Blood Th17 cells and IL-17A as candidate biomarkers estimating the progression of cognitive impairment in stroke patients

Immune cells and the trajectories of depression, anxiety, and cognitive function among people with amyotrophic lateral sclerosis

Background

Amyotrophic lateral sclerosis (ALS) represents a complex syndrome characterized by motor, psychiatric, and cognitive symptoms, where associations between cellular immune features and non-motor manifestations remain unknown.

Methods

In this cohort study, we enrolled 250 incident people with ALS (pwALS) assessed with the Hospital Anxiety and Depression Scale, and 226 pwALS with the Montreal Cognitive Assessment, including 218 overlapping pwALS. All individuals were diagnosed between January 2015 and January 2023 in Stockholm, Sweden. We applied joint latent class models to delineate distinct trajectories of anxiety, depression, and cognition, incorporating survival outcomes. A majority of the pwALS had data on leukocyte counts and flow cytometric analyses using a comprehensive T cell panel. We then used immune cell subtypes measured at diagnosis to predict trajectories of these outcomes following ALS diagnosis.

Results

We identified two distinct trajectories for anxiety, depression, and cognitive function following ALS diagnosis. PwALS with longer survival displayed more stable trajectories, while those with shorter survival showed decreasing anxiety symptom, increasing depressive symptom, and declining cognitive function. Higher count of leukocytes at the time of ALS diagnosis tended to associate with anxiety and depression trajectories related to shorter survival. Among T cell subpopulations, several CD8+ T cell subsets were associated with a stable trajectory of depressive symptom, and, in turn, better survival.

Conclusion

ALS-associated psychiatric and cognitive trajectories vary significantly between pwALS with different prognosis. Certain T cell subsets measured at diagnosis might be indicative of depression trajectories post-diagnosis.

Impact of the gut microbiota-Th17 cell axis on inflammatory depression

Depression is a serious cognitive disorder that results in significant and pervasive deficits in social behavior. These deficits can be traced back to the intricate interplay between social, psychological, and biological factors. Inflammatory depression, a treatment-resistant or non-responsive subtype of depression, may be related to the interaction between the gut microbiota and interleukin-17-producing CD4+ T cells (Th17 cells). The heterogeneity, plasticity, and effector role of Th17 cells in depression may be influenced by microbiota factors. Commensals-elicited homeostatic Th17 cells preserve the morphological and functional integrity of the intestinal barrier. In addition to pathogen-elicited inflammatory Th17 cells, commensal-elicited homeostatic Th17 cells can become conditionally pathogenic and contribute to the development of inflammatory depression. This review delves into the possible involvement of Th17 cells in inflammatory depression and examines the interplay between gut microbiota and either homeostatic or inflammatory Th17 cells.

Th17 Cells and IL-17A in Ischemic Stroke

The neurological injury and repair mechanisms after ischemic stroke are complex. The inflammatory response is present throughout stroke onset and functional recovery, in which CD4 + T helper(Th) cells play a non-negligible role. Th17 cells, differentiated from CD4 + Th cells, are regulated by various extracellular signals, transcription factors, RNA, and post-translational modifications. Th17 cells specifically produce interleukin-17A(IL-17A), which has been reported to have pro-inflammatory effects in many studies. Recently, experimental researches showed that Th17 cells and IL-17A play an important role in promoting stroke pathogenesis (atherosclerosis), inducing secondary damage after stroke, and regulating post-stroke repair. This makes Th17 and IL-17A a possible target for the treatment of stroke. In this paper, we review the mechanism of action of Th17 cells and IL-17A in ischemic stroke and the progress of research on targeted therapy.

Serum autophagy-related gene 5 level in stroke patients: correlation with CD4+ T cells and cognition impairment during a 3-year follow-up

Autophagy-related gene (ATG) 5 regulates blood lipids, chronic inflammation, CD4+ T-cell differentiation, and neuronal death and is involved in post-stroke cognitive impairment. This study aimed to explore the correlation of serum ATG5 with CD4+ T cells and cognition impairment in stroke patients. Peripheral blood was collected from 180 stroke patients for serum ATG5 and T helper (Th) 1, Th2, Th17, and regulatory T (Treg) cell detection via enzyme-linked immunosorbent assays and flow cytometry. The Mini-Mental State Examination (MMSE) scale was completed at enrollment, year (Y)1, Y2, and Y3 in stroke patients. Serum ATG5 was also measured in 50 healthy controls (HCs). Serum ATG5 was elevated in stroke patients compared to HCs (P<0.001) and was positively correlated to Th2 cells (P=0.022), Th17 cells (P<0.001), and Th17/Treg ratio (P<0.001) in stroke patients but not correlated with Th1 cells, Th1/Th2 ratio, or Treg cells (all P>0.050). Serum ATG5 (P=0.037), Th1 cells (P=0.022), Th17 cells (P=0.002), and Th17/Treg ratio (P=0.018) were elevated in stroke patients with MMSE score-identified cognition impairment vs those without cognition impairment, whereas Th2 cells, Th1/Th2 ratio, and Treg cells were not different between them (all P>0.050). Importantly, serum ATG5 was negatively linked with MMSE score at enrollment (P=0.004), Y1 (P=0.002), Y2 (P=0.014), and Y3 (P=0.001); moreover, it was positively related to 2-year (P=0.024) and 3-year (P=0.012) MMSE score decline in stroke patients. Serum ATG5 was positively correlated with Th2 and Th17 cells and estimated cognitive function decline in stroke patients.

Relation between LRG1 and CD4+ T cells, cognitive impairment and neurological function in patients with acute ischemic stroke

Objective: To assess the relationship between LRG1 and CD4+ T cells, cognitive impairment and neurological function in acute ischemic stroke (AIS). Methods: Plasma LRG1 was detected by ELISA in 175 patients with AIS at baseline, day (D) 1, D7, month (M) 1 and M3. Results: LRG1 was negatively related to Th2 and Treg cells and positively linked to Th17 (all p < 0.05). LRG1 increased from baseline to D1, then decreased until M3 (p < 0.001). LRG1 at each assessment point was increased in patients with cognitive impairment or poor neurological function at M3 versus those without (all p < 0.05). Conclusion: LRG1 is linked to decreased Th2 and Tregs, increased Th17, cognitive impairment and nonideal neurological function recovery in patients with AIS.

Serum retinol-binding protein 4 in stroke patients: correlation with T helper 17/regulatory T cell imbalance and 3-year cognitive function decline

Objective

Retinol-binding protein 4 (RBP4) promotes atherosclerotic progression and neuronal loss, whereas its association with cognitive impairment in stroke is unclear. Hence, this prospective study aimed to explore the association of serum RBP4 with the T helper (Th)17/regulatory T (Treg) cell ratio and its correlation with cognitive impairment in stroke patients.

Methods

Peripheral blood samples from 265 stroke patients and 50 healthy controls (HCs) were collected at enrollment for serum RBP4 (by enzyme-linked immunosorbent assay) and Th17 and Treg cells (by flow cytometry) determination. Additionally, stroke patients underwent routine follow-ups, and their Mini-Mental State Examination (MMSE) scores were assessed at baseline and in years 1, 2, and 3 after enrollment.

Results

Serum RBP4 was elevated in stroke patients compared to HCs (p < 0.001), with a good ability to differentiate stroke patients from HCs (area under the curve: 0.815). Serum RBP4 was positively associated with Th17 cells (p < 0.001) and the Th17/Treg cell ratio (p < 0.001) and negatively associated with Treg cells (p = 0.003) in stroke patients, whereas it was only positively associated with the Th17/Treg cell ratio (p = 0.027) but not with Th17 (p = 0.075) or Treg (p = 0.130) cells in HCs. Furthermore, increased serum RBP4 was associated with a lower MMSE score (p < 0.001) and a lower incidence of cognition impairment (p = 0.005) at enrollment in stroke patients, as were Th17 cells and the Th17/Treg cell ratio (all p < 0.050). The 1-, 2-, and 3-year MMSE scores in stroke patients were 25.9 ± 2.0, 25.3 ± 2.3, and 24.9 ± 2.3, respectively. More importantly, serum RBP4 was negatively correlated with 1-, 2-, and 3-year MMSE scores (all p < 0.001) and positively associated with 1-year (p = 0.013), 2-year (p = 0.007), and 3-year (p = 0.001) MMSE score declines in stroke patients.

Conclusion

Serum RBP4 is positively associated with a Th17/Treg cell imbalance and, more importantly, it is indicative of cognitive function decline within 3 years in stroke patients. Thus, early and timely interventions and physical rehabilitation are more necessary in stroke patients with high serum RBP4.

The longitudinal changes of serum JKAP and IL-17A, and their linkage with anxiety, depression, and cognitive impairment in acute ischemic stroke patients

BACKGROUND

Our previous study discovers that Jun N-terminal kinase pathway-associated phosphatase (JKAP) is dysregulated and negatively links with the disease severity in acute ischemic stroke (AIS) patients. This study intended to further evaluate the linkage of JKAP and interleukin (IL)-17A with anxiety, depression, and cognitive impairment in AIS patients.

METHODS

Serum JKAP and IL-17A levels in 120 AIS patients at admission, 1st (D1), 3rd (D3), 7th (D7) day after admission, and from 20 controls, were detected by ELISA. Hospital Anxiety and Depression Scale (HADS) and Mini-Mental State Examination (MMSE) were assessed in AIS patients at discharge.

RESULTS

JKAP (p < 0.001) was reduced, but IL-17A (p < 0.001) was increased in AIS patients versus controls, and negatively correlated with each other in AIS patients (p = 0.014). In AIS patients, JKAP was reduced from baseline to D1 and then increased to D7 (p < 0.001), while IL-17A exhibited an opposite trend (p < 0.001). Notably, JKAP at D3 was negatively linked with HADS-anxiety score (p = 0.044), then decreased JKAP at D3 (p = 0.017) and D7 (p = 0.037) related to increased anxiety occurrence. However, JKAP was not linked to HADS-depression score or depression occurrence. Besides, JKAP at multiple time points were positively associated with MMSE score (all p < 0.05); decreased JKAP at D3 (p = 0.017) and D7 (p = 0.026) related to raised cognitive impairment occurrence.

CONCLUSION

JKAP initially decreases then shows an increasing trend after disease onset, and its decrement relates to elevated IL-17A, anxiety and cognitive impairment in AIS patients.