Honors & Awards
1st Young Researcher’s Science Award, Universität Ulm (2022)
Proteomics grant award, Uni. of St. Gallen, Switzerland & CONICET, Argentina (2021)
Interreg ITALIA-Slovenia ICGEB sponsor grant, ICGEB (2019)
Hannelore Kohl Foundation research grant, Hannelore Kohl Foundation (2018-2019)
Rector’s High Achievers award, National University of Sciences and Technology (NUST), Pakistan (2016)
Summer school travel grant, IBRO-APRC (2016)
2015 MacJannet Prize for Educational Empowerment in Pakistan, MacJannet Foundation, Tallories Network (2015)
Award for outstanding academic performance, Prime Minister Office, Pakistan (2015)
Master of Science, National University of Sciences and Technology (2016)
Doctor of Philosophy, Universitat Ulm (2023)
Bachelor of Science, National University of Sciences and Technology (2014)
Dr. rer. Nat., Ulm University, Neurosciences (2023)
M.Sc. in Biomedical Sciences, SMME, NUST, Pakistan, Neurosciences (2016)
B.Sc. in Applied Biosciences, ASAB, NUST, Pakistan, Healthcare biotechnology (2014)
Interleukin-13 and its receptor are synaptic proteins involved in plasticity and neuroprotection.
2023; 14 (1): 200
Immune system molecules are expressed by neurons, yet their functions are often unknown. We have identified IL-13 and its receptor IL-13Ra1 as neuronal, synaptic proteins in mouse, rat, and human brains, whose engagement upregulates the phosphorylation of NMDAR and AMPAR subunits and, in turn, increases synaptic activity and CREB-mediated transcription. We demonstrate that increased IL-13 is a hallmark of traumatic brain injury (TBI) in male mice as well as in two distinct cohorts of human patients. We also provide evidence that IL-13 upregulation protects neurons from excitotoxic death. We show IL-13 upregulation occurring in several cohorts of human brain samples and in cerebrospinal fluid (CSF). Thus, IL-13 is a physiological modulator of synaptic physiology of neuronal origin, with implications for the establishment of synaptic plasticity and the survival of neurons under injury conditions. Furthermore, we suggest that the neuroprotection afforded through the upregulation of IL-13 represents an entry point for interventions in the pathophysiology of TBI.
View details for DOI 10.1038/s41467-023-35806-8
View details for PubMedID 36639371
View details for PubMedCentralID PMC9839781
Met/HGFR triggers detrimental reactive microglia in TBI
2022; 41 (13): 111867
The complexity of signaling events and cellular responses unfolding in neuronal, glial, and immune cells upon traumatic brain injury (TBI) constitutes an obstacle in elucidating pathophysiological links and targets for intervention. We use array phosphoproteomics in a murine mild blunt TBI to reconstruct the temporal dynamics of tyrosine-kinase signaling in TBI and then scrutinize the large-scale effects of perturbation of Met/HGFR, VEGFR1, and Btk signaling by small molecules. We show Met/HGFR as a selective modifier of early microglial response and that Met/HGFR blockade prevents the induction of microglial inflammatory mediators, of reactive microglia morphology, and TBI-associated responses in neurons and vasculature. Both acute and prolonged Met/HGFR inhibition ameliorate neuronal survival and motor recovery. Early elevation of HGF itself in the cerebrospinal fluid of TBI patients suggests that this mechanism has translational value in human subjects. Our findings identify Met/HGFR as a modulator of early neuroinflammation in TBI with promising translational potential.
View details for DOI 10.1016/j.celrep.2022.111867
View details for Web of Science ID 000916492600001
View details for PubMedID 36577378
Neuronal nuclear calcium signaling suppression of microglial reactivity is mediated by osteoprotegerin after traumatic brain injury
JOURNAL OF NEUROINFLAMMATION
2022; 19 (1): 279
Traumatic brain injury (TBI) is characterized by massive changes in neuronal excitation, from acute excitotoxicity to chronic hyper- or hypoexcitability. Nuclear calcium signaling pathways are involved in translating changes in synaptic inputs and neuronal activity into discrete transcriptional programs which not only affect neuronal survival and synaptic integrity, but also the crosstalk between neurons and glial cells. Here, we report the effects of blunting neuronal nuclear calcium signals in the context of TBI.We used AAV vectors to express the genetically encoded and nuclear-targeted calcium buffer parvalbumin (PV.NLS.mCherry) or the calcium/calmodulin buffer CaMBP4.mCherry in neurons only. Upon TBI, the extent of neuroinflammation, neuronal death and synaptic loss were assessed by immunohistochemistry and targeted transcriptome analysis. Modulation of the overall level of neuronal activity was achieved by PSAM/PSEM chemogenetics targeted to parvalbumin interneurons. The functional impact of neuronal nuclear calcium buffering in TBI was assessed by quantification of spontaneous whisking.Buffering neuronal nuclear calcium unexpectedly resulted in a massive and long-lasting increase in the recruitment of reactive microglia to the injury site, which was characterized by a disease-associated and phagocytic phenotype. This effect was accompanied by a substantial surge in synaptic loss and significantly reduced whisking activity. Transcriptome analysis revealed a complex effect of TBI in the context of neuronal nuclear calcium buffering, with upregulation of complement factors, chemokines and interferon-response genes, as well as the downregulation of synaptic genes and epigenetic regulators compared to control conditions. Notably, nuclear calcium buffering led to a substantial loss in neuronal osteoprotegerin (OPG), whereas stimulation of neuronal firing induced OPG expression. Viral re-expression of OPG resulted in decreased microglial recruitment and synaptic loss. OPG upregulation was also observed in the CSF of human TBI patients, underscoring its translational value.Neuronal nuclear calcium signals regulate the degree of microglial recruitment and reactivity upon TBI via, among others, osteoprotegerin signals. Our findings support a model whereby neuronal activity altered after TBI exerts a powerful impact on the neuroinflammatory cascade, which in turn contributes to the overall loss of synapses and functional impairment.
View details for DOI 10.1186/s12974-022-02634-4
View details for Web of Science ID 000886138700002
View details for PubMedID 36403069
View details for PubMedCentralID PMC9675197
Differential effect of ethanol intoxication on peripheral markers of cerebral injury in murine blunt traumatic brain injury
BURNS & TRAUMA
2021; 9: tkab027
Blood-based biomarkers have proven to be a reliable measure of the severity and outcome of traumatic brain injury (TBI) in both murine models and patients. In particular, neuron-specific enolase (NSE), neurofilament light (NFL) and S100 beta (S100B) have been investigated in the clinical setting post-injury. Ethanol intoxication (EI) remains a significant comorbidity in TBI, with 30-40% of patients having a positive blood alcohol concentration post-TBI. The effect of ethanol on blood-based biomarkers for the prognosis and diagnosis of TBI remains unclear. In this study, we investigated the effect of EI on NSE, NFL and S100B and their correlation with blood-brain barrier integrity in a murine model of TBI.We used ultra-sensitive single-molecule array technology and enzyme-linked immunosorbent assay methods to measure NFL, NSE, S100B and claudin-5 concentrations in plasma 3 hours post-TBI.We showed that NFL, NSE and S100B were increased at 3 hours post-TBI. Interestingly, ethanol blood concentrations showed an inverse correlation with NSE but not with NFL or S100B. Claudin-5 levels were increased post-injury but no difference was detected compared to ethanol pretreatment. The increase in claudin-5 post-TBI was correlated with NFL but not with NSE or S100B.Ethanol induces an effect on biomarker release in the bloodstream that is different from TBI not influenced by alcohol. This could be the basis of investigations into humans.
View details for DOI 10.1093/burnst/tkab027
View details for Web of Science ID 000710935200020
View details for PubMedID 34604393
View details for PubMedCentralID PMC8484207
Acute TBK1/IKK-epsilon Inhibition Enhances the Generation of Disease-Associated Microglia-Like Phenotype Upon Cortical Stab-Wound Injury
FRONTIERS IN AGING NEUROSCIENCE
2021; 13: 684171
Traumatic brain injury has a poorer prognosis in elderly patients, possibly because of the enhanced inflammatory response characteristic of advanced age, known as "inflammaging." Recently, reduced activation of the TANK-Binding-Kinase 1 (Tbk1) pathway has been linked to age-associated neurodegeneration and neuroinflammation. Here we investigated how the blockade of Tbk1 and of the closely related IKK-ε by the small molecule Amlexanox could modify the microglial and immune response to cortical stab-wound injury in mice. We demonstrated that Tbk1/IKK-ε inhibition resulted in a massive expansion of microglial cells characterized by the TMEM119+/CD11c+ phenotype, expressing high levels of CD68 and CD317, and with the upregulation of Cst7a, Prgn and Ccl4 and the decrease in the expression levels of Tmem119 itself and P2yr12, thus a profile close to Disease-Associated Microglia (DAM, a subset of reactive microglia abundant in Alzheimer's Disease and other neurodegenerative conditions). Furthermore, Tbk1/IKK-ε inhibition increased the infiltration of CD3+ lymphocytes, CD169+ macrophages and CD11c+/CD169+ cells. The enhanced immune response was associated with increased expression of Il-33, Ifn-g, Il-17, and Il-19. This upsurge in the response to the stab wound was associated with the expanded astroglial scars and increased deposition of chondroitin-sulfate proteoglycans at 7 days post injury. Thus, Tbk1/IKK-ε blockade results in a massive expansion of microglial cells with a phenotype resembling DAM and with the substantial enhancement of neuroinflammatory responses. In this context, the induction of DAM is associated with a detrimental outcome such as larger injury-related glial scars. Thus, the Tbk1/IKK-ε pathway is critical to repress neuroinflammation upon stab-wound injury and Tbk1/IKK-ε inhibitors may provide an innovative approach to investigate the consequences of DAM induction.
View details for DOI 10.3389/fnagi.2021.684171
View details for Web of Science ID 000679082900001
View details for PubMedID 34326766
View details for PubMedCentralID PMC8313992
STAT6 mediates the effect of ethanol on neuroinflammatory response in TBI
BRAIN BEHAVIOR AND IMMUNITY
2019; 81: 228-246
Traumatic brain injury (TBI) and ethanol intoxication (EI) frequently coincide, particularly in young subjects. However, the mechanisms of their interaction remain poorly understood. Among other pathogenic pathways, TBI induces glial activation and neuroinflammation in the hippocampus, resulting in acute and chronic hippocampal dysfunction. In this regard, we investigated the role of EI affecting these responses unfolding after TBI. We used a blunt, weight-drop approach to model TBI in mice. Male mice were pre-administered with ethanol or vehicle to simulate EI. The neuroinflammatory response in the hippocampus was assessed by monitoring the expression levels of >20 cytokines, the phosphorylation status of transcription factors and the phenotype of microglia and astrocytes. We used AS1517499, a brain-permeable STAT6 inhibitor, to elucidate the role of this pathway in the EI/TBI interaction. We showed that TBI causes the elevation of IL-33, IL-1β, IL-38, TNF-α, IFN-α, IL-19 in the hippocampus at 3 h time point and concomitant EI results in the dose-dependent downregulation of IL-33, IL-1β, IL-38, TNF-α and IL-19 (but not of IFN-α) and in the selective upregulation of IL-13 and IL-12. EI is associated with the phosphorylation of STAT6 and the transcription of STAT6-controlled genes. Moreover, ethanol-induced STAT6 phosphorylation and transcriptional activation can be recapitulated in vitro by concomitant exposure of neurons to ethanol, depolarization and inflammatory stimuli (simulating the acute trauma). Acute STAT6 inhibition prevents the effects of EI on IL-33 and TNF-α, but not on IL-13 and negates acute EI beneficial effects on TBI-associated neurological impairment. Additionally, EI is associated with reduced microglial activation and astrogliosis as well as preserved synaptic density and baseline neuronal activity 7 days after TBI and all these effects are prevented by acute administration of the STAT6 inhibitor concomitant to EI. EI concomitant to TBI exerts significant immunomodulatory effects on cytokine induction and microglial activation, largely through the activation of STAT6 pathway, ultimately with beneficial outcomes.
View details for DOI 10.1016/j.bbi.2019.06.019
View details for Web of Science ID 000488135800030
View details for PubMedID 31207335
NEUROINFLAMMATION AFTER TRAUMATIC BRAIN INJURY (TBI) IS ENHANCED IN ACTIVATING TRANSCRIPTION FACTOR 3 (ATF3) DEFICIENT MICE
MARY ANN LIEBERT, INC. 2018: A72-A73
View details for Web of Science ID 000441527400203
The Neuroprotective Effect of Ethanol Intoxication in Traumatic Brain Injury Is Associated with the Suppression of ErbB Signaling in Parvalbumin-Positive Interneurons
JOURNAL OF NEUROTRAUMA
2018; 35 (22): 2718-2735
Ethanol intoxication (EI) is a frequent comorbidity of traumatic brain injury (TBI), but the impact of EI on TBI pathogenic cascades and prognosis is unclear. Although clinical evidence suggests that EI may have neuroprotective effects, experimental support is, to date, inconclusive. We aimed at elucidating the impact of EI on TBI-associated neurological deficits, signaling pathways, and pathogenic cascades in order to identify new modifiers of TBI pathophysiology. We have shown that ethanol administration (5 g/kg) before trauma enhances behavioral recovery in a weight-drop TBI model. Neuronal survival in the injured somatosensory cortex was also enhanced by EI. We have used phospho-receptor tyrosine kinase (RTK) arrays to screen the impact of ethanol on TBI-induced activation of RTK in somatosensory cortex, identifying ErbB2/ErbB3 among the RTKs activated by TBI and suppressed by ethanol. Phosphorylation of ErbB2/3/4 RTKs were upregulated in vGlut2+ excitatory synapses in the injured cortex, including excitatory synapses located on parvalbumin (PV)-positive interneurons. Administration of selective ErbB inhibitors was able to recapitulate, to a significant extent, the neuroprotective effects of ethanol both in sensorimotor performance and structural integrity. Further, suppression of PV interneurons in somatosensory cortex before TBI, by engineered receptors with orthogonal pharmacology, could mimic the beneficial effects of ErbB inhibitors. Thus, we have shown that EI interferes with TBI-induced pathogenic cascades at multiple levels, with one prominent pathway, involving ErbB-dependent modulation of PV interneurons.
View details for DOI 10.1089/neu.2017.5270
View details for Web of Science ID 000439629900001
View details for PubMedID 29774782
Neuroinflammation after Traumatic Brain Injury Is Enhanced in Activating Transcription Factor 3 Mutant Mice
JOURNAL OF NEUROTRAUMA
2018; 35 (19): 2317-2329
Traumatic brain injury (TBI) induces a neuroinflammatory response resulting in astrocyte and microglia activation at the lesion site. This involves upregulation of neuroinflammatory genes, including chemokines and interleukins. However, so far, there is lack of knowledge on transcription factors (TFs) modulating this TBI-associated gene expression response. Herein, we analyzed activating transcription factor 3 (ATF3), a TF encoding a regeneration-associated gene (RAG) predominantly studied in peripheral nervous system (PNS) injury. ATF3 contributes to PNS axon regeneration and was shown before to regulate inflammatory processes in other injury models. In contrast to PNS injury, data on ATF3 in central nervous system (CNS) injury are sparse. We used Atf3 mouse mutants and a closed-head weight-drop-based TBI model in adult mice to target the rostrolateral cortex resulting in moderate injury severity. Post-TBI, ATF3 was upregulated already at early time points (i.e,. 1-4 h) post-injury in the brain. Mortality and weight loss upon TBI were slightly elevated in Atf3 mutants. ATF3 deficiency enhanced TBI-induced paresis and hematoma formation, suggesting that ATF3 limits these injury outcomes in wild-type mice. Next, we analyzed TBI-associated RAG and inflammatory gene expression in the cortical impact area. In contrast to the PNS, only some RAGs (Atf3, Timp1, and Sprr1a) were induced by TBI, and, surprisingly, some RAG encoding neuropeptides were downregulated. Notably, we identified ATF3 as TF-regulating proneuroinflammatory gene expression, including CCL and CXCL chemokines (Ccl2, Ccl3, Ccl4, and Cxcl1) and lipocalin. In Atf3 mutant mice, mRNA abundance was further enhanced upon TBI compared to wild-type mice, suggesting immune gene repression by wild-type ATF3. In accord, more immune cells were present in the lesion area of ATF3-deficient mice. Overall, we identified ATF3 as a new TF-mediating TBI-associated CNS inflammatory responses.
View details for DOI 10.1089/neu.2017.5593
View details for Web of Science ID 000434224900001
View details for PubMedID 29463176
Neuroprotective effect of acute ethanol intoxication in TBI is associated to the hierarchical modulation of early transcriptional responses
2018; 302: 34-45
Ethanol intoxication is a risk factor for traumatic brain injury (TBI) but clinical evidence suggests that it may actually improve the prognosis of intoxicated TBI patients. We have employed a closed, weight-drop TBI model of different severity (2cm or 3cm falling height), preceded (-30min) or followed (+20min) by ethanol administration (5g/Kg). This protocol allows us to study the interaction of binge ethanol intoxication in TBI, monitoring behavioral changes, histological responses and the transcriptional regulation of a series of activity-regulated genes (immediate early genes, IEGs). We demonstrate that ethanol pretreatment before moderate TBI (2cm) significantly reduces neurological impairment and accelerates recovery. In addition, better preservation of neuronal numbers and cFos+cells was observed 7days after TBI. At transcriptional level, ethanol reduced the upregulation of a subset of IEGs encoding for transcription factors such as Atf3, c-Fos, FosB, Egr1, Egr3 and Npas4 but did not affect the upregulation of others (e.g. Gadd45b and Gadd45c). While a subset of IEGs encoding for effector proteins (such as Bdnf, InhbA and Dusp5) were downregulated by ethanol, others (such as Il-6) were unaffected. Notably, the majority of genes were sensitive to ethanol only when administered before TBI and not afterwards (the exceptions being c-Fos, Egr1 and Dusp5). Furthermore, while severe TBI (3cm) induced a qualitatively similar (but quantitatively larger) transcriptional response to moderate TBI, it was no longer sensitive to ethanol pretreatment. Thus, we have shown that a subset of the TBI-induced transcriptional responses were sensitive to ethanol intoxication at the instance of trauma (ultimately resulting in beneficial outcomes) and that the effect of ethanol was restricted to a certain time window (pre TBI treatment) and to TBI severity (moderate). This information could be critical for the translational value of ethanol in TBI and for the design of clinical studies aimed at disentangling the role of ethanol intoxication in TBI.
View details for DOI 10.1016/j.expneurol.2017.12.017
View details for Web of Science ID 000430265300004
View details for PubMedID 29306704