP, and the only available treatments are supportive. Recent advances in antisense oligonucleotide (ASO) therapy have demonstrated that transcript targeting can be a successful strategy for human neurodegenerative diseases amenable to this approach. We have previously used mouse models of AxD to show that Gfap-targeted ASO suppresses protein accumulation and reverses pathology; however, the mice have a mild phenotype with no apparent leukodystrophy or overt clinical features and are therefore limited for assessing functional outcomes. In this report, we introduce a rat model of AxD that exhibits hallmark pathology with GFAP aggregation in the form of Rosenthal fibers, widespread astrogliosis, and white matter deficits. These animals develop normally during the first postnatal weeks but fail to thrive after weaning and develop severe motor deficits as they mature, with about 14% dying of unknown cause between 6 and 12 weeks of age. In this model, a single treatment with Gfap-targeted ASO provides long-lasting suppression, reverses GFAP pathology, and, depending on age of treatment, prevents or mitigates white matter deficits and motor impairment. In this report, we characterize an improved animal model of AxD with myelin pathology and motor impairment, recapitulating prominent features of the human disease, and use this model to show that ASO therapy has the potential to not only prevent but also reverse many aspects of disease.

Background Alexander disease (AxD) is an autosomal-dominant leukodystrophy caused by heterozygous mutations in the glial fibrillary acidic protein (GFAP) gene. Objectives The objective of this report is to characterize the clinical phenotype and identify the genetic mutation associated with adult-onset AxD. Methods A man presented with progressive unsteadiness since age 16. Magnetic resonance imaging findings revealed characteristic features of AxD. The GFAP gene was screened, and a candidate variant was functionally tested to evaluate causality. Results A homozygous c.197G > A (p.Arg66Gln) mutation was found in the proband, and his asymptomatic parents were heterozygous for the same mutation. This mutation affected GFAP solubility and promoted filament aggregation. The presence of the wild-type protein rescued mutational effects, consistent with the recessive nature of this mutation. Conclusions This study is the first report of AxD caused by a homozygous mutation in GFAP. The clinical implication is while examining patients with characteristic features on suspicion of AxD, GFAP screening is recommended even without a supportive family history. (c) 2020 International Parkinson and Movement Disorder Society

Cisplatin chemotherapy causes myelosuppression and often limits treatment duration and dose escalation in patients. Novel approaches to circumvent or lessen myelotoxicity may improve clinical outcome and quality of life in these patients. Chlorella sorokiniana (CS) is a freshwater unicellular green alga and exhibits encouraging efficacy in immunomodulation and anticancer in preclinical studies. However, the efficacy of CS on chemoprotection remains unclear. We report here, for the first time, that CS extract (CSE) could protect normal myeloid cells and PBMCs from cisplatin toxicity. Also, cisplatin-induced apoptosis in HL-60 cells was rescued through reservation of mitochondrial function, inhibition of cytochrome c release to cytosol, and suppression of caspase and PARP activation. Intriguingly, cotreatment of CSE attenuated cisplatin-evoked hypocellularity of bone marrow in mice. Furthermore, we observed the enhancement of CSF-GM activity in bone marrow and spleen in mice administered CSE and cisplatin, along with increased CD11b levels in spleen. In conclusion, we uncovered a novel mechanism of CSE on myeloprotection, whereby potentially supports the use of CSE as a chemoprotector against cisplatin-induced bone marrow toxicity. Further clinical investigation of CSE in combination with cisplatin is warranted.