Relationship between Brain-Derived Neurotrophic Factor and Cognitive Decline in Patients with Mild Cognitive Impairment and Dementia

Association between reduced plasma BDNF concentration and MMSE scores in both chronic schizophrenia and mild cognitive impairment

Reduced brain derived neurotrophic factor (BDNF) concentration is reported to be associated with a cognitive decline in schizophrenia, depending on the stage of the disease. Aim of the study was to examine the possible association between plasma BDNF and cognitive decline in chronic stable schizophrenia and mild cognitive impairment (MCI). The study included 123 inpatients of both sexes with schizophrenia, 123 patients with MCI and 208 healthy control subjects. Cognitive abilities were assessed using mini mental state examination (MMSE), Clock Drawing test (CDT) and cognitive subscale of the Positive and Negative Syndrome Scale (PANSS). Plasma BDNF concentration was determined using ELISA. BDNF concentration was lower in patients with schizophrenia and MCI compared to age-matched healthy controls and was similar in carriers of different BDNF Val/66Met genotypes. The MMSE and CDT scores were lower in patients with schizophrenia compared to healthy controls and subjects with MCI. Reduced plasma BDNF was significantly associated with lower MMSE scores in all subjects. BDNF concentration in patients with schizophrenia was not affected by clinical and demographic factors. BDNF Val66Met polymorphism was not associated with the MMSE scores in all participants. Further studies should include longitudinal follow-up and other cognitive scales to confirm these results and offer cognition-improving strategies to prevent cognitive decline in chronic schizophrenia.

Effects of computerized cognitive training on biomarker responses in older adults with mild cognitive impairment: A scoping review

Background and Aims

Mild cognitive impairment (MCI) is a widespread condition in older individuals, posing significant risk of dementia. However, limited research has been conducted to explore effective interventions and clarify their impact at the neural level. Therefore, this study aimed to investigate the effects of computerized cognitive training (CCT) and explore the associated neural mechanisms in preventing dementia in older individuals with MCI, with a view to inform future intervention efforts.

Methods

We reviewed the effects of CCT on biomarker outcomes in older adults with MCI. The search was conducted for studies published between 2010 and May 10, 2023, using three search engines: PubMed, Scopus, and Cumulative Index to Nursing and Allied Health Literature. The inclusion criteria were as follows: studies that involved participants diagnosed with MCI, included CCT, included quantitative assessment of biomarker results, and conducted randomized controlled trials.

Results

Sixteen studies that used biomarkers, including magnetic resonance imaging, electroencephalography (EEG), functional near-infrared spectroscopy (fNIRS), and blood or salivary biomarkers, were extracted. The results showed that CCT caused changes in structure and function within the main brain network, including the default mode network, and decreased both theta rhythm activity on EEG and prefrontal activity on fNIRS, with improvement in cognitive function. Furthermore, CCT combined with physical exercise showed more significant structural and functional changes in extensive brain regions compared with CCT alone. Virtual reality-based cognitive training improved not only executive function but also instrumental activities of daily living.

Conclusion

CCT causes functional and structural changes in extensive brain regions and improves cognitive function in older adults with MCI. Our findings highlight the potential of individualized intervention methods and biomarker assessment according to the specific causes of MCI. Future research should aim to optimize these personalized therapeutic strategies to maximize the benefits of CCT in older adults with MCI.

Job burnout, cognitive functioning, and Brain-derived neurotrophic factor expression among hospital Mexican nurses

AIM

To analyze the relationship between burnout syndrome, cognitive functions, and sBDNF (Serum Brain-derived Neurotrophic Factor) in Mexican nurses.

METHOD

A descriptive cross-sectional design was used. This study target staff nurses working in hospitals in Guanajuato, México. Demographic and working condition data were collected via questionnaire. The Maslach Burnout Inventory (MBI) was used to evaluate burnout. A blood sample were collected and processed by ELISA technique to measure sBDNF. Finally, the General Cognitive Assessment (CAB) of the Cognifit© neuropsychological battery was used to evaluated cognitive functions.

RESULTS

Findings showed that there are sociodemographic characteristics and working conditions associated with burnout syndrome among nurses. Furthermore, the data demonstrated a significant decrease in sBDNF levels in burnout nurses and a negative correlation between BDNF levels and burnout syndrome. Additionally, these burnout nurse also revealed significant cognitive impairment in reasoning, memory, and attention as well as total scores of CAB. Interestingly, we found a positive correlation between sBDNF levels and the cognitive deficits in burnout nurse.

CONCLUSION

Reduced BDNF levels could be a biological indicator or part of the pathological process of burnout, which could affect cognitive abilities. Reduced cognitive function in nurses has relevant implications and emphasizes the need for specialized preventive strategies because nurses make clinical decisions concerning their patients, whose situations are constantly changing.

Serum levels of IL-9 and IL-11 serve as predictors for the occurrence of early neurologic deterioration in patients with cerebral infarction

BACKGROUND AND AIM

Early neurological deterioration (END) is a common complication of cerebral infarction and a significant contributor to poor prognosis. Our study aimed to investigate the predictive value of interleukin-9 (IL-9) and interleukin-11 (IL-11) in relation to the occurrence of END in patients with cerebral infarction.

MATERIALS AND METHODS

102 patients with cerebral infarction and 64 healthy controls were collected. Patients were categorized into two groups based on the development of END following admission: the END group (n = 44) and the non-END group (n = 58). Enzyme-linked immunosorbent assay was used to determine the serum levels of IL-9, IL-11, and BDNF.

RESULTS

Serum IL-9 was higher and IL-11 lower in the END group than those in the non-END group (P < 0.01). IL-9 correlated positively with NIHSS score (r = 0.627) and infarction volume (r = 0.686), while IL-11 correlated negatively (r = -0.613, -0.679, respectively). Logistic regression identified age, NIHSS score, and IL-9 as risk factors (P < 0.01), and IL-11 as protective (P < 0.01). Combined IL-9 and IL-11 had an ROC curve area of 0.849. BDNF correlated negatively with IL-9 (r = -0.703) and positively with IL-11 (r = 0.711).

CONCLUSION

Serum IL-9 and IL-11 levels can predict the occurrence of END in patient with cerebral infarction and are correlated with serum BDNF levels.

Brain-derived neurotrophic factor interplay with oxidative stress: neuropathology approach in potential biomarker of Alzheimer's disease

The aging population poses a serious challenge concerning an increased prevalence of Alzheimer's disease (AD) and its impact on global burden, morbidity, and mortality. Oxidative stress, as a molecular hallmark that causes susceptibility in AD, interplays to other AD-related neuropathology cascades and decreases the expression of central and circulation brain-derived neurotrophic factor (BDNF), an essential neurotrophin that serves as nerve development and survival, and synaptic plasticity in AD. By its significant correlation with the molecular and clinical progression of AD, BDNF can potentially be used as an objectively accurate biomarker for AD diagnosis and progressivity follow-up in future clinical practice. This comprehensive review highlights the oxidative stress interplay with BDNF in AD neuropathology and its potential use as an AD biomarker.

Polyphenols' Impact on Selected Biomarkers of Brain Aging in Healthy Middle-Aged and Elderly Subjects: A Review of Clinical Trials

With a constantly growing elderly population, incidences of neurodegenerative diseases are also rising and are expected to further increase over the next years, while costing health systems across the world trillions of dollars. Therefore, biomarkers to detect manifestations of brain aging early and interventions to slow down its pace are of great interest. In the last years, the importance of the neurotrophins brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) in the context of cognitive function and the aging brain has increased, besides the already well-established amyloid-beta (Aβ) and tau plaques. Due to their wide range of beneficial health effects as well as their antioxidant and anti-inflammatory properties, a class of secondary plant-metabolites, the so-called polyphenols, gained increasing attention. In this review, we discuss the roles of BDNF, Aβ, NGF, and tau proteins as biomarkers of brain aging and the effect of dietary polyphenol interventions on these biomarkers, assessed via blood analysis, magnetic resonance imaging (MRI), and positron emission tomography (PET).

Smilagenin induces expression and epigenetic remodeling of BDNF in alzheimer's disease

BACKGROUND

Smilagenin (SMI) is a lipid-soluble steroidal sapogenin, extracted from traditional Chinses medicinal herbs Radix Asparagi, which is extracted from the dry root of Asparagus cochinchinensis (Lour.) Merr. We previously found that SMI significantly increased brain-derived neurotrophic factor (BDNF) expression in Aβ-intoxicated SH-SY5Y cells.

METHODS

In this study, we performed behavioral tests to analyze cognitive function of WT and APP/PS1 mice treated with or without SMI, and found that SMI could significantly improve the learning and memory ability of APP/PS1 mice. Moreover, immunofluorescence and ELISA results showed that SMI pretreatment could effectively reduce the deposition of β-amyloid plaques in the cortex and hippocampus of APP/PS1 mice (26 mg/kg/day for 60 days) and inhibit the secretion of Aβ1-42 in N2a/APPswe cells (10 μM concentration for 24 hours).

RESULTS

Mechanistically, SMI enhanced BDNF mRNA expression, elevated the global level of H3AC and H4AC, and increased the expression of P300 in AD models. Furthermore, chromatin immunoprecipitation results showed that SMI could increase the levels of H3AC and H4AC at the promoter of BDNF promoter Ⅱ and Ⅳ, indicating that SMI epigenetically regulates BDNF expression through HAT enhancement. To further verify the critical role of P300 by which SMI upregulated histone acetylation in BDNF, AD mice were treated with SMI and C646 simultaneously. Behavioral experiments showed that the improvement effects of SMI on cognitive impairment were abolished after P300 inhibition in APP/PS1 mice.

CONCLUSIONS

Our research for the first time demonstrated that SMI showed neuroprotective effects by increasing the expression of P300 protein, thus upregulating histone acetylation levels in the promoter region of BDNF and promoting its transcription. Our findings provide an important theoretical basis for the treatment of Alzheimer's disease with SMI extracted from Asparagus cochinchinensis (Lour.) Merr.

Regulation of mild cognitive impairment associated with liver disease by humoral factors derived from the gastrointestinal tract and MRI research progress: a literature review

Patients with liver disease are prone to various cognitive impairments. It is undeniable that cognitive impairment is often regulated by both the nervous system and the immune system. In this review our research focused on the regulation of mild cognitive impairment associated with liver disease by humoral factors derived from the gastrointestinal tract, and revealed that its mechanisms may be involved with hyperammonemia, neuroinflammation, brain energy and neurotransmitter metabolic disorders, and liver-derived factors. In addition, we share the emerging research progress in magnetic resonance imaging techniques of the brain during mild cognitive impairment associated with liver disease, in order to provide ideas for the prevention and treatment of mild cognitive impairment in liver disease.

Exploring the Causality Between Plasma Brain-Derived Neurotrophic Factor and Neurological Diseases: A Mendelian Randomization Study

BACKGROUND

Brain-derived neurotrophic factor (BDNF) is a protein synthesized in the brain and widely expressed in the nervous system. Previous studies have demonstrated a controversial role of BDNF in neurological diseases.

OBJECTIVE

In this study, we aimed to assess the association between BDNF levels and the risk of neurological diseases by Mendelian randomization analysis.

METHODS

From a genome-wide association analysis of plasma proteins comprising 3,301 European participants, we isolated 25 genetic variations as instrumental variables for BDNF levels. Summary statistics data on six common neurological diseases as outcome variables. Two-sample Mendelian randomization (MR) analysis was used to assess whether plasma BDNF is causally related to neurological diseases. We also performed sensitivity analysis to ensure the robustness of the results and reverse MR to exclude potential reverse causality.

RESULTS

We confirmed the significant causal relationship between BDNF levels and the risk of Alzheimer's disease (AD) (OR, 0.92; 95% CI, 0.85, 0.98; p = 0.013). Other methods have also shown similar results. We infer that BDNF also reduces the risk of epilepsy (OR, 0.94; 95% CI, 0.90, 0.98; p = 0.004). In reverse MR analysis, we also found that AD can affect the level of BDNF.

CONCLUSIONS

Our study suggests higher plasma BDNF was associated with the reduced risk of AD. Moreover, higher plasma BDNF is a protective factor on AD and focal epilepsy. The results provide credence to the idea that BDNF may play a significant role in the development of focal epilepsy and AD.