Biology subjects

Berner, J.

Publications and source records attributed to Berner, J..

6 recordsLinked to original sources

bioRxiv2024

Elevated plasma pTau181 in a specialty neuropsychiatric clinic is associated with opioid use and guides medication titration on a clinically relevant short-time scale

A combinatorial explosion of agents that delay neurodegeneration in animal models has created a crisis of abundance in human applications with too many combinations to try when time is short. Plasma biomarkers of premature neuronal aging, the amyloid-tau-neurodegeneration (ATN) profile, may provide a tool to rapidly optimize treatment in single-patient trials. We retrospectively analyzed plasma ATN profiles in patients with extensive neuropsychiatric polypharmacy and premature neuronal aging. ATN profiles were based on the biomarkers amyloid-{beta} ratio, phosphorylated Tau 181 (pTau181), and neurofilament light chain (NfL). We investigated whether ATN profile biomarkers were associated with age, gender, metabolic syndrome markers, and medication use. Two case reports additionally provide examples of the application of ATN profiles in clinical settings. We found that in 80 patients with ATN profiles and complete clinical phenotypes, pTau181 was elevated in 31 (38.75%), amyloid-{beta} ratio was below normal ranges in 11 (13.75%), and NfL was elevated in three (3.75%). The biomarkers correlated with age, as expected. Opioid use was significantly associated with pTau181 (p=0.004) and NfL (p=0.002), also after Bonferroni correction (both p <0.05), but not with amyloid-{beta} ratio. No other medications were associated with the biomarkers. In conclusion, identifying the overlaps between complex behavioral phenotypes (pain and cognition), plasma endophenotypes (ATN profile), and medication-targeted components of age-related pathophysiology is now a technical problem rather than theoretical speculation. Rapid progress in single-patient trials for treatment optimization will require funding to promote using repurposed generic treatments, educate patients and providers regarding optimization principles, and continue developing sensitive biomarkers.

pharmacology and toxicology↗

bioRxiv2024

mTORC1 ACTIVATION IN PRESUMED CLASSICAL MONOCYTES:OBSERVED CORRELATES WITH HUMAN SIZE VARIATION AND NEUROPSYCHIATRIC DISEASE

BackgroundGain of function disturbances in nutrient sensing are likely the largest component in human age-related disease. Mammalian target of rapamycin complex 1 (mTORC1) activity affects health span and longevity. The drugs ketamine and rapamycin are effective against chronic pain and depression, and both affect mTORC1 activity. Our objective was to measure phosphorylated p70S6K, a marker for mTORC1 activity, in individuals with psychiatric disease to determine whether phosphorylated p70S6K could predict medication response. MethodsTwenty-seven females provided blood samples in which p70S6K and phosphorylated p70S6K were analyzed. Chart review gathered biometric measurements, clinical phenotypes, and medication response. Questionnaires assessed anxiety, depression, autism traits, and mitochondrial dysfunction, to determine neuropsychiatric disease profiles. Univariate and multivariate statistical analyses were used to identify predictors of medication response. ResultsmTORC1 activity correlated highly with both classical biometrics (height, macrocephaly, pupil distance) and specific neuropsychiatric disease profiles (anxiety and autism). Across all cases, phosphorylated p70S6K was the best predictor for ketamine response, and also the best predictor for rapamycin response in a single instance. ConclusionsThe data illustrates the importance of mTORC1 activity in both observable body structure and medication response. This report suggests that a simple assay may allow cost-effective prediction of medication response.

neuroscience↗

bioRxiv2023

Identification of chemotherapy targets reveals a nucleus-to-mitochondria ROS sensing pathway

Multiple chemotherapies are proposed to cause cell death in part by increasing the steady-state levels of cellular reactive oxygen species (ROS). However, for most of these drugs exactly how the resultant ROS function and are sensed is poorly understood. In particular, its unclear which proteins the ROS modify and their roles in chemotherapy sensitivity/resistance. To answer these questions, we examined 11 chemotherapies with an integrated proteogenomic approach identifying many unique targets for these drugs but also shared ones including ribosomal components, suggesting one mechanism by which chemotherapies regulate translation. We focus on CHK1 which we find is a nuclear H2O2 sensor that promotes an anti-ROS cellular program. CHK1 acts by phosphorylating the mitochondrial-DNA binding protein SSBP1, preventing its mitochondrial localization, which in turn decreases nuclear H2O2. Our results reveal a druggable nucleus-to-mitochondria ROS sensing pathway required to resolve nuclear H2O2 accumulation, which mediates resistance to platinum-based chemotherapies in ovarian cancers.

molecular biology↗

bioRxiv2022

Absence of microbiome in chronic infections impairs viral control without affecting CD8 T cell function

Prolonged antigen exposure in chronic viral infections reduces the effector capacity of cytotoxic T cells - a phenomenon known as T cell exhaustion. Development of T cell exhaustion is driven by high viral titers, strong TCR stimulation, and high antigen concentrations associated with strong inflammatory signals. A largely unexplored factor has been the influence of the microbiome in these processes. Here, we report that T cell exhaustion progresses independently of the presence or absence of a microbiome in chronic lymphocytic choriomeningitis virus (LCMV) infections. Virus-specific CD8 T cells in germ-free mice showed high expression of the inhibitory receptor PD-1 and decreased cytokine production. Moreover, their global gene expression patterns, as determined by single-cell sequencing, were similar to those of cells in specific pathogen-free mice. In line with this, we observed similar pathogen loads with and without a microbiome. Thus, our study demonstrates that the microbiome is dispensable for the induction of T cell exhaustion and for the limited virus control seen in chronic LCMV infections.

immunology↗

bioRxiv2022

Human repair-related Schwann cells adopt functions of antigen-presenting cells in vitro

The plastic potential of Schwann cells (SCs) is increasingly recognized to play a role after nerve injury and in diseases of the peripheral nervous system. In addition, reports on the interaction between SCs and immune cells indicate their involvement in inflammatory processes. However, data about the immunocompetence of human SCs are primarily derived from neuropathies and it is currently unknown whether SCs directly regulate an adaptive immune response after nerve injury. Here, we performed a comprehensive analysis of the immunomodulatory capacities of human repair-related SCs (hrSCs), which recapitulate SC response to nerve injury in vitro. We used our previously established protocol for the culture of primary hrSCs from human peripheral nerves and analyzed the transcriptome, secretome, and cell surface proteins for signatures and markers relevant in innate and adaptive immunity, performed phagocytosis assays, and monitored T-cell subset activation in co-cultures with autologous human T-cells. Our findings show that hrSCs are highly phagocytic, which is in line with high MHCII expression. In addition, hrSCs express co-regulatory molecules, such as CD40, CD80, B7H3, CD58, CD86, HVEM, release a plethora of chemoattractants, matrix remodelling proteins and pro- as well as anti-inflammatory cytokines, and upregulate the T-cell inhibiting PD-L1 molecule upon pro-inflammatory stimulation with IFN{gamma}. Furthermore, hrSC contact reduced the number and activation status of allogenic CD4+ and CD8+ T-cells. This study demonstrates that hrSCs possess features and functions typical for professional antigen presenting cells in vitro, and suggest a new role of these cells as negative regulators of T-cell immunity during nerve regeneration. Main pointsO_LIHuman repair-related Schwann cells (hrSC) function as professional antigen presenting cells. C_LIO_LIHrSCs up-regulate PD-L1 upon pro-inflammatory IFN{gamma} stimulation. C_LIO_LIHrSCs hamper CD4+ and CD8+ T-cell activation. C_LI Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=115 SRC="FIGDIR/small/483322v1_ufig1.gif" ALT="Figure 1"> View larger version (24K): org.highwire.dtl.DTLVardef@1b5fbb7org.highwire.dtl.DTLVardef@a0de85org.highwire.dtl.DTLVardef@1710ee9org.highwire.dtl.DTLVardef@189e3bc_HPS_FORMAT_FIGEXP M_FIG C_FIG

cell biology↗

bioRxiv2021

Inflammatory signals are sufficient to elicit TOX expression in mouse and human CD8 T cells

T cell receptor (TCR) stimulation leads to expression of the transcription factor TOX. Prolonged TCR signaling, such as encountered during chronic infections or in tumors, leads to sustained TOX expression, which induces a state of exhaustion or dysfunction. While CD8 memory T cells (Tmem) in specific pathogen-free laboratory mice typically do not express TOX, functional human Tmem show heterogeneous TOX expression levels. Whether TCR-independent mechanisms can alter TOX expression in human and murine Tmem has not been defined. We report that human and mouse Tmem increase TOX expression following stimulation with inflammatory cytokines IL-12, IL-15, and IL-18. TOX and PD-1 expression patterns often appear to be directly correlated, however, we found that TOX is not necessary for cytokine-driven expression of PD-1. Together, these observations highlight that inflammation is sufficient to alter TOX and PD-1 expression and that the signals regulating TOX expression appear well conserved in human and murine Tmem.

immunology↗