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Biology subjects

Klein, Y.

Publications and source records attributed to Klein, Y..

3 recordsLinked to original sources

Immune Aging is an Independent Risk Factor for Cardiovascular Disease

Cardiovascular disease remains the leading cause of mortality, yet current clinical predictors miss substantial disease-risk. While the immune system contributes to this residual risk, its complexity has hindered broadly applicable, clinically scalable metrics of immune-state. Here, we establish the prognostic relevance of IMM-AGE, a system-level metric of immune-aging, to cardiovascular disease. We learn reference-free, low-dimensional representations of IMM-AGE across cell, protein, and mRNA measurements, enabling high-fidelity quantification across modalities, blood fractions, and platforms, including standard hospital flow cytometers. Among UK-Biobank participants, 56.9% of IMM-AGE variation remained unexplained by routine clinical measures, and across diverse cohorts totaling ~48,000 individuals, elevated IMM-AGE was independently associated with future cardiovascular risk, intervention outcomes, and mortality. Moreover, incorporation of IMM-AGE into the PREVENT 10-year risk equation significantly improved risk stratification. These findings establish immune-aging as an independent biological dimension of cardiovascular disease-risk and support IMM-AGE as a practical tool for precision risk assessment.

immunology↗

Systems level analysis of B-cell development identifies BDNF as a driver for human B lymphopoiesis

B-cell aplasia is a major consequence of aging, chemotherapy, and B-cell-depleting immunotherapies, compromising immune protection against infections, cancer, and vaccines. Yet, unlike the myeloid and erythroid lineages, no strategy exists to accelerate human B-cell reconstitution. Here, we used an integrative systems biology approach to identify regulators of human B lymphopoiesis in the bone marrow (BM) microenvironment. By combining single-cell transcriptomic analysis of human BM with intercellular communication mapping, we generated an initial set of candidate factors predicted to act on developing B cells. To distinguish biologically meaningful putative regulators from a broad candidate space, we further intersected these findings with orthogonal human datasets capturing age-impaired B lymphopoiesis and protein dynamics associated with B-cell depletion and reconstitution. This convergent prioritization strategy highlighted a focused set of putative regulators, among which brain-derived neurotrophic factor (BDNF) emerged repeatedly as a top putative regulator. Functional interrogation in progenitor BM cells showed that several prioritized putative regulators induced transcriptional programs linked to early immune development, with BDNF consistently promoting pathways associated with B-cell differentiation. Importantly, in a human in vitro BM co-culture system, BDNF enhanced the differentiation of CD34+ hematopoietic progenitors into CD19+ progenitor B cells. Together, these findings identify BDNF as a previously unrecognized regulator of early human B lymphopoiesis and establish a general framework for uncovering functional hematopoietic regulators by integrating single-cell analysis with complementary biological and clinical signals. This approach may support future strategies to improve immune reconstitution in settings of prolonged B-cell depletion.

systems biology↗

Redox-driven control of Yuh1/UCHL3 impacts mitochondrial health via NEDD8/Rub1 pathway

The ubiquitin-like protein NEDD8/Rub1 undergoes processing by the enzyme Yuh1/UCHL3 to become functional. While the processed NEDD8/Rub1 modifies Cullin-RING E3 ligases (CRLs) among all studied organisms, its role in facilitating CRL-based substrate degradation is absent in S. cerevisiae. This prompts questions about NEDD8/Rub1 functionality if it does not activate CRLs universally. Previous studies revealed that increased production of reactive oxygen species (ROS) during the glycolysis to mitochondrial respiration transition inhibits cullin NEDDylation in S. cerevisiae, yet the specific affected enzymes remain unidentified. Here, we investigate how redox changes affect Yuh1 activity, revealing a thiol-based redox switch modulating its catalytic function in response to ROS. Temporal inactivation of Yuh1 fine-tunes NEDD8/Rub1 mature and precursor species, both crucial for maintaining mitochondrial integrity and enhancing oxidative stress resilience. These findings unveil a novel role for Rub1/NEDD8 beyond CRL activation, linking redox signaling to NEDD8/Rub1 pathways. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=137 SRC="FIGDIR/small/594945v1_ufig1.gif" ALT="Figure 1"> View larger version (28K): org.highwire.dtl.DTLVardef@1ce0c41org.highwire.dtl.DTLVardef@8690bdorg.highwire.dtl.DTLVardef@8898c6org.highwire.dtl.DTLVardef@1e61a85_HPS_FORMAT_FIGEXP M_FIG C_FIG

cell biology↗